Programs & Examples On #String.h

Visual Studio 2017 errors on standard headers

If anyone's still stuck on this, the easiest solution I found was to "Retarget Solution". In my case, the project was built of SDK 8.1, upgrading to VS2017 brought with it SDK 10.0.xxx.

To retarget solution: Project->Retarget Solution->"Select whichever SDK you have installed"->OK

From there on you can simply build/debug your solution. Hope it helps

enter image description here

How to resolve the "EVP_DecryptFInal_ex: bad decrypt" during file decryption

This message digital envelope routines: EVP_DecryptFInal_ex: bad decrypt can also occur when you encrypt and decrypt with an incompatible versions of openssl.

The issue I was having was that I was encrypting on Windows which had version 1.1.0 and then decrypting on a generic Linux system which had 1.0.2g.

It is not a very helpful error message!


Working solution:

A possible solution from @AndrewSavinykh that worked for many (see the comments):

Default digest has changed between those versions from md5 to sha256. One can specify the default digest on the command line as -md sha256 or -md md5 respectively

C compile : collect2: error: ld returned 1 exit status

If you are using Dev C++ then your .exe or mean to say your program already running and you are trying to run it again.

Returning string from C function

word is on the stack and goes out of scope as soon as getStr() returns. You are invoking undefined behavior.

How do I use setsockopt(SO_REUSEADDR)?

After :

sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) 
    error("ERROR opening socket");

You can add (with standard C99 compound literal support) :

if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &(int){1}, sizeof(int)) < 0)
    error("setsockopt(SO_REUSEADDR) failed");

Or :

int enable = 1;
if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int)) < 0)
    error("setsockopt(SO_REUSEADDR) failed");

size of uint8, uint16 and uint32?

uint8, uint16, uint32, and uint64 are probably Microsoft-specific types.

As of the 1999 standard, C supports standard typedefs with similar meanings, defined in <stdint.h>: uint8_t, uint16_t, uint32_t, and uint64_t. I'll assume that the Microsoft-specific types are defined similarly. Microsoft does support <stdint.h>, at least as of Visual Studio 2010, but older code may use uint8 et al.

The predefined types char, short, int et al have sizes that vary from one C implementation to another. The C standard has certain minimum requirements (char is at least 8 bits, short and int are at least 16, long is at least 32, and each type in that list is at least as wide as the previous type), but permits some flexibility. For example, I've seen systems where int is 16, 32, or 64 bits.

char is almost always exactly 8 bits, but it's permitted to be wider. And plain char may be either signed or unsigned.

uint8_t is required to be an unsigned integer type that's exactly 8 bits wide. It's likely to be a typedef for unsigned char, though it might be a typedef for plain char if plain char happens to be unsigned. If there is no predefined 8-bit unsigned type, then uint8_t will not be defined at all.

Similarly, each uintN_t type is an unsigned type that's exactly N bits wide.

In addition, <stdint.h> defines corresponding signed intN_t types, as well as int_fastN_t and int_leastN_t types that are at least the specified width.

The [u]intN_t types are guaranteed to have no padding bits, so the size of each is exactly N bits. The signed intN_t types are required to use a 2's-complement representation.

Although uint32_t might be the same as unsigned int, for example, you shouldn't assume that. Use unsigned int when you need an unsigned integer type that's at least 16 bits wide, and that's the "natural" size for the current system. Use uint32_t when you need an unsigned integer type that's exactly 32 bits wide.

(And no, uint64 or uint64_t is not the same as double; double is a floating-point type.)

no match for ‘operator<<’ in ‘std::operator

Object is a collection of methods and variables.You can't print the variables in object by just cout operation . if you want to show the things inside the object you have to declare either a getter or a display text method in class.

ex

#include <iostream>

using namespace std;

class mystruct

{
private:
    int m_a;
    float m_b;

public:
    mystruct(int x, float y)
    {
            m_a = x;
            m_b = y;
    }
    public:
    void getm_aAndm_b()
    {
        cout<<m_a<<endl;
        cout<<m_b<<endl;
    }



};

int main()
{

    mystruct m = mystruct(5,3.14);

    cout << "my structure " << endl;
    m.getm_aAndm_b();
    return 0;

}

Not that this is just a one way of doing it

C free(): invalid pointer

You can't call free on the pointers returned from strsep. Those are not individually allocated strings, but just pointers into the string s that you've already allocated. When you're done with s altogether, you should free it, but you do not have to do that with the return values of strsep.

Reading from file using read() function

Read Byte by Byte and check that each byte against '\n' if it is not, then store it into buffer
if it is '\n' add '\0' to buffer and then use atoi()

You can read a single byte like this

char c;
read(fd,&c,1);

See read()

Convert ascii value to char

To convert an int ASCII value to character you can also use:

int asciiValue = 65;
char character = char(asciiValue);
cout << character; // output: A
cout << char(90); // output: Z

error: Libtool library used but 'LIBTOOL' is undefined

For folks who ended up here and are using CYGWIN, install following packages in cygwin and re-run:

  • cygwin32-libtool
  • libtool
  • libtool-debuginfo

Arduino error: does not name a type?

My code was out of void setup() or void loop() in Arduino.

Reading and writing to serial port in C on Linux

Some receivers expect EOL sequence, which is typically two characters \r\n, so try in your code replace the line

unsigned char cmd[] = {'I', 'N', 'I', 'T', ' ', '\r', '\0'};

with

unsigned char cmd[] = "INIT\r\n";

BTW, the above way is probably more efficient. There is no need to quote every character.

Error LNK2019: Unresolved External Symbol in Visual Studio

When you have everything #included, an unresolved external symbol is often a missing * or & in the declaration or definition of a function.

How do I open a URL from C++?

Here's an example in windows code using winsock.

#include <winsock2.h>
#include <windows.h>
#include <iostream>
#include <string>
#include <locale>
#pragma comment(lib,"ws2_32.lib")
using namespace std;

string website_HTML;
locale local;


void get_Website(char *url );

int main ()
{
    //open website
    get_Website("www.google.com" );

    //format website HTML
    for (size_t i=0; i<website_HTML.length(); ++i) 
        website_HTML[i]= tolower(website_HTML[i],local);

    //display HTML
    cout <<website_HTML;

    cout<<"\n\n";



    return 0;
}



//***************************
void get_Website(char *url )
{
    WSADATA wsaData;
    SOCKET Socket;
    SOCKADDR_IN SockAddr;


    int lineCount=0;
    int rowCount=0;

    struct hostent *host;
    char *get_http= new char[256];

        memset(get_http,' ', sizeof(get_http) );
        strcpy(get_http,"GET / HTTP/1.1\r\nHost: ");
        strcat(get_http,url);
        strcat(get_http,"\r\nConnection: close\r\n\r\n");

        if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0) 
        {
            cout << "WSAStartup failed.\n";
            system("pause");
            //return 1;
        }

        Socket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
        host = gethostbyname(url);

        SockAddr.sin_port=htons(80);
        SockAddr.sin_family=AF_INET;
        SockAddr.sin_addr.s_addr = *((unsigned long*)host->h_addr);

        cout << "Connecting to "<< url<<" ...\n";

        if(connect(Socket,(SOCKADDR*)(&SockAddr),sizeof(SockAddr)) != 0)
        {
            cout << "Could not connect";
            system("pause");
            //return 1;
        }

        cout << "Connected.\n";     
        send(Socket,get_http, strlen(get_http),0 );

        char buffer[10000];

        int nDataLength;
            while ((nDataLength = recv(Socket,buffer,10000,0)) > 0)
            {       
                int i = 0;

                while (buffer[i] >= 32 || buffer[i] == '\n' || buffer[i] == '\r') 
                {                    
                    website_HTML+=buffer[i];                     
                    i += 1;
                }               
            }
        closesocket(Socket);
        WSACleanup();

            delete[] get_http;
}

Is there an equivalent method to C's scanf in Java?

There is not a pure scanf replacement in standard Java, but you could use a java.util.Scanner for the same problems you would use scanf to solve.

Remove a prefix from a string

def remove_prefix(str, prefix):
    if str.startswith(prefix):
        return str[len(prefix):]
    else:
        return str

As an aside note, str is a bad name for a variable because it shadows the str type.

how to return a char array from a function in C

Lazy notes in comments.

#include <stdio.h>
// for malloc
#include <stdlib.h>

// you need the prototype
char *substring(int i,int j,char *ch);


int main(void /* std compliance */)
{
  int i=0,j=2;
  char s[]="String";
  char *test;
  // s points to the first char, S
  // *s "is" the first char, S
  test=substring(i,j,s); // so s only is ok
  // if test == NULL, failed, give up
  printf("%s",test);
  free(test); // you should free it
  return 0;
}


char *substring(int i,int j,char *ch)
{
  int k=0;
  // avoid calc same things several time
  int n = j-i+1; 
  char *ch1;
  // you can omit casting - and sizeof(char) := 1
  ch1=malloc(n*sizeof(char));
  // if (!ch1) error...; return NULL;

  // any kind of check missing:
  // are i, j ok? 
  // is n > 0... ch[i] is "inside" the string?...
  while(k<n)
    {   
      ch1[k]=ch[i];
      i++;k++;
    }   

  return ch1;
}

Removing elements from an array in C

There are really two separate issues. The first is keeping the elements of the array in proper order so that there are no "holes" after removing an element. The second is actually resizing the array itself.

Arrays in C are allocated as a fixed number of contiguous elements. There is no way to actually remove the memory used by an individual element in the array but the elements can be shifted to fill the hole made by removing an element. For example:

void remove_element(array_type *array, int index, int array_length)
{
   int i;
   for(i = index; i < array_length - 1; i++) array[i] = array[i + 1];
}

Statically allocated arrays can not be resized. Dynamically allocated arrays can be resized with realloc(). This will potentially move the entire array to another location in memory, so all pointers to the array or to its elements will have to be updated. For example:

remove_element(array, index, array_length);  /* First shift the elements, then reallocate */
array_type *tmp = realloc(array, (array_length - 1) * sizeof(array_type) );
if (tmp == NULL && array_length > 1) {
   /* No memory available */
   exit(EXIT_FAILURE);
}
array_length = array_length - 1;
array = tmp;

realloc will return a NULL pointer if the requested size is 0, or if there is an error. Otherwise it returns a pointer to the reallocated array. The temporary pointer is used to detect errors when calling realloc because instead of exiting it is also possible to just leave the original array as it was. When realloc fails to reallocate an array it does not alter the original array.

Note that both of these operations will be fairly slow if the array is large or if a lot of elements are removed. There are other data structures like linked lists and hashes that can be used if efficient insertion and deletion is a priority.

How to JUnit test that two List<E> contain the same elements in the same order?

Why not simply use List#equals?

assertEquals(argumentComponents, imapPathComponents);

Contract of List#equals:

two lists are defined to be equal if they contain the same elements in the same order.

strcpy() error in Visual studio 2012

The message you are getting is advice from MS that they recommend that you do not use the standard strcpy function. Their motivation in this is that it is easy to misuse in bad ways (and the compiler generally can't detect and warn you about such misuse). In your post, you are doing exactly that. You can get rid of the message by telling the compiler to not give you that advice. The serious error in your code would remain, however.

You are creating a buffer with room for 10 chars. You are then stuffing 11 chars into it. (Remember the terminating '\0'?) You have taken a box with exactly enough room for 10 eggs and tried to jam 11 eggs into it. What does that get you? Not doing this is your responsibility and the compiler will generally not detect such things.

You have tagged this C++ and included string. I do not know your motivation for using strcpy, but if you use std::string instead of C style strings, you will get boxes that expand to accommodate what you stuff in them.

C++ - Assigning null to a std::string

There are two methods to consider which achieve the same effect for handling null pointers to C-style strings.

The ternary operator

void setvalue(const char *value)
{
    std::string mValue = value ? value : "";

}

or the humble if statement

void setvalue(const char *value)
{
    std::string mValue;
    if(value) mValue = value;

}

In both cases, value is only assigned to mValue when value is not a null pointer. In all other cases (i.e. when value is null), mValue will contain an empty string.

The ternary operator method may be useful for providing an alternative default string literal in the absence of a value from value:

std::string mValue = value ? value : "(NULL)";

Exact difference between CharSequence and String in java

In charSequence you don't have very useful methods which are available for String. If you don't want to look in the documentation, type: obj. and str.

and see what methods your compilator offers you. That's the basic difference for me.

how to convert from int to char*?

This might be a bit late, but i also had the same issue. Converting to char was addressed in C++17 with the "charconv" library.

https://en.cppreference.com/w/cpp/utility/to_chars

Ruby replace string with captured regex pattern

 "foobar".gsub(/(o+)/){|s|s+'ball'}
 #=> "fooballbar"

Declaring an unsigned int in Java

For unsigned numbers you can use these classes from Guava library:

They support various operations:

  • plus
  • minus
  • times
  • mod
  • dividedBy

The thing that seems missing at the moment are byte shift operators. If you need those you can use BigInteger from Java.

What is the meaning of Bus: error 10 in C

Let me explain why you do you got this error "Bus error: 10"

char *str1 = "First string";
// for this statement the memory will be allocated into the CODE/TEXT segment which is READ-ONLY

char *str2 = "Second string";
// for this statement the memory will be allocated into the CODE/TEXT segment which is READ-ONLY

strcpy(str1, str2);
// This function will copy the content from str2 into str1, this is not possible because you are try to perform READ WRITE operation inside the READ-ONLY segment.Which was the root cause 

If you want to perform string manipulation use automatic variables(STACK segment) or dynamic variables(HEAP segment)

Vasanth

How to convert string to float?

Unfortunately, there is no way to do this easily. Every solution has its drawbacks.

  1. Use atof() or strtof() directly: this is what most people will tell you to do and it will work most of the time. However, if the program sets a locale or it uses a library that sets the locale (for instance, a graphics library that displays localised menus) and the user has their locale set to a language where the decimal separator is not . (such as fr_FR where the separator is ,) these functions will stop parsing at the . and you will stil get 4.0.

  2. Use atof() or strtof() but change the locale; it's a matter of calling setlocale(LC_ALL|~LC_NUMERIC, ""); before any call to atof() or the likes. The problem with setlocale is that it will be global to the process and you might interfer with the rest of the program. Note that you might query the current locale with setlocale() and restore it after you're done.

  3. Write your own float parsing routine. This might be quite quick if you do not need advanced features such as exponent parsing or hexadecimal floats.

Also, note that the value 4.08 cannot be represented exactly as a float; the actual value you will get is 4.0799999237060546875.

identifier "string" undefined?

#include <string> would be the correct c++ include, also you need to specify the namespace with std::string or more generally with using namespace std;

Which header file do you include to use bool type in c in linux?

#include <stdbool.h>

For someone like me here to copy and paste.

c++ boost split string

My best guess at why you had problems with the ----- covering your first result is that you actually read the input line from a file. That line probably had a \r on the end so you ended up with something like this:

-----------test2-------test3

What happened is the machine actually printed this:

test-------test2-------test3\r-------

That means, because of the carriage return at the end of test3, that the dashes after test3 were printed over the top of the first word (and a few of the existing dashes between test and test2 but you wouldn't notice that because they were already dashes).

How to remove the character at a given index from a string in C?

This code will delete all characters that you enter from string

#include <stdio.h>
#include <string.h>

#define SIZE 1000

char *erase_c(char *p, int ch)
{
    char *ptr;

    while (ptr = strchr(p, ch))
        strcpy(ptr, ptr + 1);

    return p;
}

int main()
{
    char str[SIZE];
    int ch;

    printf("Enter a string\n");
    gets(str);
    printf("Enter the character to delete\n");
    ch = getchar();

    erase_c(str, ch);

    puts(str);

    return 0;
}

input

a man, a plan, a canal Panama

output

 A mn,  pln,  cnl, Pnm!

Calling a java method from c++ in Android

Solution posted by Denys S. in the question post:

I quite messed it up with c to c++ conversion (basically env variable stuff), but I got it working with the following code for C++:

#include <string.h>
#include <stdio.h>
#include <jni.h>

jstring Java_the_package_MainActivity_getJniString( JNIEnv* env, jobject obj){

    jstring jstr = (*env)->NewStringUTF(env, "This comes from jni.");
    jclass clazz = (*env)->FindClass(env, "com/inceptix/android/t3d/MainActivity");
    jmethodID messageMe = (*env)->GetMethodID(env, clazz, "messageMe", "(Ljava/lang/String;)Ljava/lang/String;");
    jobject result = (*env)->CallObjectMethod(env, obj, messageMe, jstr);

    const char* str = (*env)->GetStringUTFChars(env,(jstring) result, NULL); // should be released but what a heck, it's a tutorial :)
    printf("%s\n", str);

    return (*env)->NewStringUTF(env, str);
}

And next code for java methods:

    public class MainActivity extends Activity {
    private static String LIB_NAME = "thelib";

    static {
        System.loadLibrary(LIB_NAME);
    }

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        TextView tv = (TextView) findViewById(R.id.textview);
        tv.setText(this.getJniString());
    }

    // please, let me live even though I used this dark programming technique
    public String messageMe(String text) {
        System.out.println(text);
        return text;
    }

    public native String getJniString();
}

How to use S_ISREG() and S_ISDIR() POSIX Macros?

[Posted on behalf of fossuser] Thanks to "mu is too short" I was able to fix the bug. Here is my working code has been edited in for those looking for a nice example (since I couldn't find any others online).

#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <dirent.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>

void helper(DIR *, struct dirent *, struct stat, char *, int, char **);
void dircheck(DIR *, struct dirent *, struct stat, char *, int, char **);

int main(int argc, char *argv[]){

  DIR *dip;
  struct dirent *dit;
  struct stat statbuf;
  char currentPath[FILENAME_MAX];
  int depth = 0; /*Used to correctly space output*/

  /*Open Current Directory*/
  if((dip = opendir(".")) == NULL)
    return errno;

  /*Store Current Working Directory in currentPath*/
  if((getcwd(currentPath, FILENAME_MAX)) == NULL)
    return errno;

  /*Read all items in directory*/
  while((dit = readdir(dip)) != NULL){

    /*Skips . and ..*/
    if(strcmp(dit->d_name, ".") == 0 || strcmp(dit->d_name, "..") == 0)
      continue;

    /*Correctly forms the path for stat and then resets it for rest of algorithm*/
    getcwd(currentPath, FILENAME_MAX);
    strcat(currentPath, "/");
    strcat(currentPath, dit->d_name);
    if(stat(currentPath, &statbuf) == -1){
      perror("stat");
      return errno;
    }
    getcwd(currentPath, FILENAME_MAX);


    /*Checks if current item is of the type file (type 8) and no command line arguments*/
    if(S_ISREG(statbuf.st_mode) && argv[1] == NULL)
      printf("%s (%d bytes)\n", dit->d_name, (int)statbuf.st_size);

    /*If a command line argument is given, checks for filename match*/
    if(S_ISREG(statbuf.st_mode) && argv[1] != NULL)
      if(strcmp(dit->d_name, argv[1]) == 0)
         printf("%s (%d bytes)\n", dit->d_name, (int)statbuf.st_size);

    /*Checks if current item is of the type directory (type 4)*/
    if(S_ISDIR(statbuf.st_mode))
      dircheck(dip, dit, statbuf, currentPath, depth, argv);

  }
  closedir(dip);
  return 0;
}

/*Recursively called helper function*/
void helper(DIR *dip, struct dirent *dit, struct stat statbuf, 
        char currentPath[FILENAME_MAX], int depth, char *argv[]){
  int i = 0;

  if((dip = opendir(currentPath)) == NULL)
    printf("Error: Failed to open Directory ==> %s\n", currentPath);

  while((dit = readdir(dip)) != NULL){

    if(strcmp(dit->d_name, ".") == 0 || strcmp(dit->d_name, "..") == 0)
      continue;

    strcat(currentPath, "/");
    strcat(currentPath, dit->d_name);
    stat(currentPath, &statbuf);
    getcwd(currentPath, FILENAME_MAX);

    if(S_ISREG(statbuf.st_mode) && argv[1] == NULL){
      for(i = 0; i < depth; i++)
    printf("    ");
      printf("%s (%d bytes)\n", dit->d_name, (int)statbuf.st_size);
    }

    if(S_ISREG(statbuf.st_mode) && argv[1] != NULL){
      if(strcmp(dit->d_name, argv[1]) == 0){
    for(i = 0; i < depth; i++)
      printf("    ");
    printf("%s (%d bytes)\n", dit->d_name, (int)statbuf.st_size);
      }
    }

    if(S_ISDIR(statbuf.st_mode))
      dircheck(dip, dit, statbuf, currentPath, depth, argv);
  }
  /*Changing back here is necessary because of how stat is done*/
    chdir("..");
    closedir(dip);
}

void dircheck(DIR *dip, struct dirent *dit, struct stat statbuf, 
          char currentPath[FILENAME_MAX], int depth, char *argv[]){
  int i = 0;

  strcat(currentPath, "/");
  strcat(currentPath, dit->d_name);

  /*If two directories exist at the same level the path
    is built wrong and needs to be corrected*/
  if((chdir(currentPath)) == -1){
    chdir("..");
    getcwd(currentPath, FILENAME_MAX);
    strcat(currentPath, "/");
    strcat(currentPath, dit->d_name);

    for(i = 0; i < depth; i++)
      printf ("    ");
    printf("%s (subdirectory)\n", dit->d_name);
    depth++;
    helper(dip, dit, statbuf, currentPath, depth, argv);
  }

  else{
    for(i =0; i < depth; i++)
      printf("    ");
    printf("%s (subdirectory)\n", dit->d_name);
    chdir(currentPath);
    depth++;
    helper(dip, dit, statbuf, currentPath, depth, argv);
  }
}

memcpy() vs memmove()

As already pointed out in other answers, memmove is more sophisticated than memcpy such that it accounts for memory overlaps. The result of memmove is defined as if the src was copied into a buffer and then buffer copied into dst. This does NOT mean that the actual implementation uses any buffer, but probably does some pointer arithmetic.

How do I include the string header?

Use this:

#include < string>

How to read from stdin with fgets()?

If you want to concatenate the input, then replace printf("%s\n", buffer); with strcat(big_buffer, buffer);. Also create and initialize the big buffer at the beginning: char *big_buffer = new char[BIG_BUFFERSIZE]; big_buffer[0] = '\0';. You should also prevent a buffer overrun by verifying the current buffer length plus the new buffer length does not exceed the limit: if ((strlen(big_buffer) + strlen(buffer)) < BIG_BUFFERSIZE). The modified program would look like this:

#include <stdio.h>
#include <string.h>

#define BUFFERSIZE 10
#define BIG_BUFFERSIZE 1024

int main (int argc, char *argv[])
{
    char buffer[BUFFERSIZE];
    char *big_buffer = new char[BIG_BUFFERSIZE];
    big_buffer[0] = '\0';
    printf("Enter a message: \n");
    while(fgets(buffer, BUFFERSIZE , stdin) != NULL)
    {
        if ((strlen(big_buffer) + strlen(buffer)) < BIG_BUFFERSIZE)
        {
            strcat(big_buffer, buffer);
        }
    }
    return 0;
}

How does strtok() split the string into tokens in C?

The first time you call it, you provide the string to tokenize to strtok. And then, to get the following tokens, you just give NULL to that function, as long as it returns a non NULL pointer.

The strtok function records the string you first provided when you call it. (Which is really dangerous for multi-thread applications)

Faster way to zero memory than with memset?

memset is generally designed to be very very fast general-purpose setting/zeroing code. It handles all cases with different sizes and alignments, which affect the kinds of instructions you can use to do your work. Depending on what system you're on (and what vendor your stdlib comes from), the underlying implementation might be in assembler specific to that architecture to take advantage of whatever its native properties are. It might also have internal special cases to handle the case of zeroing (versus setting some other value).

That said, if you have very specific, very performance critical memory zeroing to do, it's certainly possible that you could beat a specific memset implementation by doing it yourself. memset and its friends in the standard library are always fun targets for one-upmanship programming. :)

Warning: comparison with string literals results in unspecified behaviour

if (args[i] == "&")

Ok, let's disect what this does.

args is an array of pointers. So, here you are comparing args[i] (a pointer) to "&" (also a pointer). Well, the only way this will every be true is if somewhere you have args[i]="&" and even then, "&" is not guaranteed to point to the same place everywhere.

I believe what you are actually looking for is either strcmp to compare the entire string or your wanting to do if (*args[i] == '&') to compare the first character of the args[i] string to the & character

C: socket connection timeout

Is there anything wrong with Nahuel Greco's solution aside from the compilation error?

If I change one line

// Compilation error
setsockopt(fd, SO_SNDTIMEO, &timeout, sizeof(timeout));

to

// Fixed?
setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));

then it seems to work as advertised - socket() returns a timeout error.

Resulting code:

struct timeval timeout;
timeout.tv_sec  = 7;  // after 7 seconds connect() will timeout
timeout.tv_usec = 0;
setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));
connect(...)

I'm not versed enough to know the tradeoffs are between a send timeout and a non-blocking socket, but I'm curious to learn.

Assignment makes pointer from integer without cast

  • 1) Don't use gets! You're introducing a buffer-overflow vulnerability. Use fgets(..., stdin) instead.

  • 2) In strToLower you're returning a char instead of a char-array. Either return char* as Autopulated suggested, or just return void since you're modifying the input anyway. As a result, just write

 

 strToLower(cString1);
 strToLower(cString2);
  • 3) To compare case-insensitive strings, you can use strcasecmp (Linux & Mac) or stricmp (Windows).

How to capitalize the first character of each word in a string

package corejava.string.intern;

import java.io.DataInputStream;

import java.util.ArrayList;

/*
 * wap to accept only 3 sentences and convert first character of each word into upper case
 */

public class Accept3Lines_FirstCharUppercase {

    static String line;
    static String words[];
    static ArrayList<String> list=new ArrayList<String>();

    /**
     * @param args
     */
    public static void main(String[] args) throws java.lang.Exception{

        DataInputStream read=new DataInputStream(System.in);
        System.out.println("Enter only three sentences");
        int i=0;
        while((line=read.readLine())!=null){
            method(line);       //main logic of the code
            if((i++)==2){
                break;
            }
        }
        display();
        System.out.println("\n End of the program");

    }

    /*
     * this will display all the elements in an array
     */
    public static void display(){
        for(String display:list){
            System.out.println(display);
        }
    }

    /*
     * this divide the line of string into words 
     * and first char of the each word is converted to upper case
     * and to an array list
     */
    public static void method(String lineParam){
        words=line.split("\\s");
        for(String s:words){
            String result=s.substring(0,1).toUpperCase()+s.substring(1);
            list.add(result);
        }
    }

}

When should we use intern method of String on String literals

On a recent project, some huge data structures were set up with data that was read in from a database (and hence not String constants/literals) but with a huge amount of duplication. It was a banking application, and things like the names of a modest set (maybe 100 or 200) corporations appeared all over the place. The data structures were already large, and if all those corp names had been unique objects they would have overflowed memory. Instead, all the data structures had references to the same 100 or 200 String objects, thus saving lots of space.

Another small advantage of interned Strings is that == can be used (successfully!) to compare Strings if all involved strings are guaranteed to be interned. Apart from the leaner syntax, this is also a performance enhancement. But as others have pointed out, doing this harbors a great risk of introducing programming errors, so this should be done only as a desparate measure of last resort.

The downside is that interning a String takes more time than simply throwing it on the heap, and that the space for interned Strings may be limited, depending on the Java implementation. It's best done when you're dealing with a known reasonable number of Strings with many duplications.

Improve INSERT-per-second performance of SQLite

Several tips:

  1. Put inserts/updates in a transaction.
  2. For older versions of SQLite - Consider a less paranoid journal mode (pragma journal_mode). There is NORMAL, and then there is OFF, which can significantly increase insert speed if you're not too worried about the database possibly getting corrupted if the OS crashes. If your application crashes the data should be fine. Note that in newer versions, the OFF/MEMORY settings are not safe for application level crashes.
  3. Playing with page sizes makes a difference as well (PRAGMA page_size). Having larger page sizes can make reads and writes go a bit faster as larger pages are held in memory. Note that more memory will be used for your database.
  4. If you have indices, consider calling CREATE INDEX after doing all your inserts. This is significantly faster than creating the index and then doing your inserts.
  5. You have to be quite careful if you have concurrent access to SQLite, as the whole database is locked when writes are done, and although multiple readers are possible, writes will be locked out. This has been improved somewhat with the addition of a WAL in newer SQLite versions.
  6. Take advantage of saving space...smaller databases go faster. For instance, if you have key value pairs, try making the key an INTEGER PRIMARY KEY if possible, which will replace the implied unique row number column in the table.
  7. If you are using multiple threads, you can try using the shared page cache, which will allow loaded pages to be shared between threads, which can avoid expensive I/O calls.
  8. Don't use !feof(file)!

I've also asked similar questions here and here.

How to convert a String into an array of Strings containing one character each

You can use String.split(String regex):

String input = "aabbab";
String[] parts = input.split("(?!^)");

Consistency of hashCode() on a Java string

The hashcode will be calculated based on the ASCII values of the characters in the String.

This is the implementation in the String Class is as follows

public int hashCode() {
    int h = hash;
    if (h == 0 && value.length > 0) {
        hash = h = isLatin1() ? StringLatin1.hashCode(value)
                              : StringUTF16.hashCode(value);
    }
    return h;
}

Collisions in hashcode are unavoidable. For example, the strings "Ea" and "FB" give the same hashcode as 2236

What function is to replace a substring from a string in C?

There isn't one.

You'd need to roll your own using something like strstr and strcat or strcpy.

Why does Java's hashCode() in String use 31 as a multiplier?

You can read Bloch's original reasoning under "Comments" in http://bugs.java.com/bugdatabase/view_bug.do?bug_id=4045622. He investigated the performance of different hash functions in regards to the resulting "average chain size" in a hash table. P(31) was one of the common functions during that time which he found in K&R's book (but even Kernighan and Ritchie couldn't remember where it came from). In the end he basically had to choose one and so he took P(31) since it seemed to perform well enough. Even though P(33) was not really worse and multiplication by 33 is equally fast to calculate (just a shift by 5 and an addition), he opted for 31 since 33 is not a prime:

Of the remaining four, I'd probably select P(31), as it's the cheapest to calculate on a RISC machine (because 31 is the difference of two powers of two). P(33) is similarly cheap to calculate, but it's performance is marginally worse, and 33 is composite, which makes me a bit nervous.

So the reasoning was not as rational as many of the answers here seem to imply. But we're all good in coming up with rational reasons after gut decisions (and even Bloch might be prone to that).

How can I create a dynamically sized array of structs?

If you want to dynamically allocate arrays, you can use malloc from stdlib.h.

If you want to allocate an array of 100 elements using your words struct, try the following:

words* array = (words*)malloc(sizeof(words) * 100);

The size of the memory that you want to allocate is passed into malloc and then it will return a pointer of type void (void*). In most cases you'll probably want to cast it to the pointer type you desire, which in this case is words*.

The sizeof keyword is used here to find out the size of the words struct, then that size is multiplied by the number of elements you want to allocate.

Once you are done, be sure to use free() to free up the heap memory you used in order to prevent memory leaks:

free(array);

If you want to change the size of the allocated array, you can try to use realloc as others have mentioned, but keep in mind that if you do many reallocs you may end up fragmenting the memory. If you want to dynamically resize the array in order to keep a low memory footprint for your program, it may be better to not do too many reallocs.

Converting an integer to a hexadecimal string in Ruby

You can give to_s a base other than 10:

10.to_s(16)  #=> "a"

Note that in ruby 2.4 FixNum and BigNum were unified in the Integer class. If you are using an older ruby check the documentation of FixNum#to_s and BigNum#to_s

Entity Framework change connection at runtime

I have two extension methods to convert the normal connection string to the Entity Framework format. This version working well with class library projects without copying the connection strings from app.config file to the primary project. This is VB.Net but easy to convert to C#.

Public Module Extensions

    <Extension>
    Public Function ToEntityConnectionString(ByRef sqlClientConnStr As String, ByVal modelFileName As String, Optional ByVal multipleActiceResultSet As Boolean = True)
        Dim sqlb As New SqlConnectionStringBuilder(sqlClientConnStr)
        Return ToEntityConnectionString(sqlb, modelFileName, multipleActiceResultSet)
    End Function

    <Extension>
    Public Function ToEntityConnectionString(ByRef sqlClientConnStrBldr As SqlConnectionStringBuilder, ByVal modelFileName As String, Optional ByVal multipleActiceResultSet As Boolean = True)
        sqlClientConnStrBldr.MultipleActiveResultSets = multipleActiceResultSet
        sqlClientConnStrBldr.ApplicationName = "EntityFramework"

        Dim metaData As String = "metadata=res://*/{0}.csdl|res://*/{0}.ssdl|res://*/{0}.msl;provider=System.Data.SqlClient;provider connection string='{1}'"
        Return String.Format(metaData, modelFileName, sqlClientConnStrBldr.ConnectionString)
    End Function

End Module

After that I create a partial class for DbContext:

Partial Public Class DlmsDataContext

    Public Shared Property ModelFileName As String = "AvrEntities" ' (AvrEntities.edmx)

    Public Sub New(ByVal avrConnectionString As String)
        MyBase.New(CStr(avrConnectionString.ToEntityConnectionString(ModelFileName, True)))
    End Sub

End Class

Creating a query:

Dim newConnectionString As String = "Data Source=.\SQLEXPRESS;Initial Catalog=DB;Persist Security Info=True;User ID=sa;Password=pass"

Using ctx As New DlmsDataContext(newConnectionString)
    ' ...
    ctx.SaveChanges()
End Using

Find largest and smallest number in an array

int main () //start of main fcn
{

    int values[ 20 ]; //delcares array and how many elements
    int small,big; //declares integer
     for ( int i = 0; i < 20; i++ ) //counts to 20 and prompts user for value and stores it
    {
        cout << "Enter value " << i << ": ";
        cin >> values[i];
    }
    big=small=values[0]; //assigns element to be highest or lowest value
    for (int i = 0; i < 20; i++) //works out bigggest number
    {
        if(values[i]>big) //compare biggest value with current element
        {
            big=values[i];
        }
         if(values[i]<small) //compares smallest value with current element
        {
            small=values[i];
        }
    }
     cout << "The biggest number is " << big << endl; //prints outs biggest no
    cout << "The smallest number is " << small << endl; //prints out smalles no
}

PHP executable not found. Install PHP 7 and add it to your PATH or set the php.executablePath setting

Try this !!!. This will solve your problem for sure!

Method 1 -

Step 1 - Go to 'Environmental Variables'.

Step 2 - Find PATH variable and add the path to your PHP folder.

Step 3 - For 'XAMPP' users put 'C:\xampp\php' and 'WAMP' users put 'C:\wamp64\bin\php\php7.1.9' ) and save.

Method 2-

In VS Code

File -> Preferences -> Settings.

enter image description here

Open 'settings.json' file and put the below codes.

If you are using WAMP put this code and Save.

  "php.validate.executablePath": "C:\\wamp64\\bin\\php\\php7.1.9\\php.exe",
  "php.executablePath": "C:\\wamp64\\bin\\php\\php7.1.9\\php.exe"

If you are using XAMPP put this code and Save.

  "php.validate.executablePath": "C:\\xampp\\php\\php.exe",
  "php.executablePath": "C:\\xampp\\php\\php.exe"

Note - Replace php7.1.9 with your PHP version.

How to get a list of installed android applications and pick one to run

I had a requirement to filter out the system apps which user do not really use(eg. "com.qualcomm.service", "update services", etc). Ultimately I added another condition to filter down the app list. I just checked whether the app has 'launcher intent'.

So, the resultant code looks like...

PackageManager pm = getPackageManager();
        List<ApplicationInfo> apps = pm.getInstalledApplications(PackageManager.GET_GIDS);

        for (ApplicationInfo app : apps) {
            if(pm.getLaunchIntentForPackage(app.packageName) != null) {
                // apps with launcher intent
                if((app.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0) {
                    // updated system apps

                } else if ((app.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
                    // system apps

                } else {
                    // user installed apps

                }
                appsList.add(app);
            }

        }

MIT vs GPL license

You are correct that the GPL is more restrictive than the MIT license.

You cannot include GPL code in a MIT licensed product. If you distribute a combined work that combines GPL and MIT code (except in some particular situations, e.g. 'mere aggregation'), that distribution must be compliant with the GPL.

You can include MIT licensed code in a GPL product. The whole combined work must be distributed in a way compliant with the GPL. If you have made changes to the MIT parts of the code, you would be required to publish the source for those changes if you distribute an application that contains GPL and MIT code.

If you are the copyright owner of the GPL code, you can of course choose to release that code under the MIT license instead - in that case it's your code and you can publish it under as many licenses as you want.

Configuring so that pip install can work from github

If you want to use requirements.txt file, you will need git and something like the entry below to anonymously fetch the master branch in your requirements.txt.

For regular install:

git+git://github.com/celery/django-celery.git

For "editable" install:

-e git://github.com/celery/django-celery.git#egg=django-celery

Editable mode downloads the project's source code into ./src in the current directory. It allows pip freeze to output the correct github location of the package.

Python Web Crawlers and "getting" html source code

Use Python 2.7, is has more 3rd party libs at the moment. (Edit: see below).

I recommend you using the stdlib module urllib2, it will allow you to comfortably get web resources. Example:

import urllib2

response = urllib2.urlopen("http://google.de")
page_source = response.read()

For parsing the code, have a look at BeautifulSoup.

BTW: what exactly do you want to do:

Just for background, I need to download a page and replace any img with ones I have

Edit: It's 2014 now, most of the important libraries have been ported, and you should definitely use Python 3 if you can. python-requests is a very nice high-level library which is easier to use than urllib2.

Python conversion from binary string to hexadecimal

>>> import string
>>> s="0000 0100 1000 1101"
>>> ''.join([ "%x"%string.atoi(bin,2) for bin in s.split() ]  )
'048d'
>>>

or

>>> s="0000 0100 1000 1101"
>>> hex(string.atoi(s.replace(" ",""),2))
'0x48d'

Change navbar color in Twitter Bootstrap

Example

Just try it like this:

<!-- A light one -->
<nav class="navbar navbar-default" role="navigation"></nav>
<!-- A dark one -->
<nav class="navbar navbar-inverse" role="navigation"></nav>

File navabr.css

/* Navbar */
.navbar-default {
    background-color: #F8F8F8;
    border-color: #E7E7E7;
}
/* Title */
.navbar-default .navbar-brand {
    color: #777;
}
.navbar-default .navbar-brand:hover,
.navbar-default .navbar-brand:focus {
    color: #5E5E5E;
}
/* Link */
.navbar-default .navbar-nav > li > a {
    color: #777;
}
.navbar-default .navbar-nav > li > a:hover,
.navbar-default .navbar-nav > li > a:focus {
    color: #333;
}
.navbar-default .navbar-nav > .active > a,
.navbar-default .navbar-nav > .active > a:hover,
.navbar-default .navbar-nav > .active > a:focus {
    color: #555;
    background-color: #E7E7E7;
}
.navbar-default .navbar-nav > .open > a,
.navbar-default .navbar-nav > .open > a:hover,
.navbar-default .navbar-nav > .open > a:focus {
    color: #555;
    background-color: #D5D5D5;
}
/* Caret */
.navbar-default .navbar-nav > .dropdown > a .caret {
    border-top-color: #777;
    border-bottom-color: #777;
}
.navbar-default .navbar-nav > .dropdown > a:hover .caret,
.navbar-default .navbar-nav > .dropdown > a:focus .caret {
    border-top-color: #333;
    border-bottom-color: #333;
}
.navbar-default .navbar-nav > .open > a .caret,
.navbar-default .navbar-nav > .open > a:hover .caret,
.navbar-default .navbar-nav > .open > a:focus .caret {
    border-top-color: #555;
    border-bottom-color: #555;
}
/* Mobile version */
.navbar-default .navbar-toggle {
    border-color: #DDD;
}
.navbar-default .navbar-toggle:hover,
.navbar-default .navbar-toggle:focus {
    background-color: #DDD;
}
.navbar-default .navbar-toggle .icon-bar {
    background-color: #CCC;
}
@media (max-width: 767px) {
    .navbar-default .navbar-nav .open .dropdown-menu > li > a {
        color: #777;
    }
    .navbar-default .navbar-nav .open .dropdown-menu > li > a:hover,
    .navbar-default .navbar-nav .open .dropdown-menu > li > a:focus {
        color: #333;
    }
}

The default major color uses are as below:

  • Navbar Background: #F8F8F8
  • Navbar Border: #E7E7E7
  • Default Color: #777
  • Nav-brand Hover Color: #5E5E5E
  • Hover Color: #333
  • Active Background: #D5D5D5
  • Active Color: #555

You can learn more in To change navbar color in Twitter Bootstrap 3.

How can I link to a specific glibc version?

Link with -static. When you link with -static the linker embeds the library inside the executable, so the executable will be bigger, but it can be executed on a system with an older version of glibc because the program will use it's own library instead of that of the system.

How to link 2 cell of excel sheet?

Just follow these Steps :

If you want the contents of, say, C1 to mirror the contents of cell A1, you just need to set the formula in C1 to =A1. From this point forward, anything you type in A1 will show up in C1 as well.

To Link Multiple Cells in Excel From Another Worksheet :

Step 1

Click the worksheet tab at the bottom of the screen that contains a range of precedent cells to which you want to link. A range is a block or group of adjacent cells. For example, assume you want to link a range of blank cells in “Sheet1” to a range of precedent cells in “Sheet2.” Click the “Sheet2” tab.

Step 2

Determine the precedent range’s width in columns and height in rows. In this example, assume cells A1 through A4 on “Sheet2” contain a list of numbers 1, 2, 3 and 4, respectively, which will be your precedent cells. This precedent range is one column wide by four rows high.

Step 3

Click the worksheet tab at the bottom of the screen that contains the blank cells in which you will insert a link. In this example, click the “Sheet1” tab.

Step 4

Select the range of blank cells you want to link to the precedent cells. This range must be the same size as the precedent range, but can be in a different location on the worksheet. Click and hold the mouse button on the top left cell of the range, drag the mouse cursor to the bottom right cell in the range and release the mouse button to select the range. In this example, assume you want to link cells C1 through C4 to the precedent range. Click and hold on cell C1, drag the mouse to cell C4 and release the mouse to highlight the range.

Step 5

Type “=,” the worksheet name containing the precedent cells, “!,” the top left cell of the precedent range, “:” and the bottom right cell of the precedent range. Press “Ctrl,” “Shift” and “Enter” simultaneously to complete the array formula. Each dependent cell is now linked to the cell in the precedent range that’s in the same respective location within the range. In this example, type “=Sheet2!A1:A4” and press “Ctrl,” “Shift” and “Enter” simultaneously. Cells C1 through C4 on “Sheet1” now contain the array formula “{=Sheet2!A1:A4}” surrounded by curly brackets, and show the same data as the precedent cells in “Sheet2.”

Good Luck !!!

How to define a relative path in java

 File f1 = new File("..\\..\\..\\config.properties");  

this path trying to access file is in Project directory then just access file like this.

File f=new File("filename.txt");

if your file is in OtherSources/Resources

this.getClass().getClassLoader().getResource("relative path");//-> relative path from resources folder

Does file_get_contents() have a timeout setting?

It is worth noting that if changing default_socket_timeout on the fly, it might be useful to restore its value after your file_get_contents call:

$default_socket_timeout = ini_get('default_socket_timeout');
....
ini_set('default_socket_timeout', 10);
file_get_contents($url);
...
ini_set('default_socket_timeout', $default_socket_timeout);

Get all messages from Whatsapp

Yes, it must be ways to get msgs from WhatsApp, since there are some tools available on the market help WhatsApp users to backup WhatsApp chat history to their computer, I know this from here. Therefore, you must be able to implement such kind of app. Maybe you can find these tool on the market to see how they work.

Check if any ancestor has a class using jQuery

You can use parents method with specified .class selector and check if any of them matches it:

if ($elem.parents('.left').length != 0) {
    //someone has this class
}

What is the point of "final class" in Java?

One scenario where final is important, when you want to prevent inheritance of a class, for security reasons. This allows you to make sure that code you are running cannot be overridden by someone.

Another scenario is for optimization: I seem to remember that the Java compiler inlines some function calls from final classes. So, if you call a.x() and a is declared final, we know at compile-time what the code will be and can inline into the calling function. I have no idea whether this is actually done, but with final it is a possibility.

git stash -> merge stashed change with current changes

The way I do this is to git add this first then git stash apply <stash code>. It's the most simple way.

Error Handler - Exit Sub vs. End Sub

Your ProcExit label is your place where you release all the resources whether an error happened or not. For instance:

Public Sub SubA()
  On Error Goto ProcError

  Connection.Open
  Open File for Writing
  SomePreciousResource.GrabIt

ProcExit:  
  Connection.Close
  Connection = Nothing
  Close File
  SomePreciousResource.Release

  Exit Sub

ProcError:  
  MsgBox Err.Description  
  Resume ProcExit
End Sub

Local file access with JavaScript

NW.js allows you to create desktop applications using Javascript without all the security restrictions usually placed on the browser. So you can run executables with a function, or create/edit/read/write/delete files. You can access the hardware, such as current CPU usage or total ram in use, etc.

You can create a windows, linux, or mac desktop application with it that doesn't require any installation.

Editable 'Select' element

Nothing is impossible. Here's a solution that simply sets the value of a text input whenever the value of the <select> changes (rendering has been tested on Firefox and Google Chrome):

_x000D_
_x000D_
.select-editable {position:relative; background-color:white; border:solid grey 1px;  width:120px; height:18px;}_x000D_
.select-editable select {position:absolute; top:0px; left:0px; font-size:14px; border:none; width:120px; margin:0;}_x000D_
.select-editable input {position:absolute; top:0px; left:0px; width:100px; padding:1px; font-size:12px; border:none;}_x000D_
.select-editable select:focus, .select-editable input:focus {outline:none;}
_x000D_
<div class="select-editable">_x000D_
  <select onchange="this.nextElementSibling.value=this.value">_x000D_
    <option value=""></option>_x000D_
    <option value="115x175 mm">115x175 mm</option>_x000D_
    <option value="120x160 mm">120x160 mm</option>_x000D_
    <option value="120x287 mm">120x287 mm</option>_x000D_
  </select>_x000D_
  <input type="text" name="format" value=""/>_x000D_
</div>
_x000D_
_x000D_
_x000D_ jsfiddle: https://jsfiddle.net/nwH8A/

The next example adds the user input to the empty option slot of the <select> (thanks to @TomerPeled). It also has a little bit more flexible/variable CSS:

_x000D_
_x000D_
.select-editable {position:relative; width:120px;}_x000D_
.select-editable > * {position:absolute; top:0; left:0; box-sizing:border-box; outline:none;}_x000D_
.select-editable select {width:100%;}_x000D_
.select-editable input {width:calc(100% - 20px); margin:1px; border:none; text-overflow:ellipsis;}
_x000D_
<div class="select-editable">_x000D_
  <select onchange="this.nextElementSibling.value=this.value">_x000D_
    <option value=""></option>_x000D_
    <option value="115x175 mm">115x175 mm</option>_x000D_
    <option value="120x160 mm">120x160 mm</option>_x000D_
    <option value="120x287 mm">120x287 mm</option>_x000D_
  </select>_x000D_
  <input type="text" oninput="this.previousElementSibling.options[0].value=this.value; this.previousElementSibling.options[0].innerHTML=this.value" onchange="this.previousElementSibling.selectedIndex=0" value="" />_x000D_
</div>
_x000D_
_x000D_
_x000D_ jsfiddle: https://jsfiddle.net/pu7cndLv/1/


DataList

In HTML5 you can also do this with the <input> list attribute and <datalist> element:

_x000D_
_x000D_
<input list="browsers" name="browser">_x000D_
<datalist id="browsers">_x000D_
  <option value="Internet Explorer">_x000D_
  <option value="Firefox">_x000D_
  <option value="Chrome">_x000D_
  <option value="Opera">_x000D_
  <option value="Safari">_x000D_
</datalist>_x000D_
(click once to focus and edit, click again to see option dropdown)
_x000D_
_x000D_
_x000D_ jsfiddle: https://jsfiddle.net/hrkxebtw/

But this acts more like an auto-complete list; once you start typing, only the options that contain the typed string are left as suggestions. Depending on what you want to use it for, this may or may not be practical.

window.history.pushState refreshing the browser

window.history.pushState({urlPath:'/page1'},"",'/page1')

Only works after page is loaded, and when you will click on refresh it doesn't mean that there is any real URL.

What you should do here is knowing to which URL you are getting redirected when you reload this page. And on that page you can get the conditions by getting the current URL and making all of your conditions.

Does Java support structs?

Yes, a class is what you need. An class defines an own type.

How to uninstall jupyter

If you don't want to use pip-autoremove (since it removes dependencies shared among other packages) and pip3 uninstall jupyter just removed some packages, then do the following:

Copy-Paste:

sudo may be needed as per your need.

python3 -m pip uninstall -y jupyter jupyter_core jupyter-client jupyter-console jupyterlab_pygments notebook qtconsole nbconvert nbformat

Note:

The above command will only uninstall jupyter specific packages. I have not added other packages to uninstall since they might be shared among other packages (eg: Jinja2 is used by Flask, ipython is a separate set of packages themselves, tornado again might be used by others).

In any case, all the dependencies are mentioned below(as of 21 Nov, 2020. jupyter==4.4.0 )

If you are sure you want to remove all the dependencies, then you can use Stan_MD's answer.

attrs
backcall
bleach
decorator
defusedxml
entrypoints
importlib-metadata
ipykernel
ipython
ipython-genutils
ipywidgets
jedi
Jinja2
jsonschema
jupyter
jupyter-client
jupyter-console
jupyter-core
jupyterlab-pygments
MarkupSafe
mistune
more-itertools
nbconvert
nbformat
notebook
pandocfilters
parso
pexpect
pickleshare
prometheus-client
prompt-toolkit
ptyprocess
Pygments
pyrsistent
python-dateutil
pyzmq
qtconsole
Send2Trash
six
terminado
testpath
tornado
traitlets
wcwidth
webencodings
widgetsnbextension
zipp

Executive Edit:

pip3 uninstall jupyter
pip3 uninstall jupyter_core
pip3 uninstall jupyter-client
pip3 uninstall jupyter-console
pip3 uninstall jupyterlab_pygments
pip3 uninstall notebook
pip3 uninstall qtconsole
pip3 uninstall nbconvert
pip3 uninstall nbformat

Explanation of each:

  1. Uninstall jupyter dist-packages:

    pip3 uninstall jupyter

  2. Uninstall jupyter_core dist-packages (It also uninstalls following binaries: jupyter, jupyter-migrate,jupyter-troubleshoot):

    pip3 uninstall jupyter_core

  3. Uninstall jupyter-client:

    pip3 uninstall jupyter-client

  4. Uninstall jupyter-console:

    pip3 uninstall jupyter-console

  5. Uninstall jupyter-notebook (It also uninstalls following binaries: jupyter-bundlerextension, jupyter-nbextension, jupyter-notebook, jupyter-serverextension):

    pip3 uninstall notebook

  6. Uninstall jupyter-qtconsole :

    pip3 uninstall qtconsole

  7. Uninstall jupyter-nbconvert:

    pip3 uninstall nbconvert

  8. Uninstall jupyter-trust:

    pip3 uninstall nbformat

How do you get total amount of RAM the computer has?

.NIT has a limit to the amount of memory it can access of the total. Theres a percentage, and then 2 GB in xp was the hard ceiling.

You could have 4 GB in it, and it would kill the app when it hit 2GB.

Also in 64 bit mode, there is a percentage of memory you can use out of the system, so I'm not sure if you can ask for the whole thing or if this is specifically guarded against.

Git merge is not possible because I have unmerged files

I ran into the same issue and couldn't decide between laughing or smashing my head on the table when I read this error...

What git really tries to tell you: "You are already in a merge state and need to resolve the conflicts there first!"

You tried a merge and a conflict occured. Then, git stays in the merge state and if you want to resolve the merge with other commands git thinks you want to execute a new merge and so it tells you you can't do this because of your current unmerged files...

You can leave this state with git merge --abort and now try to execute other commands.

In my case I tried a pull and wanted to resolve the conflicts by hand when the error occured...

ORA-01830: date format picture ends before converting entire input string / Select sum where date query

In SQL Developer ..Go to Preferences-->NLS-->and change your date format accordingly

Can we locate a user via user's phone number in Android?

Quick answer: No, at least not with native SMS service.

Long answer: Sure, but the receiver's phone should have the correct setup first. An app that detects incoming sms, and if a keyword matches, reports its current location to your server, which then pushes that info to the sender.

Argument Exception "Item with Same Key has already been added"

Clear the dictionary before adding any items to it. I don't know how a dictionary of one object affects another's during assignment but I got the error after creating another object with the same key,value pairs.

NB: If you are going to add items in a loop just make sure you clear the dictionary before entering the loop.

How to properly set the 100% DIV height to match document/window height?

Use #element{ height:100vh}

This will set the height of the #element to 100% of viewport. Hope this helps.

Creating a LINQ select from multiple tables

You must create a new anonymous type:

 select new { op, pg }

Refer to the official guide.

Attach (open) mdf file database with SQL Server Management Studio

You may need to repair your mdf file first using some tools. There are lot of tool available in the market. There is tool called SQL Database Recovery Tool Repairs which is very useful to repair the mdf files.

The issue might me because of corrupted transaction logs, you may use tool SQL Database Recovery Tool Repairs to repair your corrupted mdf file.

How to get all Windows service names starting with a common word?

Save it as a .ps1 file and then execute

powershell -file "path\to your\start stop nation service command file.ps1"

How can I determine the direction of a jQuery scroll event?

You can use this as well

_x000D_
_x000D_
$(document).ready(function(){_x000D_
_x000D_
  var currentscroll_position = $(window).scrollTop();_x000D_
$(window).on('scroll', function(){_x000D_
Get_page_scroll_direction();_x000D_
});_x000D_
_x000D_
function Get_page_scroll_direction(){_x000D_
  var running_scroll_position = $(window).scrollTop();_x000D_
  if(running_scroll_position > currentscroll_position) {_x000D_
      _x000D_
      $('.direction_value').text('Scrolling Down Scripts');_x000D_
_x000D_
  } else {_x000D_
       _x000D_
       $('.direction_value').text('Scrolling Up Scripts');_x000D_
_x000D_
  }_x000D_
  currentscroll_position = running_scroll_position;_x000D_
}_x000D_
_x000D_
});
_x000D_
.direction_value{_x000D_
  position: fixed;_x000D_
  height: 30px;_x000D_
  background-color: #333;_x000D_
  color: #fff;_x000D_
  text-align: center;_x000D_
  z-index: 99;_x000D_
  left: 0;_x000D_
  top: 0;_x000D_
  width: 100%;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
_x000D_
<div class="direction_value">_x000D_
</div>_x000D_
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nisi ducimus expedita facilis architecto fugiat veniam natus suscipit amet beatae atque, enim recusandae quos, magnam, perferendis accusamus cumque nemo modi unde!</p>_x000D_
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nisi ducimus expedita facilis architecto fugiat veniam natus suscipit amet beatae atque, enim recusandae quos, magnam, perferendis accusamus cumque nemo modi unde!</p>_x000D_
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nisi ducimus expedita facilis architecto fugiat veniam natus suscipit amet beatae atque, enim recusandae quos, magnam, perferendis accusamus cumque nemo modi unde!</p>_x000D_
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nisi ducimus expedita facilis architecto fugiat veniam natus suscipit amet beatae atque, enim recusandae quos, magnam, perferendis accusamus cumque nemo modi unde!</p>_x000D_
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nisi ducimus expedita facilis architecto fugiat veniam natus suscipit amet beatae atque, enim recusandae quos, magnam, perferendis accusamus cumque nemo modi unde!</p>_x000D_
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nisi ducimus expedita facilis architecto fugiat veniam natus suscipit amet beatae atque, enim recusandae quos, magnam, perferendis accusamus cumque nemo modi unde!</p>
_x000D_
_x000D_
_x000D_

How to create multiple class objects with a loop in python?

Using a dictionary for unique names without a name list:

class MyClass:
    def __init__(self, name):
        self.name = name
        self.pretty_print_name()

    def pretty_print_name(self):
    print("This object's name is {}.".format(self.name))

my_objects = {}
for i in range(1,11):
    name = 'obj_{}'.format(i)
    my_objects[name] = my_objects.get(name, MyClass(name = name))

Output:

"This object's name is obj_1."
"This object's name is obj_2."
"This object's name is obj_3."
"This object's name is obj_4."
"This object's name is obj_5."
"This object's name is obj_6."
"This object's name is obj_7."
"This object's name is obj_8."
"This object's name is obj_9."
"This object's name is obj_10."

How to label each equation in align environment?

\tag also works in align*. Example:

\begin{align*}
  a(x)^{2} &= bx\tag{1}\\ 
  a(x)^{2} &= b\tag{2}\\ 
  ax &= b\tag{3}\\ 
  a(x)^{2}+bx &= c\tag{4}\\ 
  a(x)^{2}+c &= bx\tag{5}\\ 
  a(x)^{2} &= bx+c\tag{6}\\ \\ 
  Where\quad a, b, c \, \in N
\end{align*}

Output:

PDF output for \tag example

String date to xmlgregoriancalendar conversion

For me the most elegant solution is this one:

XMLGregorianCalendar result = DatatypeFactory.newInstance()
    .newXMLGregorianCalendar("2014-01-07");

Using Java 8.

Extended example:

XMLGregorianCalendar result = DatatypeFactory.newInstance()
    .newXMLGregorianCalendar("2014-01-07");
System.out.println(result.getDay());
System.out.println(result.getMonth());
System.out.println(result.getYear());

This prints out:

7
1
2014

How to Create a circular progressbar in Android which rotates on it?

@Pedram, your old solution works actually fine in lollipop too (and better than new one since it's usable everywhere, including in remote views) just change your circular_progress_bar.xml code to this:

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="270"
    android:toDegrees="270">
    <shape
        android:innerRadiusRatio="2.5"
        android:shape="ring"
        android:thickness="1dp"
        android:useLevel="true"> <!-- Just add this line -->
        <gradient
            android:angle="0"
            android:endColor="#007DD6"
            android:startColor="#007DD6"
            android:type="sweep"
            android:useLevel="false" />
    </shape>
</rotate>

Length of the String without using length() method

Just for completeness (and this is not at all recommended):

int length;
try
{
   length = str.getBytes("UTF-16BE").length / 2
}
catch (UnsupportedEncodingException e)
{
   throw new AssertionError("Cannot happen: UTF-16BE is always a supported encoding");
}

This works because a char is a UTF-16 code unit, and str.length() returns the number of such code units. Each UTF-16 code unit takes up 2 bytes, so we divide by 2. Additionally, there is no byte order mark written with UTF-16BE.

Test for array of string type in TypeScript

Try this:

if (value instanceof Array) {
alert('value is Array!');
} else {
alert('Not an array');
}

What's the difference between Apache's Mesos and Google's Kubernetes

Kubernetes is an open source project that brings 'Google style' cluster management capabilities to the world of virtual machines, or 'on the metal' scenarios. It works very well with modern operating system environments (like CoreOS or Red Hat Atomic) that offer up lightweight computing 'nodes' that are managed for you. It is written in Golang and is lightweight, modular, portable and extensible. We (the Kubernetes team) are working with a number of different technology companies (including Mesosphere who curate the Mesos open source project) to establish Kubernetes as the standard way to interact with computing clusters. The idea is to reproduce the patterns that we see people needing to build cluster applications based on our experience at Google. Some of these concepts include:

  • pods — a way to group containers together
  • replication controllers — a way to handle the lifecycle of containers
  • labels — a way to find and query containers, and
  • services — a set of containers performing a common function.

So with Kubernetes alone you will have something that is simple, easy to get up-and-running, portable and extensible that adds 'cluster' as a noun to the things that you manage in the lightest weight manner possible. Run an application on a cluster, and stop worrying about an individual machine. In this case, cluster is a flexible resource just like a VM. It is a logical computing unit. Turn it up, use it, resize it, turn it down quickly and easily.

With Mesos, there is a fair amount of overlap in terms of the basic vision, but the products are at quite different points in their lifecycle and have different sweet spots. Mesos is a distributed systems kernel that stitches together a lot of different machines into a logical computer. It was born for a world where you own a lot of physical resources to create a big static computing cluster. The great thing about it is that lots of modern scalable data processing application run well on Mesos (Hadoop, Kafka, Spark) and it is nice because you can run them all on the same basic resource pool, along with your new age container packaged apps. It is somewhat more heavy weight than the Kubernetes project, but is getting easier and easier to manage thanks to the work of folks like Mesosphere.

Now what gets really interesting is that Mesos is currently being adapted to add a lot of the Kubernetes concepts and to support the Kubernetes API. So it will be a gateway to getting more capabilities for your Kubernetes app (high availability master, more advanced scheduling semantics, ability to scale to a very large number of nodes) if you need them, and is well suited to run production workloads (Kubernetes is still in an alpha state).

When asked, I tend to say:

  1. Kubernetes is a great place to start if you are new to the clustering world; it is the quickest, easiest and lightest way to kick the tires and start experimenting with cluster oriented development. It offers a very high level of portability since it is being supported by a lot of different providers (Microsoft, IBM, Red Hat, CoreOs, MesoSphere, VMWare, etc).

  2. If you have existing workloads (Hadoop, Spark, Kafka, etc), Mesos gives you a framework that let's you interleave those workloads with each other, and mix in a some of the new stuff including Kubernetes apps.

  3. Mesos gives you an escape valve if you need capabilities that are not yet implemented by the community in the Kubernetes framework.

How do I set the value property in AngularJS' ng-options?

Please use track by property which differentiate values and labels in select box.

Please try

<select ng-options="obj.text for obj in array track by obj.value"></select>

which will assign labels with text and value with value(from the array)

How to make an alert dialog fill 90% of screen size?

After initialize your dialog object and set the content view. Do this and enjoy.

(in the case i am setting 90% to width and 70% to height because width 90% it will be over toolbar )

DisplayMetrics displaymetrics = new DisplayMetrics();
getActivity().getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int width = (int) ((int)displaymetrics.widthPixels * 0.9);
int height = (int) ((int)displaymetrics.heightPixels * 0.7);
d.getWindow().setLayout(width,height);
d.show();

Take screenshots in the iOS simulator

Press ?S or go to File > Save screenshot from your simulator menu and you will get the screenshot saved on your desktop.

current/duration time of html5 video?

https://www.w3schools.com/tags/av_event_timeupdate.asp

// Get the <video> element with id="myVideo"
var vid = document.getElementById("myVideo");

// Assign an ontimeupdate event to the <video> element, and execute a function if the current playback position has changed
vid.ontimeupdate = function() {myFunction()};

function myFunction() {
// Display the current position of the video in a <p> element with id="demo"
    document.getElementById("demo").innerHTML = vid.currentTime;
}

Generate pdf from HTML in div using Javascript

To capture div as PDF you can use https://grabz.it solution. It's got a JavaScript API which is easy and flexible and will allow you to capture the contents of a single HTML element such as a div or a span

In order to implement it you will need to first get an app key and secret and download the (free) SDK.

And now an example.

Let's say you have the HTML:

<div id="features">
    <h4>Acme Camera</h4>
    <label>Price</label>$399<br />
    <label>Rating</label>4.5 out of 5
</div>
<p>Cras ut velit sed purus porttitor aliquam. Nulla tristique magna ac libero tempor, ac vestibulum felisvulput ate. Nam ut velit eget
risus porttitor tristique at ac diam. Sed nisi risus, rutrum a metus suscipit, euismod tristique nulla. Etiam venenatis rutrum risus at
blandit. In hac habitasse platea dictumst. Suspendisse potenti. Phasellus eget vehicula felis.</p>

To capture what is under the features id you will need to:

//add the sdk
<script type="text/javascript" src="grabzit.min.js"></script>
<script type="text/javascript">
//login with your key and secret. 
GrabzIt("KEY", "SECRET").ConvertURL("http://www.example.com/my-page.html",
{"target": "#features", "format": "pdf"}).Create();
</script>

Please note the target: #feature. #feature is you CSS selector, like in the previous example. Now, when the page is loaded an image screenshot will now be created in the same location as the script tag, which will contain all of the contents of the features div and nothing else.

The are other configuration and customization you can do to the div-screenshot mechanism, please check them out here

Should image size be defined in the img tag height/width attributes or in CSS?

I'm using contentEditable to allow rich text editing in my app. I don't know how it slips through, but when an image is inserted, and then resized (by dragging the anchors on its side), it generates something like this:

  <img style="width:55px;height:55px" width="100" height="100" src="pic.gif" border=0/>

(subsequent testing shown that inserted images did not contain this "rogue" style attr+param).

When rendered by the browser (IE7), the width and height in the style overrides the img width/height param (so the image is shown like how I wanted it.. resized to 55px x 55px. So everything went well so it seems.

When I output the page to a ms-word document via setting the mime type application/msword or pasting the browser rendering to msword document, all the images reverted back to its default size. I finally found out that msword is discarding the style and using the img width and height tag (which has the value of the original image size).

Took me a while to found this out. Anyway... I've coded a javascript function to traverse all tags and "transferring" the img style.width and style.height values into the img.width and img.height, then clearing both the values in style, before I proceed saving this piece of html/richtext data into the database.

cheers.

opps.. my answer is.. no. leave both attributes directly under img, rather than style.

Copy all values from fields in one class to another through reflection

If you don't mind using a third party library, BeanUtils from Apache Commons will handle this quite easily, using copyProperties(Object, Object).

How to find out line-endings in a text file?

In vi...

:set list to see line-endings.

:set nolist to go back to normal.

While I don't think you can see \n or \r\n in vi, you can see which type of file it is (UNIX, DOS, etc.) to infer which line endings it has...

:set ff

Alternatively, from bash you can use od -t c <filename> or just od -c <filename> to display the returns.

How to pass ArrayList<CustomeObject> from one activity to another?

You can pass an ArrayList<E> the same way, if the E type is Serializable.

You would call the putExtra (String name, Serializable value) of Intent to store, and getSerializableExtra (String name) for retrieval.

Example:

ArrayList<String> myList = new ArrayList<String>();
intent.putExtra("mylist", myList);

In the other Activity:

ArrayList<String> myList = (ArrayList<String>) getIntent().getSerializableExtra("mylist");

Can I simultaneously declare and assign a variable in VBA?

in fact, you can, but not that way.

Sub MySub( Optional Byval Counter as Long=1 , Optional Byval Events as Boolean= True)

'code...

End Sub

And you can set the variables differently when calling the sub, or let them at their default values.

How do I pass a command line argument while starting up GDB in Linux?

Try

gdb --args InsertionSortWithErrors arg1toinsort arg2toinsort

How to Toggle a div's visibility by using a button click

In case you are interested in a jQuery soluton:

This is the HTML

<a id="button" href="#">Show/Hide</a>
<div id="item">Item</div>

This is the jQuery script

$( "#button" ).click(function() {
    $( "#item" ).toggle();
});

You can see it working here:

http://jsfiddle.net/BQUyT/

If you don't know how to use jQuery, you have to use this line to load the library:

<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>

And then use this line to start:

<script>
$(function() {
    // code to fire once the library finishes downloading.
});
</script>

So for this case the final code would be this:

<script>
$(function() {
    $( "#button" ).click(function() {
        $( "#item" ).toggle();
    });
});
</script>

Let me know if you need anything else

You can read more about jQuery here: http://jquery.com/

jquery - fastest way to remove all rows from a very large table

this works for me :

1- add class for each row "removeRow"

2- in the jQuery

$(".removeRow").remove();

Output first 100 characters in a string

From python tutorial:

Degenerate slice indices are handled gracefully: an index that is too large is replaced by the string size, an upper bound smaller than the lower bound returns an empty string.

So it is safe to use x[:100].

Android: How to open a specific folder via Intent and show its content in a file browser?

Thread is old but I needed this kind of feature in my application and I found a way to do it so I decided to post it if it can help anyone in my situation.

As our device fleet is composed only by Samsung Galaxy Tab 2, I just had to find the file explorer's package name, give the right path and I succeed open my file explorer where I wanted to. I wish I could use Intent.CATEGORY_APP_FILES but it is only available in API 29.

  Intent intent = context.getPackageManager().getLaunchIntentForPackage("com.sec.android.app.myfiles");
  Uri uri = Uri.parse(rootPath);
  if (intent != null) {
      intent.setData(uri);
      startActivity(intent);
  }

As I said, it was easy for me because our clients have the same device but it may help others to find a workaround for their own situation.

How to generate the whole database script in MySQL Workbench?

In the top menu of MySQL Workbench click on database and then on forward engineer. In the options menu with which you will be presented, make sure to have "generate insert statements for tables" set.

How to solve "Unresolved inclusion: <iostream>" in a C++ file in Eclipse CDT?

I use Eclipse for cross compiling and I have to add the explicit directories for some of the standard C++ libraries. Right click your project and select Properties. You'll get the dialog shown in the image. Follow the image and use the + icon to explicitly add the paths to your C++ libraries. enter image description here

CSS: How to have position:absolute div inside a position:relative div not be cropped by an overflow:hidden on a container

I don't really see a way to do this as-is. I think you might need to remove the overflow:hidden from div#1 and add another div within div#1 (ie as a sibling to div#2) to hold your unspecified 'content' and add the overflow:hidden to that instead. I don't think that overflow can be (or should be able to be) over-ridden.

Making text bold using attributed string in swift

Usage:

let label = UILabel()
label.attributedText =
    NSMutableAttributedString()
        .bold("Address: ")
        .normal(" Kathmandu, Nepal\n\n")
        .orangeHighlight(" Email: ")
        .blackHighlight(" [email protected] ")
        .bold("\n\nCopyright: ")
        .underlined(" All rights reserved. 2020.")

Result:

enter image description here

Here is a neat way to make a combination of bold and normal texts in a single label plus some other bonus methods.

Extension: Swift 5.*

extension NSMutableAttributedString {
    var fontSize:CGFloat { return 14 }
    var boldFont:UIFont { return UIFont(name: "AvenirNext-Bold", size: fontSize) ?? UIFont.boldSystemFont(ofSize: fontSize) }
    var normalFont:UIFont { return UIFont(name: "AvenirNext-Regular", size: fontSize) ?? UIFont.systemFont(ofSize: fontSize)}
    
    func bold(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font : boldFont
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    
    func normal(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font : normalFont,
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    /* Other styling methods */
    func orangeHighlight(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font :  normalFont,
            .foregroundColor : UIColor.white,
            .backgroundColor : UIColor.orange
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    
    func blackHighlight(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font :  normalFont,
            .foregroundColor : UIColor.white,
            .backgroundColor : UIColor.black
            
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
    
    func underlined(_ value:String) -> NSMutableAttributedString {
        
        let attributes:[NSAttributedString.Key : Any] = [
            .font :  normalFont,
            .underlineStyle : NSUnderlineStyle.single.rawValue
            
        ]
        
        self.append(NSAttributedString(string: value, attributes:attributes))
        return self
    }
}

Note: If compiler is missing UIFont/UIColor, replace them with NSFont/NSColor.

Working with dictionaries/lists in R

The package hash is now available: https://cran.r-project.org/web/packages/hash/hash.pdf

Examples

h <- hash( keys=letters, values=1:26 )
h <- hash( letters, 1:26 )
h$a
# [1] 1
h$foo <- "bar"
h[ "foo" ]
# <hash> containing 1 key-value pair(s).
#   foo : bar
h[[ "foo" ]]
# [1] "bar"

Build error: You must add a reference to System.Runtime

I had this problem in some solutions on VS 2015 (not MVC though), and even in the same solution on one workstation but not on another. The errors started appeared after changing .NET version to 4.6 and referencing PCL.

The solution is simple: Close the solution and delete the hidden .vs folder in the same folder as the solution.

Adding the missing references as suggested in other answers also solves the problem, but the error remains solved even after you remove the references again.

As for TeamCity, I cannot say since my configuration never had a problem. But make sure that you reset the working catalog as a part of your debugging effort.

PHP foreach with Nested Array?

foreach ($tmpArray as $innerArray) {
    //  Check type
    if (is_array($innerArray)){
        //  Scan through inner loop
        foreach ($innerArray as $value) {
            echo $value;
        }
    }else{
        // one, two, three
        echo $innerArray;
    }
}

Swift: How to get substring from start to last index of character

var url = "www.stackoverflow.com"
let str = path.suffix(3)
print(str) //low

What is a raw type and why shouldn't we use it?

tutorial page.

A raw type is the name of a generic class or interface without any type arguments. For example, given the generic Box class:

public class Box<T> {
    public void set(T t) { /* ... */ }
    // ...
}

To create a parameterized type of Box, you supply an actual type argument for the formal type parameter T:

Box<Integer> intBox = new Box<>();

If the actual type argument is omitted, you create a raw type of Box:

Box rawBox = new Box();

Insert value into a string at a certain position?

If you just want to insert a value at a certain position in a string, you can use the String.Insert method:

public string Insert(int startIndex, string value)

Example:

"abc".Insert(2, "XYZ") == "abXYZc"

The difference between Classes, Objects, and Instances

Class : Structure

Object : Physical Manifestation

Instance : each object created from class

Reference : Address of Object

Radio Buttons "Checked" Attribute Not Working

I could repro this by setting the name of input tag the same for two groups of input like below:

<body>
  <div>
      <div>
        <h3>Header1</h3>
      </div>
      <div>
          <input type="radio" name="gender" id="male_1" value="male"> Male<br>
          <input type="radio" name="gender" id="female_1" value="female" checked="checked"> Female<br>
          <input type="submit" value="Submit">
      </div>
  </div>


  <div>
      <div>
        <h3>Header2</h3>
      </div>
      <div>
          <input type="radio" name="gender" id="male_2" value="male"> Male<br>
          <input type="radio" name="gender" id="female_2" value="female" checked="checked"> Female<br>
          <input type="submit" value="Submit">
      </div>
  </div>
</body>

(To see this running, click here)

The following two solutions both fix the problem:

  1. Use different names for the inputs in the second group
  2. Use form tag instead of div tag for one of the groups (can't really figure out the real reason why this would solve the problem. Would love to hear some opinions on this!)

How to read one single line of csv data in Python?

The simple way to get any row in csv file

import csv
csvfile = open('some.csv','rb')
csvFileArray = []
for row in csv.reader(csvfile, delimiter = '.'):
    csvFileArray.append(row)
print(csvFileArray[0])

Wait until flag=true

For iterating over ($.each) objects and executing a longish-running operation (containing nested ajax sync calls) on each object:

I first set a custom done=false property on each.

Then, in a recursive function, set each done=true and continued using setTimeout. (It's an operation meant to stop all other UI, show a progress bar and block all other use so I forgave myself for the sync calls.)

function start()
{
    GlobalProducts = getproductsfromsomewhere();
    $.each(GlobalProducts, function(index, product) {
         product["done"] = false;
    });

    DoProducts();
}
function DoProducts()
{
    var doneProducts = Enumerable.From(GlobalProducts).Where("$.done == true").ToArray(); //linqjs

    //update progress bar here

    var nextProduct = Enumerable.From(GlobalProducts).Where("$.done == false").First();

        if (nextProduct) {
            nextProduct.done = true;
            Me.UploadProduct(nextProduct.id); //does the long-running work

            setTimeout(Me.UpdateProducts, 500)
        }
}

Visual Studio Code: Auto-refresh file changes

{
    "files.useExperimentalFileWatcher" : true
}

in Code -> Preferences -> Settings

Tested with Visual Studio Code Version 1.26.1 on mac and win

How to enable remote access of mysql in centos?

so do the following edit my.cnf:

[mysqld]
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
language = /usr/share/mysql/English
bind-address = xxx.xxx.xxx.xxx
# skip-networking

after edit hit service mysqld restart

login into mysql and hit this query:

GRANT ALL ON foo.* TO bar@'xxx.xxx.xxx.xxx' IDENTIFIED BY 'PASSWORD';

thats it make sure your iptables allow connection from 3306 if not put the following:

iptables -A INPUT -i lo -p tcp --dport 3306 -j ACCEPT

iptables -A OUTPUT -p tcp --sport 3306 -j ACCEPT

How to swap two variables in JavaScript

(function(A, B){ b=A; a=B; })(parseInt(a), parseInt(b));

jQuery add text to span within a div

You can use:

$("#tagscloud span").text("Your text here");

The same code will also work for the second case. You could also use:

$("#tagscloud #WebPartCaptionWPQ2").text("Your text here");

Javascript: How to pass a function with string parameters as a parameter to another function

Try this:

onclick="myfunction(
    '/myController/myAction',
    function(){myfuncionOnOK('/myController2/myAction2','myParameter2');},
    function(){myfuncionOnCancel('/myController3/myAction3','myParameter3');}
);"

Then you just need to call these two functions passed to myfunction:

function myfunction(url, f1, f2) {
    // …
    f1();
    f2();
}

What is the best way to implement a "timer"?

Use the Timer class.

public static void Main()
{
    System.Timers.Timer aTimer = new System.Timers.Timer();
    aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
    aTimer.Interval = 5000;
    aTimer.Enabled = true;

    Console.WriteLine("Press \'q\' to quit the sample.");
    while(Console.Read() != 'q');
}

 // Specify what you want to happen when the Elapsed event is raised.
 private static void OnTimedEvent(object source, ElapsedEventArgs e)
 {
     Console.WriteLine("Hello World!");
 }

The Elapsed event will be raised every X amount of milliseconds, specified by the Interval property on the Timer object. It will call the Event Handler method you specify. In the example above, it is OnTimedEvent.

Can I have multiple :before pseudo-elements for the same element?

In CSS2.1, an element can only have at most one of any kind of pseudo-element at any time. (This means an element can have both a :before and an :after pseudo-element — it just cannot have more than one of each kind.)

As a result, when you have multiple :before rules matching the same element, they will all cascade and apply to a single :before pseudo-element, as with a normal element. In your example, the end result looks like this:

.circle.now:before {
    content: "Now";
    font-size: 19px;
    color: black;
}

As you can see, only the content declaration that has highest precedence (as mentioned, the one that comes last) will take effect — the rest of the declarations are discarded, as is the case with any other CSS property.

This behavior is described in the Selectors section of CSS2.1:

Pseudo-elements behave just like real elements in CSS with the exceptions described below and elsewhere.

This implies that selectors with pseudo-elements work just like selectors for normal elements. It also means the cascade should work the same way. Strangely, CSS2.1 appears to be the only reference; neither css3-selectors nor css3-cascade mention this at all, and it remains to be seen whether it will be clarified in a future specification.

If an element can match more than one selector with the same pseudo-element, and you want all of them to apply somehow, you will need to create additional CSS rules with combined selectors so that you can specify exactly what the browser should do in those cases. I can't provide a complete example including the content property here, since it's not clear for instance whether the symbol or the text should come first. But the selector you need for this combined rule is either .circle.now:before or .now.circle:before — whichever selector you choose is personal preference as both selectors are equivalent, it's only the value of the content property that you will need to define yourself.

If you still need a concrete example, see my answer to this similar question.

The legacy css3-content specification contains a section on inserting multiple ::before and ::after pseudo-elements using a notation that's compatible with the CSS2.1 cascade, but note that that particular document is obsolete — it hasn't been updated since 2003, and no one has implemented that feature in the past decade. The good news is that the abandoned document is actively undergoing a rewrite in the guise of css-content-3 and css-pseudo-4. The bad news is that the multiple pseudo-elements feature is nowhere to be found in either specification, presumably owing, again, to lack of implementer interest.

Stopping a windows service when the stop option is grayed out

Open command prompt with admin access and type the following commands there .

a)

tasklist

it displays list of all available services . There you can see the service you want to stop/start/restart . Remember PID value of the service you want to force stop.

b) Now type

taskkill /f /PID [PID value of the service] 

and press enter. On success you will get the message “SUCCESS: The process with PID has been terminated”.

Ex : taskkill /f /PID 5088

This will forcibly kill the frozen service. You can now return to Server Manager and restart the service.

How to convert PDF files to images

https://www.codeproject.com/articles/317700/convert-a-pdf-into-a-series-of-images-using-csharp

I found this GhostScript wrapper to be working like a charm for converting the PDFs to PNGs, page by page.

Usage:

string pdf_filename = @"C:\TEMP\test.pdf";            
var pdf2Image = new Cyotek.GhostScript.PdfConversion.Pdf2Image(pdf_filename);
for (var page = 1; page < pdf2Image.PageCount; page++)
{
    string png_filename = @"C:\TEMP\test" + page + ".png";
    pdf2Image.ConvertPdfPageToImage(png_filename, page);
}

Being built on GhostScript, obviously for commercial application the licensing question remains.

jquery change button color onclick

Use css:

<style>
input[name=btnsubmit]:active {
color: green;
}
</style>

How to place two divs next to each other?

  1. Add float:left; property in both divs.

  2. Add display:inline-block; property.

  3. Add display:flex; property in parent div.

System.Net.WebException: The remote name could not be resolved:

It's probably caused by a local network connectivity issue (but also a DNS error is possible). Unfortunately HResult is generic, however you can determine the exact issue catching HttpRequestException and then inspecting InnerException: if it's a WebException then you can check the WebException.Status property, for example WebExceptionStatus.NameResolutionFailure should indicate a DNS resolution problem.


It may happen, there isn't much you can do.

What I'd suggest to always wrap that (network related) code in a loop with a try/catch block (as also suggested here for other fallible operations). Handle known exceptions, wait a little (say 1000 msec) and try again (for say 3 times). Only if failed all times then you can quit/report an error to your users. Very raw example like this:

private const int NumberOfRetries = 3;
private const int DelayOnRetry = 1000;

public static async Task<HttpResponseMessage> GetFromUrlAsync(string url) {
    using (var client = new HttpClient()) {
        for (int i=1; i <= NumberOfRetries; ++i) {
            try {
                return await client.GetAsync(url); 
            }
            catch (Exception e) when (i < NumberOfRetries) {
                await Task.Delay(DelayOnRetry);
            }
        }
    }
}

How do I ignore ampersands in a SQL script running from SQL Plus?

set define off <- This is the best solution I found

I also tried...

set define }

I was able to insert several records containing ampersand characters '&' but I cannot use the '}' character into the text So I decided to use "set define off" and everything works as it should.

Yahoo Finance All Currencies quote API Documentation

I'm developing an application that needs currency conversion, and been using Open Exchange Rates because I wouldn't be paying since the app is in testing. But as of September 2012 Open Exchange Rates is gonna be paid for non-personal, so I checked out that they were using the Yahoo Finance Webservice (the one that "doesn't exist") and looking for documentation on it got here, and opted to use YQL.

Using YQL with the Yahoo Finance table (yahoo.finance.quotes) linked by NT3RP, currencies appear with symbol="ISOCODE=X", for example: "ARS=X" for Argentine Peso, "AUD=X" for Australian Dollar. "USD=X" doesn't exist, but it would be 1, since the rest are rates against USD.

The "price" value on the OP API is in the field "LastTradePriceOnly" of the table. For my application I used the "Ask" field.

Deep cloning objects

Disclaimer: I'm the author of the mentioned package.

I was surprised how the top answers to this question in 2019 still use serialization or reflection.

Serialization is limiting (requires attributes, specific constructors, etc.) and is very slow

BinaryFormatter requires the Serializable attribute, JsonConverter requires a parameterless constructor or attributes, neither handle read only fields or interfaces very well and both are 10-30x slower than necessary.

Expression Trees

You can instead use Expression Trees or Reflection.Emit to generate cloning code only once, then use that compiled code instead of slow reflection or serialization.

Having come across the problem myself and seeing no satisfactory solution, I decided to create a package that does just that and works with every type and is a almost as fast as custom written code.

You can find the project on GitHub: https://github.com/marcelltoth/ObjectCloner

Usage

You can install it from NuGet. Either get the ObjectCloner package and use it as:

var clone = ObjectCloner.DeepClone(original);

or if you don't mind polluting your object type with extensions get ObjectCloner.Extensions as well and write:

var clone = original.DeepClone();

Performance

A simple benchmark of cloning a class hierarchy showed performance ~3x faster than using Reflection, ~12x faster than Newtonsoft.Json serialization and ~36x faster than the highly suggested BinaryFormatter.

How to use getJSON, sending data with post method?

This is my "one-line" solution:

$.postJSON = function(url, data, func) { $.post(url+(url.indexOf("?") == -1 ? "?" : "&")+"callback=?", data, func, "json"); }

In order to use jsonp, and POST method, this function adds the "callback" GET parameter to the URL. This is the way to use it:

$.postJSON("http://example.com/json.php",{ id : 287 }, function (data) {
   console.log(data.name);
});

The server must be prepared to handle the callback GET parameter and return the json string as:

jsonp000000 ({"name":"John", "age": 25});

in which "jsonp000000" is the callback GET value.

In PHP the implementation would be like:

print_r($_GET['callback']."(".json_encode($myarr).");");

I made some cross-domain tests and it seems to work. Still need more testing though.

Typescript input onchange event.target.value

the correct way to use in TypeScript is

  handleChange(e: React.ChangeEvent<HTMLInputElement>) {
    // No longer need to cast to any - hooray for react!
    this.setState({temperature: e.target.value});
  }

  render() {
        ...
        <input value={temperature} onChange={this.handleChange} />
        ...
    );
  }

Follow the complete class, it's better to understand:

import * as React from "react";

const scaleNames = {
  c: 'Celsius',
  f: 'Fahrenheit'
};


interface TemperatureState {
   temperature: string;
}

interface TemperatureProps {
   scale: string;

}

class TemperatureInput extends React.Component<TemperatureProps, TemperatureState> {
  constructor(props: TemperatureProps) {
    super(props);
    this.handleChange = this.handleChange.bind(this);
    this.state = {temperature: ''};
  }

  //  handleChange(e: { target: { value: string; }; }) {
  //    this.setState({temperature: e.target.value});  
  //  }


  handleChange(e: React.ChangeEvent<HTMLInputElement>) {
    // No longer need to cast to any - hooray for react!
    this.setState({temperature: e.target.value});
  }

  render() {
    const temperature = this.state.temperature;
    const scale = this.props.scale;
    return (
      <fieldset>
        <legend>Enter temperature in {scaleNames[scale]}:</legend>
        <input value={temperature} onChange={this.handleChange} />
      </fieldset>
    );
  }
}

export default TemperatureInput;

getString Outside of a Context or Activity

Yes, we can access resources without using `Context`

You can use:

Resources.getSystem().getString(android.R.string.somecommonstuff)

... everywhere in your application, even in static constants declarations. Unfortunately, it supports the system resources only.

For local resources use this solution. It is not trivial, but it works.

How to get base url with jquery or javascript?

I am surprised that non of the answers consider the base url if it was set in <base> tag. All current answers try to get the host name or server name or first part of address. This is the complete logic which also considers the <base> tag (which may refer to another domain or protocol):

function getBaseURL(){
  var elem=document.getElementsByTagName("base")[0];
  if (typeof(elem) != 'undefined' && elem != null){
     return elem.href;
  }
  return window.location.origin;
}

Jquery format:

function getBaseURL(){
  if ($("base").length){
     return $("base").attr("href");
  }
  return window.location.origin;
}

Without getting involved with the logic above, the shorthand solution which considers both <base> tag and window.location.origin:

Js:

var a=document.createElement("a");
a.href=".";
var baseURL= a.href;

Jquery:

var baseURL= $('<a href=".">')[0].href

Final note: for a local file in your computer (not on a host) the window.location.origin only returns the file:// but the sorthand solution above returns the complete correct path.

LocalDate to java.util.Date and vice versa simplest conversion?

You can convert the java.util.Date object into a String object, which will format the date as yyyy-mm-dd.

LocalDate has a parse method that will convert it to a LocalDate object. The string must represent a valid date and is parsed using DateTimeFormatter.ISO_LOCAL_DATE.

Date to LocalDate

LocalDate.parse(Date.toString())

How do I request and receive user input in a .bat and use it to run a certain program?

I don't know the platform you're doing this on but I assume Windows due to the .bat extension.

Also I don't have a way to check this but this seems like the batch processor skips the If lines due to some errors and then executes the one with -dev.

You could try this by chaning the two jump targets (:yes and :no) along with the code. If then the line without -dev is executed you know your If lines are erroneous.

If so, please check if == is really the right way to do a comparison in .bat files.

Also, judging from the way bash does this stuff, %foo=="y" might evaluate to true only if %foo includes the quotes. So maybe "%foo"=="y" is the way to go.

Cannot push to GitHub - keeps saying need merge

I had a similar issue and it turned out that my workflow for keeping my branch up to date was at fault. I was doing the following:

In my local 'master'

git fetch upstream
git merge upstream/master --ff-only

then back in my local branch

git rebase master

This worked well for a previous git flow but not with github. The git rebase was the problem here causing issues with syncing (and I'll admit that's something I've had to accept without fully understanding) and unfortunately put me in a position where git push -f became probably the easiest option. Not good.

My new flow is to update the branch directly using git merge as follows:

In my local branch

git fetch upstream
git merge upstream/master

No fast forward, as I will have made changes of course in the local branch.

As you can probably tell, I'm no git expert but I'm reliably informed that this workflow will probably avoid the specific problems that I had.

javascript remove "disabled" attribute from html input

method 1 <input type="text" onclick="this.disabled=false;" disabled>
<hr>
method 2 <input type="text" onclick="this.removeAttribute('disabled');" disabled>
<hr>
method 3 <input type="text" onclick="this.removeAttribute('readonly');" readonly>

code of the previous answers don't seem to work in inline mode, but there is a workaround: method 3.

see demo https://jsfiddle.net/eliz82/xqzccdfg/

How to find out what is locking my tables?

As per the official docs the sp_lock is mark as deprecated:

This feature is in maintenance mode and may be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature.

and it is recommended to use sys.dm_tran_locks instead. This dynamic management object returns information about currently active lock manager resources. Each row represents a currently active request to the lock manager for a lock that has been granted or is waiting to be granted.

It generally returns more details in more user friendly syntax then sp_lock does.

The whoisactive routine written by Adam Machanic is very good to check the current activity in your environment and see what types of waits/locks are slowing your queries. You can very easily find what is blocking your queries and tons of other handy information.


For example, let's say we have the following queries running in the default SQL Server Isolation Level - Read Committed. Each query is executing in separate query window:

-- creating sample data
CREATE TABLE [dbo].[DataSource]
(
    [RowID] INT PRIMARY KEY
   ,[RowValue] VARCHAR(12)
);

INSERT INTO [dbo].[DataSource]([RowID], [RowValue])
VALUES (1,  'samle data');

-- query window 1
BEGIN TRANSACTION;

    UPDATE [dbo].[DataSource]
    SET [RowValue] = 'new data'
    WHERE [RowID] = 1;

--COMMIT TRANSACTION;

-- query window 2
SELECT *
FROM [dbo].[DataSource];

Then execute the sp_whoisactive (only part of the columns are displayed):

enter image description here

You can easily seen the session which is blocking the SELECT statement and even its T-SQL code. The routine has a lot of parameters, so you can check the docs for more details.

If we query the sys.dm_tran_locks view we can see that one of the session is waiting for a share lock of a resource, that has exclusive lock by other session:

enter image description here

Extract a substring using PowerShell

Since the string is not complex, no need to add RegEx strings. A simple match will do the trick

$line = "----start----Hello World----end----"
$line -match "Hello World"
$matches[0]
Hello World

$result = $matches[0]
$result
Hello World

How to remove numbers from string using Regex.Replace?

the best design is:

public static string RemoveIntegers(this string input)
    {
        return Regex.Replace(input, @"[\d-]", string.Empty);
    }

How to change the color of a button?

Here is my code, to make different colors on button, and Linear, Constraint and Scroll Layout

First, you need to make a custom_button.xml on your drawable

  1. Go to res
  2. Expand it, right click on drawable
  3. New -> Drawable Resource File
  4. File Name : custom_button, Click OK

Custom_Button.xml Code

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@color/red"/> <!-- pressed -->
    <item android:state_focused="true" android:drawable="@color/blue"/> <!-- focused -->
    <item android:drawable="@color/black"/> <!-- default -->
</selector>

Second, go to res

  1. Expand values
  2. Double click on colors.xml
  3. Copy the code below

Colors.xml Code

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>

    <color name="black">#000</color>
    <color name="violet">#9400D3</color>
    <color name="indigo">#4B0082</color>
    <color name="blue">#0000FF</color>
    <color name="green">#00FF00</color>
    <color name="yellow">#FFFF00</color>
    <color name="orange">#FF7F00</color>
    <color name="red">#FF0000</color>
</resources>

Screenshots below

enter image description here XML Coding enter image description here Design Preview

Excel compare two columns and highlight duplicates

NOTE: You may want to remove duplicate items (eg duplicate entries in the same column) before doing these steps to prevent false positives.

  1. Select both columns
  2. click Conditional Formatting
  3. click Highlight Cells Rules
  4. click Duplicate Values (the defaults should be OK)
  5. Duplicates are now highlighted in red:

enter image description here

enter image description here

How to dynamically remove items from ListView on a button click?

      private List<DataValue> datavalue=new ArrayList<Datavalue>;

     @Override
    public View getView(int position, View view, ViewGroup viewGroup) {

            view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                datavalue.remove(position);
                notifyDataSetChanged();
            }
        });
    }
    }

How to get started with Windows 7 gadgets

Here's an MSDN article on Vista Gadgets. Some preliminary documentation on 7 gadgets, and changes. I think the only major changes are that Gadgets don't reside in the Sidebar anymore, and as such "dock/undock events" are now backwards-compatibility cludges that really shouldn't be used.

Best way to get started is probably to just tweak an existing gadget. There's an example gadget in the above link, or you could pick a different one out on your own.

Gadgets are written in HTML, CSS, and some IE scripting language (generally Javascript, but I believe VBScript also works). For really fancy things you might need to create an ActiveX object, so C#/C++ for COM could be useful to know.

Gadgets are packaged as ".gadget" files, which are just renamed Zip archives that contain a gadget manifest (gadget.xml) in their top level.

Git push requires username and password

If you have cloned HTTPS instead of SSH and facing issue with username and password prompt on pull, push and fetch. You can solve this problem simply for UBUNTU

Step 1: move to root directory

cd ~/

create a file .git-credentials

Add this content to that file with you usename password and githosting URL

https://user:[email protected]

Then execute the command

git config --global credential.helper store

Now you will be able to pull push and fetch all details from your repo without any hassle.

Android overlay a view ontop of everything?

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/root_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<LinearLayout
    android:id = "@+id/Everything"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <!-- other actual layout stuff here EVERYTHING HERE -->

   </LinearLayout>

<LinearLayout
    android:id="@+id/overlay"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="right" >
</LinearLayout>

Now any view you add under LinearLayout with android:id = "@+id/overlay" will appear as overlay with gravity = right on Linear Layout with android:id="@+id/Everything"

JNI and Gradle in Android Studio

Android Studio 2.2 came out with the ability to use ndk-build and cMake. Though, we had to wait til 2.2.3 for the Application.mk support. I've tried it, it works...though, my variables aren't showing up in the debugger. I can still query them via command line though.

You need to do something like this:

externalNativeBuild{
   ndkBuild{
        path "Android.mk"
    }
}

defaultConfig {
  externalNativeBuild{
    ndkBuild {
      arguments "NDK_APPLICATION_MK:=Application.mk"
      cFlags "-DTEST_C_FLAG1"  "-DTEST_C_FLAG2"
      cppFlags "-DTEST_CPP_FLAG2"  "-DTEST_CPP_FLAG2"
      abiFilters "armeabi-v7a", "armeabi"
    }
  } 
}

See http://tools.android.com/tech-docs/external-c-builds

NB: The extra nesting of externalNativeBuild inside defaultConfig was a breaking change introduced with Android Studio 2.2 Preview 5 (July 8, 2016). See the release notes at the above link.

What are the differences between struct and class in C++?

  • . In classes all the members by default are private but in structure members are public by default.

    1. There is no term like constructor and destructor for structs, but for class compiler creates default if you don't provide.

    2. Sizeof empty structure is 0 Bytes wer as Sizeof empty class is 1 Byte The struct default access type is public. A struct should typically be used for grouping data.

    The class default access type is private, and the default mode for inheritance is private. A class should be used for grouping data and methods that operate on that data.

    In short, the convention is to use struct when the purpose is to group data, and use classes when we require data abstraction and, perhaps inheritance.

    In C++ structures and classes are passed by value, unless explicitly de-referenced. In other languages classes and structures may have distinct semantics - ie. objects (instances of classes) may be passed by reference and structures may be passed by value. Note: There are comments associated with this question. See the discussion page to add to the conversation.

Homebrew: Could not symlink, /usr/local/bin is not writable

I found for my particular setup the following commands worked

brew doctor

And then that showed me where my errors were, and then this slightly different command from the comment above.

sudo chown -R $(whoami) /usr/local/opt

Can a Byte[] Array be written to a file in C#?

You can do this using System.IO.BinaryWriter which takes a Stream so:

var bw = new BinaryWriter(File.Open("path",FileMode.OpenOrCreate);
bw.Write(byteArray);

"Failed to load platform plugin "xcb" " while launching qt5 app on linux without qt installed

Use ldd (man ldd) to show shared library dependencies. Running this on libqxcb.so

.../platforms$ ldd libqxcb.so

shows that xcb depends on libQt5DBus.so.5 in addition to libQt5Core.so.5 and libQt5Gui.so.5 (and many other system libs). Add libQt5DBus.so.5 to your collection of shared libs and you should be ready to move on.

How do I abort/cancel TPL Tasks?

This sort of thing is one of the logistical reasons why Abort is deprecated. First and foremost, do not use Thread.Abort() to cancel or stop a thread if at all possible. Abort() should only be used to forcefully kill a thread that is not responding to more peaceful requests to stop in a timely fashion.

That being said, you need to provide a shared cancellation indicator that one thread sets and waits while the other thread periodically checks and gracefully exits. .NET 4 includes a structure designed specifically for this purpose, the CancellationToken.

How to write a Unit Test?

Other answers have shown you how to use JUnit to set up test classes. JUnit is not the only Java test framework. Concentrating on the technical details of using a framework however detracts from the most important concepts that should be guiding your actions, so I will talk about those.

  • Testing (of all kinds of all kinds of things) compares the actual behaviour of something (The System Under Test, SUT) with its expected behaviour.

  • Automated testing can be done using a computer program. Because that comparison is being done by an inflexible and unintelligent computer program, the expected behaviour must be precisely and unambiguously known.

  • What a program or part of a program (a class or method) is expected to do is its specification. Testing software therefore requires that you have a specification for the SUT. This might be an explicit description, or an implicit specification in your head of what is expected.

  • Automated unit testing therefore requires a precise and unambiguous specification of the class or method you are testing.

  • But you needed that specification when you set out to write that code. So part of what testing is about actually begins before you write even one line of the SUT. The testing technique of Test Driven Development (TDD) takes that idea to an extreme, and has you create the unit testing code before you write the code to be tested.

  • Unit testing frameworks test your SUT using assertions. An assertion is a logical expression (an expression with a boolean result type; a predicate) that must be true if the SUT is behaving correctly. The specification must therefore be expressed (or re-expressed) as assertions.

  • A useful technique for expressing a specification as assertions is programming by contract. These specifications are in terms of postconditions. A postcondition is an assertion about the publicly visible state of the SUT after return from a method or a constructor. Some methods have postconditions that are invariants, which are predicates that are true before and after execution of the method. A class can also be said to have invariants, which are postconditions of every constructor and method of the class, and hence should always be true. Postconditions (And invariants) are expressed only in terms of publicity visible state: public and protected fields, the values returned by returned by public and protected methods (such as getters), and the publicly visible state of objects passed (by reference) to methods.


Many beginners post questions here asking how they can test some code, presenting the code but without stating the specification for that code. As this discussion shows, it is impossible for anyone to give a good answer to such a question, because at best potential answereres must guess the specification, and might do so incorrectly. The asker of the question evidently does not understand the importance of a specification, and is thus a novice who needs to understand the fundamentals I've described here before trying to write some test code.

SQL Server using wildcard within IN

In Access SQL, I would use this. I'd imagine that SQLserver has the same syntax.

select * from jobdetails where job_no like "0711*" or job_no like "0712*"

WebSocket with SSL

1 additional caveat (besides the answer by kanaka/peter): if you use WSS, and the server certificate is not acceptable to the browser, you may not get any browser rendered dialog (like it happens for Web pages). This is because WebSockets is treated as a so-called "subresource", and certificate accept / security exception / whatever dialogs are not rendered for subresources.

Reading from a text file and storing in a String

These are the necersary imports:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

And this is a method that will allow you to read from a File by passing it the filename as a parameter like this: readFile("yourFile.txt");

String readFile(String fileName) throws IOException {
    BufferedReader br = new BufferedReader(new FileReader(fileName));
    try {
        StringBuilder sb = new StringBuilder();
        String line = br.readLine();

        while (line != null) {
            sb.append(line);
            sb.append("\n");
            line = br.readLine();
        }
        return sb.toString();
    } finally {
        br.close();
    }
}

Using variables inside a bash heredoc

In answer to your first question, there's no parameter substitution because you've put the delimiter in quotes - the bash manual says:

The format of here-documents is:

      <<[-]word
              here-document
      delimiter

No parameter expansion, command substitution, arithmetic expansion, or pathname expansion is performed on word. If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded. If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion. [...]

If you change your first example to use <<EOF instead of << "EOF" you'll find that it works.

In your second example, the shell invokes sudo only with the parameter cat, and the redirection applies to the output of sudo cat as the original user. It'll work if you try:

sudo sh -c "cat > /path/to/outfile" <<EOT
my text...
EOT

Git remote branch deleted, but still it appears in 'branch -a'

Don't forget the awesome

git fetch -p

which fetches and prunes all origins.

How to handle a lost KeyStore password in Android?

Brute is your best bet!

Here is a script that helped me out:

https://code.google.com/p/android-keystore-password-recover/wiki/HowTo

You can optionally give it a list of words the password might include for a very fast recover (for me it worked in <1 sec)

Fatal error: Call to undefined function base_url() in C:\wamp\www\Test-CI\application\views\layout.php on line 5

There is only three way to solve. paste in following code in this path application/config/autoload.php.

most of them I use this

require_once BASEPATH . '/helpers/url_helper.php';

this is good but some time, it fail

$autoload['helper'] = array('url');

I never use it but I know it work

$this->load->helper('url');

How to create a notification with NotificationCompat.Builder?

Notification in depth

CODE

Intent intent = new Intent(this, SecondActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,0,intent,0);

NotificationCompat.Builder mBuilder =
                new NotificationCompat.Builder(context)
                        .setSmallIcon(R.drawable.your_notification_icon)
                        .setContentTitle("Notification Title")
                        .setContentText("Notification ")
                        .setContentIntent(pendingIntent );

NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0, mBuilder.build());

Depth knowledge

Notification can be build using Notification. Builder or NotificationCompat.Builder classes.
But if you want backward compatibility you should use NotificationCompat.Builder class as it is part of v4 Support library as it takes care of heavy lifting for providing consistent look and functionalities of Notification for API 4 and above.

Core Notification Properties

A notification has 4 core properties (3 Basic display properties + 1 click action property)

  • Small icon
  • Title
  • Text
  • Button click event (Click event when you tap the notification )

Button click event is made optional on Android 3.0 and above. It means that you can build your notification using only display properties if your minSdk targets Android 3.0 or above. But if you want your notification to run on older devices than Android 3.0 then you must provide Click event otherwise you will see IllegalArgumentException.

Notification Display

Notification are displayed by calling notify() method of NotificationManger class

notify() parameters

There are two variants available for notify method

notify(String tag, int id, Notification notification)

or

notify(int id, Notification notification)

notify method takes an integer id to uniquely identify your notification. However, you can also provide an optional String tag for further identification of your notification in case of conflict.

This type of conflict is rare but say, you have created some library and other developers are using your library. Now they create their own notification and somehow your notification and other dev's notification id is same then you will face conflict.

Notification after API 11 (More control)

API 11 provides additional control on Notification behavior

  • Notification Dismissal
    By default, if a user taps on notification then it performs the assigned click event but it does not clear away the notification. If you want your notification to get cleared when then you should add this

    mBuilder.setAutoClear(true);

  • Prevent user from dismissing notification
    A user may also dismiss the notification by swiping it. You can disable this default behavior by adding this while building your notification

    mBuilder.setOngoing(true);

  • Positioning of notification
    You can set the relative priority to your notification by

    mBuilder.setOngoing(int pri);

If your app runs on lower API than 11 then your notification will work without above mentioned additional features. This is the advantage to choosing NotificationCompat.Builder over Notification.Builder

Notification after API 16 (More informative)

With the introduction of API 16, notifications were given so many new features
Notification can be so much more informative.
You can add a bigPicture to your logo. Say you get a message from a person now with the mBuilder.setLargeIcon(Bitmap bitmap) you can show that person's photo. So in the statusbar you will see the icon when you scroll you will see the person photo in place of the icon. There are other features too

  • Add a counter in the notification
  • Ticker message when you see the notification for the first time
  • Expandable notification
  • Multiline notification and so on

How do I correctly upgrade angular 2 (npm) to the latest version?

npm uninstall --save-dev angular-cli

npm install --save-dev @angular/cli@latest

ng update @angular/cli

ng update @angular/core --force

ng update @angular/material or npm i @angular/cdk@6 @angular/material@6 --save

npm install typescript@'>=2.7.0 <2.8.0'

Change CSS properties on click

With jquery you can do it like:

$('img').click(function(){
    $('#foo').css('background-color', 'red').css('color', 'white');
});

this applies for all img tags you should set an id attribute for it like image and then:

$('#image').click(function(){
    $('#foo').css('background-color', 'red').css('color', 'white');
});

How to output MySQL query results in CSV format?

Try this code:

SELECT 'Column1', 'Column2', 'Column3', 'Column4', 'Column5'
UNION ALL
SELECT column1, column2,
column3 , column4, column5 FROM demo
INTO OUTFILE '/tmp/demo.csv'
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\n';

For more information: http://dev.mysql.com/doc/refman/5.1/en/select-into.html

Determine if 2 lists have the same elements, regardless of order?

This seems to work, though possibly cumbersome for large lists.

>>> A = [0, 1]
>>> B = [1, 0]
>>> C = [0, 2]
>>> not sum([not i in A for i in B])
True
>>> not sum([not i in A for i in C])
False
>>> 

However, if each list must contain all the elements of other then the above code is problematic.

>>> A = [0, 1, 2]
>>> not sum([not i in A for i in B])
True

The problem arises when len(A) != len(B) and, in this example, len(A) > len(B). To avoid this, you can add one more statement.

>>> not sum([not i in A for i in B]) if len(A) == len(B) else False
False

One more thing, I benchmarked my solution with timeit.repeat, under the same conditions used by Aaron Hall in his post. As suspected, the results are disappointing. My method is the last one. set(x) == set(y) it is.

>>> def foocomprehend(): return not sum([not i in data for i in data2])
>>> min(timeit.repeat('fooset()', 'from __main__ import fooset, foocount, foocomprehend'))
25.2893661496
>>> min(timeit.repeat('foosort()', 'from __main__ import fooset, foocount, foocomprehend'))
94.3974742993
>>> min(timeit.repeat('foocomprehend()', 'from __main__ import fooset, foocount, foocomprehend'))
187.224562545

What are Makefile.am and Makefile.in?

Makefile.am is a programmer-defined file and is used by automake to generate the Makefile.in file (the .am stands for automake). The configure script typically seen in source tarballs will use the Makefile.in to generate a Makefile.

The configure script itself is generated from a programmer-defined file named either configure.ac or configure.in (deprecated). I prefer .ac (for autoconf) since it differentiates it from the generated Makefile.in files and that way I can have rules such as make dist-clean which runs rm -f *.in. Since it is a generated file, it is not typically stored in a revision system such as Git, SVN, Mercurial or CVS, rather the .ac file would be.

Read more on GNU Autotools. Read about make and Makefile first, then learn about automake, autoconf, libtool, etc.

No Activity found to handle Intent : android.intent.action.VIEW

For me when trying to open a link :

Uri uri = Uri.parse("https://www.facebook.com/abc/");
                Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                startActivity(intent);

I got the same error android.content.ActivityNotFoundException: No Activity found to handle Intent

The problem was because i didnt have any app that can open URLs (i.e. browsers) installed in my phone. So after Installing a browser the problem was solved.

*Lesson : Make sure there is at least one app which handles the intent you are calling *

BEGIN - END block atomic transactions in PL/SQL

BEGIN-END blocks are the building blocks of PL/SQL, and each PL/SQL unit is contained within at least one such block. Nesting BEGIN-END blocks within PL/SQL blocks is usually done to trap certain exceptions and handle that special exception and then raise unrelated exceptions. Nevertheless, in PL/SQL you (the client) must always issue a commit or rollback for the transaction.

If you wish to have atomic transactions within a PL/SQL containing transaction, you need to declare a PRAGMA AUTONOMOUS_TRANSACTION in the declaration block. This will ensure that any DML within that block can be committed or rolledback independently of the containing transaction.

However, you cannot declare this pragma for nested blocks. You can only declare this for:

  • Top-level (not nested) anonymous PL/SQL blocks
  • List item
  • Local, standalone, and packaged functions and procedures
  • Methods of a SQL object type
  • Database triggers

Reference: Oracle

Generate PDF from HTML using pdfMake in Angularjs

Okay, I figured this out.

  1. You will need html2canvas and pdfmake. You do NOT need to do any injection in your app.js to either, just include in your script tags

  2. On the div that you want to create the PDF of, add an ID name like below:

     <div id="exportthis">
    
  3. In your Angular controller use the id of the div in your call to html2canvas:

  4. change the canvas to an image using toDataURL()

  5. Then in your docDefinition for pdfmake assign the image to the content.

  6. The completed code in your controller will look like this:

           html2canvas(document.getElementById('exportthis'), {
                onrendered: function (canvas) {
                    var data = canvas.toDataURL();
                    var docDefinition = {
                        content: [{
                            image: data,
                            width: 500,
                        }]
                    };
                    pdfMake.createPdf(docDefinition).download("Score_Details.pdf");
                }
            });
    

I hope this helps someone else. Happy coding!

How do I create a file at a specific path?

The file path "c:\Test\blah" will have a tab character for the `\T'. You need to use either:

"C:\\Test"

or

r"C:\Test"

How many characters can you store with 1 byte?

Yes, 1 byte does encode a character (inc spaces etc) from the ASCII set. However in data units assigned to character encoding it can and often requires in practice up to 4 bytes. This is because English is not the only character set. And even in English documents other languages and characters are often represented. The numbers of these are very many and there are very many other encoding sets, which you may have heard of e.g. BIG-5, UTF-8, UTF-32. Most computers now allow for these uses and ensure the least amount of garbled text (which usually means a missing encoding set.) 4 bytes is enough to cover these possible encodings. I byte per character does not allow for this and in use it is larger often 4 bytes per possible character for all encodings, not just ASCII. The final character may only need a byte to function or be represented on screen, but requires 4 bytes to be located in the rather vast global encoding "works".

How can I see what I am about to push with git?

There is always dry-run:

git push --dry-run

It will do everything except for the actually sending of the data.

If you want a more graphical view you have a bunch of options.

Tig and the gitk script that come with git both display the current branch of your local copy and the branch of the remote or origin.

alt text

So any commits you make that are after the origin are the commits that will be pushed.

Open gitk from shell while in the branch you want to push by typing gitk&, then to see the difference between what is on the remote and what you are about to push to the remote, select your local unpushed commit and right-click on the remote and choose "Diff this -> selected": alt text

Flutter - Wrap text on overflow, like insert ellipsis or fade

You can use this code snipped to show text with ellipsis

Text(
    "Introduction to Very very very long text",
    maxLines: 1,
    overflow: TextOverflow.ellipsis,
    softWrap: false,
    style: TextStyle(color: Colors.black, fontWeight: FontWeight.bold),
),

How to read file contents into a variable in a batch file?

Read file contents into a variable:

for /f "delims=" %%x in (version.txt) do set Build=%%x

or

set /p Build=<version.txt

Both will act the same with only a single line in the file, for more lines the for variant will put the last line into the variable, while set /p will use the first.

Using the variable – just like any other environment variable – it is one, after all:

%Build%

So to check for existence:

if exist \\fileserver\myapp\releasedocs\%Build%.doc ...

Although it may well be that no UNC paths are allowed there. Can't test this right now but keep this in mind.

Using Python's ftplib to get a directory listing, portably

Try to use ftp.nlst(dir).

However, note that if the folder is empty, it might throw an error:

files = []

try:
    files = ftp.nlst()
except ftplib.error_perm, resp:
    if str(resp) == "550 No files found":
        print "No files in this directory"
    else:
        raise

for f in files:
    print f

Merge two rows in SQL

if one row has value in field1 column and other rows have null value then this Query might work.

SELECT
  FK,
  MAX(Field1) as Field1,
  MAX(Field2) as Field2
FROM 
(
select FK,ISNULL(Field1,'') as Field1,ISNULL(Field2,'') as Field2 from table1
)
tbl
GROUP BY FK

How to reload the current state?

$state.go($state.current, $stateParams, {reload: true, inherit: false});

Where is the Keytool application?

If you are working with a Mac... the keytool is part of the Java SDK and can be found in the following location /System/Library/Java/JavaVirtualMachines/[VERSION].jdk/Contents/Home/bin/keytool

Can anonymous class implement interface?

Using Roslyn, you can dynamically create a class which inherits from an interface (or abstract class).

I use the following to create concrete classes from abstract classes.

In this example, AAnimal is an abstract class.

var personClass = typeof(AAnimal).CreateSubclass("Person");

Then you can instantiate some objects:

var person1 = Activator.CreateInstance(personClass);
var person2 = Activator.CreateInstance(personClass);

Without a doubt this won't work for every case, but it should be enough to get you started:

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;

namespace Publisher
{
    public static class Extensions
    {
        public static Type CreateSubclass(this Type baseType, string newClassName, string newNamespace = "Magic")
        {
            //todo: handle ref, out etc.
            var concreteMethods = baseType
                                    .GetMethods()
                                    .Where(method => method.IsAbstract)
                                    .Select(method =>
                                    {
                                        var parameters = method
                                                            .GetParameters()
                                                            .Select(param => $"{param.ParameterType.FullName} {param.Name}")
                                                            .ToString(", ");

                                        var returnTypeStr = method.ReturnParameter.ParameterType.Name;
                                        if (returnTypeStr.Equals("Void")) returnTypeStr = "void";

                                        var methodString = @$"
                                        public override {returnTypeStr} {method.Name}({parameters})
                                        {{
                                            Console.WriteLine(""{newNamespace}.{newClassName}.{method.Name}() was called"");
                                        }}";

                                        return methodString.Trim();
                                    })
                                    .ToList();

            var concreteMethodsString = concreteMethods
                                        .ToString(Environment.NewLine + Environment.NewLine);

            var classCode = @$"
            using System;

            namespace {newNamespace}
            {{
                public class {newClassName}: {baseType.FullName}
                {{
                    public {newClassName}()
                    {{
                    }}

                    {concreteMethodsString}
                }}
            }}
            ".Trim();

            classCode = FormatUsingRoslyn(classCode);


            /*
            var assemblies = new[]
            {
                MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
                MetadataReference.CreateFromFile(baseType.Assembly.Location),
            };
            */

            var assemblies = AppDomain
                        .CurrentDomain
                        .GetAssemblies()
                        .Where(a => !string.IsNullOrEmpty(a.Location))
                        .Select(a => MetadataReference.CreateFromFile(a.Location))
                        .ToArray();

            var syntaxTree = CSharpSyntaxTree.ParseText(classCode);

            var compilation = CSharpCompilation
                                .Create(newNamespace)
                                .AddSyntaxTrees(syntaxTree)
                                .AddReferences(assemblies)
                                .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));

            using (var ms = new MemoryStream())
            {
                var result = compilation.Emit(ms);
                //compilation.Emit($"C:\\Temp\\{newNamespace}.dll");

                if (result.Success)
                {
                    ms.Seek(0, SeekOrigin.Begin);
                    Assembly assembly = Assembly.Load(ms.ToArray());

                    var newTypeFullName = $"{newNamespace}.{newClassName}";

                    var type = assembly.GetType(newTypeFullName);
                    return type;
                }
                else
                {
                    IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
                        diagnostic.IsWarningAsError ||
                        diagnostic.Severity == DiagnosticSeverity.Error);

                    foreach (Diagnostic diagnostic in failures)
                    {
                        Console.Error.WriteLine("{0}: {1}", diagnostic.Id, diagnostic.GetMessage());
                    }

                    return null;
                }
            }
        }

        public static string ToString(this IEnumerable<string> list, string separator)
        {
            string result = string.Join(separator, list);
            return result;
        }

        public static string FormatUsingRoslyn(string csCode)
        {
            var tree = CSharpSyntaxTree.ParseText(csCode);
            var root = tree.GetRoot().NormalizeWhitespace();
            var result = root.ToFullString();
            return result;
        }
    }
}

Facebook Javascript SDK Problem: "FB is not defined"

Try to load your scripts in Head section. Moreover, it will be better if you define your scripts under some call like: document.ready, if you defined these scripts in body section

How to round a number to n decimal places in Java

The code snippet below shows how to display n digits. The trick is to set variable pp to 1 followed by n zeros. In the example below, variable pp value has 5 zeros, so 5 digits will be displayed.

double pp = 10000;

double myVal = 22.268699999999967;
String needVal = "22.2687";

double i = (5.0/pp);

String format = "%10.4f";
String getVal = String.format(format,(Math.round((myVal +i)*pp)/pp)-i).trim();

Using Excel VBA to export data to MS Access table

@Ahmed

Below is code that specifies fields from a named range for insertion into MS Access. The nice thing about this code is that you can name your fields in Excel whatever the hell you want (If you use * then the fields have to match exactly between Excel and Access) as you can see I have named an Excel column "Haha" even though the Access column is called "dte".

Sub test()
    dbWb = Application.ActiveWorkbook.FullName
    dsh = "[" & Application.ActiveSheet.Name & "$]" & "Data2"  'Data2 is a named range


sdbpath = "C:\Users\myname\Desktop\Database2.mdb"
sCommand = "INSERT INTO [main] ([dte], [test1], [values], [values2]) SELECT [haha],[test1],[values],[values2] FROM [Excel 8.0;HDR=YES;DATABASE=" & dbWb & "]." & dsh

Dim dbCon As New ADODB.Connection
Dim dbCommand As New ADODB.Command

dbCon.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & sdbpath & "; Jet OLEDB:Database Password=;"
dbCommand.ActiveConnection = dbCon

dbCommand.CommandText = sCommand
dbCommand.Execute

dbCon.Close


End Sub

What does <> mean?

Yes, it's "not equal".

Plotting using a CSV file

You can also plot to a png file using gnuplot (which is free):

terminal commands

gnuplot> set title '<title>'
gnuplot> set ylabel '<yLabel>'
gnuplot> set xlabel '<xLabel>'
gnuplot> set grid
gnuplot> set term png
gnuplot> set output '<Output file name>.png'
gnuplot> plot '<fromfile.csv>'

note: you always need to give the right extension (.png here) at set output

Then it is also possible that the ouput is not lines, because your data is not continues. To fix this simply change the 'plot' line to:

plot '<Fromfile.csv>' with line lt -1 lw 2

More line editing options (dashes and line color ect.) at: http://gnuplot.sourceforge.net/demo_canvas/dashcolor.html

  • gnuplot is available in most linux distros via the package manager (e.g. on an apt based distro, run apt-get install gnuplot)
  • gnuplot is available in windows via Cygwin
  • gnuplot is available on macOS via homebrew (run brew install gnuplot)

Get User Selected Range

This depends on what you mean by "get the range of selection". If you mean getting the range address (like "A1:B1") then use the Address property of Selection object - as Michael stated Selection object is much like a Range object, so most properties and methods works on it.

Sub test()
    Dim myString As String
    myString = Selection.Address
End Sub

How to install packages offline?

As a continues to @chaokunyang answer, I want to put here the script I write that does the work:

  1. Write a "requirements.txt" file that specifies the libraries you want to pack.
  2. Create a tar file that contains all your libraries (see the Packer script).
  3. Put the created tar file in the target machine and untar it.
  4. run the Installer script (which is also packed into the tar file).

"requirements.txt" file

docker==4.4.0

Packer side: file name: "create-offline-python3.6-dependencies-repository.sh"

#!/usr/bin/env bash

# This script follows the steps described in this link:
# https://stackoverflow.com/a/51646354/8808983

LIBRARIES_DIR="python3.6-wheelhouse"

if [ -d ${LIBRARIES_DIR} ]; then
    rm -rf ${LIBRARIES_DIR}/*
else
    mkdir ${LIBRARIES_DIR}
fi

pip download -r requirements.txt -d ${LIBRARIES_DIR}

files_to_add=("requirements.txt" "install-python-libraries-offline.sh")

for file in "${files_to_add[@]}"; do
    echo "Adding file ${file}"
    cp "$file" ${LIBRARIES_DIR}
done

tar -cf ${LIBRARIES_DIR}.tar ${LIBRARIES_DIR}

Installer side: file name: "install-python-libraries-offline.sh"

#!/usr/bin/env bash

# This script follows the steps described in this link:
# https://stackoverflow.com/a/51646354/8808983

# This file should run during the installation process from inside the libraries directory, after it was untared:
# pythonX-wheelhouse.tar -> untar -> pythonX-wheelhouse
# |
# |--requirements.txt
# |--install-python-libraries-offline.sh


pip3 install -r requirements.txt --no-index --find-links .

hadoop copy a local file system folder to HDFS

You could try:

hadoop fs -put /path/in/linux /hdfs/path

or even

hadoop fs -copyFromLocal /path/in/linux /hdfs/path

By default both put and copyFromLocal would upload directories recursively to HDFS.

Running shell command and capturing the output

If you need to run a shell command on multiple files, this did the trick for me.

import os
import subprocess

# Define a function for running commands and capturing stdout line by line
# (Modified from Vartec's solution because it wasn't printing all lines)
def runProcess(exe):    
    p = subprocess.Popen(exe, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    return iter(p.stdout.readline, b'')

# Get all filenames in working directory
for filename in os.listdir('./'):
    # This command will be run on each file
    cmd = 'nm ' + filename

    # Run the command and capture the output line by line.
    for line in runProcess(cmd.split()):
        # Eliminate leading and trailing whitespace
        line.strip()
        # Split the output 
        output = line.split()

        # Filter the output and print relevant lines
        if len(output) > 2:
            if ((output[2] == 'set_program_name')):
                print filename
                print line

Edit: Just saw Max Persson's solution with J.F. Sebastian's suggestion. Went ahead and incorporated that.

Fatal error: Call to undefined function mb_strlen()

In case Google search for this error

Call to undefined function mb_ereg_match()

takes somebody to this thread. Installing php-mbstring resolves it too.

Ubuntu 18.04.1, PHP 7.2.10

sudo apt-get install php7.2-mbstring

Swift: print() vs println() vs NSLog()

There's another method called dump() which can also be used for logging:

func dump<T>(T, name: String?, indent: Int, maxDepth: Int, maxItems: Int)

Dumps an object’s contents using its mirror to standard output.

From Swift Standard Library Functions

Working copy XXX locked and cleanup failed in SVN

I am sure It working fine for you

Goto top level SVN folder.

Right Click on folder(that has your svn files) -> TortoiseSVN -> CleanUp

This will surely solve your problem.

Build .so file from .c file using gcc command line

To generate a shared library you need first to compile your C code with the -fPIC (position independent code) flag.

gcc -c -fPIC hello.c -o hello.o

This will generate an object file (.o), now you take it and create the .so file:

gcc hello.o -shared -o libhello.so

EDIT: Suggestions from the comments:

You can use

gcc -shared -o libhello.so -fPIC hello.c

to do it in one step. – Jonathan Leffler

I also suggest to add -Wall to get all warnings, and -g to get debugging information, to your gcc commands. – Basile Starynkevitch

Why specify @charset "UTF-8"; in your CSS file?

One reason to always include a character set specification on every page containing text is to avoid cross site scripting vulnerabilities. In most cases the UTF-8 character set is the best choice for text, including HTML pages.

Using the "animated circle" in an ImageView while loading stuff

For the ones developing in Kotlin, there is a sweet method provided by the Anko library that makes the process of displaying a ProgressDialog a breeze!

Based on that link:

val dialog = progressDialog(message = "Please wait a bit…", title = "Fetching data")
dialog.show()
//....
dialog.dismiss()

This will show a Progress Dialog with the progress % displayed (for which you have to pass the init parameter also to calculate the progress).

There is also the indeterminateProgressDialog() method, which provides the Spinning Circle animation indefinitely until dismissed:

indeterminateProgressDialog("Loading...").show()

Shout out to this blog which led me to this solution.

ASP.net Getting the error "Access to the path is denied." while trying to upload files to my Windows Server 2008 R2 Web server

the problem might be that networkservice has no read rights

salution:

rightclick your upload folder -> poperty's -> security ->Edit -> add -> type :NETWORK SERVICE -> check box full control allow-> press ok or apply

Regular expression [Any number]

UPDATE: for your updated question

variable.match(/\[[0-9]+\]/);

Try this:

variable.match(/[0-9]+/);    // for unsigned integers
variable.match(/[-0-9]+/);   // for signed integers
variable.match(/[-.0-9]+/);  // for signed float numbers

Hope this helps!

Configure hibernate (using JPA) to store Y/N for type Boolean instead of 0/1

To do it in a generic JPA way using getter annotations, the example below works for me with Hibernate 3.5.4 and Oracle 11g. Note that the mapped getter and setter (getOpenedYnString and setOpenedYnString) are private methods. Those methods provide the mapping but all programmatic access to the class is using the getOpenedYn and setOpenedYn methods.

private String openedYn;

@Transient
public Boolean getOpenedYn() {
  return toBoolean(openedYn);
}

public void setOpenedYn(Boolean openedYn) {
  setOpenedYnString(toYesNo(openedYn));
}

@Column(name = "OPENED_YN", length = 1)
private String getOpenedYnString() {
  return openedYn;
}

private void setOpenedYnString(String openedYn) {
  this.openedYn = openedYn;
}

Here's the util class with static methods toYesNo and toBoolean:

public class JpaUtil {

    private static final String NO = "N";
    private static final String YES = "Y";

    public static String toYesNo(Boolean value) {
        if (value == null)
            return null;
        else if (value)
            return YES;
        else
            return NO;
    }

    public static Boolean toBoolean(String yesNo) {
        if (yesNo == null)
            return null;
        else if (YES.equals(yesNo))
            return true;
        else if (NO.equals(yesNo))
            return false;
        else
            throw new RuntimeException("unexpected yes/no value:" + yesNo);
    }
}

How to assign an action for UIImageView object in Swift

You can add a UITapGestureRecognizer to the imageView, just drag one into your Storyboard/xib, Ctrl-drag from the imageView to the gestureRecognizer, and Ctrl-drag from the gestureRecognizer to the Swift-file to make an IBAction.

You'll also need to enable user interactions on the UIImageView, as shown in this image: enter image description here

iPhone: Setting Navigation Bar Title

if you are doing it all by code in the viewDidLoad method of the UIViewController you should only add self.title = @"title text";

something like this:

- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"title";
}

you could also try self.navigationItem.title = @"title";

also check if your navigationItem is not null and if you have set a custom background to the navigationbar check if the title is set without it.

How to pass a type as a method parameter in Java

Oh, but that's ugly, non-object-oriented code. The moment you see "if/else" and "typeof", you should be thinking polymorphism. This is the wrong way to go. I think generics are your friend here.

How many types do you plan to deal with?

UPDATE:

If you're just talking about String and int, here's one way you might do it. Start with the interface XmlGenerator (enough with "foo"):

package generics;

public interface XmlGenerator<T>
{
   String getXml(T value);
}

And the concrete implementation XmlGeneratorImpl:

    package generics;

public class XmlGeneratorImpl<T> implements XmlGenerator<T>
{
    private Class<T> valueType;
    private static final int DEFAULT_CAPACITY = 1024;

    public static void main(String [] args)
    {
        Integer x = 42;
        String y = "foobar";

        XmlGenerator<Integer> intXmlGenerator = new XmlGeneratorImpl<Integer>(Integer.class);
        XmlGenerator<String> stringXmlGenerator = new XmlGeneratorImpl<String>(String.class);

        System.out.println("integer: " + intXmlGenerator.getXml(x));
        System.out.println("string : " + stringXmlGenerator.getXml(y));
    }

    public XmlGeneratorImpl(Class<T> clazz)
    {
        this.valueType = clazz;
    }

    public String getXml(T value)
    {
        StringBuilder builder = new StringBuilder(DEFAULT_CAPACITY);

        appendTag(builder);
        builder.append(value);
        appendTag(builder, false);

        return builder.toString();
    }

    private void appendTag(StringBuilder builder) { this.appendTag(builder, false); }

    private void appendTag(StringBuilder builder, boolean isClosing)
    {
        String valueTypeName = valueType.getName();
        builder.append("<").append(valueTypeName);
        if (isClosing)
        {
            builder.append("/");
        }
        builder.append(">");
    }
}

If I run this, I get the following result:

integer: <java.lang.Integer>42<java.lang.Integer>
string : <java.lang.String>foobar<java.lang.String>

I don't know if this is what you had in mind.

How to make grep only match if the entire line matches?

This worked well for me when trying to do something similar:

grep -F ABB.log a.tmp

Replace first occurrence of pattern in a string

public string ReplaceFirst(string text, string search, string replace)
{
  int pos = text.IndexOf(search);
  if (pos < 0)
  {
    return text;
  }
  return text.Substring(0, pos) + replace + text.Substring(pos + search.Length);
}

here is an Extension Method that could also work as well per VoidKing request

public static class StringExtensionMethods
{
    public static string ReplaceFirst(this string text, string search, string replace)
    {
      int pos = text.IndexOf(search);
      if (pos < 0)
      {
        return text;
      }
      return text.Substring(0, pos) + replace + text.Substring(pos + search.Length);
    }
}

'Class' does not contain a definition for 'Method'

Today I encountered a problem with the exact same symptoms as you describe. I closed all files and restarted VS only to find out that some files disappeared from the Solution Explorer.

The following solved my problem: by selecting the current project in the Solution Explorer, a little icon Show all files appears on the top bar. Right-clicking the file and selecting Include In Project does the thing.

Credit

Evaluate list.contains string in JSTL

The following is more of a workaround than an answer to your question but it may be what you are looking for. If you can put your values in a map instead of a list, that would solve your problem. Just map your values to a non null value and do this <c:if test="${mymap.myValue ne null}">style='display:none;'</c:if> or you can even map to style='display:none; and simply output ${mymap.myValue}

How do I get the total Json record count using JQuery?

Why would you want length in this case?

If you do want to check for length, have the server return a JSON array with key-value pairs like this:

[
  {key:value},
  {key:value}
]

In JSON, [ and ] represents an array (with a length property), { and } represents a object (without a length property). You can iterate through the members of a object, but you will get functions as well, making a length check of the numbers of members useless except for iterating over them.

Align text to the bottom of a div

Flex Solution

It is perfectly fine if you want to go with the display: table-cell solution. But instead of hacking it out, we have a better way to accomplish the same using display: flex;. flex is something which has a decent support.

_x000D_
_x000D_
.wrap {_x000D_
  height: 200px;_x000D_
  width: 200px;_x000D_
  border: 1px solid #aaa;_x000D_
  margin: 10px;_x000D_
  display: flex;_x000D_
}_x000D_
_x000D_
.wrap span {_x000D_
  align-self: flex-end;_x000D_
}
_x000D_
<div class="wrap">_x000D_
  <span>Align me to the bottom</span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

In the above example, we first set the parent element to display: flex; and later, we use align-self to flex-end. This helps you push the item to the end of the flex parent.


Old Solution (Valid if you are not willing to use flex)

If you want to align the text to the bottom, you don't have to write so many properties for that, using display: table-cell; with vertical-align: bottom; is enough

_x000D_
_x000D_
div {_x000D_
  display: table-cell;_x000D_
  vertical-align: bottom;_x000D_
  border: 1px solid #f00;_x000D_
  height: 100px;_x000D_
  width: 100px;_x000D_
}
_x000D_
<div>Hello</div>
_x000D_
_x000D_
_x000D_

(Or JSFiddle)

PHP + MySQL transactions examples

Please check which storage engine you are using. If it is MyISAM, then Transaction('COMMIT','ROLLBACK') will not be supported because only the InnoDB storage engine, not MyISAM, supports transactions.

Where do I find some good examples for DDD?

This is a good example based on domain driven design and explains why it is important to have separate domain layer.
Microsoft spain - DDD N Layer Architecture

how to call a onclick function in <a> tag?

You should read up on the onclick html attribute and the window.open() documentation. Below is what you want.

_x000D_
_x000D_
<a href='#' onclick='window.open("http://www.google.com", "myWin", "scrollbars=yes,width=400,height=650"); return false;'>1</a>
_x000D_
_x000D_
_x000D_

JSFiddle: http://jsfiddle.net/TBcVN/

javac: file not found: first.java Usage: javac <options> <source files>

I had the same issue and it was to do with my file name. If you set the file location using CD in CMD, and then type DIR it will list the files in that directory. Check that the file name appears and check that the spelling and filename ending is correct.

It should be .java but mine was .java.txt. The instructions on the Java tutorials website state that you should select "Save as Type Text Documents" but for me that always adds .txt onto the end of the file name. If I change it to "Save as Type All Documents" it correctly saved the file name.

CMD DIR Example

Checking if a key exists in a JS object

map.has(key) is the latest ECMAScript 2015 way of checking the existance of a key in a map. Refer to this for complete details.

Unable to locate tools.jar

Incase it helps, the problem for me was that I had 2 entries in my PATH environment variable which pointed to a location containing the javaw executable.

I cleaned up the variable to make sure that "%JAVA_HOME%\bin" was the only entry referencing a location containing my java executables.

Read XML file using javascript

The code below will convert any XMLObject or string to a native JavaScript object. Then you can walk on the object to extract any value you want.

/**
 * Tries to convert a given XML data to a native JavaScript object by traversing the DOM tree.
 * If a string is given, it first tries to create an XMLDomElement from the given string.
 * 
 * @param {XMLDomElement|String} source The XML string or the XMLDomElement prefreably which containts the necessary data for the object.
 * @param {Boolean} [includeRoot] Whether the "required" main container node should be a part of the resultant object or not.
 * @return {Object} The native JavaScript object which is contructed from the given XML data or false if any error occured.
 */
Object.fromXML = function( source, includeRoot ) {
    if( typeof source == 'string' )
    {
        try
        {
            if ( window.DOMParser )
                source = ( new DOMParser() ).parseFromString( source, "application/xml" );
            else if( window.ActiveXObject )
            {
                var xmlObject = new ActiveXObject( "Microsoft.XMLDOM" );
                xmlObject.async = false;
                xmlObject.loadXML( source );
                source = xmlObject;
                xmlObject = undefined;
            }
            else
                throw new Error( "Cannot find an XML parser!" );
        }
        catch( error )
        {
            return false;
        }
    }

    var result = {};

    if( source.nodeType == 9 )
        source = source.firstChild;
    if( !includeRoot )
        source = source.firstChild;

    while( source ) {
        if( source.childNodes.length ) {
            if( source.tagName in result ) {
                if( result[source.tagName].constructor != Array ) 
                    result[source.tagName] = [result[source.tagName]];
                result[source.tagName].push( Object.fromXML( source ) );
            }
            else 
                result[source.tagName] = Object.fromXML( source );
        } else if( source.tagName )
            result[source.tagName] = source.nodeValue;
        else if( !source.nextSibling ) {
            if( source.nodeValue.clean() != "" ) {
                result = source.nodeValue.clean();
            }
        }
        source = source.nextSibling;
    }
    return result;
};

String.prototype.clean = function() {
    var self = this;
    return this.replace(/(\r\n|\n|\r)/gm, "").replace(/^\s+|\s+$/g, "");
}

How can I transform string to UTF-8 in C#?

Your code is reading a sequence of UTF8-encoded bytes, and decoding them using an 8-bit encoding.

You need to fix that code to decode the bytes as UTF8.

Alternatively (not ideal), you could convert the bad string back to the original byte array—by encoding it using the incorrect encoding—then re-decode the bytes as UTF8.

jQuery "blinking highlight" effect on div?

Check it out -

<input type="button" id="btnclick" value="click" />
var intervalA;
        var intervalB;

        $(document).ready(function () {

            $('#btnclick').click(function () {
                blinkFont();

                setTimeout(function () {
                    clearInterval(intervalA);
                    clearInterval(intervalB);
                }, 5000);
            });
        });

        function blinkFont() {
            document.getElementById("blink").style.color = "red"
            document.getElementById("blink").style.background = "black"
            intervalA = setTimeout("blinkFont()", 500);
        }

        function setblinkFont() {
            document.getElementById("blink").style.color = "black"
            document.getElementById("blink").style.background = "red"
            intervalB = setTimeout("blinkFont()", 500);
        }

    </script>

    <div id="blink" class="live-chat">
        <span>This is blinking text and background</span>
    </div>

'No JUnit tests found' in Eclipse

Right Click on Project > Properties > Java Build Path > Add the Test folder as source folder.

All source folders including Test Classes need to be in Eclipse Java Build Path. So that the sources such as main and test classes can be compiled into the build directory (Eclipse default folder is bin).

Do I need a content-type header for HTTP GET requests?

According to the RFC 7231 section 3.1.5.5:

A sender that generates a message containing a payload body SHOULD generate a Content-Type header field in that message unless the intended media type of the enclosed representation is unknown to the sender. If a Content-Type header field is not present, the recipient MAY either assume a media type of "application/octet-stream" ([RFC2046], Section 4.5.1) or examine the data to determine its type.

It means that the Content-Type HTTP header should be set only for PUT and POST requests.

Validate phone number with JavaScript

If you using on input tag than this code will help you. I write this code by myself and I think this is very good way to use in input. but you can change it using your format. It will help user to correct their format on input tag.

$("#phone").on('input', function() {  //this is use for every time input change.
        var inputValue = getInputValue(); //get value from input and make it usefull number
        var length = inputValue.length; //get lenth of input

        if (inputValue < 1000)
        {
            inputValue = '1('+inputValue;
        }else if (inputValue < 1000000) 
        {
            inputValue = '1('+ inputValue.substring(0, 3) + ')' + inputValue.substring(3, length);
        }else if (inputValue < 10000000000) 
        {
            inputValue = '1('+ inputValue.substring(0, 3) + ')' + inputValue.substring(3, 6) + '-' + inputValue.substring(6, length);
        }else
        {
            inputValue = '1('+ inputValue.substring(0, 3) + ')' + inputValue.substring(3, 6) + '-' + inputValue.substring(6, 10);
        }       
        $("#phone").val(inputValue); //correct value entered to your input.
        inputValue = getInputValue();//get value again, becuase it changed, this one using for changing color of input border
       if ((inputValue > 2000000000) && (inputValue < 9999999999))
      {
          $("#phone").css("border","black solid 1px");//if it is valid phone number than border will be black.
      }else
      {
          $("#phone").css("border","red solid 1px");//if it is invalid phone number than border will be red.
      }
  });

    function getInputValue() {
         var inputValue = $("#phone").val().replace(/\D/g,'');  //remove all non numeric character
        if (inputValue.charAt(0) == 1) // if first character is 1 than remove it.
        {
            var inputValue = inputValue.substring(1, inputValue.length);
        }
        return inputValue;
}

Where does SVN client store user authentication data?

I know I'm uprising a very old topic, but after a couple of hours struggling with this very problem and not finding a solution anywhere else, I think this is a good place to put an answer.

We have some Build Servers WindowsXP based and found this very problem: svn command line client is not caching auth credentials.

We finally found out that we are using Cygwin's svn client! not a "native" Windows. So... this client stores all the auth credentials in /home/<user>/.subversion/auth

This /home directory in Cygwin, in our installation is in c:\cygwin\home. AND: the problem was that the Windows user that is running svn did never ever "logged in" in Cygwin, and so there was no /home/<user> directory.

A simple "bash -ls" from a Windows command terminal created the directory, and after the first access to our SVN server with interactive prompting for access credentials, alás, they got cached.

So if you are using Cygwin's svn client, be sure to have a "home" directory created for the local Windows user.

how to get GET and POST variables with JQuery?

why not use good old PHP? for example, let us say we receive a GET parameter 'target':

function getTarget() {
    var targetParam = "<?php  echo $_GET['target'];  ?>";
    //alert(targetParam);
}

PermissionError: [Errno 13] Permission denied

You can run CMD as Administrator and change the permission of the directory using cacls.exe. For example:

cacls.exe c: /t /e /g everyone:F # means everyone can totally control the C: disc

Multidimensional Lists in C#

It's old but thought I'd add my two cents... Not sure if it will work but try using a KeyValuePair:

 List<KeyValuePair<?, ?>> LinkList = new List<KeyValuePair<?, ?>>();
 LinkList.Add(new KeyValuePair<?, ?>(Object, Object));

You'll end up with something like this:

 LinkList[0] = <Object, Object>
 LinkList[1] = <Object, Object>
 LinkList[2] = <Object, Object>

and so on...

Get type of a generic parameter in Java with reflection

Just for me reading this snippet of code was hard, I just divided it into 2 readable lines :

// assuming that the Generic Type parameter is of type "T"
ParameterizedType p = (ParameterizedType) getClass().getGenericSuperclass();
Class<T> c =(Class<T>)p.getActualTypeArguments()[0];

I wanted to create an instance of the Type parameter without having any parameters to my method :

publc T getNewTypeInstance(){
    ParameterizedType p = (ParameterizedType) getClass().getGenericSuperclass();
    Class<T> c =(Class<T>)p.getActualTypeArguments()[0];

    // for me i wanted to get the type to create an instance
    // from the no-args default constructor
    T t = null;
    try{
        t = c.newInstance();
    }catch(Exception e){
        // no default constructor available
    }
    return t;
}

Getting Image from API in Angular 4/5+?

You should set responseType: ResponseContentType.Blob in your GET-Request settings, because so you can get your image as blob and convert it later da base64-encoded source. You code above is not good. If you would like to do this correctly, then create separate service to get images from API. Beacuse it ism't good to call HTTP-Request in components.

Here is an working example:

Create image.service.ts and put following code:

Angular 4:

getImage(imageUrl: string): Observable<File> {
    return this.http
        .get(imageUrl, { responseType: ResponseContentType.Blob })
        .map((res: Response) => res.blob());
}

Angular 5+:

getImage(imageUrl: string): Observable<Blob> {
  return this.httpClient.get(imageUrl, { responseType: 'blob' });
}

Important: Since Angular 5+ you should use the new HttpClient.

The new HttpClient returns JSON by default. If you need other response type, so you can specify that by setting responseType: 'blob'. Read more about that here.

Now you need to create some function in your image.component.ts to get image and show it in html.

For creating an image from Blob you need to use JavaScript's FileReader. Here is function which creates new FileReader and listen to FileReader's load-Event. As result this function returns base64-encoded image, which you can use in img src-attribute:

imageToShow: any;

createImageFromBlob(image: Blob) {
   let reader = new FileReader();
   reader.addEventListener("load", () => {
      this.imageToShow = reader.result;
   }, false);

   if (image) {
      reader.readAsDataURL(image);
   }
}

Now you should use your created ImageService to get image from api. You should to subscribe to data and give this data to createImageFromBlob-function. Here is an example function:

getImageFromService() {
      this.isImageLoading = true;
      this.imageService.getImage(yourImageUrl).subscribe(data => {
        this.createImageFromBlob(data);
        this.isImageLoading = false;
      }, error => {
        this.isImageLoading = false;
        console.log(error);
      });
}

Now you can use your imageToShow-variable in HTML template like this:

<img [src]="imageToShow"
     alt="Place image title"
     *ngIf="!isImageLoading; else noImageFound">
<ng-template #noImageFound>
     <img src="fallbackImage.png" alt="Fallbackimage">
</ng-template>

I hope this description is clear to understand and you can use it in your project.

See the working example for Angular 5+ here.

blur vs focusout -- any real differences?

As stated in the JQuery documentation

The focusout event is sent to an element when it, or any element inside of it, loses focus. This is distinct from the blur event in that it supports detecting the loss of focus on descendant elements (in other words, it supports event bubbling).

Which comment style should I use in batch files?

This page tell that using "::" will be faster under certain constraints Just a thing to consider when choosing

Upper memory limit?

You're reading the entire file into memory (line = u.readlines()) which will fail of course if the file is too large (and you say that some are up to 20 GB), so that's your problem right there.

Better iterate over each line:

for current_line in u:
    do_something_with(current_line)

is the recommended approach.

Later in your script, you're doing some very strange things like first counting all the items in a list, then constructing a for loop over the range of that count. Why not iterate over the list directly? What is the purpose of your script? I have the impression that this could be done much easier.

This is one of the advantages of high-level languages like Python (as opposed to C where you do have to do these housekeeping tasks yourself): Allow Python to handle iteration for you, and only collect in memory what you actually need to have in memory at any given time.

Also, as it seems that you're processing TSV files (tabulator-separated values), you should take a look at the csv module which will handle all the splitting, removing of \ns etc. for you.

What is the equivalent of the C++ Pair<L,R> in Java?

According to the nature of Java language, I suppose people do not actually require a Pair, an interface is usually what they need. Here is an example:

interface Pair<L, R> {
    public L getL();
    public R getR();
}

So, when people want to return two values they can do the following:

... //Calcuate the return value
final Integer v1 = result1;
final String v2 = result2;
return new Pair<Integer, String>(){
    Integer getL(){ return v1; }
    String getR(){ return v2; }
}

This is a pretty lightweight solution, and it answers the question "What is the semantic of a Pair<L,R>?". The answer is, this is an interface build with two (may be different) types, and it has methods to return each of them. It is up to you to add further semantic to it. For example, if you are using Position and REALLY want to indicate it in you code, you can define PositionX and PositionY that contains Integer, to make up a Pair<PositionX,PositionY>. If JSR 308 is available, you may also use Pair<@PositionX Integer, @PositionY Ingeger> to simplify that.

EDIT: One thing I should indicate here is that the above definition explicitly relates the type parameter name and the method name. This is an answer to those argues that a Pair is lack of semantic information. Actually, the method getL means "give me the element that correspond to the type of type parameter L", which do means something.

EDIT: Here is a simple utility class that can make life easier:

class Pairs {
    static <L,R> Pair<L,R> makePair(final L l, final R r){
        return new Pair<L,R>(){
            public L getL() { return l; }
            public R getR() { return r; }   
        };
    }
}

usage:

return Pairs.makePair(new Integer(100), "123");

Default interface methods are only supported starting with Android N

This also happened to me but using Dynamic Features. I already had Java 8 compatibility enabled in the app module but I had to add this compatibility lines to the Dynamic Feature module and then it worked.

Read/write to file using jQuery

Yes it is possible.

The technique is described below

http://jquery.tiddlywiki.org/twFile.html

How to pipe list of files returned by find command to cat to view all the files

This will print the name and contents of files-only recursively..

find . -type f -printf '\n\n%p:\n' -exec cat {} \;

Edit (Improved version): This will print the name and contents of text (ascii) files-only recursively..

find . -type f -exec grep -Iq . {} \; -print | xargs awk 'FNR==1{print FILENAME ":" $0; }'

One more attempt

find . -type f -exec grep -Iq . {} \; -printf "\n%p:" -exec cat {} \;

CKEditor automatically strips classes from div

I found that switching to use full html instead of filtered html (below the editor in the Text Format dropdown box) is what fixed this problem for me. Otherwise the style would disappear.

How can I replace newline or \r\n with <br/>?

Try using this:

$description = preg_replace("/\r\n|\r|\n/", '<br/>', $description);

Lotus Notes email as an attachment to another email

Copy the mail as a document link (right click on the mail and you should get this option) and paste it in the new mail. This worked for me

Powershell folder size of folders without listing Subdirectories

from sysinternals.com with du.exe or du64.exe -l 1 . or 2 levels down: **du -l 2 c:**

Much shorter than Linux though ;)

How to add new column to MYSQL table?

You should look into normalizing your database to avoid creating columns at runtime.

Make 3 tables:

  1. assessment
  2. question
  3. assessment_question (columns assessmentId, questionId)

Put questions and assessments in their respective tables and link them together through assessment_question using foreign keys.

Binding arrow keys in JS/jQuery

This is a bit late, but HotKeys has a very major bug which causes events to get executed multiple times if you attach more than one hotkey to an element. Just use plain jQuery.

$(element).keydown(function(ev) {
    if(ev.which == $.ui.keyCode.DOWN) {
        // your code
        ev.preventDefault();
    }
});

Using .Select and .Where in a single LINQ statement

Did you add the Select() after the Where() or before?

You should add it after, because of the concurrency logic:

 1 Take the entire table  
 2 Filter it accordingly  
 3 Select only the ID's  
 4 Make them distinct.  

If you do a Select first, the Where clause can only contain the ID attribute because all other attributes have already been edited out.

Update: For clarity, this order of operators should work:

db.Items.Where(x=> x.userid == user_ID).Select(x=>x.Id).Distinct();

Probably want to add a .toList() at the end but that's optional :)

Auto Generate Database Diagram MySQL

MySQL Workbench worked like a charm.

I just backed up database structure to SQL script and used it in "Create EER Model From SQL Script" of MWB 5.2.37 for Windows.

Abort a Git Merge

Truth be told there are many, many resources explaining how to do this already out on the web:

Git: how to reverse-merge a commit?

Git: how to reverse-merge a commit?

Undoing Merges, from Git's blog (retrieved from archive.org's Wayback Machine)

So I guess I'll just summarize some of these:

  1. git revert <merge commit hash>
    This creates an extra "revert" commit saying you undid a merge

  2. git reset --hard <commit hash *before* the merge>
    This reset history to before you did the merge. If you have commits after the merge you will need to cherry-pick them on to afterwards.

But honestly this guide here is better than anything I can explain, with diagrams! :)

How do I find out what version of Sybase is running

There are two ways to know the about Sybase version,

1) Using this System procedure to get the information about Sybase version

> sp_version
> go

2) Using this command to get Sybase version

> select @@version
> go

TSQL DATETIME ISO 8601

Gosh, NO!!! You're asking for a world of hurt if you store formatted dates in SQL Server. Always store your dates and times and one of the SQL Server "date/time" datatypes (DATETIME, DATE, TIME, DATETIME2, whatever). Let the front end code resolve the method of display and only store formatted dates when you're building a staging table to build a file from. If you absolutely must display ISO date/time formats from SQL Server, only do it at display time. I can't emphasize enough... do NOT store formatted dates/times in SQL Server.

{Edit}. The reasons for this are many but the most obvious are that, even with a nice ISO format (which is sortable), all future date calculations and searches (search for all rows in a given month, for example) will require at least an implicit conversion (which takes extra time) and if the stored formatted date isn't the format that you currently need, you'll need to first convert it to a date and then to the format you want.

The same holds true for front end code. If you store a formatted date (which is text), it requires the same gyrations to display the local date format defined either by windows or the app.

My recommendation is to always store the date/time as a DATETIME or other temporal datatype and only format the date at display time.

apc vs eaccelerator vs xcache

If you want PHP file caching only, you can use eAccelerator directly. Very easy to install and configure, and give great results.

But too bad, they removed the eaccelerator_put and eaccelerator_put from the latest version 0.9.6.