Programs & Examples On #Symbol capture

Calling a parent window function from an iframe

Another addition for those who need it. Ash Clarke's solution does not work if they are using different protocols so be sure that if you are using SSL, your iframe is using SSL as well or it will break the function. His solution did work for the domains itself though, so thanks for that.

Adding git branch on the Bash command prompt

vim ~/.bash

parse_git_branch() {
     git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}

export PS1="\u@\h \[\033[32m\]\w\[\033[33m\]\$(parse_git_branch)\[\033[00m\] $"

To reflect latest changes run following command

source ~/.bashrc

Output:-

chandrakant@NDL41104 ~/Chandrakant/CodeBase/LaravelApp (development) $

How to store image in SQL Server database tables column

Insert Into FEMALE(ID, Image)
Select '1', BulkColumn 
from Openrowset (Bulk 'D:\thepathofimage.jpg', Single_Blob) as Image

You will also need admin rights to run the query.

Return a `struct` from a function in C

As far as I can remember, the first versions of C only allowed to return a value that could fit into a processor register, which means that you could only return a pointer to a struct. The same restriction applied to function arguments.

More recent versions allow to pass around larger data objects like structs. I think this feature was already common during the eighties or early nineties.

Arrays, however, can still be passed and returned only as pointers.

SQL permissions for roles

USE DataBaseName; GO --------- CREATE ROLE --------- CREATE ROLE Doctors ; GO  ---- Assign Role To users -------  CREATE USER [Username] FOR LOGIN [Domain\Username] EXEC sp_addrolemember N'Doctors', N'Username'  ----- GRANT Permission to Users Assinged with this Role----- GRANT ALL ON Table1, Table2, Table3 TO Doctors; GO 

Warning: #1265 Data truncated for column 'pdd' at row 1

As the message error says, you need to Increase the length of your column to fit the length of the data you are trying to insert (0000-00-00)

EDIT 1:

Following your comment, I run a test table:

mysql> create table testDate(id int(2) not null auto_increment, pdd date default null, primary key(id));
Query OK, 0 rows affected (0.20 sec)

Insertion:

mysql> insert into testDate values(1,'0000-00-00');
Query OK, 1 row affected (0.06 sec)

EDIT 2:

So, aparently you want to insert a NULL value to pdd field as your comment states ? You can do that in 2 ways like this:

Method 1:

mysql> insert into testDate values(2,'');
Query OK, 1 row affected, 1 warning (0.06 sec)

Method 2:

mysql> insert into testDate values(3,NULL);
Query OK, 1 row affected (0.07 sec)

EDIT 3:

You failed to change the default value of pdd field. Here is the syntax how to do it (in my case, I set it to NULL in the start, now I will change it to NOT NULL)

mysql> alter table testDate modify pdd date not null;
Query OK, 3 rows affected, 1 warning (0.60 sec)
Records: 3  Duplicates: 0  Warnings: 1

Conditional Binding: if let error – Initializer for conditional binding must have Optional type

if let/if var optional binding only works when the result of the right side of the expression is an optional. If the result of the right side is not an optional, you can not use this optional binding. The point of this optional binding is to check for nil and only use the variable if it's non-nil.

In your case, the tableView parameter is declared as the non-optional type UITableView. It is guaranteed to never be nil. So optional binding here is unnecessary.

func tableView(tableView: UITableView, commitEditingStyle editingStyle:UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == .Delete {
        // Delete the row from the data source
        myData.removeAtIndex(indexPath.row)
        tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)

All we have to do is get rid of the if let and change any occurrences of tv within it to just tableView.

Delegates in swift?

The solutions above seemed a little coupled and at the same time avoid reuse the same protocol in other controllers, that's why I've come with the solution that is more strong typed using generic type-erasure.

@noreturn public func notImplemented(){
    fatalError("not implemented yet")
}


public protocol DataChangedProtocol: class{
    typealias DataType

    func onChange(t:DataType)
}

class AbstractDataChangedWrapper<DataType> : DataChangedProtocol{

    func onChange(t: DataType) {
        notImplemented()
    }
}


class AnyDataChangedWrapper<T: DataChangedProtocol> : AbstractDataChangedWrapper<T.DataType>{

    var base: T

    init(_ base: T ){
        self.base = base
    }

    override func onChange(t: T.DataType) {
        base.onChange(t)
    }
}


class AnyDataChangedProtocol<DataType> : DataChangedProtocol{

    var base: AbstractDataChangedWrapper<DataType>

    init<S: DataChangedProtocol where S.DataType == DataType>(_ s: S){
        self.base = AnyDataChangedWrapper(s)
    }

    func onChange(t: DataType) {
        base.onChange(t)
    }
}



class Source : DataChangedProtocol {
    func onChange(data: String) {
        print( "got new value \(data)" )
    }
}


class Target {
    var delegate: AnyDataChangedProtocol<String>?

    func reportChange(data:String ){
        delegate?.onChange(data)
    }
}


var source = Source()
var target = Target()

target.delegate = AnyDataChangedProtocol(source)
target.reportChange("newValue")    

output: got new value newValue

Python JSON encoding

In simplejson (or the library json in Python 2.6 and later), loads takes a JSON string and returns a Python data structure, dumps takes a Python data structure and returns a JSON string. JSON string can encode Javascript arrays, not just objects, and a Python list corresponds to a JSON string encoding an array. To get a JSON string such as

{"apple":"cat", "banana":"dog"}

the Python object you pass to json.dumps could be:

dict(apple="cat", banana="dog")

though the JSON string is also valid Python syntax for the same dict. I believe the specific string you say you expect is simply invalid JSON syntax, however.

SQL injection that gets around mysql_real_escape_string()

TL;DR

mysql_real_escape_string() will provide no protection whatsoever (and could furthermore munge your data) if:

  • MySQL's NO_BACKSLASH_ESCAPES SQL mode is enabled (which it might be, unless you explicitly select another SQL mode every time you connect); and

  • your SQL string literals are quoted using double-quote " characters.

This was filed as bug #72458 and has been fixed in MySQL v5.7.6 (see the section headed "The Saving Grace", below).

This is another, (perhaps less?) obscure EDGE CASE!!!

In homage to @ircmaxell's excellent answer (really, this is supposed to be flattery and not plagiarism!), I will adopt his format:

The Attack

Starting off with a demonstration...

mysql_query('SET SQL_MODE="NO_BACKSLASH_ESCAPES"'); // could already be set
$var = mysql_real_escape_string('" OR 1=1 -- ');
mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');

This will return all records from the test table. A dissection:

  1. Selecting an SQL Mode

    mysql_query('SET SQL_MODE="NO_BACKSLASH_ESCAPES"');
    

    As documented under String Literals:

    There are several ways to include quote characters within a string:

    • A “'” inside a string quoted with “'” may be written as “''”.

    • A “"” inside a string quoted with “"” may be written as “""”.

    • Precede the quote character by an escape character (“\”).

    • A “'” inside a string quoted with “"” needs no special treatment and need not be doubled or escaped. In the same way, “"” inside a string quoted with “'” needs no special treatment.

    If the server's SQL mode includes NO_BACKSLASH_ESCAPES, then the third of these options—which is the usual approach adopted by mysql_real_escape_string()—is not available: one of the first two options must be used instead. Note that the effect of the fourth bullet is that one must necessarily know the character that will be used to quote the literal in order to avoid munging one's data.

  2. The Payload

    " OR 1=1 -- 
    

    The payload initiates this injection quite literally with the " character. No particular encoding. No special characters. No weird bytes.

  3. mysql_real_escape_string()

    $var = mysql_real_escape_string('" OR 1=1 -- ');
    

    Fortunately, mysql_real_escape_string() does check the SQL mode and adjust its behaviour accordingly. See libmysql.c:

    ulong STDCALL
    mysql_real_escape_string(MYSQL *mysql, char *to,const char *from,
                 ulong length)
    {
      if (mysql->server_status & SERVER_STATUS_NO_BACKSLASH_ESCAPES)
        return escape_quotes_for_mysql(mysql->charset, to, 0, from, length);
      return escape_string_for_mysql(mysql->charset, to, 0, from, length);
    }
    

    Thus a different underlying function, escape_quotes_for_mysql(), is invoked if the NO_BACKSLASH_ESCAPES SQL mode is in use. As mentioned above, such a function needs to know which character will be used to quote the literal in order to repeat it without causing the other quotation character from being repeated literally.

    However, this function arbitrarily assumes that the string will be quoted using the single-quote ' character. See charset.c:

    /*
      Escape apostrophes by doubling them up
    
    // [ deletia 839-845 ]
    
      DESCRIPTION
        This escapes the contents of a string by doubling up any apostrophes that
        it contains. This is used when the NO_BACKSLASH_ESCAPES SQL_MODE is in
        effect on the server.
    
    // [ deletia 852-858 ]
    */
    
    size_t escape_quotes_for_mysql(CHARSET_INFO *charset_info,
                                   char *to, size_t to_length,
                                   const char *from, size_t length)
    {
    // [ deletia 865-892 ]
    
        if (*from == '\'')
        {
          if (to + 2 > to_end)
          {
            overflow= TRUE;
            break;
          }
          *to++= '\'';
          *to++= '\'';
        }
    

    So, it leaves double-quote " characters untouched (and doubles all single-quote ' characters) irrespective of the actual character that is used to quote the literal! In our case $var remains exactly the same as the argument that was provided to mysql_real_escape_string()—it's as though no escaping has taken place at all.

  4. The Query

    mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');
    

    Something of a formality, the rendered query is:

    SELECT * FROM test WHERE name = "" OR 1=1 -- " LIMIT 1
    

As my learned friend put it: congratulations, you just successfully attacked a program using mysql_real_escape_string()...

The Bad

mysql_set_charset() cannot help, as this has nothing to do with character sets; nor can mysqli::real_escape_string(), since that's just a different wrapper around this same function.

The problem, if not already obvious, is that the call to mysql_real_escape_string() cannot know with which character the literal will be quoted, as that's left to the developer to decide at a later time. So, in NO_BACKSLASH_ESCAPES mode, there is literally no way that this function can safely escape every input for use with arbitrary quoting (at least, not without doubling characters that do not require doubling and thus munging your data).

The Ugly

It gets worse. NO_BACKSLASH_ESCAPES may not be all that uncommon in the wild owing to the necessity of its use for compatibility with standard SQL (e.g. see section 5.3 of the SQL-92 specification, namely the <quote symbol> ::= <quote><quote> grammar production and lack of any special meaning given to backslash). Furthermore, its use was explicitly recommended as a workaround to the (long since fixed) bug that ircmaxell's post describes. Who knows, some DBAs might even configure it to be on by default as means of discouraging use of incorrect escaping methods like addslashes().

Also, the SQL mode of a new connection is set by the server according to its configuration (which a SUPER user can change at any time); thus, to be certain of the server's behaviour, you must always explicitly specify your desired mode after connecting.

The Saving Grace

So long as you always explicitly set the SQL mode not to include NO_BACKSLASH_ESCAPES, or quote MySQL string literals using the single-quote character, this bug cannot rear its ugly head: respectively escape_quotes_for_mysql() will not be used, or its assumption about which quote characters require repeating will be correct.

For this reason, I recommend that anyone using NO_BACKSLASH_ESCAPES also enables ANSI_QUOTES mode, as it will force habitual use of single-quoted string literals. Note that this does not prevent SQL injection in the event that double-quoted literals happen to be used—it merely reduces the likelihood of that happening (because normal, non-malicious queries would fail).

In PDO, both its equivalent function PDO::quote() and its prepared statement emulator call upon mysql_handle_quoter()—which does exactly this: it ensures that the escaped literal is quoted in single-quotes, so you can be certain that PDO is always immune from this bug.

As of MySQL v5.7.6, this bug has been fixed. See change log:

Functionality Added or Changed

Safe Examples

Taken together with the bug explained by ircmaxell, the following examples are entirely safe (assuming that one is either using MySQL later than 4.1.20, 5.0.22, 5.1.11; or that one is not using a GBK/Big5 connection encoding):

mysql_set_charset($charset);
mysql_query("SET SQL_MODE=''");
$var = mysql_real_escape_string('" OR 1=1 /*');
mysql_query('SELECT * FROM test WHERE name = "'.$var.'" LIMIT 1');

...because we've explicitly selected an SQL mode that doesn't include NO_BACKSLASH_ESCAPES.

mysql_set_charset($charset);
$var = mysql_real_escape_string("' OR 1=1 /*");
mysql_query("SELECT * FROM test WHERE name = '$var' LIMIT 1");

...because we're quoting our string literal with single-quotes.

$stmt = $pdo->prepare('SELECT * FROM test WHERE name = ? LIMIT 1');
$stmt->execute(["' OR 1=1 /*"]);

...because PDO prepared statements are immune from this vulnerability (and ircmaxell's too, provided either that you're using PHP=5.3.6 and the character set has been correctly set in the DSN; or that prepared statement emulation has been disabled).

$var  = $pdo->quote("' OR 1=1 /*");
$stmt = $pdo->query("SELECT * FROM test WHERE name = $var LIMIT 1");

...because PDO's quote() function not only escapes the literal, but also quotes it (in single-quote ' characters); note that to avoid ircmaxell's bug in this case, you must be using PHP=5.3.6 and have correctly set the character set in the DSN.

$stmt = $mysqli->prepare('SELECT * FROM test WHERE name = ? LIMIT 1');
$param = "' OR 1=1 /*";
$stmt->bind_param('s', $param);
$stmt->execute();

...because MySQLi prepared statements are safe.

Wrapping Up

Thus, if you:

  • use native prepared statements

OR

  • use MySQL v5.7.6 or later

OR

  • in addition to employing one of the solutions in ircmaxell's summary, use at least one of:

    • PDO;
    • single-quoted string literals; or
    • an explicitly set SQL mode that does not include NO_BACKSLASH_ESCAPES

...then you should be completely safe (vulnerabilities outside the scope of string escaping aside).

PHP shell_exec() vs exec()

A couple of distinctions that weren't touched on here:

  • With exec(), you can pass an optional param variable which will receive an array of output lines. In some cases this might save time, especially if the output of the commands is already tabular.

Compare:

exec('ls', $out);
var_dump($out);
// Look an array

$out = shell_exec('ls');
var_dump($out);
// Look -- a string with newlines in it

Conversely, if the output of the command is xml or json, then having each line as part of an array is not what you want, as you'll need to post-process the input into some other form, so in that case use shell_exec.

It's also worth pointing out that shell_exec is an alias for the backtic operator, for those used to *nix.

$out = `ls`;
var_dump($out);

exec also supports an additional parameter that will provide the return code from the executed command:

exec('ls', $out, $status);
if (0 === $status) {
    var_dump($out);
} else {
    echo "Command failed with status: $status";
}

As noted in the shell_exec manual page, when you actually require a return code from the command being executed, you have no choice but to use exec.

How to check identical array in most efficient way?

You could compare String representations so:

array1.toString() == array2.toString()
array1.toString() !== array3.toString()

but that would also make

array4 = ['1',2,3,4,5]

equal to array1 if that matters to you

FULL OUTER JOIN vs. FULL JOIN

Actually they are the same. LEFT OUTER JOIN is same as LEFT JOIN and RIGHT OUTER JOIN is same as RIGHT JOIN. It is more informative way to compare from INNER Join.

See this Wikipedia article for details.

JavaScript: get code to run every minute

Using setInterval:

setInterval(function() {
    // your code goes here...
}, 60 * 1000); // 60 * 1000 milsec

The function returns an id you can clear your interval with clearInterval:

var timerID = setInterval(function() {
    // your code goes here...
}, 60 * 1000); 

clearInterval(timerID); // The setInterval it cleared and doesn't run anymore.

A "sister" function is setTimeout/clearTimeout look them up.


If you want to run a function on page init and then 60 seconds after, 120 sec after, ...:

function fn60sec() {
    // runs every 60 sec and runs on init.
}
fn60sec();
setInterval(fn60sec, 60*1000);

Setting timezone in Python

For windows you can use:

Running Windows command prompt commands in python.

import os
os.system('tzutil /s "Central Standard Time"')

In windows command prompt try:

This gives current timezone:

tzutil /g

This gives a list of timezones:

tzutil /l

This will set the timezone:

tzutil /s "Central America Standard Time"

For further reference: http://woshub.com/how-to-set-timezone-from-command-prompt-in-windows/

How to iterate over the file in python

You should learn about EAFP vs LBYL.

from sys import stdin, stdout
def main(infile=stdin, outfile=stdout):
    if isinstance(infile, basestring):
        infile=open(infile,'r')
    if isinstance(outfile, basestring):
        outfile=open(outfile,'w')
    for lineno, line in enumerate(infile, 1):
        line = line.strip()
         try:
             print >>outfile, int(line,16)
         except ValueError:
             return "Bad value at line %i: %r" % (lineno, line)

if __name__ == "__main__":
    from sys import argv, exit
    exit(main(*argv[1:]))

How to force browser to download file?

This is from a php script which solves the problem perfectly with every browser I've tested (FF since 3.5, IE8+, Chrome)

header("Content-Disposition: attachment; filename=\"".$fname_local."\"");
header("Content-Type: application/force-download");
header("Content-Transfer-Encoding: binary");
header("Content-Length: ".filesize($fname));

So as far as I can see, you're doing everything correctly. Have you checked your browser settings?

How to set the allowed url length for a nginx request (error code: 414, uri too large)

For anyone having issues with this on https://forge.laravel.com, I managed to get this to work using a compilation of SO answers;

You will need the sudo password.

sudo nano /etc/nginx/conf.d/uploads.conf

Replace contents with the following;

fastcgi_buffers 8 16k;
fastcgi_buffer_size 32k;

client_max_body_size 24M;
client_body_buffer_size 128k;

client_header_buffer_size 5120k;
large_client_header_buffers 16 5120k;

GET and POST methods with the same Action name in the same Controller

You can't have multiple actions with the same name. You could add a parameter to one method and that would be valid. For example:

    public ActionResult Index(int i)
    {
        Some Code--Some Code---Some Code
        return View();
    }

There are a few ways to do to have actions that differ only by request verb. My favorite and, I think, the easiest to implement is to use the AttributeRouting package. Once installed simply add an attribute to your method as follows:

  [GET("Resources")]
  public ActionResult Index()
  {
      return View();
  }

  [POST("Resources")]
  public ActionResult Create()
  {
      return RedirectToAction("Index");
  }

In the above example the methods have different names but the action name in both cases is "Resources". The only difference is the request verb.

The package can be installed using NuGet like this:

PM> Install-Package AttributeRouting

If you don't want the dependency on the AttributeRouting packages you could do this by writing a custom action selector attribute.

Global npm install location on windows?

These are typical npm paths if you install a package globally:

Windows XP -             %USERPROFILE%\Application Data\npm\node_modules
Newer Windows Versions - %AppData%\npm\node_modules
or -                     %AppData%\roaming\npm\node_modules

How to use performSelector:withObject:afterDelay: with primitive types in Cocoa?

Here is what I used to call something I couldn't change using NSInvocation:

SEL theSelector = NSSelectorFromString(@"setOrientation:animated:");
NSInvocation *anInvocation = [NSInvocation
            invocationWithMethodSignature:
            [MPMoviePlayerController instanceMethodSignatureForSelector:theSelector]];

[anInvocation setSelector:theSelector];
[anInvocation setTarget:theMovie];
UIInterfaceOrientation val = UIInterfaceOrientationPortrait;
BOOL anim = NO;
[anInvocation setArgument:&val atIndex:2];
[anInvocation setArgument:&anim atIndex:3];

[anInvocation performSelector:@selector(invoke) withObject:nil afterDelay:1];

Bulk Insert to Oracle using .NET

The solution of Rob Stevenson-Legget is slow because he doesn't bind his values but he uses string.Format( ).

When you ask Oracle to execute a sql statement it starts with calculating the has value of this statement. After that it looks in a hash table whether it already knows this statement. If it already knows it statement it can retrieve its execution path from this hash table and execute this statement really fast because Oracle has executed this statement before. This is called the library cache and it doesn't work properly if you don't bind your sql statements.

For example don't do:

int n;

    for (n = 0; n < 100000; n ++)
    {
      mycommand.CommandText = String.Format("INSERT INTO [MyTable] ([MyId]) VALUES({0})", n + 1);
      mycommand.ExecuteNonQuery();
    }

but do:

      OracleParameter myparam = new OracleParameter();
      int n;

      mycommand.CommandText = "INSERT INTO [MyTable] ([MyId]) VALUES(?)";
      mycommand.Parameters.Add(myparam);

      for (n = 0; n < 100000; n ++)
      {
        myparam.Value = n + 1;
        mycommand.ExecuteNonQuery();
      }

Not using parameters can also cause sql injection.

Multipart forms from C# client

Thanks for the answers, everybody! I recently had to get this to work, and used your suggestions heavily. However, there were a couple of tricky parts that did not work as expected, mostly having to do with actually including the file (which was an important part of the question). There are a lot of answers here already, but I think this may be useful to someone in the future (I could not find many clear examples of this online). I wrote a blog post that explains it a little more.

Basically, I first tried to pass in the file data as a UTF8 encoded string, but I was having problems with encoding files (it worked fine for a plain text file, but when uploading a Word Document, for example, if I tried to save the file that was passed through to the posted form using Request.Files[0].SaveAs(), opening the file in Word did not work properly. I found that if you write the file data directly using a Stream (rather than a StringBuilder), it worked as expected. Also, I made a couple of modifications that made it easier for me to understand.

By the way, the Multipart Forms Request for Comments and the W3C Recommendation for mulitpart/form-data are a couple of useful resources in case anyone needs a reference for the specification.

I changed the WebHelpers class to be a bit smaller and have simpler interfaces, it is now called FormUpload. If you pass a FormUpload.FileParameter you can pass the byte[] contents along with a file name and content type, and if you pass a string, it will treat it as a standard name/value combination.

Here is the FormUpload class:

// Implements multipart/form-data POST in C# http://www.ietf.org/rfc/rfc2388.txt
// http://www.briangrinstead.com/blog/multipart-form-post-in-c
public static class FormUpload
{
    private static readonly Encoding encoding = Encoding.UTF8;
    public static HttpWebResponse MultipartFormDataPost(string postUrl, string userAgent, Dictionary<string, object> postParameters)
    {
        string formDataBoundary = String.Format("----------{0:N}", Guid.NewGuid());
        string contentType = "multipart/form-data; boundary=" + formDataBoundary;

        byte[] formData = GetMultipartFormData(postParameters, formDataBoundary);

        return PostForm(postUrl, userAgent, contentType, formData);
    }
    private static HttpWebResponse PostForm(string postUrl, string userAgent, string contentType, byte[] formData)
    {
        HttpWebRequest request = WebRequest.Create(postUrl) as HttpWebRequest;

        if (request == null)
        {
            throw new NullReferenceException("request is not a http request");
        }

        // Set up the request properties.
        request.Method = "POST";
        request.ContentType = contentType;
        request.UserAgent = userAgent;
        request.CookieContainer = new CookieContainer();
        request.ContentLength = formData.Length;

        // You could add authentication here as well if needed:
        // request.PreAuthenticate = true;
        // request.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;
        // request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes("username" + ":" + "password")));

        // Send the form data to the request.
        using (Stream requestStream = request.GetRequestStream())
        {
            requestStream.Write(formData, 0, formData.Length);
            requestStream.Close();
        }

        return request.GetResponse() as HttpWebResponse;
    }

    private static byte[] GetMultipartFormData(Dictionary<string, object> postParameters, string boundary)
    {
        Stream formDataStream = new System.IO.MemoryStream();
        bool needsCLRF = false;

        foreach (var param in postParameters)
        {
            // Thanks to feedback from commenters, add a CRLF to allow multiple parameters to be added.
            // Skip it on the first parameter, add it to subsequent parameters.
            if (needsCLRF)
                formDataStream.Write(encoding.GetBytes("\r\n"), 0, encoding.GetByteCount("\r\n"));

            needsCLRF = true;

            if (param.Value is FileParameter)
            {
                FileParameter fileToUpload = (FileParameter)param.Value;

                // Add just the first part of this param, since we will write the file data directly to the Stream
                string header = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\";\r\nContent-Type: {3}\r\n\r\n",
                    boundary,
                    param.Key,
                    fileToUpload.FileName ?? param.Key,
                    fileToUpload.ContentType ?? "application/octet-stream");

                formDataStream.Write(encoding.GetBytes(header), 0, encoding.GetByteCount(header));

                // Write the file data directly to the Stream, rather than serializing it to a string.
                formDataStream.Write(fileToUpload.File, 0, fileToUpload.File.Length);
            }
            else
            {
                string postData = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}",
                    boundary,
                    param.Key,
                    param.Value);
                formDataStream.Write(encoding.GetBytes(postData), 0, encoding.GetByteCount(postData));
            }
        }

        // Add the end of the request.  Start with a newline
        string footer = "\r\n--" + boundary + "--\r\n";
        formDataStream.Write(encoding.GetBytes(footer), 0, encoding.GetByteCount(footer));

        // Dump the Stream into a byte[]
        formDataStream.Position = 0;
        byte[] formData = new byte[formDataStream.Length];
        formDataStream.Read(formData, 0, formData.Length);
        formDataStream.Close();

        return formData;
    }

    public class FileParameter
    {
        public byte[] File { get; set; }
        public string FileName { get; set; }
        public string ContentType { get; set; }
        public FileParameter(byte[] file) : this(file, null) { }
        public FileParameter(byte[] file, string filename) : this(file, filename, null) { }
        public FileParameter(byte[] file, string filename, string contenttype)
        {
            File = file;
            FileName = filename;
            ContentType = contenttype;
        }
    }
}

Here is the calling code, which uploads a file and a few normal post parameters:

// Read file data
FileStream fs = new FileStream("c:\\people.doc", FileMode.Open, FileAccess.Read);
byte[] data = new byte[fs.Length];
fs.Read(data, 0, data.Length);
fs.Close();

// Generate post objects
Dictionary<string, object> postParameters = new Dictionary<string, object>();
postParameters.Add("filename", "People.doc");
postParameters.Add("fileformat", "doc");
postParameters.Add("file", new FormUpload.FileParameter(data, "People.doc", "application/msword"));

// Create request and receive response
string postURL = "http://localhost";
string userAgent = "Someone";
HttpWebResponse webResponse = FormUpload.MultipartFormDataPost(postURL, userAgent, postParameters);

// Process response
StreamReader responseReader = new StreamReader(webResponse.GetResponseStream());
string fullResponse = responseReader.ReadToEnd();
webResponse.Close();
Response.Write(fullResponse);

How do I write a for loop in bash

#! /bin/bash

function do_something {
   echo value=${1}
}

MAX=4
for (( i=0; i<MAX; i++ )) ; {
   do_something ${i}
}

Here's an example that can also work in older shells, while still being efficient for large counts:

Z=$(date) awk 'BEGIN { for ( i=0; i<4; i++ ) { print i,"hello",ENVIRON["Z"]; } }'

But good luck doing useful things inside of awk: How do I use shell variables in an awk script?

How do I know which version of Javascript I'm using?

JavaScript 1.2 was introduced with Netscape Navigator 4 in 1997. That version number only ever had significance for Netscape browsers. For example, Microsoft's implementation (as used in Internet Explorer) is called JScript, and has its own version numbering which bears no relation to Netscape's numbering.

Swift: Determine iOS Screen size

In Swift 3.0

let screenSize = UIScreen.main.bounds
let screenWidth = screenSize.width
let screenHeight = screenSize.height

In older swift: Do something like this:

let screenSize: CGRect = UIScreen.mainScreen().bounds

then you can access the width and height like this:

let screenWidth = screenSize.width
let screenHeight = screenSize.height

if you want 75% of your screen's width you can go:

let screenWidth = screenSize.width * 0.75

Swift 4.0

// Screen width.
public var screenWidth: CGFloat {
    return UIScreen.main.bounds.width
}

// Screen height.
public var screenHeight: CGFloat {
    return UIScreen.main.bounds.height
}

In Swift 5.0

let screenSize: CGRect = UIScreen.main.bounds

browser.msie error after update to jQuery 1.9.1

You can detect the IE browser by this way.

(navigator.userAgent.toLowerCase().indexOf('msie 6') != -1)

you can get reference on this URL: jquery.browser.msie Alternative

Edit a commit message in SourceTree Windows (already pushed to remote)

If the comment message includes non-English characters, using method provided by user456814, those characters will be replaced by question marks. (tested under sourcetree Ver2.5.5.0)

So I have to use the following method.

CAUTION: if the commit has been pulled by other members, changes below might cause chaos for them.

Step1: In the sourcetree main window, locate your repo tab, and click the "terminal" button to open the git command console.

Step2:

[Situation A]: target commit is the latest one.

1) In the git command console, input

git commit --amend -m "new comment message"

2) If the target commit has been pushed to remote, you have to push again by force. In the git command console, input

git push --force

[Situation B]: target commit is not the latest one.

1) In the git command console, input

git rebase -i HEAD~n

It is to squash the latest n commits. e.g. if you want to edit the message before the last one, n is 2. This command will open a vi window, the first word of each line is "pick", and you change the "pick" to "reword" for the line you want to edit. Then, input :wq to save&quit that vi window. Now, a new vi window will be open, in this window you input your new message. Also use :wq to save&quit.

2) If the target commit has been pushed to remote, you have to push again by force. In the git command console, input

git push --force


Finally: In the sourcetree main window, Press F5 to refresh.

.attr("disabled", "disabled") issue

UPDATED

DEMO: http://jsbin.com/uneti3/3

your code is wrong, it should be something like this:

 $(bla).click(function() { 
        var disable =  $target.toggleClass('open').hasClass('open');
       $target.prev().prop("disabled", disable);
  });

you are using the toggleClass function in wrong way

What is Common Gateway Interface (CGI)?

Have a look at CGI in Wikipedia. CGI is a protocol between the web server and a external program or a script that handles the input and generates output that is sent to the browser.

CGI is a simply a way for web server and a program to communicate, nothing more, nothing less. Here the server manages the network connection and HTTP protocol and the program handles input and generates output that is sent to the browser. CGI script can be basically any program that can be executed by the webserver and follows the CGI protocol. Thus a CGI program can be implemented, for example, in C. However that is extremely rare, since C is not very well suited for the task.

/cgi-bin/*.cgi is a simply a path where people commonly put their CGI script. Web server are commonly configured by default to fetch CGI scripts from that path.

a CGI script can be implemented also in PHP, but all PHP programs are not CGI scripts. If webserver has embedded PHP interpreter (e.g. mod_php in Apache), then the CGI phase is skipped by more efficient direct protocol between the web server and the interpreter.

Whether you have implemented a CGI script or not depends on how your script is being executed by the web server.

Is there a way to get a collection of all the Models in your Rails app?

Dir.foreach("#{Rails.root.to_s}/app/models") do |model_path|
  next unless model_path.match(/.rb$/)
  model_class = model_path.gsub(/.rb$/, '').classify.constantize
  puts model_class
end

This will give to you all the model classes you have on your project.

How do I make a semi transparent background?

Try this:

.transparent
{ 
  opacity:.50;
  -moz-opacity:.50; 
  filter:alpha(opacity=50); 
}

Setting Icon for wpf application (VS 08)

After getting a XamlParseException with message: 'Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' with the given solutions, setting the icon programmatically worked for me. This is how I did it:

  1. Put the icon in a folder <icon_path> in the project directory
  2. Mimic the folder path <icon_path> in the solution
  3. Add a new item (your icon) in the solution folder you created
  4. Add the following code in the WPF window's code behind:

Icon = new BitmapImage(new Uri("<icon_path>", UriKind.Relative));

Please inform me if you have any difficulties implementing this solution so I can help.

Rename MySQL database

If your DB contains only MyISAM tables (do not use this method if you have InnoDB tables):

  1. shut down the MySQL server
  2. go to the mysql data directory and rename the database directory (Note: non-alpha characters need to be encoded in a special way)
  3. restart the server
  4. adjust privileges if needed (grant access to the new DB name)

You can script it all in one command so that downtime is just a second or two.

Adding 30 minutes to time formatted as H:i in PHP

What you need is a datetime which is 30 minutes later than your given datetime, and a datetime which is 30 minutes before a given datetime. In other words, you need a future datetime and a past datetime. Hence, classes that achieve that are called Future and Past. What data do they need to calculate what you need? Apparently, they must have a datetime relative to which to count those 30 minutes, and an interval itself -- 30 minutes in your case. Thus, the desired datetime looks like the following:

use Meringue\ISO8601DateTime\FromCustomFormat as DateTimeCreatedFromCustomFormat;

(new Future(
    new DateTimeCreatedFromCustomFormat('H:i', '10:00'),
    new NMinutes(30)
))
    ->value();

If you want to format it somehow, you can do:

use Meringue\ISO8601DateTime\FromCustomFormat as DateTimeCreatedFromCustomFormat;

(new ISO8601Formatted(
    new Future(
        new DateTimeCreatedFromCustomFormat('H:i', '10:00'),
        new NMinutes(30)
    ),
    'H:i'
))
    ->value();

It's more verbose, but I guess it's way less cryptic than built-in php functions.

If you liked this approach, you can learn some more about the meringue library used in this example, and the overall approach.

How to read file with async/await properly?

You can use fs.promises available natively since Node v11.0.0

import fs from 'fs';

const readFile = async filePath => {
  try {
    const data = await fs.promises.readFile(filePath, 'utf8')
    return data
  }
  catch(err) {
    console.log(err)
  }
}

Python - 'ascii' codec can't decode byte

In case you're dealing with Unicode, sometimes instead of encode('utf-8'), you can also try to ignore the special characters, e.g.

"??".encode('ascii','ignore')

or as something.decode('unicode_escape').encode('ascii','ignore') as suggested here.

Not particularly useful in this example, but can work better in other scenarios when it's not possible to convert some special characters.

Alternatively you can consider replacing particular character using replace().

How to POST a JSON object to a JAX-RS service

Jersey makes the process very easy, my service class worked well with JSON, all I had to do is to add the dependencies in the pom.xml

@Path("/customer")
public class CustomerService {

    private static Map<Integer, Customer> customers = new HashMap<Integer, Customer>();

    @POST
    @Path("save")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public SaveResult save(Customer c) {

        customers.put(c.getId(), c);

        SaveResult sr = new SaveResult();
        sr.sucess = true;
        return sr;
    }

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    @Path("{id}")
    public Customer getCustomer(@PathParam("id") int id) {
        Customer c = customers.get(id);
        if (c == null) {
            c = new Customer();
            c.setId(id * 3);
            c.setName("unknow " + id);
        }
        return c;
    }
}

And in the pom.xml

<dependency>
    <groupId>org.glassfish.jersey.containers</groupId>
    <artifactId>jersey-container-servlet</artifactId>
    <version>2.7</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-json-jackson</artifactId>
    <version>2.7</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-moxy</artifactId>
    <version>2.7</version>
</dependency>

How can I invert color using CSS?

Here is a different approach using mix-blend-mode: difference, that will actually invert whatever the background is, not just a single colour:

_x000D_
_x000D_
div {_x000D_
  background-image: linear-gradient(to right, red, yellow, green, cyan, blue, violet);_x000D_
}_x000D_
p {_x000D_
  color: white;_x000D_
  mix-blend-mode: difference;_x000D_
}
_x000D_
<div>_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipiscit elit, sed do</p>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Cannot Resolve Collation Conflict

The thing about collations is that although the database has its own collation, every table, and every column can have its own collation. If not specified it takes the default of its parent object, but can be different.

When you change collation of the database, it will be the new default for all new tables and columns, but it doesn't change the collation of existing objects inside the database. You have to go and change manually the collation of every table and column.

Luckily there are scripts available on the internet that can do the job. I am not going to recommend any as I haven't tried them but here are few links:

http://www.codeproject.com/Articles/302405/The-Easy-way-of-changing-Collation-of-all-Database

Update Collation of all fields in database on the fly

http://www.sqlservercentral.com/Forums/Topic820675-146-1.aspx

If you need to have different collation on two objects or can't change collations - you can still JOIN between them using COLLATE command, and choosing the collation you want for join.

SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE Latin1_General_CI_AS 

or using default database collation:

SELECT * FROM A JOIN B ON A.Text = B.Text COLLATE DATABASE_DEFAULT

Django, creating a custom 500/404 error page

Under your main views.py add your own custom implementation of the following two views, and just set up the templates 404.html and 500.html with what you want to display.

With this solution, no custom code needs to be added to urls.py

Here's the code:

from django.shortcuts import render_to_response
from django.template import RequestContext


def handler404(request, *args, **argv):
    response = render_to_response('404.html', {},
                                  context_instance=RequestContext(request))
    response.status_code = 404
    return response


def handler500(request, *args, **argv):
    response = render_to_response('500.html', {},
                                  context_instance=RequestContext(request))
    response.status_code = 500
    return response

Update

handler404 and handler500 are exported Django string configuration variables found in django/conf/urls/__init__.py. That is why the above config works.

To get the above config to work, you should define the following variables in your urls.py file and point the exported Django variables to the string Python path of where these Django functional views are defined, like so:

# project/urls.py

handler404 = 'my_app.views.handler404'
handler500 = 'my_app.views.handler500'

Update for Django 2.0

Signatures for handler views were changed in Django 2.0: https://docs.djangoproject.com/en/2.0/ref/views/#error-views

If you use views as above, handler404 will fail with message:

"handler404() got an unexpected keyword argument 'exception'"

In such case modify your views like this:

def handler404(request, exception, template_name="404.html"):
    response = render_to_response(template_name)
    response.status_code = 404
    return response

How to check if running as root in a bash script

0- Read official GNU Linux documentation, there are many ways to do it correctly.

1- make sure you put the shell signature to avoid errors in interpretation:

 #!/bin/bash

2- this is my script

#!/bin/bash 

if [[ $EUID > 0 ]]; then # we can compare directly with this syntax.
  echo "Please run as root/sudo"
  exit 1
else
  #do your stuff
fi

Bootstrap 3.0 Popovers and tooltips

You have a syntax error in your script and, as noted by xXPhenom22Xx, you must instantiate the tooltip.

<script type="text/javascript">

    $(document).ready(function() {

        $('.btn-danger').tooltip();

    }); //END $(document).ready()

</script>

Note that I used your class "btn-danger". You can create a different class, or use an id="someidthatimakeup".

How can I display a JavaScript object?

Another modification of pagewils code... his doesn't print out anything other than strings and leaves the number and boolean fields blank and I fixed the typo on the second typeof just inside the function as created by megaboss.

var print = function( o, maxLevel, level )
{
    if ( typeof level == "undefined" )
    {
        level = 0;
    }
    if ( typeof maxlevel == "undefined" )
    {
        maxLevel = 0;
    }

    var str = '';
    // Remove this if you don't want the pre tag, but make sure to remove
    // the close pre tag on the bottom as well
    if ( level == 0 )
    {
        str = '<pre>';   // can also be <pre>
    }

    var levelStr = '<br>';
    for ( var x = 0; x < level; x++ )
    {
        levelStr += '    ';   // all those spaces only work with <pre>
    }

    if ( maxLevel != 0 && level >= maxLevel )
    {
        str += levelStr + '...<br>';
        return str;
    }

    for ( var p in o )
    {
        switch(typeof o[p])
        {
          case 'string':
          case 'number':    // .tostring() gets automatically applied
          case 'boolean':   // ditto
            str += levelStr + p + ': ' + o[p] + ' <br>';
            break;

          case 'object':    // this is where we become recursive
          default:
            str += levelStr + p + ': [ <br>' + print( o[p], maxLevel, level + 1 ) + levelStr + ']</br>';
            break;
        }
    }

    // Remove this if you don't want the pre tag, but make sure to remove
    // the open pre tag on the top as well
    if ( level == 0 )
    {
        str += '</pre>';   // also can be </pre>
    }
    return str;
};

Compiling LaTex bib source

You have to run 'bibtex':

latex paper.tex
bibtex paper
latex paper.tex
latex paper.tex
dvipdf paper.dvi

Execute combine multiple Linux commands in one line

I've found that using ; to separate commands only works in the foreground. eg :

cmd1; cmd2; cmd3 & - will only execute cmd3 in the background, whereas cmd1 && cmd2 && cmd3 & - will execute the entire chain in the background IF there are no errors.

To cater for unconditional execution, using parenthesis solves this :

(cmd1; cmd2; cmd3) & - will execute the chain of commands in the background, even if any step fails.

How to export collection to CSV in MongoDB?

Also, you are not allowed spaces between comma separated field names.

BAD: -f firstname, lastname

GOOD: -f firstname,lastname

Invariant Violation: Objects are not valid as a React child

Try this

 {items && items.title ? items.title : 'No item'}

Showing empty view when ListView is empty

Activity code, its important to extend ListActivity.

package com.example.mylistactivity;

import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import com.example.mylistactivity.R;

// It's important to extend ListActivity rather than Activity
public class MyListActivity extends ListActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mylist);

        // shows list view
        String[] values = new String[] { "foo", "bar" };

        // shows empty view
        values = new String[] { };

        setListAdapter(new ArrayAdapter<String>(
                this,
                android.R.layout.simple_list_item_1,
                android.R.id.text1,
                values));
    }
}

Layout xml, the id in both views are important.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <!-- the android:id is important -->
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>

    <!-- the android:id is important -->
    <TextView
        android:id="@android:id/empty"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:text="i am empty"/>
</LinearLayout>

S3 - Access-Control-Allow-Origin Header

I was having a similar problem with loading web fonts, when I clicked on 'add CORS configuration', in the bucket properties, this code was already there:

<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
    <CORSRule>
        <AllowedOrigin>*</AllowedOrigin>
        <AllowedMethod>GET</AllowedMethod>
        <AllowedMethod>HEAD</AllowedMethod>
        <MaxAgeSeconds>3000</MaxAgeSeconds>
        <AllowedHeader>Authorization</AllowedHeader>
    </CORSRule>
</CORSConfiguration> 

I just clicked save and it worked a treat, my custom web fonts were loading in IE & Firefox. I'm no expert on this, I just thought this might help you out.

Format Date output in JSF

Use <f:convertDateTime>. You can nest this in any input and output component. Pattern rules are same as java.text.SimpleDateFormat.

<h:outputText value="#{someBean.dateField}" >
    <f:convertDateTime pattern="dd.MM.yyyy HH:mm" />
</h:outputText>

how can I copy a conditional formatting in Excel 2010 to other cells, which is based on a other cells content?

You can do this in the 'Conditional Formatting' tool in the Home tab of Excel 2010.

Assuming the existing rule is 'Use a formula to dtermine which cells to format':

Edit the existing rule, so that the 'Formula' refers to relative rows and columns (i.e. remove $s), and then in the 'Applies to' box, click the icon to make the sheet current and select the cells you want the formatting to apply to (absolute cell references are ok here), then go back to the tool panel and click Apply.

This will work assuming the relative offsets are appropriate throughout your desired apply-to range.

You can copy conditional formatting from one cell to another or a range using copy and paste-special with formatting only, assuming you do not mind copying the normal formats.

Adding List<t>.add() another list

List<T>.Add adds a single element. Instead, use List<T>.AddRange to add multiple values.

Additionally, List<T>.AddRange takes an IEnumerable<T>, so you don't need to convert tripDetails into a List<TripDetails>, you can pass it directly, e.g.:

tripDetailsCollection.AddRange(tripDetails);

What is the most efficient/elegant way to parse a flat table into a tree?

This was written quickly, and is neither pretty nor efficient (plus it autoboxes alot, converting between int and Integer is annoying!), but it works.

It probably breaks the rules since I'm creating my own objects but hey I'm doing this as a diversion from real work :)

This also assumes that the resultSet/table is completely read into some sort of structure before you start building Nodes, which wouldn't be the best solution if you have hundreds of thousands of rows.

public class Node {

    private Node parent = null;

    private List<Node> children;

    private String name;

    private int id = -1;

    public Node(Node parent, int id, String name) {
        this.parent = parent;
        this.children = new ArrayList<Node>();
        this.name = name;
        this.id = id;
    }

    public int getId() {
        return this.id;
    }

    public String getName() {
        return this.name;
    }

    public void addChild(Node child) {
        children.add(child);
    }

    public List<Node> getChildren() {
        return children;
    }

    public boolean isRoot() {
        return (this.parent == null);
    }

    @Override
    public String toString() {
        return "id=" + id + ", name=" + name + ", parent=" + parent;
    }
}

public class NodeBuilder {

    public static Node build(List<Map<String, String>> input) {

        // maps id of a node to it's Node object
        Map<Integer, Node> nodeMap = new HashMap<Integer, Node>();

        // maps id of a node to the id of it's parent
        Map<Integer, Integer> childParentMap = new HashMap<Integer, Integer>();

        // create special 'root' Node with id=0
        Node root = new Node(null, 0, "root");
        nodeMap.put(root.getId(), root);

        // iterate thru the input
        for (Map<String, String> map : input) {

            // expect each Map to have keys for "id", "name", "parent" ... a
            // real implementation would read from a SQL object or resultset
            int id = Integer.parseInt(map.get("id"));
            String name = map.get("name");
            int parent = Integer.parseInt(map.get("parent"));

            Node node = new Node(null, id, name);
            nodeMap.put(id, node);

            childParentMap.put(id, parent);
        }

        // now that each Node is created, setup the child-parent relationships
        for (Map.Entry<Integer, Integer> entry : childParentMap.entrySet()) {
            int nodeId = entry.getKey();
            int parentId = entry.getValue();

            Node child = nodeMap.get(nodeId);
            Node parent = nodeMap.get(parentId);
            parent.addChild(child);
        }

        return root;
    }
}

public class NodePrinter {

    static void printRootNode(Node root) {
        printNodes(root, 0);
    }

    static void printNodes(Node node, int indentLevel) {

        printNode(node, indentLevel);
        // recurse
        for (Node child : node.getChildren()) {
            printNodes(child, indentLevel + 1);
        }
    }

    static void printNode(Node node, int indentLevel) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < indentLevel; i++) {
            sb.append("\t");
        }
        sb.append(node);

        System.out.println(sb.toString());
    }

    public static void main(String[] args) {

        // setup dummy data
        List<Map<String, String>> resultSet = new ArrayList<Map<String, String>>();
        resultSet.add(newMap("1", "Node 1", "0"));
        resultSet.add(newMap("2", "Node 1.1", "1"));
        resultSet.add(newMap("3", "Node 2", "0"));
        resultSet.add(newMap("4", "Node 1.1.1", "2"));
        resultSet.add(newMap("5", "Node 2.1", "3"));
        resultSet.add(newMap("6", "Node 1.2", "1"));

        Node root = NodeBuilder.build(resultSet);
        printRootNode(root);

    }

    //convenience method for creating our dummy data
    private static Map<String, String> newMap(String id, String name, String parentId) {
        Map<String, String> row = new HashMap<String, String>();
        row.put("id", id);
        row.put("name", name);
        row.put("parent", parentId);
        return row;
    }
}

Can I give the col-md-1.5 in bootstrap?

Bootstrap has column offsets, so if you want columns with equal width without specifying size use this.

<div class="row">
  <div class="col">col</div>
  <div class="col">col</div>
  <div class="col">col</div>
  <div class="col">col</div>
</div>

Also check out this link https://getbootstrap.com/docs/4.0/layout/grid/#all-breakpoints

how to take user input in Array using java?

**How to accept array by user Input

Answer:-

import java.io.*;

import java.lang.*;

class Reverse1  {

   public static void main(String args[]) throws IOException {

     int a[]=new int[25];

     int num=0,i=0;

     BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

     System.out.println("Enter the Number of element");

     num=Integer.parseInt(br.readLine());

     System.out.println("Enter the array");

     for(i=1;i<=num;i++) {
        a[i]=Integer.parseInt(br.readLine());
     }

     for(i=num;i>=1;i--) {
        System.out.println(a[i]);    
     }

   }

}

How to change value for innodb_buffer_pool_size in MySQL on Mac OS?

In the earlier versions of MySQL ( < 5.7.5 ) the only way to set

'innodb_buffer_pool_size'

variable was by writing it to my.cnf (for linux) and my.ini (for windows) under [mysqld] section :

[mysqld]

innodb_buffer_pool_size = 2147483648

You need to restart your mysql server to have it's effect in action.

UPDATE :

As of MySQL 5.7.5, the innodb_buffer_pool_size configuration option can be set dynamically using a SET statement, allowing you to resize the buffer pool without restarting the server. For example:

mysql> SET GLOBAL innodb_buffer_pool_size=402653184;

Reference : https://dev.mysql.com/doc/refman/5.7/en/innodb-buffer-pool-resize.html

addID in jQuery?

Like this :

var id = $('div.foo').attr('id');
$('div.foo').attr('id', id + ' id_adding');
  1. get actual ID
  2. put actuel ID and add the new one

Reverse each individual word of "Hello World" string with Java

        String input = "Welcome To The Java Programming";
        String output  = "";
        String[] cutAry = input.split("\\s+");
        StringBuilder sb = new StringBuilder();
        for(String s:cutAry){
            sb.append(s);
            output += sb.reverse().toString()+" ";
            sb.replace(0, sb.length(), "");
        }
        System.out.println(output);

Ajax - 500 Internal Server Error

I had the same error. It turns out that the cause was that the back end method was expecting different json data. In my Ajax call i had something like this:

$.ajax({
        async: false,
        type: "POST",
        url: "http://13.82.13.196/api.aspx/PostAjax",
        data: '{"url":"test"}',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
    });

Now in my WebMethod, inside my C# backend code i had declared my endpoint like this:

public static string PostAjax(AjaxSettings settings)

Where AjaxSettings was declared:

public class AjaxSettings
{
    public string url { get; set; }
}

The problem then was that the mapping between my ajax call and my back-end endpoint was not the same. As soon as i changed my ajax call to the following, it all worked well!

var data ='{"url":"test"}';    
$.ajax({
    async: false,
    type: "POST",
    url: "http://13.82.13.196/api.aspx/PostAjax",
    data: '{"settings":'+data+'}',
    contentType: "application/json; charset=utf-8",
    dataType: "json"
});

I had to change the data variable inside the Ajax call in order to match the method signature exactly.

Deleting a pointer in C++

int value, *ptr;

value = 8;
ptr = &value;
// ptr points to value, which lives on a stack frame.
// you are not responsible for managing its lifetime.

ptr = new int;
delete ptr;
// yes this is the normal way to manage the lifetime of
// dynamically allocated memory, you new'ed it, you delete it.

ptr = nullptr;
delete ptr;
// this is illogical, essentially you are saying delete nothing.

Extracting text OpenCV

Here is an alternative approach that I used to detect the text blocks:

  1. Converted the image to grayscale
  2. Applied threshold (simple binary threshold, with a handpicked value of 150 as the threshold value)
  3. Applied dilation to thicken lines in image, leading to more compact objects and less white space fragments. Used a high value for number of iterations, so dilation is very heavy (13 iterations, also handpicked for optimal results).
  4. Identified contours of objects in resulted image using opencv findContours function.
  5. Drew a bounding box (rectangle) circumscribing each contoured object - each of them frames a block of text.
  6. Optionally discarded areas that are unlikely to be the object you are searching for (e.g. text blocks) given their size, as the algorithm above can also find intersecting or nested objects (like the entire top area for the first card) some of which could be uninteresting for your purposes.

Below is the code written in python with pyopencv, it should easy to port to C++.

import cv2

image = cv2.imread("card.png")
gray = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY) # grayscale
_,thresh = cv2.threshold(gray,150,255,cv2.THRESH_BINARY_INV) # threshold
kernel = cv2.getStructuringElement(cv2.MORPH_CROSS,(3,3))
dilated = cv2.dilate(thresh,kernel,iterations = 13) # dilate
_, contours, hierarchy = cv2.findContours(dilated,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE) # get contours

# for each contour found, draw a rectangle around it on original image
for contour in contours:
    # get rectangle bounding contour
    [x,y,w,h] = cv2.boundingRect(contour)

    # discard areas that are too large
    if h>300 and w>300:
        continue

    # discard areas that are too small
    if h<40 or w<40:
        continue

    # draw rectangle around contour on original image
    cv2.rectangle(image,(x,y),(x+w,y+h),(255,0,255),2)

# write original image with added contours to disk  
cv2.imwrite("contoured.jpg", image) 

The original image is the first image in your post.

After preprocessing (grayscale, threshold and dilate - so after step 3) the image looked like this:

Dilated image

Below is the resulted image ("contoured.jpg" in the last line); the final bounding boxes for the objects in the image look like this:

enter image description here

You can see the text block on the left is detected as a separate block, delimited from its surroundings.

Using the same script with the same parameters (except for thresholding type that was changed for the second image like described below), here are the results for the other 2 cards:

enter image description here

enter image description here

Tuning the parameters

The parameters (threshold value, dilation parameters) were optimized for this image and this task (finding text blocks) and can be adjusted, if needed, for other cards images or other types of objects to be found.

For thresholding (step 2), I used a black threshold. For images where text is lighter than the background, such as the second image in your post, a white threshold should be used, so replace thesholding type with cv2.THRESH_BINARY). For the second image I also used a slightly higher value for the threshold (180). Varying the parameters for the threshold value and the number of iterations for dilation will result in different degrees of sensitivity in delimiting objects in the image.

Finding other object types:

For example, decreasing the dilation to 5 iterations in the first image gives us a more fine delimitation of objects in the image, roughly finding all words in the image (rather than text blocks):

enter image description here

Knowing the rough size of a word, here I discarded areas that were too small (below 20 pixels width or height) or too large (above 100 pixels width or height) to ignore objects that are unlikely to be words, to get the results in the above image.

Executing JavaScript after X seconds

onclick = "setTimeout(function() { document.getElementById('div1').style.display='none';document.getElementById('div2').style.display='none'}, 1000)"

Change 1000 to the number of milliseconds you want to delay.

Change SQLite database mode to read-write

On Ubuntu, change the owner to the Apache group and grant the right permissions (no, it's not 777):

sudo chgrp www-data <path to db.sqlite3>
sudo chmod 664 <path to db.sqlite3>

Update

You can set the permissions for group and user as well.

sudo chown www-data:www-data <path to db.sqlite3>

Moving uncommitted changes to a new branch

Just create a new branch with git checkout -b ABC_1; your uncommitted changes will be kept, and you then commit them to that branch.

How to open a new form from another form

Try this..

//button1 will be clicked to open a new form
private void button1_Click(object sender, EventArgs e)
{
    this.Visible = false;     // this = is the current form
    SignUp s = new SignUp();  //SignUp is the name of  my other form
    s.Visible = true;
}

Using two CSS classes on one element

I know this post is getting outdated, but here's what they asked. In your style sheet:

.social {
    width: 330px;
    height: 75px;
    float: right;
    text-align: left;
    padding: 10px 0;
    border-bottom: dotted 1px #6d6d6d;
}
[class~="first"] {
    padding-top:0;
}
[class~="last"] {
    border:0;
}

But it may be a bad way to use selectors. Also, if you need multiple "first" extension, you'll have to be sure to set different name, or to refine your selector.

[class="social first"] {...}

I hope this will help someone, it can be pretty handy in some situation.

For exemple, if you have a tiny piece of css that has to be linked to many different components, and you don't want to write a hundred time the same code.

div.myClass1 {font-weight:bold;}
div.myClass2 {font-style:italic;}
...
div.myClassN {text-shadow:silver 1px 1px 1px;}

div.myClass1.red {color:red;}
div.myClass2.red {color:red;}
...
div.myClassN.red {color:red;}

Becomes:

div.myClass1 {font-weight:bold;}
div.myClass2 {font-style:italic;}
...
div.myClassN {text-shadow:silver 1px 1px 1px;}

[class~=red] {color:red;}

I get "Http failure response for (unknown url): 0 Unknown Error" instead of actual error message in Angular

In case anyone else ends up as lost as I was... My issues were NOT due to CORS (I have full control of the server(s) and CORS was configured correctly!).

My issue was because I am using Android platform level 28 which disables cleartext network communications by default and I was trying to develop the app which points at my laptop's IP (which is running the API server). The API base URL is something like http://[LAPTOP_IP]:8081. Since it's not https, android webview completely blocks the network xfer between the phone/emulator and the server on my laptop. In order to fix this:

Add a network security config

New file in project: resources/android/xml/network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
  <!-- Set application-wide security config -->
  <base-config cleartextTrafficPermitted="true"/>
</network-security-config>

NOTE: This should be used carefully as it will allow all cleartext from your app (nothing forced to use https). You can restrict it further if you wish.

Reference the config in main config.xml

<platform name="android">
    ...
    <edit-config file="app/src/main/AndroidManifest.xml" mode="merge" target="/manifest/application" xmlns:android="http://schemas.android.com/apk/res/android">
        <application android:networkSecurityConfig="@xml/network_security_config" />
    </edit-config>
    <resource-file src="resources/android/xml/network_security_config.xml" target="app/src/main/res/xml/network_security_config.xml" />
    ....
</platform>

That's it! From there I rebuilt the APK and the app was now able to communicate from both the emulator and phone.

More info on network sec: https://developer.android.com/training/articles/security-config.html#CleartextTrafficPermitted

How to set cache: false in jQuery.get call

Add the parameter yourself.

$.get(url,{ "_": $.now() }, function(rdata){
  console.log(rdata);
});

As of jQuery 3.0, you can now do this:

$.get({
  url: url, 
  cache: false
}).then(function(rdata){
  console.log(rdata);
});

Deleting an object in java?

Yea, java is Garbage collected, it will delete the memory for you.

How can I get column names from a table in Oracle?

SELECT A.COLUMN_NAME, A.* FROM all_tab_columns a 
WHERE table_name = 'Your Table Name'
AND A.COLUMN_NAME = 'COLUMN NAME' AND a.owner = 'Schema'

Write a function that returns the longest palindrome in a given string

See Wikipedia article on this topic. Sample Manacher's Algorithm Java implementation for linear O(n) solution from the article below:

import java.util.Arrays; public class ManachersAlgorithm { public static String findLongestPalindrome(String s) { if (s==null || s.length()==0) return "";

char[] s2 = addBoundaries(s.toCharArray());
int[] p = new int[s2.length]; 
int c = 0, r = 0; // Here the first element in s2 has been processed.
int m = 0, n = 0; // The walking indices to compare if two elements are the same
for (int i = 1; i<s2.length; i++) {
  if (i>r) {
    p[i] = 0; m = i-1; n = i+1;
  } else {
    int i2 = c*2-i;
    if (p[i2]<(r-i)) {
      p[i] = p[i2];
      m = -1; // This signals bypassing the while loop below. 
    } else {
      p[i] = r-i;
      n = r+1; m = i*2-n;
    }
  }
  while (m>=0 && n<s2.length && s2[m]==s2[n]) {
    p[i]++; m--; n++;
  }
  if ((i+p[i])>r) {
    c = i; r = i+p[i];
  }
}
int len = 0; c = 0;
for (int i = 1; i<s2.length; i++) {
  if (len<p[i]) {
    len = p[i]; c = i;
  }
}
char[] ss = Arrays.copyOfRange(s2, c-len, c+len+1);
return String.valueOf(removeBoundaries(ss));   }
private static char[] addBoundaries(char[] cs) {
if (cs==null || cs.length==0)
  return "||".toCharArray();

char[] cs2 = new char[cs.length*2+1];
for (int i = 0; i<(cs2.length-1); i = i+2) {
  cs2[i] = '|';
  cs2[i+1] = cs[i/2];
}
cs2[cs2.length-1] = '|';
return cs2;   }
private static char[] removeBoundaries(char[] cs) {
if (cs==null || cs.length<3)
  return "".toCharArray();

char[] cs2 = new char[(cs.length-1)/2];
for (int i = 0; i<cs2.length; i++) {
  cs2[i] = cs[i*2+1];
}
return cs2;   }     }

How can I increase the size of a bootstrap button?

Just simply add to the class of the bootstrap code.

_x000D_
_x000D_
.login
{
width: 20%;
margin-top: 39.5%;
margin-left: 35%;
}
_x000D_
<button type="button" class="btn btn-outline-dark btn-lg login">Login</button> 
_x000D_
_x000D_
_x000D_

Set a request header in JavaScript

For people looking this up now:

It seems that now setting the User-Agent header is allowed since Firefox 43. See https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_header_name for the current list of forbidden headers.

Update React component every second

Owing to changes in React V16 where componentWillReceiveProps() has been deprecated, this is the methodology that I use for updating a component. Notice that the below example is in Typescript and uses the static getDerivedStateFromProps method to get the initial state and updated state whenever the Props are updated.

    class SomeClass extends React.Component<Props, State> {
  static getDerivedStateFromProps(nextProps: Readonly<Props>): Partial<State> | null {
    return {
      time: nextProps.time
    };
  }

  timerInterval: any;

  componentDidMount() {
    this.timerInterval = setInterval(this.tick.bind(this), 1000);
  }

  tick() {
    this.setState({ time: this.props.time });
  }

  componentWillUnmount() {
    clearInterval(this.timerInterval);
  }

  render() {
    return <div>{this.state.time}</div>;
  }
}

How do I convert from a string to an integer in Visual Basic?

You can use the following to convert string to int:

  • CInt(String) for ints
  • CDec(String) for decimals

For details refer to Type Conversion Functions (Visual Basic).

How to detect chrome and safari browser (webkit)

/WebKit/.test(navigator.userAgent) — that's it.

nodejs vs node on ubuntu 12.04

Apparently the solution differs between Ubuntu versions. Following worked for me on Ubuntu 13.10:

sudo apt-get install nodejs-legacy

HTH

Edit: Rule of thumb:

If you have installed nodejs but are missing the /usr/bin/node binary, then also install nodejs-legacy. This just creates the missing softlink.

According to my tests, Ubuntu 17.10 and above already have the compatibility-softlink /usr/bin/node in place after nodejs is installed, so nodejs-legacy is missing from these releases as it is no more needed.

org.postgresql.util.PSQLException: FATAL: sorry, too many clients already

No need to increase the MaxConnections & InitialConnections. Just close your connections after after doing your work. For example if you are creating connection:

try {
     connection = DriverManager.getConnection(
                    "jdbc:postgresql://127.0.0.1/"+dbname,user,pass);

   } catch (SQLException e) {
    e.printStackTrace();
    return;
}

After doing your work close connection:

try {
    connection.commit();
    connection.close();
} catch (SQLException e) {
    e.printStackTrace();
}

How to remove duplicate white spaces in string using Java?

You can also try using String Tokeniser, for any space, tab, newline, and all. A simple way is,

String s = "Your Text Here";        
StringTokenizer st = new StringTokenizer( s, " " );
while(st.hasMoreTokens())
{
    System.out.print(st.nextToken());
}

how to show confirmation alert with three buttons 'Yes' 'No' and 'Cancel' as it shows in MS Word

If you don't want to use a separate JS library to create a custom control for that, you could use two confirm dialogs to do the checks:

if (confirm("Are you sure you want to quit?") ) {
    if (confirm("Save your work before leaving?") ) {
        // code here for save then leave (Yes)
    } else {
        //code here for no save but leave (No)
    }
} else {
    //code here for don't leave (Cancel)
}

How can I get System variable value in Java?

Are you on a linux system? If so be sure you are exporting your variable.

myVar=testvalue; export myVar

I get null unless I use export to define the value globally.

What does 'stale file handle' in Linux mean?

When the directory is deleted, the inode for that directory (and the inodes for its contents) are recycled. The pointer your shell has to that directory's inode (and its contents's inodes) are now no longer valid. When the directory is restored from backup, the old inodes are not (necessarily) reused; the directory and its contents are stored on random inodes. The only thing that stays the same is that the parent directory reuses the same name for the restored directory (because you told it to).

Now if you attempt to access the contents of the directory that your original shell is still pointing to, it communicates that request to the file system as a request for the original inode, which has since been recycled (and may even be in use for something entirely different now). So you get a stale file handle message because you asked for some nonexistent data.

When you perform a cd operation, the shell reevaluates the inode location of whatever destination you give it. Now that your shell knows the new inode for the directory (and the new inodes for its contents), future requests for its contents will be valid.

Passing variables through handlebars partial

The accepted answer works great if you just want to use a different context in your partial. However, it doesn't let you reference any of the parent context. To pass in multiple arguments, you need to write your own helper. Here's a working helper for Handlebars 2.0.0 (the other answer works for versions <2.0.0):

Handlebars.registerHelper('renderPartial', function(partialName, options) {
    if (!partialName) {
        console.error('No partial name given.');
        return '';
    }
    var partial = Handlebars.partials[partialName];
    if (!partial) {
        console.error('Couldnt find the compiled partial: ' + partialName);
        return '';
    }
    return new Handlebars.SafeString( partial(options.hash) );
});

Then in your template, you can do something like:

{{renderPartial 'myPartialName' foo=this bar=../bar}}

And in your partial, you'll be able to access those values as context like:

<div id={{bar.id}}>{{foo}}</div>

Include another JSP file

What you're doing is a static include. A static include is resolved at compile time, and may thus not use a parameter value, which is only known at execution time.

What you need is a dynamic include:

<jsp:include page="..." />

Note that you should use the JSP EL rather than scriptlets. It also seems that you're implementing a central controller with index.jsp. You should use a servlet to do that instead, and dispatch to the appropriate JSP from this servlet. Or better, use an existing MVC framework like Stripes or Spring MVC.

Send email using java

You can find a complete and very simple java class for sending emails using Google(gmail) account here,

Send email using java and Google account

It uses following properties

Properties props = new Properties();
  props.put("mail.smtp.auth", "true");
  props.put("mail.smtp.starttls.enable", "true");
  props.put("mail.smtp.host", "smtp.gmail.com");
  props.put("mail.smtp.port", "587");

How to plot vectors in python using matplotlib

What did you expect the following to do?

v1 = [0,0],[M[i,0],M[i,1]]
v1 = [M[i,0]],[M[i,1]]

This is making two different tuples, and you overwrite what you did the first time... Anyway, matplotlib does not understand what a "vector" is in the sense you are using. You have to be explicit, and plot "arrows":

In [5]: ax = plt.axes()

In [6]: ax.arrow(0, 0, *v1, head_width=0.05, head_length=0.1)
Out[6]: <matplotlib.patches.FancyArrow at 0x114fc8358>

In [7]: ax.arrow(0, 0, *v2, head_width=0.05, head_length=0.1)
Out[7]: <matplotlib.patches.FancyArrow at 0x115bb1470>

In [8]: plt.ylim(-5,5)
Out[8]: (-5, 5)

In [9]: plt.xlim(-5,5)
Out[9]: (-5, 5)

In [10]: plt.show()

Result:

enter image description here

C: Run a System Command and Get Output?

Usually, if the command is an external program, you can use the OS to help you here.

command > file_output.txt

So your C code would be doing something like

exec("command > file_output.txt");

Then you can use the file_output.txt file.

Get Value of Row in Datatable c#

for (Int32 i = 1; i < dt_pattern.Rows.Count - 1; i++){ double yATmax = ToDouble(dt_pattern.Rows[i]["Ampl"].ToString()) + AT; }

if you want to get around the + 1 issue

bash shell nested for loop

One one line (semi-colons necessary):

for i in 0 1 2 3 4 5 6 7 8 9; do for j in 0 1 2 3 4 5 6 7 8 9; do echo "$i$j"; done; done

Formatted for legibility (no semi-colons needed):

for i in 0 1 2 3 4 5 6 7 8 9
do
    for j in 0 1 2 3 4 5 6 7 8 9
    do 
        echo "$i$j"
    done
done

There are different views on how the shell code should be laid out over multiple lines; that's about what I normally use, unless I put the next operation on the same line as the do (saving two lines here).

Gradients in Internet Explorer 9

Looks like I'm a little late to the party, but here's an example for some of the top browsers:

/* IE10 */ 
background-image: -ms-linear-gradient(top, #444444 0%, #999999 100%);

/* Mozilla Firefox */ 
background-image: -moz-linear-gradient(top, #444444 0%, #999999 100%);

/* Opera */ 
background-image: -o-linear-gradient(top, #444444 0%, #999999 100%);

/* Webkit (Safari/Chrome 10) */ 
background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0, #444444), color-stop(1, #999999));

/* Webkit (Chrome 11+) */ 
background-image: -webkit-linear-gradient(top, #444444 0%, #999999 100%);

/* Proposed W3C Markup */ 
background-image: linear-gradient(top, #444444 0%, #999999 100%);

Source: http://ie.microsoft.com/testdrive/Graphics/CSSGradientBackgroundMaker/Default.html

Note: all of these browsers also support rgb/rgba in place of hexadecimal notation.

Global environment variables in a shell script

#!/bin/bash
export FOO=bar

or

#!/bin/bash
FOO=bar
export FOO

man export:

The shell shall give the export attribute to the variables corresponding to the specified names, which shall cause them to be in the environment of subsequently executed commands. If the name of a variable is followed by = word, then the value of that variable shall be set to word.

JavaScript - document.getElementByID with onClick

In JavaScript functions are objects.

document.getElementById('foo').onclick = function(){
    prompt('Hello world');
}

Read input numbers separated by spaces

You'll want to:

  • Read in an entire line from the console
  • Tokenize the line, splitting along spaces.
  • Place those split pieces into an array or list
  • Step through that array/list, performing your prime/perfect/etc tests.

What has your class covered along these lines so far?

android - setting LayoutParams programmatically

Just replace from bottom and add this

tv.setLayoutParams(new ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.WRAP_CONTENT,
    ViewGroup.LayoutParams.WRAP_CONTENT));

before

llview.addView(tv);

Matching a Forward Slash with a regex

If you want to use / you need to escape it with a \

var word = /\/(\w+)/ig;

Convert bytes to bits in python

The other answers here provide the bits in big-endian order ('\x01' becomes '00000001')

In case you're interested in little-endian order of bits, which is useful in many cases, like common representations of bignums etc - here's a snippet for that:

def bits_little_endian_from_bytes(s):
    return ''.join(bin(ord(x))[2:].rjust(8,'0')[::-1] for x in s)

And for the other direction:

def bytes_from_bits_little_endian(s):
    return ''.join(chr(int(s[i:i+8][::-1], 2)) for i in range(0, len(s), 8))

A div with auto resize when changing window width\height

  <!DOCTYPE html>
    <html>
  <head>
  <style> 
   div {

   padding: 20px; 

   resize: both;
  overflow: auto;
   }
    img{
   height: 100%;
    width: 100%;
 object-fit: contain;
 }
 </style>
  </head>
  <body>
 <h1>The resize Property</h1>

 <div>
 <p>Let the user resize both the height and the width of this 1234567891011 div 
   element. 
  </p>
 <p>To resize: Click and drag the bottom right corner of this div element.</p>
  <img src="images/scenery.jpg" alt="Italian ">
  </div>

   <p><b>Note:</b> Internet Explorer does not support the resize property.</p>

 </body>
 </html>

ERROR 1049 (42000): Unknown database

Very simple solution. Just rename your database and configure your new database name in your project.

The problem is the when you import your database, you got any errors and then the database will be corrupted. The log files will have the corrupted database name. You can rename your database easily using phpmyadmin for mysql.

phpmyadmin -> operations -> Rename database to

Relational Database Design Patterns?

There's a book in Martin Fowler's Signature Series called Refactoring Databases. That provides a list of techniques for refactoring databases. I can't say I've heard a list of database patterns so much.

I would also highly recommend David C. Hay's Data Model Patterns and the follow up A Metadata Map which builds on the first and is far more ambitious and intriguing. The Preface alone is enlightening.

Also a great place to look for some pre-canned database models is Len Silverston's Data Model Resource Book Series Volume 1 contains universally applicable data models (employees, accounts, shipping, purchases, etc), Volume 2 contains industry specific data models (accounting, healthcare, etc), Volume 3 provides data model patterns.

Finally, while this book is ostensibly about UML and Object Modelling, Peter Coad's Modeling in Color With UML provides an "archetype" driven process of entity modeling starting from the premise that there are 4 core archetypes of any object/data model

How to use hex() without 0x in Python?

You can simply write

hex(x)[2:]

to get the first two characters removed.

How to build a Debian/Ubuntu package from source?

you can use the special package "checkinstall" for all packages which are not even in debian/ubuntu yet.

You can use "uupdate" (apt-get install devscripts) to build a package from source with existing debian sources:

Example for libdrm2:

apt-get build-dep libdrm2
apt-get source libdrm2
cd libdrm-2.3.1
uupdate ~/Downloads/libdrm-2.4.1.tar.gz
cd ../libdrm-2.4.1
dpkg-buildpackage -us -uc -nc

Getting the last n elements of a vector. Is there a better way than using the length() function?

I just add here something related. I was wanted to access a vector with backend indices, ie writting something like tail(x, i) but to return x[length(x) - i + 1] and not the whole tail.

Following commentaries I benchmarked two solutions:

accessRevTail <- function(x, n) {
    tail(x,n)[1]
}

accessRevLen <- function(x, n) {
  x[length(x) - n + 1]
}

microbenchmark::microbenchmark(accessRevLen(1:100, 87), accessRevTail(1:100, 87))
Unit: microseconds
                     expr    min      lq     mean median      uq     max neval
  accessRevLen(1:100, 87)  1.860  2.3775  2.84976  2.803  3.2740   6.755   100
 accessRevTail(1:100, 87) 22.214 23.5295 28.54027 25.112 28.4705 110.833   100

So it appears in this case that even for small vectors, tail is very slow comparing to direct access

'npm' is not recognized as internal or external command, operable program or batch file

If the package is successfully installed and still shows the message "'npm' is not recognized as an internal or external command, operable program or batch file."

  1. Click windows start button.
  2. Look for "ALL APPS", you will see Node.js and Node.js Command prompt there.
  3. You can run the Node.js Command prompt as administrator and soon as its run it will show the message "Your environment has been set up for using Node.js 6.3.0 (x64) and npm."

and then it works from there...

What is a Data Transfer Object (DTO)?

  1. To me the best answer to the question what is a DTO is that DTO's are simple objects that should not contain any business logic or methods implementation that would require testing.
  2. Normally your model (using the MVC pattern) are intelligent models, and they can contain a lot of/some methods that do some different operations for that model specifically (not business logic, this should be at the controllers). However, when you transfer data (eg. calling a REST (GET/POST/whatever) endpoint from somewhere, or consuming a webservice using SOA, etc...) you do not want to transmit the big sized object with code that is not necessary for the endpoint, will consume data, and slow down the transfer.

Calling a Sub in VBA

Try -

Call CatSubProduktAreakum(Stattyp, Daty + UBound(SubCategories) + 2)

As for the reason, this from MSDN via this question - What does the Call keyword do in VB6?

You are not required to use the Call keyword when calling a procedure. However, if you use the Call keyword to call a procedure that requires arguments, argumentlist must be enclosed in parentheses. If you omit the Call keyword, you also must omit the parentheses around argumentlist. If you use either Call syntax to call any intrinsic or user-defined function, the function's return value is discarded.

startsWith() and endsWith() functions in PHP

in short:

function startsWith($str, $needle){
   return substr($str, 0, strlen($needle)) === $needle;
}

function endsWith($str, $needle){
   $length = strlen($needle);
   return !$length || substr($str, - $length) === $needle;
}

JavaScript Chart.js - Custom data formatting to display on tooltip

In chart.js 2.1.6, I did something like this (in typescript):

  let that = this;
  options = {
    legend: {
      display: false,
      responsive: false
    },
    tooltips: {
      callbacks: {
        label: function(tooltipItem, data) {
          let account: Account = that.accounts[tooltipItem.index];
          return account.accountNumber+":"+account.balance+"€";
        }
      }
    }
  }

How to access shared folder without giving username and password

I found one way to access the shared folder without giving the username and password.

We need to change the share folder protect settings in the machine where the folder has been shared.

Go to Control Panel > Network and sharing center > Change advanced sharing settings > Enable Turn Off password protect sharing option.

By doing the above settings we can access the shared folder without any username/password.

How do I set a fixed background image for a PHP file?

You should consider have other php files included if you're going to derive a website from it. Instead of doing all the css/etc in that file, you can do

<head>
    <?php include_once('C:\Users\George\Documents\HTML\style.css'); ?>
    <title>Title</title>
</hea>

Then you can have a separate CSS file that is just being pulled into your php file. It provides some "neater" coding.

Proper way to exit command line program?

Take a look at Job Control on UNIX systems

If you don't have control of your shell, simply hitting ctrl + C should stop the process. If that doesn't work, you can try ctrl + Z and using the jobs and kill -9 %<job #> to kill it. The '-9' is a type of signal. You can man kill to see a list of signals.

WHERE IS NULL, IS NOT NULL or NO WHERE clause depending on SQL Server parameter value

I've had success with this solution. It's almost like Patrick's, with a little twist. You can use these expressions separately or in sequence. If the parameter is blank, it will be ignored and all values for the column that your searching will be displayed, including NULLS.

SELECT * FROM MyTable
WHERE 
    --check to see if @param1 exists, if @param1 is blank, return all
    --records excluding filters below
(Col1 LIKE '%' + @param1 + '%' OR @param1 = '')
AND
    --where you want to search multiple columns using the same parameter
    --enclose the first 'OR' expression in braces and enclose the entire 
    --expression 
((Col2 LIKE '%' + @searchString + '%' OR Col3 LIKE '%' + @searchString + '%') OR @searchString = '')
AND
    --if your search requires a date you could do the following
(Cast(DateCol AS DATE) BETWEEN CAST(@dateParam AS Date) AND CAST(GETDATE() AS DATE) OR @dateParam = '')

I want to remove double quotes from a String

If you're trying to remove the double quotes try following

  var Stringstr = "\"I am here\"";
  var mystring = String(Stringstr);
  mystring = mystring.substring(1, mystring.length - 1);
  alert(mystring);

How can I bring my application window to the front?

While I agree with everyone, this is no-nice behavior, here is code:

[DllImport("User32.dll")]
public static extern Int32 SetForegroundWindow(int hWnd);   


SetForegroundWindow(Handle.ToInt32());

Update

David is completely right, for completeness I include the list of conditions that must apply for this to work (+1 for David!):

  • The process is the foreground process.
  • The process was started by the foreground process.
  • The process received the last input event.
  • There is no foreground process.
  • The foreground process is being debugged.
  • The foreground is not locked (see LockSetForegroundWindow).
  • The foreground lock time-out has expired (see SPI_GETFOREGROUNDLOCKTIMEOUT in SystemParametersInfo).
  • No menus are active.

Passing a String by Reference in Java?

All arguments in Java are passed by value. When you pass a String to a function, the value that's passed is a reference to a String object, but you can't modify that reference, and the underlying String object is immutable.

The assignment

zText += foo;

is equivalent to:

zText = new String(zText + "foo");

That is, it (locally) reassigns the parameter zText as a new reference, which points to a new memory location, in which is a new String that contains the original contents of zText with "foo" appended.

The original object is not modified, and the main() method's local variable zText still points to the original (empty) string.

class StringFiller {
  static void fillString(String zText) {
    zText += "foo";
    System.out.println("Local value: " + zText);
  }

  public static void main(String[] args) {
    String zText = "";
    System.out.println("Original value: " + zText);
    fillString(zText);
    System.out.println("Final value: " + zText);
  }
}

prints:

Original value:
Local value: foo
Final value:

If you want to modify the string, you can as noted use StringBuilder or else some container (an array or an AtomicReference or a custom container class) that gives you an additional level of pointer indirection. Alternatively, just return the new value and assign it:

class StringFiller2 {
  static String fillString(String zText) {
    zText += "foo";
    System.out.println("Local value: " + zText);
    return zText;
  }

  public static void main(String[] args) {
    String zText = "";
    System.out.println("Original value: " + zText);
    zText = fillString(zText);
    System.out.println("Final value: " + zText);
  }
}

prints:

Original value:
Local value: foo
Final value: foo

This is probably the most Java-like solution in the general case -- see the Effective Java item "Favor immutability."

As noted, though, StringBuilder will often give you better performance -- if you have a lot of appending to do, particularly inside a loop, use StringBuilder.

But try to pass around immutable Strings rather than mutable StringBuilders if you can -- your code will be easier to read and more maintainable. Consider making your parameters final, and configuring your IDE to warn you when you reassign a method parameter to a new value.

Install shows error in console: INSTALL FAILED CONFLICTING PROVIDER

I had a similar problem when I used one library in several applications. It was necessary just update your AndroidManifest.xml with this exact provider declaration below.

<manifest ...>
    <application ...>
        <provider android:name="android.support.v4.content.FileProvider" android:authorities="${applicationId}.here.this.library.provider" android:exported="false" android:grantUriPermissions="true" tools:replace="android:authorities">
        </provider>
    </application>  
</manifest> 

Easiest way to copy a single file from host to Vagrant guest?

If someone wants to transfer file from windows host to vagrant, then this solution worked for me.

1. Make sure to install **winscp** on your windows system
2. run **vagrant up** command
3. run **vagrant ssh-config** command and note down below details
4. Enter Hostname, Port, Username: vagrant, Password: vagrant in winscp and select **SCP**, file protocol 
5. In most cases, hostname: 127.0.0.1, port: 2222, username: vagrant, password: vagrant.

You should be able to see directories in your vagrant machine.

build failed with: ld: duplicate symbol _OBJC_CLASS_$_Algebra5FirstViewController

In my case I had a reference to a library in Other Linker Flags. Removing it got rid of the error.

enter image description here

enter image description here

Cloning an Object in Node.js

Check out underscore.js. It has both clone and extend and many other very useful functions.

This can be useful: Using the Underscore module with Node.js

RegEx - Match Numbers of Variable Length

{[0-9]+:[0-9]+}

try adding plus(es)

Is this a good way to clone an object in ES6?

All the methods above do not handle deep cloning of objects where it is nested to n levels. I did not check its performance over others but it is short and simple.

The first example below shows object cloning using Object.assign which clones just till first level.

_x000D_
_x000D_
var person = {_x000D_
    name:'saksham',_x000D_
    age:22,_x000D_
    skills: {_x000D_
        lang:'javascript',_x000D_
        experience:5_x000D_
    }_x000D_
}_x000D_
_x000D_
newPerson = Object.assign({},person);_x000D_
newPerson.skills.lang = 'angular';_x000D_
console.log(newPerson.skills.lang); //logs Angular
_x000D_
_x000D_
_x000D_

Using the below approach deep clones object

_x000D_
_x000D_
var person = {_x000D_
    name:'saksham',_x000D_
    age:22,_x000D_
    skills: {_x000D_
        lang:'javascript',_x000D_
        experience:5_x000D_
    }_x000D_
}_x000D_
_x000D_
anotherNewPerson = JSON.parse(JSON.stringify(person));_x000D_
anotherNewPerson.skills.lang = 'angular';_x000D_
console.log(person.skills.lang); //logs javascript
_x000D_
_x000D_
_x000D_

CSS media query to target only iOS devices

As mentioned above, the short answer is no. But I'm in need of something similar in the app I'm working on now, yet the areas where the CSS needs to be different are limited to very specific areas of a page.

If you're like me and don't need to serve up an entirely different stylesheet, another option would be to detect a device running iOS in the way described in this question's selected answer: Detect if device is iOS

Once you've detected the iOS device you could add a class to the area you're targeting using Javascript (eg. the document.getElementsByTagName("yourElementHere")[0].setAttribute("class", "iOS-device");, jQuery, PHP or whatever, and style that class accordingly using the pre-existing stylesheet.

.iOS-device {
      style-you-want-to-set: yada;
}

How can I view an object with an alert()

Depending on which property you are interested in:

alert(product.ProductName);
alert(product.UnitPrice);
alert(product.Stock);

Superscript in CSS only?

Honestly I don't see the point in doing superscript/subscript in CSS only. There's no handy CSS attribute for it, just a bunch of homegrown implementations including:

.superscript { position: relative; top: -0.5em; font-size: 80%; }

or using vertical-align or I'm sure other ways. Thing is, it starts to get complicated:

The second point is worth emphasizing. Typically superscript/subscript is not actually a styling issue but is indicative of meaning.

Side note: It's worth mentioning this list of entities for common mathematical superscript and subscript expressions even though this question doesn't relate to that.

The sub/sup tags are in HTML and XHTML. I would just use those.

As for the rest of your CSS, the :after pseudo-element and content attributes are not widely supported. If you really don't want to put this manually in the HTML I think a Javascript-based solution is your next best bet. With jQuery this is as simple as:

$(function() {
  $("a.external").append("<sup>+</sup>");
};

Simplest way to detect a mobile device in PHP

I found mobile detect to be really simple and you can just use the isMobile() function :)

Copy the entire contents of a directory in C#

One variant with only one loop for copying of all folders and files:

foreach (var f in Directory.GetFileSystemEntries(path, "*", SearchOption.AllDirectories))
{
    var output = Regex.Replace(f, @"^" + path, newPath);
    if (File.Exists(f)) File.Copy(f, output, true);
    else Directory.CreateDirectory(output);
}

Windows 7: unable to register DLL - Error Code:0X80004005

Use following command should work on windows 7. don't forget to enclose the dll name with full path in double quotations.

C:\Windows\SysWOW64>regsvr32 "c:\dll.name" 

Execute a shell function with timeout

Putting my comment to Tiago Lopo's answer into more readable form:

I think it's more readable to impose a timeout on the most recent subshell, this way we don't need to eval a string and the whole script can be highlighted as shell by your favourite editor. I simply put the commands after the subshell with eval has spawned into a shell-function (tested with zsh, but should work with bash):

timeout_child () {
    trap -- "" SIGTERM
    child=$!
    timeout=$1
    (
            sleep $timeout
            kill $child
    ) &
    wait $child
}

Example usage:

( while true; do echo -n .; sleep 0.1; done) & timeout_child 2

And this way it also works with a shell function (if it runs in the background):

 print_dots () {
     while true
     do
         sleep 0.1
         echo -n .
     done
 }


 > print_dots & timeout_child 2
 [1] 21725
 [3] 21727
 ...................[1]    21725 terminated  print_dots
 [3]  + 21727 done       ( sleep $timeout; kill $child; )

Changing background colour of tr element on mouseover

tr:hover td.someclass {
   background: #EDB01C;
   color:#FFF;
}

only someclass cell highlight

How to preview git-pull without doing fetch?

If you don't want git-fetch to update your local .git, just copy your local repo to a temp dir and do a pull there. Here is a shor-hand:

$ alias gtp="tar -c . | (cd /tmp && mkdir tp && cd tp && tar -x && git pull; rm -rf /tmp/tp)"

Ex.:

$ git status
# On branch master
nothing to commit (working directory clean)

$ gtp
remote: Finding sources: 100% (25/25)
remote: Total 25 (delta 10), reused 25 (delta 10)
Unpacking objects: 100% (25/25), done.
From ssh://my.git.domain/reapO
   32d61dc..05287d6  master     -> origin/master
Updating 32d61dc..05287d6
Fast-forward
 subdir/some.file       |    2 +-
 .../somepath/by.tes    |    3 ++-
 .../somepath/data      |   11 +++++++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

$ git status
# On branch master
nothing to commit (working directory clean)

$ git fetch
remote: Finding sources: 100% (25/25)
remote: Total 25 (delta 10), reused 25 (delta 10)
Unpacking objects: 100% (25/25), done.
From ssh://my.git.domain/reapO
   32d61dc..05287d6  master     -> origin/master

$ git status
# On branch master
# Your branch is behind 'origin/master' by 3 commits, and can be fast-forwarded.
#
nothing to commit (working directory clean)

When should an Excel VBA variable be killed or set to Nothing?

I have at least one situation where the data is not automatically cleaned up, which would eventually lead to "Out of Memory" errors. In a UserForm I had:

Public mainPicture As StdPicture
...
mainPicture = LoadPicture(PAGE_FILE)

When UserForm was destroyed (after Unload Me) the memory allocated for the data loaded in the mainPicture was not being de-allocated. I had to add an explicit

mainPicture = Nothing

in the terminate event.

How to uninstall Golang?

I'm using Ubuntu. I spent a whole morning fixing this, tried all different solutions, when I type go version, it's still there, really annoying... Finally this worked for me, hope this will help!

sudo apt-get remove golang-go
sudo apt-get remove --auto-remove golang-go

Git diff says subproject is dirty

To ignore all untracked files in any submodule use the following command to ignore those changes.

git config --global diff.ignoreSubmodules dirty

It will add the following configuration option to your local git config:

[diff]
  ignoreSubmodules = dirty

Further information can be found here

MS SQL compare dates?

SELECT CASE WHEN CAST(date1 AS DATE) <= CAST(date2 AS DATE) ...

Should do what you need.

Test Case

WITH dates(date1, date2, date3, date4)
     AS (SELECT CAST('20101231 15:13:48.593' AS DATETIME),
                CAST('20101231 00:00:00.000' AS DATETIME),
                CAST('20101231 15:13:48.593' AS DATETIME),
                CAST('20101231 00:00:00.000' AS DATETIME))
SELECT CASE
         WHEN CAST(date1 AS DATE) <= CAST(date2 AS DATE) THEN 'Y'
         ELSE 'N'
       END AS COMPARISON_WITH_CAST,
       CASE
         WHEN date3 <= date4 THEN 'Y'
         ELSE 'N'
       END AS COMPARISON_WITHOUT_CAST
FROM   dates 

Returns

COMPARISON_WITH_CAST   |  COMPARISON_WITHOUT_CAST
Y                         N

How connect Postgres to localhost server using pgAdmin on Ubuntu?

Create a user first. You must do this as user postgres. Because the postgres system account has no password assigned, you can either set a password first, or you go like this:

sudo /bin/bash
# you should be root now  
su postgres
# you are postgres now
createuser --interactive

and the programm will prompt you.

Cell Style Alignment on a range

Something that works for me. Enjoy.

Excel.Application excelApplication =  new Excel.Application()  // start excel and turn off msg boxes
{
     DisplayAlerts = false,
     Visible = false
};

Excel.Workbook workBook = excelApplication.Workbooks.Open(targetFile);
Excel.Worksheet workSheet = (Excel.Worksheet)workBook.Worksheets[1];

var rDT = workSheet.Range(workSheet.Cells[monthYearNameRow, monthYearNameCol], workSheet.Cells[monthYearNameRow, maxTableColumnIndex]);
rDT.Merge();
rDT.Value = monthName + " " + year;
var reportDateRowStyle = workBook.Styles.Add("ReportDateRowStyle");
reportDateRowStyle.HorizontalAlignment = XlHAlign.xlHAlignCenter;
reportDateRowStyle.Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Black);
reportDateRowStyle.Font.Bold = true;
reportDateRowStyle.Font.Size = 14;
rDT.Style = reportDateRowStyle;

ssh connection refused on Raspberry Pi

I think pi has ssh server enabled by default. Mine have always worked out of the box. Depends which operating system version maybe.

Most of the time when it fails for me it is because the ip address has been changed. Perhaps you are pinging something else now? Also sometimes they just refuse to connect and need a restart.

How to move child element from one parent to another using jQuery

Detach is unnecessary.

The answer (as of 2013) is simple:

$('#parentNode').append($('#childNode'));

According to http://api.jquery.com/append/

You can also select an element on the page and insert it into another:

$('.container').append($('h2'));

If an element selected this way is inserted into a single location elsewhere in the DOM, it will be moved into the target (not cloned).

How do I give text or an image a transparent background using CSS?

Opacity of background, but not the text has some ideas. Either use a semi-transparent image, or overlay an additional element.

Resize HTML5 canvas to fit window

If you're interested in preserving aspect ratios and doing so in pure CSS (given the aspect ratio) you can do something like below. The key is the padding-bottom on the ::content element that sizes the container element. This is sized relative to its parent's width, which is 100% by default. The ratio specified here has to match up with the ratio of the sizes on the canvas element.

_x000D_
_x000D_
// Javascript_x000D_
_x000D_
var canvas = document.querySelector('canvas'),_x000D_
    context = canvas.getContext('2d');_x000D_
_x000D_
context.fillStyle = '#ff0000';_x000D_
context.fillRect(500, 200, 200, 200);_x000D_
_x000D_
context.fillStyle = '#000000';_x000D_
context.font = '30px serif';_x000D_
context.fillText('This is some text that should not be distorted, just scaled', 10, 40);
_x000D_
/*CSS*/_x000D_
_x000D_
.container {_x000D_
  position: relative; _x000D_
  background-color: green;_x000D_
}_x000D_
_x000D_
.container::after {_x000D_
  content: ' ';_x000D_
  display: block;_x000D_
  padding: 0 0 50%;_x000D_
}_x000D_
_x000D_
.wrapper {_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  right: 0;_x000D_
  left: 0;_x000D_
  bottom: 0;_x000D_
}_x000D_
_x000D_
canvas {_x000D_
  width: 100%;_x000D_
  height: 100%;_x000D_
}
_x000D_
<!-- HTML -->_x000D_
_x000D_
<div class=container>_x000D_
  <div class=wrapper>_x000D_
    <canvas width=1200 height=600></canvas>  _x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Graphviz: How to go from .dot to a graph?

You can use a very good online tool for it. Here is the link dreampuf.github.io Just replace the code inside editer with your code.

How to implement oauth2 server in ASP.NET MVC 5 and WEB API 2

Gmail: OAuth

  • Goto the link
  • Login with your gmail username password
  • Click on the google menu at the top left
  • Click API Manager
  • Click on Credentials
  • Click Create Credentials and select OAuth Client
  • Select Web Application as Application type and Enter the Name-> Enter Authorised Redirect URL (Eg: http://localhost:53922/signin-google) ->Click on Create button. This will create the credentials. Pls make a note of Client ID and Secret ID. Finally click OK to close the credentials pop up.
  • Next important step is to enable the Google API. Click on Overview in the left pane.
  • Click on the Google API under Social APIs section.
  • Click Enable.

That’s all from the Google part.

Come back to your application, open App_start/Startup.Auth.cs and uncomment the following snippet

        app.UseGoogleAuthentication(new GoogleOAuth2AuthenticationOptions()
        {
            ClientId = "",
            ClientSecret = ""
        });

Update the ClientId and ClientSecret with the values from Google API credentials which you have created already.

  • Run your application
  • Click Login
  • You will see the Google button under ‘Use Another Section to log in’ section
  • Click on the Google button
  • Application will prompt you to enter the username and password
  • Enter the gmail username and password and click Sign In
  • This will perform the OAuth and come back to your application and prompting you to register with the Gmail id.
  • Click register to register the Gmail id into your application database.
  • You will see the Identity details appear in the top as normal registration
  • Try logout and login again thru Gmail. This will automatically logs you into the app.

Location Services not working in iOS 8

I add those key in InfoPlist.strings in iOS 8.4, iPad mini 2. It works too. I don't set any key, like NSLocationWhenInUseUsageDescription, in my Info.plist.


InfoPlist.strings:

"NSLocationWhenInUseUsageDescription" = "I need GPS information....";

Base on this thread, it said, as in iOS 7, can be localized in the InfoPlist.strings. In my test, those keys can be configured directly in the file InfoPlist.strings.

So the first thing you need to do is to add one or both of the > following keys to your Info.plist file:

  • NSLocationWhenInUseUsageDescription
  • NSLocationAlwaysUsageDescription

Both of these keys take a string which is a description of why you need location services. You can enter a string like “Location is required to find out where you are” which, as in iOS 7, can be localized in the InfoPlist.strings file.


UPDATE:

I think @IOS's method is better. Add key to Info.plist with empty value and add localized strings to InfoPlist.strings.

Real escape string and PDO

You should use PDO Prepare

From the link:

Calling PDO::prepare() and PDOStatement::execute() for statements that will be issued multiple times with different parameter values optimizes the performance of your application by allowing the driver to negotiate client and/or server side caching of the query plan and meta information, and helps to prevent SQL injection attacks by eliminating the need to manually quote the parameters.

How can I extract embedded fonts from a PDF as valid font files?

You have several options. All these methods work on Linux as well as on Windows or Mac OS X. However, be aware that most PDFs do not include to full, complete fontface when they have a font embedded. Mostly they include just the subset of glyphs used in the document.


Using pdftops

One of the most frequently used methods to do this on *nix systems consists of the following steps:

  1. Convert the PDF to PostScript, for example by using XPDF's pdftops (on Windows: pdftops.exe helper program.
  2. Now fonts will be embedded in .pfa (PostScript) format + you can extract them using a text editor.
  3. You may need to convert the .pfa (ASCII) to a .pfb (binary) file using the t1utils and pfa2pfb.
  4. In PDFs there are never .pfm or .afm files (font metric files) embedded (because PDF viewer have internal knowledge about these). Without these, font files are hardly usable in a visually pleasing way.

Using fontforge

Another method is to use the Free font editor FontForge:

  1. Use the "Open Font" dialogbox used when opening files.
  2. Then select "Extract from PDF" in the filter section of dialog.
  3. Select the PDF file with the font to be extracted.
  4. A "Pick a font" dialogbox opens -- select here which font to open.

Check the FontForge manual. You may need to follow a few specific steps which are not necessarily straightforward in order to save the extracted font data as a file which is re-usable.


Using mupdf

Next, MuPDF. This application comes with a utility called pdfextract (on Windows: pdfextract.exe) which can extract fonts and images from PDFs. (In case you don't know about MuPDF, which still is relatively unknown and new: "MuPDF is a Free lightweight PDF viewer and toolkit written in portable C.", written by Artifex Software developers, the same company that gave us Ghostscript.)
(Update: Newer versions of MuPDF have moved the former functionality of 'pdfextract' to the command 'mutool extract'. Download it here: mupdf.com/downloads)

Note: pdfextract.exe is a command-line program. To use it, do the following:

c:\>  pdfextract.exe  c:\path\to\filename.pdf         # (on Windows)
$>    pdfextract  /path/tofilename.pdf                # (on Linux, Unix, Mac OS X)

This command will dump all of the extractable files from the pdf file referenced into the current directory. Generally you will see a variety of files: images as well as fonts. These include PNG, TTF, CFF, CID, etc. The image names will be like img-0412.png if the PDF object number of the image was 412. The fontnames will be like FGETYK+LinLibertineI-0966.ttf, if the font's PDF object number was 966.

CFF (Compact Font Format) files are a recognized format that can be converted to other formats via a variety of converters for use on different operating systems.

Again: be aware that most of these font files may have only a subset of characters and may not represent the complete typeface.

Update: (Jul 2013) Recent versions of mupdf have seen an internal reshuffling and renaming of their binaries, not just once, but several times. The main utility used to be a 'swiss knife'-alike binary called mubusy (name inspired by busybox?), which more recently was renamed to mutool. These support the sub-commands info, clean, extract, poster and show. Unfortunatey, the official documentation for these tools isn't up to date (yet). If you're on a Mac using 'MacPorts': then the utility was renamed in order to avoid name clashes with other utilities using identical names, and you may need to use mupdfextract.

To achieve the (roughly) equivalent results with mutool as its previous tool pdfextract did, just run mubusy extract ....*

So to extract fonts and images, you may need to run one of the following commandlines:

c:\>  mutool.exe extract filename.pdf      # (on Windows)
$>    mutool     extract filename.pdf      # (on Linux, Unix, Mac OS X)

Downloads are here: mupdf.com/downloads


Using gs (Ghostscript)

Then, Ghostscript can also extract fonts directly from PDFs. However, it needs the help of a special utility program named extractFonts.ps, written in PostScript language, which is available from the Ghostscript source code repository.

Now use it, you need to run both, this file extractFonts.ps and your PDF file. Ghostscript will then use the instructions from the PostScript program to extract the fonts from the PDF. It looks like this on Windows (yes, Ghostscript understands the 'forward slash', /, as a path separator also on Windows!):

gswin32c.exe                  ^
  -q -dNODISPLAY              ^
   c:/path/to/extractFonts.ps ^
  -c "(c:/path/to/your/PDFFile.pdf) extractFonts quit"

or on Linux, Unix or Mac OS X:

gs                          \
  -q -dNODISPLAY            \
   /path/to/extractFonts.ps \
  -c "(/path/to/your/PDFFile.pdf) extractFonts quit"

I've tested the Ghostscript method a few years ago. At the time it did extract *.ttf (TrueType) just fine. I don't know if other font types will also be extracted at all, and if so, in a re-usable way. I don't know if the utility does block extracting of fonts which are marked as protected.


Using pdf-parser.py

Finally, Didier Stevens' pdf-parser.py: this one is probably not as easy to use, because you need to have some know-how about internal PDF structures. pdf-parser.py is a Python script which can do a lot of other things too. It can also decompress and extract arbitrary streams from objects, and therefore it can extract embedded font files too.

But you need to know what to look for. Let's see it with an example. I have a file named big.pdf. As a first step I use the -s parameter to search the PDF for any occurrence of the keyword FontFile (pdf-parser.py does not require a case sensitive search):

pdf-parser.py -s fontfile big.pdf

In my case, for my big1.pdf, I get this result:

obj 9 0
 Type: /FontDescriptor
 Referencing: 15 0 R
  <<   
    /Ascent 728
    /CapHeight 716
    /Descent -210 
    /Flags 32
    /FontBBox [ -665 -325 2000 1006 ]
    /FontFile2 15 0 R
    /FontName /ArialMT
    /ItalicAngle 0
    /StemV 87
    /Type /FontDescriptor
    /XHeight 519
  >>   

obj 11 0 
 Type: /FontDescriptor
 Referencing: 16 0 R
  <<   
    /Ascent 728
    /CapHeight 716
    /Descent -210 
    /Flags 262176
    /FontBBox [ -628 -376 2000 1018 ]
    /FontFile2 16 0 R
    /FontName /Arial-BoldMT
    /ItalicAngle 0
    /StemV 165
    /Type /FontDescriptor
    /XHeight 519
  >>   

It tells me that there are two instances of FontFile2 inside the PDF, and these are in PDF objects no. 15 and no. 16, respectively. Object no. 15 holds the /FontFile2 for font /ArialMT, object no. 16 holds the /FontFile2 for font /Arial-BoldMT.

To show this more clearly:

pdf-parser.py -s fontfile big1.pdf | grep -i fontfile
  /FontFile2 15 0 R
  /FontFile2 16 0 R

A quick peeking into the PDF specification reveals the the keyword /FontFile2 relates to a 'stream containing a TrueType font program' (/FontFile would relate to a 'stream containing a Type 1 font program' and /FontFile3 would relate to a 'stream containing a font program whose format is specified by the Subtype entry in the stream dictionary' {hence being either a Type1C or a CIDFontType0C subtype}.)

To look specifically at PDF object no. 15 (which holds the font /ArialMT), one can use the -o 15 parameter:

pdf-parser.py -o 15 big1.pdf

 obj 15 0
  Type: 
  Referencing: 
  Contains stream
   <<
     /Length1 778552
     /Length 1581435
     /Filter /ASCIIHexDecode
   >>

This pdf-parser.py output tells us that this object contains a stream (which it will not directly display) that has a length of 1.581.435 Bytes and is encoded ( == "compressed") with ASCIIHexEncode and needs to be decoded ( == "de-compressed" or "filtered") with the help of the standard /ASCIIHexDecode filter.

To dump any stream from an object, pdf-parser.py can be called with the -d dumpname parameter. Let's do it:

pdf-parser.py -o 15 -d dumped-data.ext big1.pdf

Our extracted data dump will be in the file named dumped-data.ext. Let's see how big it is:

ls -l dumped-data.ext
  -rw-r--r--  1 kurtpfeifle  staff  1581435 Apr 11 00:29 dumped-data.ext

Oh look, it is 1.581.435 Bytes. We saw this figure in the previous command's output. Opening this file with a text editor confirms that its content is ASCII hex encoded data.

Opening the file with a font reading tool like otfinfo (this is a part of the lcdf-typetools package) will lead to some disappointment at first:

otfinfo -i dumped-data.ext
  otfinfo: dumped-data.ext: not an OpenType font (bad magic number)

OK, this is because we did not (yet) let pdf-parser.py make use of its full magic: to dump a filtered, decoded stream. For this we have to add the -f parameter:

pdf-parser.py -o 15 -f -d dumped-data-decoded.ext big1.pdf

What's the size is this new file?

ls -l dumped-data-decoded.ext
  -rw-r--r--  1 kurtpfeifle  staff  778552 Apr 11 00:39 dumped-data-decoded.ext

Oh, look: that exact number was also already stored in the PDF object no. 15 dictionary as the value for key /Length1...

What does file think it is?

file dumped-data-decoded.ext
  dumped-data-decoded.ext: TrueType font data

What does otfinfo tell us about it?

otfinfo -i dumped-data-decoded.ext
  Family:              Arial
  Subfamily:           Regular
  Full name:           Arial
  PostScript name:     ArialMT
  Version:             Version 5.10
  Unique ID:           Monotype:Arial Regular:Version 5.10 (Microsoft)
  Designer:            Monotype Type Drawing Office - Robin Nicholas, Patricia Saunders 1982
  Manufacturer:        The Monotype Corporation
  Trademark:           Arial is a trademark of The Monotype Corporation.
  Copyright:           © 2011 The Monotype Corporation. All Rights Reserved.
  License Description: You may use this font to display and print content as permitted by
                       the license terms for the product in which this font is included.
                       You may only (i) embed this font in content as permitted by the 
                       embedding restrictions included in this font; and (ii) temporarily 
                       download this font to a printer or other output device to help
                       print content.
  Vendor ID:           TMC

So Bingo!, we have a winner: pdf-parser.py did indeed extract a valid font file for us. Given the size of this file (778.552 Bytes), it looks like this font had been embedded even completely in the PDF...

We could rename it to arial-regular.ttf and install it as such and happily make use of it.


Caveats:

  • In any case you need to follow the license that applies to the font. Some font licences do not allow free use and/or distribution. Pirating fonts is like pirating any software or other copyrighted material.

  • Most PDFs which are in the wild out there do not embed the full font anyway, but only subsets. Extracting a subset of a font is only useful in a very limited scope, if at all.

Please do also read the following about Pros and (more) Cons regarding font extraction efforts:

How to select data from 30 days?

Try this : Using this you can select date by last 30 days,

SELECT DATEADD(DAY,-30,GETDATE())

Clear dropdown using jQuery Select2

I found the answer (compliments to user780178) I was looking for in this other question:

Reset select2 value and show placeholdler

$("#customers_select").select2("val", "");

CURL to pass SSL certifcate and password

Should be:

curl --cert certificate_file.pem:password https://www.example.com/some_protected_page

How to restrict SSH users to a predefined set of commands after login?

You can also restrict keys to permissible commands (in the authorized_keys file).

I.e. the user would not log in via ssh and then have a restricted set of commands but rather would only be allowed to execute those commands via ssh (e.g. "ssh somehost bin/showlogfile")

Install specific branch from github using Npm

Another approach would be to add the following line to package.json dependencies:

"package-name": "user/repo#branch"

For example:

"dependencies": {
    ... other dependencies ...

    "react-native": "facebook/react-native#master"
}

And then do npm install or yarn install

checking if a number is divisible by 6 PHP

I see some of the other answers calling the modulo twice.

My preference is not to ask php to do the same thing more than once. For this reason, I cache the remainder.

Other devs may prefer to not generate the extra global variable or have other justifications for using modulo operator twice.

Code: (Demo)

$factor = 6;
for($x = 0; $x < 10; ++$x){  // battery of 10 tests
    $number = rand( 0 , 100 );
    echo "Number: $number Becomes: ";
    if( $remainder = $number % $factor ) {  // if not zero
        $number += $factor - $remainder;  // use cached $remainder instead of calculating again
    }
    echo "$number\n";
}

Possible Output:

Number: 80 Becomes: 84
Number: 57 Becomes: 60
Number: 94 Becomes: 96
Number: 48 Becomes: 48
Number: 80 Becomes: 84
Number: 36 Becomes: 36
Number: 17 Becomes: 18
Number: 41 Becomes: 42
Number: 3 Becomes: 6
Number: 64 Becomes: 66

how to check if a datareader is null or empty

@Joe Philllips

SQlDataReader.IsDBNull(int index) requires the ordinal number of the column. Is there a way to check for nulls using Column Name, and not it's Ordinal Number?

How to load a resource bundle from a file resource in Java?

ResourceBundle rb = ResourceBundle.getBundle("service"); //service.properties
System.out.println(rb.getString("server.dns")); //server.dns=http://....

jquery ajax function not working

Give this a go:

<form name="postcontent" id="postcontent">
    <input name="postsubmit" type="submit" id="postsubmit" value="POST"/>
    <textarea id="postdata" name="postdata" placeholder="What's Up ?"></textarea>
</form>
<script>
    (function() {
        $("#postcontent").on('submit', function(e) {
            e.preventDefault();
        $.ajax({
            type:"POST",
            url:"add_new_post.php",
            data:$("#postcontent").serialize(),
            beforeSend:function(){
                $(".post_submitting").show().html("<center><img src='images/loading.gif'/></center>");
            },success:function(response){   
                //alert(response);
                $("#return_update_msg").html(response); 
                $(".post_submitting").fadeOut(1000);                
            }
        });
   });
})();
</script>

How can I print each command before executing?

set -x is fine.

Another way to print each executed command is to use trap with DEBUG. Put this line at the beginning of your script :

trap 'echo "# $BASH_COMMAND"' DEBUG

You can find a lot of other trap usages here.

CSS text-align: center; is not centering things

Use display: block; margin: auto; it will center the div

Forms authentication timeout vs sessionState timeout

They are different things. The Forms Authentication Timeout value sets the amount of time in minutes that the authentication cookie is set to be valid, meaning, that after value number of minutes, the cookie will expire and the user will no longer be authenticated—they will be redirected to the login page automatically. The slidingExpiration=true value is basically saying that as long as the user makes a request within the timeout value, they will continue to be authenticated (more details here). If you set slidingExpiration=false the authentication cookie will expire after value number of minutes regardless of whether the user makes a request within the timeout value or not.

The SessionState timeout value sets the amount of time a Session State provider is required to hold data in memory (or whatever backing store is being used, SQL Server, OutOfProc, etc) for a particular session. For example, if you put an object in Session using the value in your example, this data will be removed after 30 minutes. The user may still be authenticated but the data in the Session may no longer be present. The Session Timeout value is always reset after every request.

Change DIV content using ajax, php and jQuery

jQuery.load()

$('#summary').load('ajax.php', function() {
  alert('Loaded.');
});

HTML img onclick Javascript

I think your error was in calling the function.

In your HTML code, onclick is calling the image() function. However, in your script the function is named imgWindow(). Try changing the onclick to imgWindow().

I don't do much JavaScript so if I have missed something, please let me know.

Good Luck!

Remove/ truncate leading zeros by javascript/jquery

You can use a regular expression that matches zeroes at the beginning of the string:

s = s.replace(/^0+/, '');

What is a thread exit code?

what happened to me is that I have multiple projects in my solution. I meant to debug project 1, however, the project 2 was set as the default starting project. I fixed this by, right click on the project and select "Set as startup project", then running debugging is fine.

Import pandas dataframe column as string not int

This probably isn't the most elegant way to do it, but it gets the job done.

In[1]: import numpy as np

In[2]: import pandas as pd

In[3]: df = pd.DataFrame(np.genfromtxt('/Users/spencerlyon2/Desktop/test.csv', dtype=str)[1:], columns=['ID'])

In[4]: df
Out[4]: 
                       ID
0  00013007854817840016671868
1  00013007854817840016749251
2  00013007854817840016754630
3  00013007854817840016781876
4  00013007854817840017028824
5  00013007854817840017963235
6  00013007854817840018860166

Just replace '/Users/spencerlyon2/Desktop/test.csv' with the path to your file

Returning JSON object as response in Spring Boot

you can also use a hashmap for this

@GetMapping
public HashMap<String, Object> get() {
    HashMap<String, Object> map = new HashMap<>();
    map.put("key1", "value1");
    map.put("results", somePOJO);
    return map;
}

How to set the max value and min value of <input> in html5 by javascript or jquery?

Try this

 $(function(){
   $("input[type='number']").prop('min',1);
   $("input[type='number']").prop('max',10);
});

Demo

Received an invalid column length from the bcp client for colid 6

I got this error message with a much more recent ssis version (vs 2015 enterprise, i think it's ssis 2016). I will comment here because this is the first reference that comes up when you google this error message. I think it happens mostly with character columns when the source character size is larger than the target character size. I got this message when I was using an ado.net input to ms sql from a teradata database. Funny because the prior oledb writes to ms sql handled all the character conversion perfectly with no coding overrides. The colid number and the a corresponding Destination Input column # you sometimes get with the colid message are worthless. It's not the column when you count down from the top of the mapping or anything like that. If I were microsoft, I'd be embarrased to give an error message that looks like it's pointing at the problem column when it isn't. I found the problem colid by making an educated guess and then changing the input to the mapping to "Ignore" and then rerun and see if the message went away. In my case and in my environment I fixed it by substr( 'ing the Teradata input to the character size of the ms sql declaration for the output column. Check and make sure your input substr propagates through all you data conversions and mappings. In my case it didn't and I had to delete all my Data Conversion's and Mappings and start over again. Again funny that OLEDB just handled it and ADO.net threw the error and had to have all this intervention to make it work. In general you should use OLEDB when your target is MS Sql.

How can I pass a Bitmap object from one activity to another

In my case, the way mentioned above didn't worked for me. Every time I put the bitmap in the intent, the 2nd activity didn't start. The same happened when I passed the bitmap as byte[].

I followed this link and it worked like a charme and very fast:

package your.packagename

import android.graphics.Bitmap;

public class CommonResources { 
      public static Bitmap photoFinishBitmap = null;
}

in my 1st acitiviy:

Constants.photoFinishBitmap = photoFinishBitmap;
Intent intent = new Intent(mContext, ImageViewerActivity.class);
startActivity(intent);

and here is the onCreate() of my 2nd Activity:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Bitmap photo = Constants.photoFinishBitmap;
    if (photo != null) {
        mViewHolder.imageViewerImage.setImageDrawable(new BitmapDrawable(getResources(), photo));
    }
}

Setting a spinner onClickListener() in Android

The following works how you want it, but it is not ideal.

public class Tester extends Activity {

    String[] vals = { "here", "are", "some", "values" };
    Spinner spinner;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        spinner = (Spinner) findViewById(R.id.spin);
        ArrayAdapter<String> ad = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, vals);
        spinner.setAdapter(ad);
        Log.i("", "" + spinner.getChildCount());
        Timer t = new Timer();
        t.schedule(new TimerTask() {

            @Override
            public void run() {
                int a = spinner.getCount();
                int b = spinner.getChildCount();
                System.out.println("Count =" + a);
                System.out.println("ChildCount =" + b);
                for (int i = 0; i < b; i++) {
                    View v = spinner.getChildAt(i);
                    if (v == null) {
                        System.out.println("View not found");
                    } else {
                        v.setOnClickListener(new View.OnClickListener() {

                            @Override
                            public void onClick(View v) {
                                        Log.i("","click");
                                        }
                        });
                    }
                }
            }
        }, 500);
    }
}

Let me know exactly how you need the spinner to behave, and we can work out a better solution.

Why does one use dependency injection?

First, I want to explain an assumption that I make for this answer. It is not always true, but quite often:

Interfaces are adjectives; classes are nouns.

(Actually, there are interfaces that are nouns as well, but I want to generalize here.)

So, e.g. an interface may be something such as IDisposable, IEnumerable or IPrintable. A class is an actual implementation of one or more of these interfaces: List or Map may both be implementations of IEnumerable.

To get the point: Often your classes depend on each other. E.g. you could have a Database class which accesses your database (hah, surprise! ;-)), but you also want this class to do logging about accessing the database. Suppose you have another class Logger, then Database has a dependency to Logger.

So far, so good.

You can model this dependency inside your Database class with the following line:

var logger = new Logger();

and everything is fine. It is fine up to the day when you realize that you need a bunch of loggers: Sometimes you want to log to the console, sometimes to the file system, sometimes using TCP/IP and a remote logging server, and so on ...

And of course you do NOT want to change all your code (meanwhile you have gazillions of it) and replace all lines

var logger = new Logger();

by:

var logger = new TcpLogger();

First, this is no fun. Second, this is error-prone. Third, this is stupid, repetitive work for a trained monkey. So what do you do?

Obviously it's a quite good idea to introduce an interface ICanLog (or similar) that is implemented by all the various loggers. So step 1 in your code is that you do:

ICanLog logger = new Logger();

Now the type inference doesn't change type any more, you always have one single interface to develop against. The next step is that you do not want to have new Logger() over and over again. So you put the reliability to create new instances to a single, central factory class, and you get code such as:

ICanLog logger = LoggerFactory.Create();

The factory itself decides what kind of logger to create. Your code doesn't care any longer, and if you want to change the type of logger being used, you change it once: Inside the factory.

Now, of course, you can generalize this factory, and make it work for any type:

ICanLog logger = TypeFactory.Create<ICanLog>();

Somewhere this TypeFactory needs configuration data which actual class to instantiate when a specific interface type is requested, so you need a mapping. Of course you can do this mapping inside your code, but then a type change means recompiling. But you could also put this mapping inside an XML file, e.g.. This allows you to change the actually used class even after compile time (!), that means dynamically, without recompiling!

To give you a useful example for this: Think of a software that does not log normally, but when your customer calls and asks for help because he has a problem, all you send to him is an updated XML config file, and now he has logging enabled, and your support can use the log files to help your customer.

And now, when you replace names a little bit, you end up with a simple implementation of a Service Locator, which is one of two patterns for Inversion of Control (since you invert control over who decides what exact class to instantiate).

All in all this reduces dependencies in your code, but now all your code has a dependency to the central, single service locator.

Dependency injection is now the next step in this line: Just get rid of this single dependency to the service locator: Instead of various classes asking the service locator for an implementation for a specific interface, you - once again - revert control over who instantiates what.

With dependency injection, your Database class now has a constructor that requires a parameter of type ICanLog:

public Database(ICanLog logger) { ... }

Now your database always has a logger to use, but it does not know any more where this logger comes from.

And this is where a DI framework comes into play: You configure your mappings once again, and then ask your DI framework to instantiate your application for you. As the Application class requires an ICanPersistData implementation, an instance of Database is injected - but for that it must first create an instance of the kind of logger which is configured for ICanLog. And so on ...

So, to cut a long story short: Dependency injection is one of two ways of how to remove dependencies in your code. It is very useful for configuration changes after compile-time, and it is a great thing for unit testing (as it makes it very easy to inject stubs and / or mocks).

In practice, there are things you can not do without a service locator (e.g., if you do not know in advance how many instances you do need of a specific interface: A DI framework always injects only one instance per parameter, but you can call a service locator inside a loop, of course), hence most often each DI framework also provides a service locator.

But basically, that's it.

P.S.: What I described here is a technique called constructor injection, there is also property injection where not constructor parameters, but properties are being used for defining and resolving dependencies. Think of property injection as an optional dependency, and of constructor injection as mandatory dependencies. But discussion on this is beyond the scope of this question.

use "netsh wlan set hostednetwork ..." to create a wifi hotspot and the authentication can't work correctly

For me, running the ad-hoc network on Windows 8.1, it was two things:

  • I had to set a static IP on my Android (under Advanced Options under where you type the Wifi password)
  • I had to use a password 8 characters long

Any IP will allow you to connect, but if you want internet access the static IP should match the subnet from the shared internet connection.

I'm not sure why I couldn't get a longer password to work, but it's worth a try. Maybe a more knowledgeable person could fill us in.

How to upload (FTP) files to server in a bash script?

if you want to use it inside a 'for' to copy the last generated files for a every-day bacakup...

j=0  
var="`find /backup/path/ -name 'something*' -type f -mtime -1`"  
#we have in $var some files with last day change date

for i in $var  
  do  
  j=$(( $j + 1 ))  
  dirname="`dirname $i`"  
  filename="`basename $i`"  
  /usr/bin/ftp -in >> /tmp/ftp.good 2>> /tmp/ftp.bad << EOF  
    open 123.456.789.012  
    user user_name passwd  
    bin  
    lcd $dirname  
    put $filename  
    quit  
  EOF      #end of ftp  
done       #end of for iteration

Change all files and folders permissions of a directory to 644/755

One approach could be using find:

for directories

find /desired_location -type d -print0 | xargs -0 chmod 0755

for files

find /desired_location -type f -print0 | xargs -0 chmod 0644

Split string by single spaces

If you are not averse to boost, boost.tokenizer is flexible enough to solve this

#include <string>
#include <iostream>
#include <boost/tokenizer.hpp>

void split_and_show(const std::string s)
{
    boost::char_separator<char> sep(" ", "", boost::keep_empty_tokens);
    boost::tokenizer<boost::char_separator<char> > tok(s, sep);
    for(auto i = tok.begin(); i!=tok.end(); ++i)
            std::cout << '"' << *i << "\"\n";
}
int main()
{
    split_and_show("This is a string");
    split_and_show("This  is a string");

}

test: https://ideone.com/mN2sR

Parse XLSX with Node and create json

Improved Version of "Josh Marinacci" answer , it will read beyond Z column (i.e. AA1).

var XLSX = require('xlsx');
var workbook = XLSX.readFile('test.xlsx');
var sheet_name_list = workbook.SheetNames;
sheet_name_list.forEach(function(y) {
    var worksheet = workbook.Sheets[y];
    var headers = {};
    var data = [];
    for(z in worksheet) {
        if(z[0] === '!') continue;
        //parse out the column, row, and value
        var tt = 0;
        for (var i = 0; i < z.length; i++) {
            if (!isNaN(z[i])) {
                tt = i;
                break;
            }
        };
        var col = z.substring(0,tt);
        var row = parseInt(z.substring(tt));
        var value = worksheet[z].v;

        //store header names
        if(row == 1 && value) {
            headers[col] = value;
            continue;
        }

        if(!data[row]) data[row]={};
        data[row][headers[col]] = value;
    }
    //drop those first two rows which are empty
    data.shift();
    data.shift();
    console.log(data);
});

SSL peer shut down incorrectly in Java

I had mutual SSL enabled on my Spring Boot app and my Jenkins pipeline was re-building the dockers, bringing the compose up and then running integration tests which failed every time with this error. I was able to test the running dockers without this SSL error every time in a standalone test on the same Jenkins machine. It turned out that server was not completely up when the tests started executing. Putting a sleep of few seconds in my bash script to allow Spring boot application to be up and running completely resolved the issue.

Numpy converting array from float to strings

If the main problem is the loss of precision when converting from a float to a string, one possible way to go is to convert the floats to the decimalS: http://docs.python.org/library/decimal.html.

In python 2.7 and higher you can directly convert a float to a decimal object.

Error message 'java.net.SocketException: socket failed: EACCES (Permission denied)'

You may need to do AndroidStudio - Build - Clean

If you updated manifest through the filesystem or Git it won't pick up the changes.

Access 2013 - Cannot open a database created with a previous version of your application

You can do all these things but the underlying problem will be incompatibility with Windows updates of library files. Eventually you will have problems again. .ocx and .dll files will be clobbered and replaced: your database will not be able to cope with the new versions and it will not build or it will malfunction unexpectedly.

How to implement endless list with RecyclerView?

Here my solution using AsyncListUtil, in the web says: Note that this class uses a single thread to load the data, so it suitable to load data from secondary storage such as disk, but not from network. but i am using odata to read the data and work fine. I miss in my example data entities and network methods. I include only the example adapter.

public class AsyncPlatoAdapter extends RecyclerView.Adapter {

    private final AsyncPlatoListUtil mAsyncListUtil;
    private final MainActivity mActivity;
    private final RecyclerView mRecyclerView;
    private final String mFilter;
    private final String mOrderby;
    private final String mExpand;

    public AsyncPlatoAdapter(String filter, String orderby, String expand, RecyclerView recyclerView, MainActivity activity) {
        mFilter = filter;
        mOrderby = orderby;
        mExpand = expand;
        mRecyclerView = recyclerView;
        mActivity = activity;
        mAsyncListUtil = new AsyncPlatoListUtil();

    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext()).
                inflate(R.layout.plato_cardview, parent, false);

        // Create a ViewHolder to find and hold these view references, and
        // register OnClick with the view holder:
        return new PlatoViewHolderAsync(itemView, this);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        final Plato item = mAsyncListUtil.getItem(position);
        PlatoViewHolderAsync vh = (PlatoViewHolderAsync) holder;
        if (item != null) {
            Integer imagen_id = item.Imagen_Id.get();
            vh.getBinding().setVariable(BR.plato, item);
            vh.getBinding().executePendingBindings();
            vh.getImage().setVisibility(View.VISIBLE);
            vh.getProgress().setVisibility(View.GONE);
            String cacheName = null;
            String urlString = null;
            if (imagen_id != null) {
                cacheName = String.format("imagenes/imagen/%d", imagen_id);
                urlString = String.format("%s/menusapi/%s", MainActivity.ROOTPATH, cacheName);
            }
            ImageHelper.downloadBitmap(mActivity, vh.getImage(), vh.getProgress(), urlString, cacheName, position);
        } else {
            vh.getBinding().setVariable(BR.plato, item);
            vh.getBinding().executePendingBindings();
            //show progress while loading.
            vh.getImage().setVisibility(View.GONE);
            vh.getProgress().setVisibility(View.VISIBLE);
        }
    }

    @Override
    public int getItemCount() {
        return mAsyncListUtil.getItemCount();
    }

    public class AsyncPlatoListUtil extends AsyncListUtil<Plato> {
        /**
         * Creates an AsyncListUtil.
         */
        public AsyncPlatoListUtil() {
            super(Plato.class, //my data class
                    10, //page size
                    new DataCallback<Plato>() {
                        @Override
                        public int refreshData() {
                            //get count calling ../$count ... odata endpoint
                            return countPlatos(mFilter, mOrderby, mExpand, mActivity);
                        }

                        @Override
                        public void fillData(Plato[] data, int startPosition, int itemCount) {
                            //get items from odata endpoint using $skip and $top
                            Platos p = loadPlatos(mFilter, mOrderby, mExpand, startPosition, itemCount, mActivity);
                            for (int i = 0; i < Math.min(itemCount, p.value.size()); i++) {
                                data[i] = p.value.get(i);
                            }

                        }
                    }, new ViewCallback() {
                        @Override
                        public void getItemRangeInto(int[] outRange) {
                            //i use LinearLayoutManager in the RecyclerView
                            LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
                            outRange[0] = layoutManager.findFirstVisibleItemPosition();
                            outRange[1] = layoutManager.findLastVisibleItemPosition();
                        }

                        @Override
                        public void onDataRefresh() {
                            mRecyclerView.getAdapter().notifyDataSetChanged();
                        }

                        @Override
                        public void onItemLoaded(int position) {
                            mRecyclerView.getAdapter().notifyItemChanged(position);
                        }
                    });
            mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                    onRangeChanged();
                }
            });
        }
    }
}

How to prevent form resubmission when page is refreshed (F5 / CTRL+R)

Use the Post/Redirect/Get pattern. http://en.wikipedia.org/wiki/Post/Redirect/Get

With my website, I will store a message in a cookie or session, redirect after the post, read the cookie/session, and then clear the value of that session or cookie variable.

All ASP.NET Web API controllers return 404

Add following line

GlobalConfiguration.Configure(WebApiConfig.Register);

in Application_Start() function in Global.ascx.cs file.

Cannot connect to repo with TortoiseSVN

You need to determine whether this is a problem with TortoiseSVN, your Subversion repository, or your network connection.

  • First of all, check your URL. I never used User-Friendly SVN, so I don't know what it does to the Apache httpd configuration. However, the standard Apache configuration for multiple repositories is usually http://<server>/svn/<module> and not http://<server>/svn/usvn/<module>. Is that /usvn/ directory suppose to be there?
    • By the way, how was Apache configured? Does User-Friendly SVN do that too, or does it merely allow you to configure the repositories? Are you using Visual-SVN, or did someone manually configure Apache httpd?
  • If the URL is correct, try pinging your Subversion server. Can you ping it from your Windows box? If not, you have a network issue. For some reason that IP address isn't even reachable from your client box.
  • Try opening a browser, and putting the URL of the Subversion repository into the window. This should work. If it does, the issue is probably with TortoiseSVN. Download a command line Subversion client, and see if you can checkout with that.
  • Try using the same URL on another box. Can you checkout from there? If so, it points to a problem with the network.

Passing enum or object through an intent (the best solution)

If you just want to send an enum you can do something like:

First declare an enum containing some value(which can be passed through intent):

 public enum MyEnum {
    ENUM_ZERO(0),
    ENUM_ONE(1),
    ENUM_TWO(2),
    ENUM_THREE(3);
    private int intValue;

    MyEnum(int intValue) {
        this.intValue = intValue;
    }

    public int getIntValue() {
        return intValue;
    }

    public static MyEnum getEnumByValue(int intValue) {
        switch (intValue) {
            case 0:
                return ENUM_ZERO;
            case 1:
                return ENUM_ONE;
            case 2:
                return ENUM_TWO;
            case 3:
                return ENUM_THREE;
            default:
                return null;
        }
    }
}

Then:

  intent.putExtra("EnumValue", MyEnum.ENUM_THREE.getIntValue());

And when you want to get it:

  NotificationController.MyEnum myEnum = NotificationController.MyEnum.getEnumByValue(intent.getIntExtra("EnumValue",-1);

Piece of cake!

How to bind DataTable to Datagrid

I'm expecting, as Rohit Vats mentioned in his Comment too, that you have a wrong structure in your DataTable.

Try something like this:

  var t = new DataTable();

  // create column header
  foreach ( string s in identifiders ) {
    t.Columns.Add(new DataColumn(s)); // <<=== i'm expecting you don't have defined any DataColumns, haven't you?
  }

  // Add data to DataTable
  for ( int lineNumber = identifierLineNumber; lineNumber < lineCount; lineNumber++ ) {
    DataRow newRow = t.NewRow();
    for ( int column = 0; column < identifierCount; column++ ) {
      newRow[column] = fileContent.ElementAt(lineNumber)[column];
    }
    t.Rows.Add(newRow);
  }

  return t.DefaultView;

I have used this DataTable in a ValueConverter and it works like a charm with the following binding.

xaml:

 <DataGrid AutoGenerateColumns="True" ItemsSource="{Binding Path=FileContent, Converter={StaticResource dataGridConverter}}" />

So what it does, the ValueConverter transforms my bounded data (what ever it is, in my case it's a List<string[]>) into a DataTable, as the code above shows, and passes this DataTable to the DataGrid. With specified data columns the data grid can generate the needed columns and visualize them.

To say it in a nutshell, in my case the binding to a DataTable works like a charm.

adb is not recognized as internal or external command on windows

You have two ways:

First go to the particular path of Android SDK:

1) Open your command prompt and traverse to the platform-tools directory through it such as

$ cd Frameworks\Android-Sdk\platform-tools

2) Run your adb commands now such as to know that your adb is working properly :

$ adb devices OR adb logcat OR simply adb

Second way is :

1) Right click on your My Computer.

2) Open Environment variables.

3) Add new variable to your System PATH variable(Add if not exist otherwise no need to add new variable if already exist).

4) Add path of platform-tools directory to as value of this variable such as C:\Program Files\android-sdk\platform-tools.

5) Restart your computer once.

6) Now run the above adb commands such adb devices or other adb commands from anywhere in command prompt.

Also on you can fire a command on terminal setx PATH "%PATH%;C:\Program Files\android-sdk\platform-tools"

Trying to detect browser close event

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />


<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>

<script type="text/javascript" language="javascript">

var validNavigation = false;

function endSession() {
// Browser or broswer tab is closed
// Do sth here ...
alert("bye");
}

function wireUpEvents() {
/*
* For a list of events that triggers onbeforeunload on IE
* check http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx
*/
window.onbeforeunload = function() {
  if (!validNavigation) {

            var ref="load";
      $.ajax({
            type: 'get',
            async: false,
            url: 'logout.php',
 data:
            {
                ref:ref               
            },
             success:function(data)
            {
                console.log(data);
            }
            });
     endSession();
  }
 }

// Attach the event keypress to exclude the F5 refresh
$(document).bind('keypress', function(e) {
if (e.keyCode == 116){
  validNavigation = true;
}
});

// Attach the event click for all links in the page
$("a").bind("click", function() {
validNavigation = true;
});

 // Attach the event submit for all forms in the page
 $("form").bind("submit", function() {
 validNavigation = true;
 });

 // Attach the event click for all inputs in the page
 $("input[type=submit]").bind("click", function() {
 validNavigation = true;
 });

}

// Wire up the events as soon as the DOM tree is ready
$(document).ready(function() {
wireUpEvents();  
}); 
</script> 

This is used for when logged in user close the browser or browser tab it will automatically logout the user account...

What does "subject" mean in certificate?

The subject of the certificate is the entity its public key is associated with (i.e. the "owner" of the certificate).

As RFC 5280 says:

The subject field identifies the entity associated with the public key stored in the subject public key field. The subject name MAY be carried in the subject field and/or the subjectAltName extension.

X.509 certificates have a Subject (Distinguished Name) field and can also have multiple names in the Subject Alternative Name extension.

The Subject DN is made of multiple relative distinguished names (RDNs) (themselves made of attribute assertion values) such as "CN=yourname" or "O=yourorganization".

In the context of the article you're linking to, the subject would be the user/owner of the cert.

Cygwin - Makefile-error: recipe for target `main.o' failed

You see the two empty -D entries in the g++ command line? They're causing the problem. You must have values in the -D items e.g. -DWIN32

if you're insistent on using something like -D$(SYSTEM) -D$(ENVIRONMENT) then you can use something like:

SYSTEM ?= generic
ENVIRONMENT ?= generic

in the makefile which gives them default values.

Your output looks to be missing the all important output:

<command-line>:0:1: error: macro names must be identifiers
<command-line>:0:1: error: macro names must be identifiers

just to clarify, what actually got sent to g++ was -D -DWindows_NT, i.e. define a preprocessor macro called -DWindows_NT; which is of course not a valid identifier (similarly for -D -I.)

How to change a Git remote on Heroku

If you have multiple applications on heroku and want to add changes to a particular application, run the following command : heroku git:remote -a appname and then run the following. 1) git add . 2)git commit -m "changes" 3)git push heroku master

How can I switch my git repository to a particular commit

All the above commands create a new branch and with the latest commit being the one specified in the command, but just in case you want your current branch HEAD to move to the specified commit, below is the command:

 git checkout <commit_hash>

It detaches and point the HEAD to specified commit and saves from creating a new branch when the user just wants to view the branch state till that particular commit.


You then might want to go back to the latest commit & fix the detached HEAD:

Fix a Git detached head?

Prevent typing non-numeric in input type number

Based on Nrzonline's answer: I fixed the problem of the multiple "." at the end of the input by adding a

let lastCharacterEntered

outside of the input and then onKeyPress

e => {
          var allowedChars = "0123456789.";
          function contains(stringValue, charValue) {
            return stringValue.indexOf(charValue) > -1;
          }
          var invalidKey =
            (e.key.length === 1 && !contains(allowedChars, e.key)) ||
            (e.key === "." && contains(e.target.value, "."));
          console.log(e.target.value);
          invalidKey && e.preventDefault();
          if (!invalidKey) {
            if (lastCharacterEntered === "." && e.key === ".") {
              e.preventDefault();
            } else {
              lastCharacterEntered = e.key;
            }
          }
        }

How to insert an image in python

Install PIL(Python Image Library) :

then:

from PIL import Image
myImage = Image.open("your_image_here");
myImage.show();

How to find out which package version is loaded in R?

You can use sessionInfo() to accomplish that.

> sessionInfo()
R version 2.15.0 (2012-03-30)
Platform: x86_64-pc-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=C                 LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] graphics  grDevices utils     datasets  stats     grid      methods   base     

other attached packages:
[1] ggplot2_0.9.0  reshape2_1.2.1 plyr_1.7.1    

loaded via a namespace (and not attached):
 [1] colorspace_1.1-1   dichromat_1.2-4    digest_0.5.2       MASS_7.3-18        memoise_0.1        munsell_0.3       
 [7] proto_0.3-9.2      RColorBrewer_1.0-5 scales_0.2.0       stringr_0.6       
> 

However, as per comments and the answer below, there are better options

> packageVersion("snow")

[1] ‘0.3.9’

Or:

"Rmpi" %in% loadedNamespaces()

Save file Javascript with file name

Use the filename property like this:

uriContent = "data:application/octet-stream;filename=filename.txt," + 
              encodeURIComponent(codeMirror.getValue());
newWindow=window.open(uriContent, 'filename.txt');

EDIT:

Apparently, there is no reliable way to do this. See: Is there any way to specify a suggested filename when using data: URI?

Get the latest record with filter in Django

last() latest()

Usign last():

ModelName.objects.last()

using latest():

ModelName.objects.latest('id')