Programs & Examples On #Exponential

Exponential can refer to a mathematics function, a curve / graph / dataset that follows the growth of that function, the exponential distribution in statistics, or a format to represent floats.

How to represent e^(-t^2) in MATLAB?

All the 3 first ways are identical. You have make sure that if t is a matrix you add . before using multiplication or the power.

for matrix:

t= [1 2 3;2 3 4;3 4 5];
tp=t.*t;
x=exp(-(t.^2));
y=exp(-(t.*t));
z=exp(-(tp));

gives the results:

x =

0.3679    0.0183    0.0001
0.0183    0.0001    0.0000
0.0001    0.0000    0.0000

y =

0.3679    0.0183    0.0001
0.0183    0.0001    0.0000
0.0001    0.0000    0.0000

z=

0.3679    0.0183    0.0001
0.0183    0.0001    0.0000
0.0001    0.0000    0.0000

And using a scalar:

p=3;
pp=p^2;
x=exp(-(p^2));
y=exp(-(p*p));
z=exp(-pp);

gives the results:

x =

1.2341e-004

y =

1.2341e-004

z =

1.2341e-004

Create a new file in git bash

Yes, it is. Just create files in the windows explorer and git automatically detects these files as currently untracked. Then add it with the command you already mentioned.

git add does not create any files. See also http://gitref.org/basic/#add

Github probably creates the file with touch and adds the file for tracking automatically. You can do this on the bash as well.

Viewing localhost website from mobile device

Know your host ip address on your lan Open cmd and type ipconfig and the if xampp the default listen port would be 80 Then for instance if 10.0.0.5 is your host ip address Type 10.0.0.5:80 from your mobile's web browser Make sure that both are connected to the same LAN However the default port that webaddress tries is 80.

Can I calculate z-score with R?

if x is a vector with raw scores then scale(x) is a vector with standardized scores.

Or manually: (x-mean(x))/sd(x)

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 23: ordinal not in range(128)

When you get a UnicodeEncodeError, it means that somewhere in your code you convert directly a byte string to a unicode one. By default in Python 2 it uses ascii encoding, and utf8 encoding in Python3 (both may fail because not every byte is valid in either encoding)

To avoid that, you must use explicit decoding.

If you may have 2 different encoding in your input file, one of them accepts any byte (say UTF8 and Latin1), you can try to first convert a string with first and use the second one if a UnicodeDecodeError occurs.

def robust_decode(bs):
    '''Takes a byte string as param and convert it into a unicode one.
First tries UTF8, and fallback to Latin1 if it fails'''
    cr = None
    try:
        cr = bs.decode('utf8')
    except UnicodeDecodeError:
        cr = bs.decode('latin1')
    return cr

If you do not know original encoding and do not care for non ascii character, you can set the optional errors parameter of the decode method to replace. Any offending byte will be replaced (from the standard library documentation):

Replace with a suitable replacement character; Python will use the official U+FFFD REPLACEMENT CHARACTER for the built-in Unicode codecs on decoding and ‘?’ on encoding.

bs.decode(errors='replace')

Java generics: multiple generic parameters?

You can declare multiple type variables on a type or method. For example, using type parameters on the method:

<P, Q> int f(Set<P>, Set<Q>) {
  return 0;
}

how to prevent "directory already exists error" in a makefile when using mkdir

A little simpler than Lars' answer:

something_needs_directory_xxx : xxx/..

and generic rule:

%/.. : ;@mkdir -p $(@D)

No touch-files to clean up or make .PRECIOUS :-)

If you want to see another little generic gmake trick, or if you're interested in non-recursive make with minimal scaffolding, you might care to check out Two more cheap gmake tricks and the other make-related posts in that blog.

Is there any simple way to convert .xls file to .csv file? (Excel)

Here's a C# method to do this. Remember to add your own error handling - this mostly assumes that things work for the sake of brevity. It's 4.0+ framework only, but that's mostly because of the optional worksheetNumber parameter. You can overload the method if you need to support earlier versions.

static void ConvertExcelToCsv(string excelFilePath, string csvOutputFile, int worksheetNumber = 1) {
   if (!File.Exists(excelFilePath)) throw new FileNotFoundException(excelFilePath);
   if (File.Exists(csvOutputFile)) throw new ArgumentException("File exists: " + csvOutputFile);

   // connection string
   var cnnStr = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=\"Excel 8.0;IMEX=1;HDR=NO\"", excelFilePath);
   var cnn = new OleDbConnection(cnnStr);

   // get schema, then data
   var dt = new DataTable();
   try {
      cnn.Open();
      var schemaTable = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
      if (schemaTable.Rows.Count < worksheetNumber) throw new ArgumentException("The worksheet number provided cannot be found in the spreadsheet");
      string worksheet = schemaTable.Rows[worksheetNumber - 1]["table_name"].ToString().Replace("'", "");
      string sql = String.Format("select * from [{0}]", worksheet);
      var da = new OleDbDataAdapter(sql, cnn);
      da.Fill(dt);
   }
   catch (Exception e) {
      // ???
      throw e;
   }
   finally {
      // free resources
      cnn.Close();
   }

   // write out CSV data
   using (var wtr = new StreamWriter(csvOutputFile)) {
      foreach (DataRow row in dt.Rows) {
         bool firstLine = true;
         foreach (DataColumn col in dt.Columns) {
            if (!firstLine) { wtr.Write(","); } else { firstLine = false; }
            var data = row[col.ColumnName].ToString().Replace("\"", "\"\"");
            wtr.Write(String.Format("\"{0}\"", data));
         }
         wtr.WriteLine();
      }
   }
}

"SetPropertiesRule" warning message when starting Tomcat from Eclipse

Make sure you have correct jsp file name in web.xml file. By replacing default .jsp filename in web.xml with my current filename solved the problem

Merge Cell values with PHPExcel - PHP

There is a specific method to do this:

$objPHPExcel->getActiveSheet()->mergeCells('A1:C1');

You can also use:

$objPHPExcel->setActiveSheetIndex(0)->mergeCells('A1:C1');

That should do the trick.

Does not contain a static 'main' method suitable for an entry point

When you want to allow paramaters to be specified from the command, they must look like this:

 [STAThread]
 static void Main(params string[] paramaters)
 {

you cannot specify more than one paramater, otherwise this will also cause the error reported above.

Variable not accessible when initialized outside function

A global variable would be best expressed in an external JavaScript file:

var system_status;

Make sure that this has not been used anywhere else. Then to access the variable on your page, just reference it as such. Say, for example, you wanted to fill in the results on a textbox,

document.getElementById("textbox1").value = system_status;

To ensure that the object exists, use the document ready feature of jQuery.

Example:

$(function() {
    $("#textbox1")[0].value = system_status;
});

default value for struct member in C

If you only use this structure for once, i.e. create a global/static variable, you can remove typedef, and initialized this variable instantly:

struct {
    int id;
    char *name;
} employee = {
    .id = 0,
    .name = "none"
};

Then, you can use employee in your code after that.

Finding what branch a Git commit came from

This simple command works like a charm:

git name-rev <SHA>

For example (where test-branch is the branch name):

git name-rev 651ad3a
251ad3a remotes/origin/test-branch

Even this is working for complex scenarios, like:

origin/branchA/
              /branchB
                      /commit<SHA1>
                                   /commit<SHA2>

Here git name-rev commit<SHA2> returns branchB.

How to get an object's property's value by property name?

You can get a property by name using the Select-Object cmdlet and specifying the property name(s) that you're interested in. Note that this doesn't simply return the raw value for that property; instead you get something that still behaves like an object.

[PS]> $property = (Get-Process)[0] | Select-Object -Property Name

[PS]> $property

Name
----
armsvc

[PS]> $property.GetType().FullName
System.Management.Automation.PSCustomObject

In order to use the value for that property, you will still need to identify which property you are after, even if there is only one property:

[PS]> $property.Name
armsvc

[PS]> $property -eq "armsvc"
False

[PS]> $property.Name -eq "armsvc"
True

[PS]> $property.Name.GetType().FullName
System.String

As per other answers here, if you want to use a single property within a string, you need to evaluate the expression (put brackets around it) and prefix with a dollar sign ($) to declare the expression dynamically as a variable to be inserted into the string:

[PS]> "The first process in the list is: $($property.Name)"
The first process in the list is: armsvc

Quite correctly, others have answered this question by recommending the -ExpandProperty parameter for the Select-Object cmdlet. This bypasses some of the headache by returning the value of the property specified, but you will want to use different approaches in different scenarios.

-ExpandProperty <String>

Specifies a property to select, and indicates that an attempt should be made to expand that property

https://technet.microsoft.com/en-us/library/hh849895.aspx

[PS]> (Get-Process)[0] | Select-Object -ExpandProperty Name
armsvc

MySQL SELECT x FROM a WHERE NOT IN ( SELECT x FROM b ) - Unexpected result

... or if you really want to use NOT IN you can use

SELECT * FROM match WHERE id NOT IN ( SELECT id FROM email WHERE id IS NOT NULL)

Difference between volatile and synchronized in Java

tl;dr:

There are 3 main issues with multithreading:

1) Race Conditions

2) Caching / stale memory

3) Complier and CPU optimisations

volatile can solve 2 & 3, but can't solve 1. synchronized/explicit locks can solve 1, 2 & 3.

Elaboration:

1) Consider this thread unsafe code:

x++;

While it may look like one operation, it's actually 3: reading the current value of x from memory, adding 1 to it, and saving it back to memory. If few threads try to do it at the same time, the result of the operation is undefined. If x originally was 1, after 2 threads operating the code it may be 2 and it may be 3, depending on which thread completed which part of the operation before control was transferred to the other thread. This is a form of race condition.

Using synchronized on a block of code makes it atomic - meaning it make it as if the 3 operations happen at once, and there's no way for another thread to come in the middle and interfere. So if x was 1, and 2 threads try to preform x++ we know in the end it will be equal to 3. So it solves the race condition problem.

synchronized (this) {
   x++; // no problem now
}

Marking x as volatile does not make x++; atomic, so it doesn't solve this problem.

2) In addition, threads have their own context - i.e. they can cache values from main memory. That means that a few threads can have copies of a variable, but they operate on their working copy without sharing the new state of the variable among other threads.

Consider that on one thread, x = 10;. And somewhat later, in another thread, x = 20;. The change in value of x might not appear in the first thread, because the other thread has saved the new value to its working memory, but hasn't copied it to the main memory. Or that it did copy it to the main memory, but the first thread hasn't updated its working copy. So if now the first thread checks if (x == 20) the answer will be false.

Marking a variable as volatile basically tells all threads to do read and write operations on main memory only. synchronized tells every thread to go update their value from main memory when they enter the block, and flush the result back to main memory when they exit the block.

Note that unlike data races, stale memory is not so easy to (re)produce, as flushes to main memory occur anyway.

3) The complier and CPU can (without any form of synchronization between threads) treat all code as single threaded. Meaning it can look at some code, that is very meaningful in a multithreading aspect, and treat it as if it’s single threaded, where it’s not so meaningful. So it can look at a code and decide, in sake of optimisation, to reorder it, or even remove parts of it completely, if it doesn’t know that this code is designed to work on multiple threads.

Consider the following code:

boolean b = false;
int x = 10;

void threadA() {
    x = 20;
    b = true;
}

void threadB() {
    if (b) {
        System.out.println(x);
    }
}

You would think that threadB could only print 20 (or not print anything at all if threadB if-check is executed before setting b to true), as b is set to true only after x is set to 20, but the compiler/CPU might decide to reorder threadA, in that case threadB could also print 10. Marking b as volatile ensures that it won’t be reordered (or discarded in certain cases). Which mean threadB could only print 20 (or nothing at all). Marking the methods as syncrhonized will achieve the same result. Also marking a variable as volatile only ensures that it won’t get reordered, but everything before/after it can still be reordered, so synchronization can be more suited in some scenarios.

Note that before Java 5 New Memory Model, volatile didn’t solve this issue.

Set margins in a LinearLayout programmatically

Try this

 LayoutParams params = new LayoutParams(
            LayoutParams.WRAP_CONTENT,      
            LayoutParams.WRAP_CONTENT
    );
    params.setMargins(left, top, right, bottom);
    yourbutton.setLayoutParams(params);

How to increase buffer size in Oracle SQL Developer to view all records?

If you are running a script, instead of a statement, you can increase this by selecting Tools/Preferences/Worksheet and increasing "Max Rows to print in a script". The default is 5000, you can change it to any size.

mappedBy reference an unknown target entity property

I know the answer by @Pascal Thivent has solved the issue. I would like to add a bit more to his answer to others who might be surfing this thread.

If you are like me in the initial days of learning and wrapping your head around the concept of using the @OneToMany annotation with the 'mappedBy' property, it also means that the other side holding the @ManyToOne annotation with the @JoinColumn is the 'owner' of this bi-directional relationship.

Also, mappedBy takes in the instance name (mCustomer in this example) of the Class variable as an input and not the Class-Type (ex:Customer) or the entity name(Ex:customer).

BONUS : Also, look into the orphanRemoval property of @OneToMany annotation. If it is set to true, then if a parent is deleted in a bi-directional relationship, Hibernate automatically deletes it's children.

"Series objects are mutable and cannot be hashed" error

Shortly: gene_name[x] is a mutable object so it cannot be hashed. To use an object as a key in a dictionary, python needs to use its hash value, and that's why you get an error.

Further explanation:

Mutable objects are objects which value can be changed. For example, list is a mutable object, since you can append to it. int is an immutable object, because you can't change it. When you do:

a = 5;
a = 3;

You don't change the value of a, you create a new object and make a point to its value.

Mutable objects cannot be hashed. See this answer.

To solve your problem, you should use immutable objects as keys in your dictionary. For example: tuple, string, int.

How to install the Raspberry Pi cross compiler on my Linux host machine?

You may use clang as well. It used to be faster than GCC, and now it is quite a stable thing. It is much easier to build clang from sources (you can really drink cup of coffee during build process).

In short:

  1. Get clang binaries (sudo apt-get install clang).. or download and build (read instructions here)
  2. Mount your raspberry rootfs (it may be the real rootfs mounted via sshfs, or an image).
  3. Compile your code:

    path/to/clang --target=arm-linux-gnueabihf --sysroot=/some/path/arm-linux-gnueabihf/sysroot my-happy-program.c -fuse-ld=lld
    

Optionally you may use legacy arm-linux-gnueabihf binutils. Then you may remove "-fuse-ld=lld" flag at the end.

Below is my cmake toolchain file.

toolchain.cmake

set(CMAKE_SYSTEM_VERSION 1)
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR arm)

# Custom toolchain-specific definitions for your project
set(PLATFORM_ARM "1")
set(PLATFORM_COMPILE_DEFS "COMPILE_GLES")

# There we go!
# Below, we specify toolchain itself!

set(TARGET_TRIPLE arm-linux-gnueabihf)

# Specify your target rootfs mount point on your compiler host machine
set(TARGET_ROOTFS /Volumes/rootfs-${TARGET_TRIPLE})

# Specify clang paths
set(LLVM_DIR /Users/stepan/projects/shared/toolchains/llvm-7.0.darwin-release-x86_64/install)
set(CLANG ${LLVM_DIR}/bin/clang)
set(CLANGXX ${LLVM_DIR}/bin/clang++)

# Specify compiler (which is clang)
set(CMAKE_C_COMPILER   ${CLANG})
set(CMAKE_CXX_COMPILER ${CLANGXX})

# Specify binutils

set (CMAKE_AR      "${LLVM_DIR}/bin/llvm-ar" CACHE FILEPATH "Archiver")
set (CMAKE_LINKER  "${LLVM_DIR}/bin/llvm-ld" CACHE FILEPATH "Linker")
set (CMAKE_NM      "${LLVM_DIR}/bin/llvm-nm" CACHE FILEPATH "NM")
set (CMAKE_OBJDUMP "${LLVM_DIR}/bin/llvm-objdump" CACHE FILEPATH "Objdump")
set (CMAKE_RANLIB  "${LLVM_DIR}/bin/llvm-ranlib" CACHE FILEPATH "ranlib")

# You may use legacy binutils though.
#set(BINUTILS /usr/local/Cellar/arm-linux-gnueabihf-binutils/2.31.1)
#set (CMAKE_AR      "${BINUTILS}/bin/${TARGET_TRIPLE}-ar" CACHE FILEPATH "Archiver")
#set (CMAKE_LINKER  "${BINUTILS}/bin/${TARGET_TRIPLE}-ld" CACHE FILEPATH "Linker")
#set (CMAKE_NM      "${BINUTILS}/bin/${TARGET_TRIPLE}-nm" CACHE FILEPATH "NM")
#set (CMAKE_OBJDUMP "${BINUTILS}/bin/${TARGET_TRIPLE}-objdump" CACHE FILEPATH "Objdump")
#set (CMAKE_RANLIB  "${BINUTILS}/bin/${TARGET_TRIPLE}-ranlib" CACHE FILEPATH "ranlib")

# Specify sysroot (almost same as rootfs)
set(CMAKE_SYSROOT ${TARGET_ROOTFS})
set(CMAKE_FIND_ROOT_PATH ${TARGET_ROOTFS})

# Specify lookup methods for cmake
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

# Sometimes you also need this:
# set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

# Specify raspberry triple
set(CROSS_FLAGS "--target=${TARGET_TRIPLE}")

# Specify other raspberry related flags
set(RASP_FLAGS "-D__STDC_CONSTANT_MACROS -D__STDC_LIMIT_MACROS")

# Gather and distribute flags specified at prev steps.
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${CROSS_FLAGS} ${RASP_FLAGS}")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CROSS_FLAGS} ${RASP_FLAGS}")

# Use clang linker. Why?
# Well, you may install custom arm-linux-gnueabihf binutils,
# but then, you also need to recompile clang, with customized triple;
# otherwise clang will try to use host 'ld' for linking,
# so... use clang linker.
set(CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=lld)

Evenly distributing n points on a sphere

edit: This does not answer the question the OP meant to ask, leaving it here in case people find it useful somehow.

We use the multiplication rule of probability, combined with infinitessimals. This results in 2 lines of code to achieve your desired result:

longitude: f = uniform([0,2pi))
azimuth:   ? = -arcsin(1 - 2*uniform([0,1]))

(defined in the following coordinate system:)

enter image description here

Your language typically has a uniform random number primitive. For example in python you can use random.random() to return a number in the range [0,1). You can multiply this number by k to get a random number in the range [0,k). Thus in python, uniform([0,2pi)) would mean random.random()*2*math.pi.


Proof

Now we can't assign ? uniformly, otherwise we'd get clumping at the poles. We wish to assign probabilities proportional to the surface area of the spherical wedge (the ? in this diagram is actually f):

enter image description here

An angular displacement df at the equator will result in a displacement of df*r. What will that displacement be at an arbitrary azimuth ?? Well, the radius from the z-axis is r*sin(?), so the arclength of that "latitude" intersecting the wedge is df * r*sin(?). Thus we calculate the cumulative distribution of the area to sample from it, by integrating the area of the slice from the south pole to the north pole.

enter image description here (where stuff=df*r)

We will now attempt to get the inverse of the CDF to sample from it: http://en.wikipedia.org/wiki/Inverse_transform_sampling

First we normalize by dividing our almost-CDF by its maximum value. This has the side-effect of cancelling out the df and r.

azimuthalCDF: cumProb = (sin(?)+1)/2 from -pi/2 to pi/2

inverseCDF: ? = -sin^(-1)(1 - 2*cumProb)

Thus:

let x by a random float in range [0,1]
? = -arcsin(1-2*x)

Transfer git repositories from GitLab to GitHub - can we, how to and pitfalls (if any)?

If you have MFA enabled on GitLab you should go to Repository Settings/Repository ->Deploy Keys and create one, then use it as login while importing repo on GitHub

In php, is 0 treated as empty?

I was wondering why nobody suggested the extremely handy Type comparison table. It answers every question about the common functions and compare operators.

A snippet:

Expression      | empty($x)
----------------+--------
$x = "";        | true    
$x = null       | true    
var $x;         | true    
$x is undefined | true    
$x = array();   | true    
$x = false;     | true    
$x = true;      | false   
$x = 1;         | false   
$x = 42;        | false   
$x = 0;         | true    
$x = -1;        | false   
$x = "1";       | false   
$x = "0";       | true    
$x = "-1";      | false   
$x = "php";     | false   
$x = "true";    | false   
$x = "false";   | false   

Along other cheatsheets, I always keep a hardcopy of this table on my desk in case I'm not sure

Trigger a Travis-CI rebuild without pushing a commit?

Please make sure to Log In to Travis first. The rebuild button doesn't appear until you're logged in. I know this is obvious, but someone just tripped on it as well ;-)

Mockito: Inject real objects into private @Autowired fields

I know this is an old question, but we were faced with the same problem when trying to inject Strings. So we invented a JUnit5/Mockito extension that does exactly what you want: https://github.com/exabrial/mockito-object-injection

EDIT:

@InjectionMap
 private Map<String, Object> injectionMap = new HashMap<>();

 @BeforeEach
 public void beforeEach() throws Exception {
  injectionMap.put("securityEnabled", Boolean.TRUE);
 }

 @AfterEach
 public void afterEach() throws Exception {
  injectionMap.clear();
 }

Redirect to specified URL on PHP script completion?

You could always just use the tag to refresh the page - or maybe just drop the necessary javascript into the page at the end that would cause the page to redirect. You could even throw that in an onload function, so once its finished, the page is redirected

<?php

  echo $htmlHeader;
  while($stuff){
    echo $stuff;
  }
  echo "<script>window.location = 'http://www.yourdomain.com'</script>";
?>

MySQL set current date in a DATETIME field on insert

Since MySQL 5.6.X you can do this:

ALTER TABLE `schema`.`users` 
CHANGE COLUMN `created` `created` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ;

That way your column will be updated with the current timestamp when a new row is inserted, or updated.

If you're using MySQL Workbench, you can just put CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP in the DEFAULT value field, like so:

enter image description here

http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-5.html

Character Limit in HTML

For the <input> element there's the maxlength attribute:

<input type="text" id="Textbox" name="Textbox" maxlength="10" />

(by the way, the type is "text", not "textbox" as others are writing), however, you have to use javascript with <textarea>s. Either way the length should be checked on the server anyway.

How to get the title of HTML page with JavaScript?

Use document.title:

_x000D_
_x000D_
console.log(document.title)
_x000D_
<title>Title test</title>
_x000D_
_x000D_
_x000D_

MDN Web Docs

How do I search for names with apostrophe in SQL Server?

Compare Names containing apostrophe in DB through Java code

String sql="select lastname  from employee where FirstName like '%"+firstName.trim().toLowerCase().replaceAll("'", "''")+"%'"

statement = conn.createStatement();
        rs=statement.executeQuery(Sql);

iterate the results.

Code formatting shortcuts in Android Studio for Operation Systems

You can use the following shortcut for code formatting: Ctrl+Alt+L

What is the difference between conversion specifiers %i and %d in formatted IO functions (*printf / *scanf)

These are identical for printf but different for scanf. For printf, both %d and %i designate a signed decimal integer. For scanf, %d and %i also means a signed integer but %i inteprets the input as a hexadecimal number if preceded by 0x and octal if preceded by 0 and otherwise interprets the input as decimal.

Auto highlight text in a textbox control

I don't know why nobody mentioned that but you can also do this, it works for me

textbox.Select(0, textbox.Text.Length)

Add Bootstrap Glyphicon to Input Box

The official method. No custom CSS required :

<form class="form-inline" role="form">
  <div class="form-group has-success has-feedback">
    <label class="control-label" for="inputSuccess4"></label>
    <input type="text" class="form-control" id="inputSuccess4">
    <span class="glyphicon glyphicon-user form-control-feedback"></span>
  </div>
</form>

DEMO : http://jsfiddle.net/yajf3b7q

This demo is based on an example in Bootstrap docs. Scroll down to "With Optional Icons" here http://getbootstrap.com/css/#forms-control-validation

enter image description here

how to display employee names starting with a and then b in sql

From A to Z:

select employee_name from employees ORDER BY employee_name ;

From Z to A:

select employee_name from employees ORDER BY employee_name desc ;

How to use a Bootstrap 3 glyphicon in an html select

I don't think the standard HTML select will display HTML content. I'd suggest checking out Bootstrap select: http://silviomoreto.github.io/bootstrap-select/

It has several options for displaying icons or other HTML markup in the select.

<select id="mySelect" data-show-icon="true">
  <option data-content="<i class='glyphicon glyphicon-cutlery'></i>">-</option>
  <option data-subtext="<i class='glyphicon glyphicon-eye-open'></i>"></option>
  <option data-subtext="<i class='glyphicon glyphicon-heart-empty'></i>"></option>
  <option data-subtext="<i class='glyphicon glyphicon-leaf'></i>"></option>
  <option data-subtext="<i class='glyphicon glyphicon-music'></i>"></option>
  <option data-subtext="<i class='glyphicon glyphicon-send'></i>"></option>
  <option data-subtext="<i class='glyphicon glyphicon-star'></i>"></option>
</select>

Here is a demo: https://www.codeply.com/go/l6ClKGBmLS

E: gnupg, gnupg2 and gnupg1 do not seem to be installed, but one of them is required for this operation

In addition to existing answers:

RUN apt-get update && apt-get install -y gnupg

-y flag agrees to terms during installation process. It is important not to break the build

Best way to serialize/unserialize objects in JavaScript?

I wrote serialijse because I faced the same problem as you.

you can find it at https://github.com/erossignon/serialijse

It can be used in nodejs or in a browser and can serve to serialize and deserialize a complex set of objects from one context (nodejs) to the other (browser) or vice-versa.

var s = require("serialijse");


var assert = require("assert");


// testing serialization of a simple javascript object with date
function testing_javascript_serialization_object_with_date() {

    var o = {
        date: new Date(),
        name: "foo"
    };
    console.log(o.name, o.date.toISOString());

    // JSON will fail as JSON doesn't preserve dates
    try {
        var jstr = JSON.stringify(o);
        var jo = JSON.parse(jstr);
        console.log(jo.name, jo.date.toISOString());
    } catch (err) {
        console.log(" JSON has failed to preserve Date during stringify/parse ");
        console.log("  and has generated the following error message", err.message);
    }
    console.log("");



    var str = s.serialize(o);
    var so = s.deserialize(str);
    console.log(" However Serialijse knows how to preserve date during serialization/deserialization :");
    console.log(so.name, so.date.toISOString());
    console.log("");
}
testing_javascript_serialization_object_with_date();


// serializing a instance of a class
function testing_javascript_serialization_instance_of_a_class() {

    function Person() {
        this.firstName = "Joe";
        this.lastName = "Doe";
        this.age = 42;
    }

    Person.prototype.fullName = function () {
        return this.firstName + " " + this.lastName;
    };


    // testing serialization using  JSON.stringify/JSON.parse
    var o = new Person();
    console.log(o.fullName(), " age=", o.age);

    try {
        var jstr = JSON.stringify(o);
        var jo = JSON.parse(jstr);
        console.log(jo.fullName(), " age=", jo.age);

    } catch (err) {
        console.log(" JSON has failed to preserve the object class ");
        console.log("  and has generated the following error message", err.message);
    }
    console.log("");

    // now testing serialization using serialijse  serialize/deserialize
    s.declarePersistable(Person);
    var str = s.serialize(o);
    var so = s.deserialize(str);

    console.log(" However Serialijse knows how to preserve object classes serialization/deserialization :");
    console.log(so.fullName(), " age=", so.age);
}
testing_javascript_serialization_instance_of_a_class();


// serializing an object with cyclic dependencies
function testing_javascript_serialization_objects_with_cyclic_dependencies() {

    var Mary = { name: "Mary", friends: [] };
    var Bob = { name: "Bob", friends: [] };

    Mary.friends.push(Bob);
    Bob.friends.push(Mary);

    var group = [ Mary, Bob];
    console.log(group);

    // testing serialization using  JSON.stringify/JSON.parse
    try {
        var jstr = JSON.stringify(group);
        var jo = JSON.parse(jstr);
        console.log(jo);

    } catch (err) {
        console.log(" JSON has failed to manage object with cyclic deps");
        console.log("  and has generated the following error message", err.message);
    }

    // now testing serialization using serialijse  serialize/deserialize
    var str = s.serialize(group);
    var so = s.deserialize(str);
    console.log(" However Serialijse knows to manage object with cyclic deps !");
    console.log(so);
    assert(so[0].friends[0] == so[1]); // Mary's friend is Bob
}
testing_javascript_serialization_objects_with_cyclic_dependencies();

Why is __dirname not defined in node REPL?

Seems like you could also do this:

__dirname=fs.realpathSync('.');

of course, dont forget fs=require('fs')

(it's not really global in node scripts exactly, its just defined on the module level)

What is "X-Content-Type-Options=nosniff"?

The X-Content-Type-Options response HTTP header is a marker used by the server to indicate that the MIME types advertised in the Content-Type headers should not be changed and be followed. This allows to opt-out of MIME type sniffing, or, in other words, it is a way to say that the webmasters knew what they were doing.

Syntax :

X-Content-Type-Options: nosniff

Directives :

nosniff Blocks a request if the requested type is 1. "style" and the MIME type is not "text/css", or 2. "script" and the MIME type is not a JavaScript MIME type.

Note: nosniff only applies to "script" and "style" types. Also applying nosniff to images turned out to be incompatible with existing web sites.

Specification :

https://fetch.spec.whatwg.org/#x-content-type-options-header

How can I reload .emacs after changing it?

If you happen to have a shell opened inside Emacs, you can also do:

. ~/.emacs

May save a few key strokes.

Class name does not name a type in C++

when you define the class A, in A.h, you explicitely say that the class has a member B.

You MUST include "B.h" in "A.h"

Webdriver findElements By xpath

The XPath turns into this:

Get me all of the div elements that have an id equal to container.

As for getting the first etc, you have two options.

Turn it into a .findElement() - this will just return the first one for you anyway.

or

To explicitly do this in XPath, you'd be looking at:

(//div[@id='container'])[1]

for the first one, for the second etc:

(//div[@id='container'])[2]

Then XPath has a special indexer, called last, which would (you guessed it) get you the last element found:

(//div[@id='container'])[last()]

Worth mentioning that XPath indexers will start from 1 not 0 like they do in most programming languages.

As for getting the parent 'node', well, you can use parent:

//div[@id='container']/parent::*

That would get the div's direct parent.

You could then go further and say I want the first *div* with an id of container, and I want his parent:

(//div[@id='container'])[1]/parent::*

Hope that helps!

New line in Sql Query

-- Access: 
SELECT CHR(13) & CHR(10) 

-- SQL Server: 
SELECT CHAR(13) + CHAR(10)

Android AudioRecord example

Here I am posting you the some code example which record good quality of sound using AudioRecord API.

Note: If you use in emulator the sound quality will not much good because we are using sample rate 8k which only supports in emulator. In device use sample rate to 44.1k for better quality.

public class Audio_Record extends Activity {
    private static final int RECORDER_SAMPLERATE = 8000;
    private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;
    private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
    private AudioRecord recorder = null;
    private Thread recordingThread = null;
    private boolean isRecording = false;

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

        setButtonHandlers();
        enableButtons(false);

        int bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,
                RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING); 
    }

    private void setButtonHandlers() {
        ((Button) findViewById(R.id.btnStart)).setOnClickListener(btnClick);
        ((Button) findViewById(R.id.btnStop)).setOnClickListener(btnClick);
    }

    private void enableButton(int id, boolean isEnable) {
        ((Button) findViewById(id)).setEnabled(isEnable);
    }

    private void enableButtons(boolean isRecording) {
        enableButton(R.id.btnStart, !isRecording);
        enableButton(R.id.btnStop, isRecording);
    }

    int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we use only 1024
    int BytesPerElement = 2; // 2 bytes in 16bit format

    private void startRecording() {

        recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
                RECORDER_SAMPLERATE, RECORDER_CHANNELS,
                RECORDER_AUDIO_ENCODING, BufferElements2Rec * BytesPerElement);

        recorder.startRecording();
        isRecording = true;
        recordingThread = new Thread(new Runnable() {
            public void run() {
                writeAudioDataToFile();
            }
        }, "AudioRecorder Thread");
        recordingThread.start();
    }

        //convert short to byte
    private byte[] short2byte(short[] sData) {
        int shortArrsize = sData.length;
        byte[] bytes = new byte[shortArrsize * 2];
        for (int i = 0; i < shortArrsize; i++) {
            bytes[i * 2] = (byte) (sData[i] & 0x00FF);
            bytes[(i * 2) + 1] = (byte) (sData[i] >> 8);
            sData[i] = 0;
        }
        return bytes;

    }

    private void writeAudioDataToFile() {
        // Write the output audio in byte

        String filePath = "/sdcard/voice8K16bitmono.pcm";
        short sData[] = new short[BufferElements2Rec];

        FileOutputStream os = null;
        try {
            os = new FileOutputStream(filePath);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        while (isRecording) {
            // gets the voice output from microphone to byte format

            recorder.read(sData, 0, BufferElements2Rec);
            System.out.println("Short writing to file" + sData.toString());
            try {
                // // writes the data to file from buffer
                // // stores the voice buffer
                byte bData[] = short2byte(sData);
                os.write(bData, 0, BufferElements2Rec * BytesPerElement);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try {
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void stopRecording() {
        // stops the recording activity
        if (null != recorder) {
            isRecording = false;
            recorder.stop();
            recorder.release();
            recorder = null;
            recordingThread = null;
        }
    }

    private View.OnClickListener btnClick = new View.OnClickListener() {
        public void onClick(View v) {
            switch (v.getId()) {
            case R.id.btnStart: {
                enableButtons(true);
                startRecording();
                break;
            }
            case R.id.btnStop: {
                enableButtons(false);
                stopRecording();
                break;
            }
            }
        }
    };

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            finish();
        }
        return super.onKeyDown(keyCode, event);
    }
}

For more detail try this AUDIORECORD BLOG.

Happy Coding !!

I can't find my git.exe file in my Github folder

The last update for "windows git" did move the git.exe file from the /bin folder to the /cmd folder. So, to use git with IDEs such as webStorm or Android Studio you can use the path :

C:\Users\<user>\AppData\Local\GitHub\PortableGit_<..numbers..>\cmd\git.exe

But if you want to have linux-like commands such as git, ssh, ls, cp under windows powerShell or cmd add to your windows PATH variables :

C:\Users\<user>\AppData\Local\GitHub\PortableGit_<...numbers...>\usr\bin

change <user> and <...numbers...> to your values and reboot!

Also, you will have to update this everytime git updates since it might change the portable folder name. If folder structure changes I will update this post.

Thx @dennisschagt for the comment above! ;)

Private pages for a private Github repo

There is an article with a working idea on how to request oAuth authorization before loading static content dynamically:

Securing Site That Runs on Github Pages With JSON Backend In Private Repository

Content should be stored in a secret GitHub repository with a viewer having read access to it. GitHub pages stores only the serving JS code.

jquery mobile background image

Here is how I scale <img> tags. If you want to make it a background image you can set it's position to absolute, place the image where you want (using the: top, bottom, left, right declarations), and set it's z-index below the rest of your page.

//simple example
.your_class_name {
    width: 100%;
    height:auto;
}
//background image example
.your_background_class_name {
    width: 100%;
    height:auto;
    top: 0px;
    left: 0px;
    z-index: -1;
    position: absolute;
}

To implement this you would simply place an image tag inside the data-role="page" element of your page(s) that has the ".your_background_class_name" class and the src attribute set to the image you want to have as your background.

I hope this helps.

How do I find the last column with data?

I think we can modify the UsedRange code from @Readify's answer above to get the last used column even if the starting columns are blank or not.

So this lColumn = ws.UsedRange.Columns.Count modified to

this lColumn = ws.UsedRange.Column + ws.UsedRange.Columns.Count - 1 will give reliable results always

enter image description here

?Sheet1.UsedRange.Column + Sheet1.UsedRange.Columns.Count - 1

Above line Yields 9 in the immediate window.

How to get root access on Android emulator?

Here is the list of commands you have to run while the emulator is running, I test this solution for an avd on Android 2.2 :

adb shell mount -o rw,remount -t yaffs2 /dev/block/mtdblock03 /system  
adb push su /system/xbin/su  
adb shell chmod 06755 /system  
adb shell chmod 06755 /system/xbin/su

It assumes that the su binary is located in the working directory. You can find su and superuser here : http://forum.xda-developers.com/showthread.php?t=682828. You need to run these commands each time you launch the emulator. You can write a script that launch the emulator and root it.

How to handle change text of span

Span does not have 'change' event by default. But you can add this event manually.

Listen to the change event of span.

$("#span1").on('change',function(){
     //Do calculation and change value of other span2,span3 here
     $("#span2").text('calculated value');
});

And wherever you change the text in span1. Trigger the change event manually.

$("#span1").text('test').trigger('change'); 

How to create Drawable from resource

Get Drawable from vector resource irrespective of, whether its vector or not:

AppCompatResources.getDrawable(context, R.drawable.icon);

Note:
ContextCompat.getDrawable(context, R.drawable.icon); will produce android.content.res.Resources$NotFoundException for vector resource.

How to restrict the selectable date ranges in Bootstrap Datepicker?

The example above can be simplify a bit. Additionally you can put date manually from keyboard instead of selecting it via datepicker only. When clearing the value you need to handle also 'on clearDate' action to remove startDate/endDate boundary:

JS file:

$(".from_date").datepicker({
    format: 'yyyy-mm-dd',
    autoclose: true,
}).on('changeDate', function (selected) {
    var startDate = new Date(selected.date.valueOf());
    $('.to_date').datepicker('setStartDate', startDate);
}).on('clearDate', function (selected) {
    $('.to_date').datepicker('setStartDate', null);
});

$(".to_date").datepicker({
    format: 'yyyy-mm-dd',
    autoclose: true,
}).on('changeDate', function (selected) {
    var endDate = new Date(selected.date.valueOf());
    $('.from_date').datepicker('setEndDate', endDate);
}).on('clearDate', function (selected) {
    $('.from_date').datepicker('setEndDate', null);
});

HTML:

<input class="from_date" placeholder="Select start date" type="text" name="from_date">
<input class="to_date" placeholder="Select end date" type="text" name="to_date">

How to combine date from one field with time from another field - MS SQL Server

This worked for me

CAST(Tbl.date as DATETIME) + CAST(Tbl.TimeFrom AS TIME)

(on SQL 2008 R2)

What's the difference between setWebViewClient vs. setWebChromeClient?

WebViewClient provides the following callback methods, with which you can interfere in how WebView makes a transition to the next content.

void doUpdateVisitedHistory (WebView view, String url, boolean isReload)
void onFormResubmission (WebView view, Message dontResend, Message resend)
void onLoadResource (WebView view, String url)
void onPageCommitVisible (WebView view, String url)
void onPageFinished (WebView view, String url)
void onPageStarted (WebView view, String url, Bitmap favicon)
void onReceivedClientCertRequest (WebView view, ClientCertRequest request)
void onReceivedError (WebView view, int errorCode, String description, String failingUrl)
void onReceivedError (WebView view, WebResourceRequest request, WebResourceError error)
void onReceivedHttpAuthRequest (WebView view, HttpAuthHandler handler, String host, String realm)
void onReceivedHttpError (WebView view, WebResourceRequest request, WebResourceResponse errorResponse)
void onReceivedLoginRequest (WebView view, String realm, String account, String args)
void onReceivedSslError (WebView view, SslErrorHandler handler, SslError error)
boolean onRenderProcessGone (WebView view, RenderProcessGoneDetail detail)
void onSafeBrowsingHit (WebView view, WebResourceRequest request, int threatType, SafeBrowsingResponse callback)
void onScaleChanged (WebView view, float oldScale, float newScale)
void onTooManyRedirects (WebView view, Message cancelMsg, Message continueMsg)
void onUnhandledKeyEvent (WebView view, KeyEvent event)
WebResourceResponse shouldInterceptRequest (WebView view, WebResourceRequest request)
WebResourceResponse shouldInterceptRequest (WebView view, String url)
boolean shouldOverrideKeyEvent (WebView view, KeyEvent event)
boolean shouldOverrideUrlLoading (WebView view, WebResourceRequest request)
boolean shouldOverrideUrlLoading (WebView view, String url)

WebChromeClient provides the following callback methods, with which your Activity or Fragment can update the surroundings of WebView.

Bitmap getDefaultVideoPoster ()
View getVideoLoadingProgressView ()
void getVisitedHistory (ValueCallback<String[]> callback)
void onCloseWindow (WebView window)
boolean onConsoleMessage (ConsoleMessage consoleMessage)
void onConsoleMessage (String message, int lineNumber, String sourceID)
boolean onCreateWindow (WebView view, boolean isDialog, boolean isUserGesture, Message resultMsg)
void onExceededDatabaseQuota (String url, String databaseIdentifier, long quota, long estimatedDatabaseSize, long totalQuota, WebStorage.QuotaUpdater quotaUpdater)
void onGeolocationPermissionsHidePrompt ()
void onGeolocationPermissionsShowPrompt (String origin, GeolocationPermissions.Callback callback)
void onHideCustomView ()
boolean onJsAlert (WebView view, String url, String message, JsResult result)
boolean onJsBeforeUnload (WebView view, String url, String message, JsResult result)
boolean onJsConfirm (WebView view, String url, String message, JsResult result)
boolean onJsPrompt (WebView view, String url, String message, String defaultValue, JsPromptResult result)
boolean onJsTimeout ()
void onPermissionRequest (PermissionRequest request)
void onPermissionRequestCanceled (PermissionRequest request)
void onProgressChanged (WebView view, int newProgress)
void onReachedMaxAppCacheSize (long requiredStorage, long quota, WebStorage.QuotaUpdater quotaUpdater)
void onReceivedIcon (WebView view, Bitmap icon)
void onReceivedTitle (WebView view, String title)
void onReceivedTouchIconUrl (WebView view, String url, boolean precomposed)
void onRequestFocus (WebView view)
void onShowCustomView (View view, int requestedOrientation, WebChromeClient.CustomViewCallback callback)
void onShowCustomView (View view, WebChromeClient.CustomViewCallback callback)
boolean onShowFileChooser (WebView webView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams)

How to extend a class in python?

Another way to extend (specifically meaning, add new methods, not change existing ones) classes, even built-in ones, is to use a preprocessor that adds the ability to extend out of/above the scope of Python itself, converting the extension to normal Python syntax before Python actually gets to see it.

I've done this to extend Python 2's str() class, for instance. str() is a particularly interesting target because of the implicit linkage to quoted data such as 'this' and 'that'.

Here's some extending code, where the only added non-Python syntax is the extend:testDottedQuad bit:

extend:testDottedQuad
def testDottedQuad(strObject):
    if not isinstance(strObject, basestring): return False
    listStrings = strObject.split('.')
    if len(listStrings) != 4: return False
    for strNum in listStrings:
        try:    val = int(strNum)
        except: return False
        if val < 0: return False
        if val > 255: return False
    return True

After which I can write in the code fed to the preprocessor:

if '192.168.1.100'.testDottedQuad():
    doSomething()

dq = '216.126.621.5'
if not dq.testDottedQuad():
    throwWarning();

dqt = ''.join(['127','.','0','.','0','.','1']).testDottedQuad()
if dqt:
    print 'well, that was fun'

The preprocessor eats that, spits out normal Python without monkeypatching, and Python does what I intended it to do.

Just as a c preprocessor adds functionality to c, so too can a Python preprocessor add functionality to Python.

My preprocessor implementation is too large for a stack overflow answer, but for those who might be interested, it is here on GitHub.

How to left align a fixed width string?

You can prefix the size requirement with - to left-justify:

sys.stdout.write("%-6s %-50s %-25s\n" % (code, name, industry))

How to create a signed APK file using Cordova command line interface?

An update to @malcubierre for Cordova 4 (and later)-

Create a file called release-signing.properties and put in APPFOLDER\platforms\android folder

Contents of the file: edit after = for all except 2nd line

storeFile=C:/yourlocation/app.keystore
storeType=jks
keyAlias=aliasname
keyPassword=aliaspass
storePassword=password

Then this command should build a release version:

cordova build android --release

UPDATE - This was not working for me Cordova 10 with android 9 - The build was replacing the release-signing.properties file. I had to make a build.json file and drop it in the appfolder, same as root. And this is the contents - replace as above:

{
"android": {
    "release": {
       "keystore": "C:/yourlocation/app.keystore",
        "storePassword": "password",
        "alias": "aliasname",
        "password" : "aliaspass",
        "keystoreType": ""
    }
}
}

Run it and it will generate one of those release-signing.properties in the android folder

How to automatically redirect HTTP to HTTPS on Apache servers?

Searched for apache redirect http to https and landed here. This is what i did on ubuntu:

1) Enable modules

sudo a2enmod rewrite
sudo a2enmod ssl

2) Edit your site config

Edit file

/etc/apache2/sites-available/000-default.conf

Content should be:

<VirtualHost *:80>
    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</VirtualHost>

<VirtualHost *:443>
    SSLEngine on
    SSLCertificateFile    <path to your crt file>
    SSLCertificateKeyFile   <path to your private key file>

    # Rest of your site config
    # ...
</VirtualHost>

3) Restart apache2

sudo service apache2 restart

Static methods - How to call a method from another method?

class.method should work.

class SomeClass:
  @classmethod
  def some_class_method(cls):
    pass

  @staticmethod
  def some_static_method():
    pass

SomeClass.some_class_method()
SomeClass.some_static_method()

Use basic authentication with jQuery and Ajax

The examples above are a bit confusing, and this is probably the best way:

$.ajaxSetup({
  headers: {
    'Authorization': "Basic " + btoa(USERNAME + ":" + PASSWORD)
  }
});

I took the above from a combination of Rico and Yossi's answer.

The btoa function Base64 encodes a string.

Where can I find the Java SDK in Linux after installing it?

This question still seems relevant, and the answer seems to be a moving target.

On my debian system (buster):

> update-java-alternatives -l
java-1.11.0-openjdk-amd64      1111       /usr/lib/jvm/java-1.11.0-openjdk-amd64

However, if you actually go look there, you'll see there are multiple directories and symbolic links placed there by the package system to simplify future maintenance.

The actual directory is java-11-openjdk-amd64, with another symlink of default-java. There is also an openjdk-11 directory, but it appears to only contain a source.zip file.

Given this, for Debian ONLY, I would guess the best value to use is /usr/lib/jvm/default-java, as this should always be valid, even if you decide to install a totally different version of java, or even switch vendors.

The normal reason to want to know the path is because some application wants it, and you probably don't want that app to break because you did an upgrade that changed version numbers.

Type converting slices of interfaces

Here is the official explanation: https://github.com/golang/go/wiki/InterfaceSlice

var dataSlice []int = foo()
var interfaceSlice []interface{} = make([]interface{}, len(dataSlice))
for i, d := range dataSlice {
    interfaceSlice[i] = d
}

mysql query result in php variable

$query="SELECT * FROM contacts";
$result=mysql_query($query);

DIV table colspan: how?

<div style="clear:both;"></div> - may do the trick in some cases; not a "colspan" but may help achieve what you are looking for...

<div id="table">
    <div class="table_row">
        <div class="table_cell1"></div>
        <div class="table_cell2"></div>
        <div class="table_cell3"></div>
    </div>
    <div class="table_row">
        <div class="table_cell1"></div>
        <div class="table_cell2"></div>
        <div class="table_cell3"></div>
    </div>

<!-- clear:both will clear any float direction to default, and
prevent the previously defined floats from affecting other elements -->
    <div style="clear:both;"></div>

    <div class="table_row">
<!-- the float is cleared, you could have 4 divs (columns) or
just one with 100% width -->
        <div class="table_cell123"></div>
    </div>
</div>

How to find most common elements of a list?

To just return a list containing the most common words:

from collections import Counter
words=["i", "love", "you", "i", "you", "a", "are", "you", "you", "fine", "green"]
most_common_words= [word for word, word_count in Counter(words).most_common(3)]
print most_common_words

this prints:

['you', 'i', 'a']

the 3 in "most_common(3)", specifies the number of items to print. Counter(words).most_common() returns a a list of tuples with each tuple having the word as the first member and the frequency as the second member.The tuples are ordered by the frequency of the word.

`most_common = [item for item in Counter(words).most_common()]
print(str(most_common))
[('you', 4), ('i', 2), ('a', 1), ('are', 1), ('green', 1), ('love',1), ('fine', 1)]`

"the word for word, word_counter in", extracts only the first member of the tuple.

How to copy a java.util.List into another java.util.List

originalArrayList.addAll(copyArrayofList);

Please keep on mind whenever using the addAll() method for copy, the contents of both the array lists (originalArrayList and copyArrayofList) references to the same objects will be added to the list so if you modify any one of them then copyArrayofList also will also reflect the same change.

If you don't want side effect then you need to copy each of element from the originalArrayList to the copyArrayofList, like using a for or while loop. for deep copy you can use below code snippet.

but one more thing you need to do, implement the Cloneable interface and override the clone() method for SomeBean class.

public static List<SomeBean> cloneList(List<SomeBean> originalArrayList) {
    List<SomeBean> copyArrayofList = new ArrayList<SomeBean>(list.size());
    for (SomeBean item : list) copyArrayofList.add(item.clone());
    return clone;
}

Prevent screen rotation on Android

Add the following to your AndroidManifest.xml

[ app > src > main > AndroidManifest.xml ]

<activity android:name=".MainActivity"
          android:configChanges="orientation"
          android:screenOrientation="portrait"/>

Example:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="xxx.zzzzzz.yyyyy">

   <uses-permission android:name="A-PERMISSION" />

   <application>
      <activity android:name=".MainActivity"
                android:screenOrientation="portrait"
                android:configChanges="orientation">
      </activity>
   </application>

</manifest>

Convert string to title case with JavaScript

here's another solution using css (and javascript, if the text you want to transform is in uppercase):

html

<span id='text'>JOHN SMITH</span>

js

var str = document.getElementById('text').innerHtml;
var return_text = str.toLowerCase();

css

#text{text-transform:capitalize;}

wkhtmltopdf: cannot connect to X server

  1. Download file from this link
  2. Extract it and move executable file(/wkhtmltox/bin/wkhtmltopdf) to /usr/bin/
  3. Rename it to wkhtmltopdf if current name is not wkhtmltopdf. So that now you have an executable at /usr/bin/wkhtmltopdf
  4. Set permissions: sudo chmod a+x /usr/bin/wkhtmltopdf
  5. Install required support packages. sudo apt-get install openssl build-essential xorg libssl-dev
  6. Now, check with wkhtmltopdf http://www.google.com test.pdf hint: detail information from this link

How to correctly assign a new string value?

The two structs are different. When you initialize the first struct, about 40 bytes of memory are allocated. When you initialize the second struct, about 10 bytesof memory are allocated. (Actual amount is architecture dependent)

You can use the string literals (string constants) to initalize character arrays. This is why

person p = {"John", "Doe",30};

works in the first example.

You cannot assign (in the conventional sense) a string in C.

The string literals you have ("John") are loaded into memory when your code executes. When you initialize an array with one of these literals, then the string is copied into a new memory location. In your second example, you are merely copying the pointer to (location of) the string literal. Doing something like:

char* string = "Hello";
*string = 'C'

might cause compile or runtime errors (I am not sure.) It is a bad idea because you are modifying the literal string "Hello" which, for example on a microcontroler, could be located in read-only memory.

Bootstrap 4 - Glyphicons migration?

It is not shipped with bootstrap 4 yet, but now Bootstrap team is developing their icon library.

https://icons.getbootstrap.com/

https://github.com/twbs/icons

Find which commit is currently checked out in Git

$ git rev-parse HEAD
273cf91b4057366a560b9ddcee8fe58d4c21e6cb

Update:

Alternatively (if you have tags):

(Good for naming a version, not very good for passing back to git.)

$ git describe
v0.1.49-localhost-ag-1-g273cf91

Or (as Mark suggested, listing here for completeness):

$ git show --oneline -s
c0235b7 Autorotate uploaded images based on EXIF orientation

SQL Server 2012 Install or add Full-text search

You can add full text to an existing instance by changing the SQL Server program in Programs and Features. Follow the steps below. You might need the original disk or ISO for the installation to complete. (Per HotN's comment: If you have SQL Server Express, make sure it is SQL Server Express With Advanced Services.)

Directions:

  1. Open the Programs and Features control panel.
  2. Select Microsoft SQL Server 2012 and click Change.
  3. When prompted to Add/Repair/Remove, select Add.
  4. Advance through the wizard until the Feature Selection screen. Then select Full-Text Search.

Step 1 Step 2

enter image description here

  1. On the Installation Type screen, select the appropriate SQL Server instance.

  2. Advance through the rest of the wizard.

Source (with screenshots): http://www.techrepublic.com/blog/networking/adding-sql-full-text-search-to-an-existing-sql-server/5546

Solutions for INSERT OR UPDATE on SQL Server

See my detailed answer to a very similar previous question

@Beau Crawford's is a good way in SQL 2005 and below, though if you're granting rep it should go to the first guy to SO it. The only problem is that for inserts it's still two IO operations.

MS Sql2008 introduces merge from the SQL:2003 standard:

merge tablename with(HOLDLOCK) as target
using (values ('new value', 'different value'))
    as source (field1, field2)
    on target.idfield = 7
when matched then
    update
    set field1 = source.field1,
        field2 = source.field2,
        ...
when not matched then
    insert ( idfield, field1, field2, ... )
    values ( 7,  source.field1, source.field2, ... )

Now it's really just one IO operation, but awful code :-(

Rails 4 LIKE query - ActiveRecord adds quotes

ActiveRecord is clever enough to know that the parameter referred to by the ? is a string, and so it encloses it in single quotes. You could as one post suggests use Ruby string interpolation to pad the string with the required % symbols. However, this might expose you to SQL-injection (which is bad). I would suggest you use the SQL CONCAT() function to prepare the string like so:

"name LIKE CONCAT('%',?,'%') OR postal_code LIKE CONCAT('%',?,'%')", search, search)

In nodeJs is there a way to loop through an array without using array size?

What you probably want is for...of, a relatively new construct built for the express purpose of enumerating the values of iterable objects:

_x000D_
_x000D_
let myArray = ["a","b","c","d"];_x000D_
for (let item of myArray) {_x000D_
  console.log(item);_x000D_
}
_x000D_
_x000D_
_x000D_

... as distinct from for...in, which enumerates property names (presumably1 numeric indices in the case of arrays). Your loop displayed unexpected results because you didn't use the property names to get the corresponding values via bracket notation... but you could have:

_x000D_
_x000D_
let myArray = ["a","b","c","d"];_x000D_
for (let key in myArray) {_x000D_
  let value =  myArray[key]; // get the value by key_x000D_
  console.log("key: %o, value: %o", key, value);_x000D_
}
_x000D_
_x000D_
_x000D_

1 Unfortunately, someone may have added enumerable properties to the array or its prototype chain which are not numeric indices... or they may have assigned an index leaving unassigned indices in the interim range. The issues are explained pretty well here. The main takeaway is that it's best to loop explicitly from 0 to array.length - 1 rather than using for...in.

So, this is not (as I'd originally thought) an academic question, i.e.:

Without regard for practicality, is it possible to avoid length when iterating over an array?

According to your comment (emphasis mine):

[...] why do I need to calculate the size of an array whereas the interpreter can know it.

You have a misguided aversion to Array.length. It's not calculated on the fly; it's updated whenever the length of the array changes. You're not going to see performance gains by avoiding it (apart from caching the array length rather than accessing the property):

loop test

Now, even if you did get some marginal performance increase, I doubt it would be enough to justify the risk of dealing with the aforementioned issues.

How to get absolute path to file in /resources folder of your project

You can use ClassLoader.getResource method to get the correct resource.

URL res = getClass().getClassLoader().getResource("abc.txt");
File file = Paths.get(res.toURI()).toFile();
String absolutePath = file.getAbsolutePath();

OR

Although this may not work all the time, a simpler solution -

You can create a File object and use getAbsolutePath method:

File file = new File("resources/abc.txt");
String absolutePath = file.getAbsolutePath();

Can I escape html special chars in javascript?

Using lodash

_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'

source code

How to Update Date and Time of Raspberry Pi With out Internet

Remember that Raspberry Pi does not have real time clock. So even you are connected to internet have to set the time every time you power on or restart.

This is how it works:

  1. Type sudo raspi-config in the Raspberry Pi command line
  2. Internationalization options
  3. Change Time Zone
  4. Select geographical area
  5. Select city or region
  6. Reboot your pi

Next thing you can set time using this command

sudo date -s "Mon Aug  12 20:14:11 UTC 2014"

More about data and time

man date

When Pi is connected to computer should have to manually set data and time

How to access private data members outside the class without making "friend"s?

http://bloglitb.blogspot.com/2010/07/access-to-private-members-thats-easy.html

this guy's blog shows you how to do it using templates. With some modifications, you can adapt this method to access a private data member, although I found it tricky despite having 10+ years experience.

I wanted to point out like everyone else, that there is an extremely few number of cases where doing this is legitimate. However, I want to point out one: I was writing unit tests for a software suite. A federal regulatory agency requires every single line of code to be exercised and tested, without modifying the original code. Due to (IMHO) poor design, a static constant was in the 'private' section, but I needed to use it in the unit test. So the method seemed to me like the best way to do it.

I'm sure the way could be simplified, and I'm sure there are other ways. I'm not posting this for the OP, since it's been 5 months, but hopefully this will be useful to some future googler.

Delete an element from a dictionary

d = {1: 2, '2': 3, 5: 7}
del d[5]
print 'd = ', d

Result: d = {1: 2, '2': 3}

How to verify if a file exists in a batch file?

Here is a good example on how to do a command if a file does or does not exist:

if exist C:\myprogram\sync\data.handler echo Now Exiting && Exit
if not exist C:\myprogram\html\data.sql Exit

We will take those three files and put it in a temporary place. After deleting the folder, it will restore those three files.

xcopy "test" "C:\temp"
xcopy "test2" "C:\temp"
del C:\myprogram\sync\
xcopy "C:\temp" "test"
xcopy "C:\temp" "test2"
del "c:\temp"

Use the XCOPY command:

xcopy "C:\myprogram\html\data.sql"  /c /d /h /e /i /y  "C:\myprogram\sync\"

I will explain what the /c /d /h /e /i /y means:

  /C           Continues copying even if errors occur.
  /D:m-d-y     Copies files changed on or after the specified date.
               If no date is given, copies only those files whose
               source time is newer than the destination time.
  /H           Copies hidden and system files also.
  /E           Copies directories and subdirectories, including empty ones.
               Same as /S /E. May be used to modify /T.
  /T           Creates directory structure, but does not copy files. Does not
               include empty directories or subdirectories. /T /E includes
  /I           If destination does not exist and copying more than one file,
               assumes that destination must be a directory.
  /Y           Suppresses prompting to confirm you want to overwrite an
               existing destination file.

`To see all the commands type`xcopy /? in cmd

Call other batch file with option sync.bat myprogram.ini.

I am not sure what you mean by this, but if you just want to open both of these files you just put the path of the file like

Path/sync.bat
Path/myprogram.ini

If it was in the Bash environment it was easy for me, but I do not know how to test if a file or folder exists and if it is a file or folder.

You are using a batch file. You mentioned earlier you have to create a .bat file to use this:

I have to create a .BAT file that does this:

How can I use ":" as an AWK field separator?

AWK works as a text interpreter that goes linewise for the whole document and that goes fieldwise for each line. Thus $1, $2...$n are references to the fields of each line ($1 is the first field, $2 is the second field, and so on...).

You can define a field separator by using the "-F" switch under the command line or within two brackets with "FS=...".

Now consider the answer of Jürgen:

echo "1: " | awk -F  ":" '/1/ {print $1}'

Above the field, boundaries are set by ":" so we have two fields $1 which is "1" and $2 which is the empty space. After comes the regular expression "/1/" that instructs the filter to output the first field only when the interpreter stumbles upon a line containing such an expression (I mean 1).

The output of the "echo" command is one line that contains "1", so the filter will work...

When dealing with the following example:

echo "1: " | awk '/1/ -F ":" {print $1}'

The syntax is messy and the interpreter chose to ignore the part F ":" and switches to the default field splitter which is the empty space, thus outputting "1:" as the first field and there will be not a second field!

The answer of Jürgen contains the good syntax...

jQuery getJSON save result into variable

$.getJSon expects a callback functions either you pass it to the callback function or in callback function assign it to global variale.

var globalJsonVar;

    $.getJSON("http://127.0.0.1:8080/horizon-update", function(json){
               //do some thing with json  or assign global variable to incoming json. 
                globalJsonVar=json;
          });

IMO best is to call the callback function. which is nicer to eyes, readability aspects.

$.getJSON("http://127.0.0.1:8080/horizon-update", callbackFuncWithData);

function callbackFuncWithData(data)
{
 // do some thing with data 
}

How to check if a value exists in an array in Ruby

array = [ 'Cat', 'Dog', 'Bird' ]
array.include?("Dog")

Method with a bool return

private bool CheckAll()
{
    if ( ....)
    {
        return true;
    }

    return false;
}

When the if-condition is false the method doesn't know what value should be returned (you probably get an error like "not all paths return a value").

As CQQL pointed out if you mean to return true when your if-condition is true you could have simply written:

private bool CheckAll()
{
    return (your_condition);
}

If you have side effects, and you want to handle them before you return, the first (long) version would be required.

How to set a value to a file input in HTML?

Define in html:

<input type="hidden" name="image" id="image"/>

In JS:

ajax.jsonRpc("/consulta/dni", 'call', {'document_number': document_number})
    .then(function (data) {
        if (data.error){
            ...;
        }
        else {
            $('#image').val(data.image);
        }
    })

After:

<input type="hidden" name="image" id="image" value="/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8U..."/>
<button type="submit">Submit</button>

How to install MinGW-w64 and MSYS2?

MSYS has not been updated a long time, MSYS2 is more active, you can download from MSYS2, it has both mingw and cygwin fork package.

To install the MinGW-w64 toolchain (Reference):

  1. Open MSYS2 shell from start menu
  2. Run pacman -Sy pacman to update the package database
  3. Re-open the shell, run pacman -Syu to update the package database and core system packages
  4. Re-open the shell, run pacman -Su to update the rest
  5. Install compiler:
    • For 32-bit target, run pacman -S mingw-w64-i686-toolchain
    • For 64-bit target, run pacman -S mingw-w64-x86_64-toolchain
  6. Select which package to install, default is all
  7. You may also need make, run pacman -S make

How to use Select2 with JSON via Ajax request?

In Version 4.0.2 slightly different Just in processResults and in result :

    processResults: function (data) {
        return {
            results: $.map(data.items, function (item) {
                return {
                    text: item.tag_value,
                    id: item.tag_id
                }
            })
        };
    }

You must add data.items in result. items is Json name :

{
  "items": [
    {"id": 1,"name": "Tetris","full_name": "s9xie/hed"},
    {"id": 2,"name": "Tetrisf","full_name": "s9xie/hed"}
  ]
}

Java/Groovy - simple date reformatting

Your DateFormat pattern does not match you input date String. You could use

new SimpleDateFormat("dd-MMM-yyyy")

Why does the PHP json_encode function convert UTF-8 strings to hexadecimal entities?

Is this the expected behavior?

the json_encode() only works with UTF-8 encoded data.

maybe you can get an answer to convert it here: cyrillic-characters-in-phps-json-encode

What is the best way to remove a table row with jQuery?

I appreciate this is an old post, but I was looking to do the same, and found the accepted answer didn't work for me. Assuming JQuery has moved on since this was written.

Anyhow, I found the following worked for me:

$('#resultstbl tr[id=nameoftr]').remove();

Not sure if this helps anyone. My example above was part of a larger function so not wrapped it in an event listener.

Only on Firefox "Loading failed for the <script> with source"

I ran in the same situation and the script was correctly loading in safe mode. However, disabling all the Add-ons and other Firefox security features didn't help. One thing I tried, and this was the solution in my case, was to temporary disable the cache from the developer window for this particular request. After I saw this was the cause, I wiped out the cache for that site and everything started word normally.

MySQL select with CONCAT condition

There is an alternative to repeating the CONCAT expression or using subqueries. You can make use of the HAVING clause, which recognizes column aliases.

SELECT 
  neededfield, CONCAT(firstname, ' ', lastname) AS firstlast 
FROM
  users 
HAVING firstlast = "Bob Michael Jones"

Here is a working SQL Fiddle.

Configuring Git over SSH to login once

Had a similar problem with the GitHub because I was using HTTPS protocol. To check what protocol you're using just run

git config -l

and look at the line starting with remote.origin.url. To switch your protocol

git config remote.origin.url [email protected]:your_username/your_project.git

Show how many characters remaining in a HTML text box using JavaScript

Try the following code for instance:

working code in jsfiddle.net

For textArea, use this:

<textarea id="txtBox"></textarea>
...
...

For textBox, use this:

<input type="text" id="txtBox"/>
<br>
<input type="text" id="counterBox"/>
<script>
 var txtBoxRef = document.querySelector("#txtBox");
 var counterRef = document.querySelector("#counterBox");
 txtBoxRef.addEventListener("keydown",function(){
  var remLength = 0;
  remLength = 160 - parseInt(txtBoxRef.value.length);
  if(remLength < 0)
   {
    txtBoxRef.value = txtBoxRef.value.substring(0, 160);
    return false;
   }
  counterRef.value = remLength + " characters remaining...";
 },true);
</script>

Hope this Helps!

Get the latest record from mongodb collection

If you are using auto-generated Mongo Object Ids in your document, it contains timestamp in it as first 4 bytes using which latest doc inserted into the collection could be found out. I understand this is an old question, but if someone is still ending up here looking for one more alternative.

db.collectionName.aggregate(
[{$group: {_id: null, latestDocId: { $max: "$_id"}}}, {$project: {_id: 0, latestDocId: 1}}])

Above query would give the _id for the latest doc inserted into the collection

In C#, why is String a reference type that behaves like a value type?

This is a late answer to an old question, but all other answers are missing the point, which is that .NET did not have generics until .NET 2.0 in 2005.

String is a reference type instead of a value type because it was of crucial importance for Microsoft to ensure that strings could be stored in the most efficient way in non-generic collections, such as System.Collections.ArrayList.

Storing a value-type in a non-generic collection requires a special conversion to the type object which is called boxing. When the CLR boxes a value type, it wraps the value inside a System.Object and stores it on the managed heap.

Reading the value from the collection requires the inverse operation which is called unboxing.

Both boxing and unboxing have non-negligible cost: boxing requires an additional allocation, unboxing requires type checking.

Some answers claim incorrectly that string could never have been implemented as a value type because its size is variable. Actually it is easy to implement string as a fixed-length data structure containing two fields: an integer for the length of the string, and a pointer to a char array. You can also use a Small String Optimization strategy on top of that.

If generics had existed from day one I guess having string as a value type would probably have been a better solution, with simpler semantics, better memory usage and better cache locality. A List<string> containing only small strings could have been a single contiguous block of memory.

How to copy and edit files in Android shell?

Android supports the dd command.

dd if=/path/file of=/path/file

SQL select * from column where year = 2010

its just simple

  select * from myTable where year(columnX) = 2010

How to pass a URI to an intent?

here how I use it; This button inside my CameraActionActivity Activity class where I call camera

 btn_frag_camera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intenImatToSec = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
                startActivityForResult(intenImatToSec, REQUEST_CODE_VIDEO);
                //intenImatToSec.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
                //intenImatToSec.putExtra(MediaStore.EXTRA_DURATION_LIMIT, 10);
                //Toast.makeText(getActivity(), "Hello From Camera", Toast.LENGTH_SHORT).show();
            }
        });



@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {

            if (requestCode == REQUEST_CODE_IMG) {
                Bundle bundle = data.getExtras();
                Bitmap bitmap = (Bitmap) bundle.get("data");
                Intent intentBitMap = new Intent(getActivity(), DisplayImage.class);
                // aldigimiz imagi burda yonlendirdigimiz sinifa iletiyoruz
                ByteArrayOutputStream _bs = new ByteArrayOutputStream();
                bitmap.compress(Bitmap.CompressFormat.PNG, 50, _bs);
                intentBitMap.putExtra("byteArray", _bs.toByteArray());
                startActivity(intentBitMap);

            } else if (requestCode == REQUEST_CODE_VIDEO) {
                Uri videoUrl = data.getData();
                Intent intenToDisplayVideo = new Intent(getActivity(), DisplayVideo.class);
                intenToDisplayVideo.putExtra("videoUri", videoUrl.toString());
                startActivity(intenToDisplayVideo);
            }
        }
    }

And my other DisplayVideo Activity Class

VideoView videoView = (VideoView) findViewById(R.id.videoview_display_video_actvity);
Bundle extras = getIntent().getExtras();
        Uri myUri=  Uri.parse(extras.getString("videoUri"));
        videoView.setVideoURI(myUri);

List columns with indexes in PostgreSQL

Create some test data...

create table test (a int, b int, c int, constraint pk_test primary key(a, b));
create table test2 (a int, b int, c int, constraint uk_test2 unique (b, c));
create table test3 (a int, b int, c int, constraint uk_test3b unique (b), constraint uk_test3c unique (c),constraint uk_test3ab unique (a, b));

List indexes and columns indexed:

select
    t.relname as table_name,
    i.relname as index_name,
    a.attname as column_name
from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname like 'test%'
order by
    t.relname,
    i.relname;

 table_name | index_name | column_name
------------+------------+-------------
 test       | pk_test    | a
 test       | pk_test    | b
 test2      | uk_test2   | b
 test2      | uk_test2   | c
 test3      | uk_test3ab | a
 test3      | uk_test3ab | b
 test3      | uk_test3b  | b
 test3      | uk_test3c  | c

Roll up the column names:

select
    t.relname as table_name,
    i.relname as index_name,
    array_to_string(array_agg(a.attname), ', ') as column_names
from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname like 'test%'
group by
    t.relname,
    i.relname
order by
    t.relname,
    i.relname;

 table_name | index_name | column_names
------------+------------+--------------
 test       | pk_test    | a, b
 test2      | uk_test2   | b, c
 test3      | uk_test3ab | a, b
 test3      | uk_test3b  | b
 test3      | uk_test3c  | c

How to change context root of a dynamic web project in Eclipse?

I'm sure you've moved on by now, but I thought I'd answer anyway.

Some of these answers give workarounds. What actually must happen is that you clean and re-publish your project to "activate" the new URI. This is done by right-clicking your server (in the Servers view) and choosing Clean. Then you start (or restart it). Most of the other answers here suggest you do things that in effect accomplish this.

The file that's changing is workspace/.metadata/.plugins/org.eclipse.wst.server.core/publish/publish.dat unless, that is, you've got more than one server in your workspace in which case it will be publishN.dat on that same path.

Hope this helps somebody.


Not sure if this is proper etiquette or not — I am editing this answer to give exact steps for Eclipse Indigo.

  1. In your project's Properties, choose Web Project Settings.

  2. Change Context root to app.

    screen shot of Eclipse project properties Web Project Settings

  3. Choose Window > Show View > Servers.

  4. Stop the server by either clicking the red square box ("Stop the server" tooltip) or context-click on the server listing to choose "Stop".

  5. On the server you want to use, context-click to choose "Clean…".

    enter image description here

  6. Click OK in this confirmation dialog box.

    Screenshot of dialog asking to update server configuration to match the changed context root

Now you can run your app with the new "app" URL such as:

http://localhost:8080/app/

Doing this outside of Eclipse, on your production server, is even easier --> Rename the war file. Export your Vaadin app as a WAR file (File > Export > Web > WAR file). Move the WAR file to your web server's servlet container such as Tomcat. Rename your WAR file, in this case to app.war. When you start the servlet container, most such as Tomcat will auto-deploy the app, which includes expanding the war file to a folder. In this case, we should see a folder named app. You should be good to go. Test your URL. For a domain such as *example.com" this would be:

http://www.example.com/app/

Vaadin toolkit programmers may need to rebuild their widget set if using visual add ons.

How to get number of rows using SqlDataReader in C#

There are only two options:

  • Find out by reading all rows (and then you might as well store them)

  • run a specialized SELECT COUNT(*) query beforehand.

Going twice through the DataReader loop is really expensive, you would have to re-execute the query.

And (thanks to Pete OHanlon) the second option is only concurrency-safe when you use a transaction with a Snapshot isolation level.

Since you want to end up storing all rows in memory anyway the only sensible option is to read all rows in a flexible storage (List<> or DataTable) and then copy the data to any format you want. The in-memory operation will always be much more efficient.

How to pass data to view in Laravel?

You can also write for passing multiple data from your controller to a view

 return \View::make('myHome')
            ->with(compact('project'))
            ->with(['hello'=>$hello])
            ->with(['hello2'=>$hello2])
            ->with(['hello3'=>$hello3]);

typeof operator in C

It is a C extension from the GCC compiler , see http://gcc.gnu.org/onlinedocs/gcc/Typeof.html

Converting Varchar Value to Integer/Decimal Value in SQL Server

You can use it without casting such as:

select sum(`stuff`) as mySum from test;

Or cast it to decimal:

select sum(cast(`stuff` as decimal(4,2))) as mySum from test;

SQLFiddle

EDIT

For SQL Server, you can use:

select sum(cast(stuff as decimal(5,2))) as mySum from test;

SQLFiddle

how to align img inside the div to the right?

<style type="text/css">
>> .imgTop {
>>  display: block;
>>  text-align: right;
>>  }
>> </style>

<img class="imgTop" src="imgName.gif" alt="image description" height="100" width="100">

launch sms application with an intent

I use:

Intent sendIntent = new Intent(Intent.ACTION_MAIN);
sendIntent.putExtra("sms_body", "text");
sendIntent.setType("vnd.android-dir/mms-sms");
startActivity(sendIntent);

Task<> does not contain a definition for 'GetAwaiter'

I had this problem because I was calling a method

await myClass.myStaticMethod(myString);

but I was setting myString with

var myString = String.Format({some dynamic-type values})

which resulted in a dynamic type, not a string, thus when I tried to await on myClass.myStaticMethod(myString), the compiler thought I meant to call myClass.myStaticMethod(dynamic myString). This compiled fine because, again, in a dynamic context, it's all good until it blows up at run-time, which is what happened because there is no implementation of the dynamic version of myStaticMethod, and this error message didn't help whatsoever, and the fact that Intellisense would take me to the correct definition didn't help either.
Tricky!

However, by forcing the result type to string, like:

var myString = String.Format({some dynamic-type values})

to

string myString = String.Format({some dynamic-type values})

my call to myStaticMethod routed properly

How can I change the image displayed in a UIImageView programmatically?

Following Jordan's advice (which should work actually), try to set the UIImageView to be visible:

 [imageView setHidden: NO];

and also - don't forget to attach it to the main UIView:

[mainView addSubview: imageView];

and to bring to the front:

[mainView bringSubviewToFront: imageView];

Hope combining all these steps will help you solve the mystery.

Selenium Webdriver move mouse to Point

Using MoveToElement you will be able to find or click in whatever point you want, you have just to define the first parameter, it can be the session(winappdriver) or driver(in other ways) which is created when you instance WindowsDriver. Otherwise you can set as first parameter a grid (my case), a list, a panel or whatever you want.

Note: The top-left of your first parameter element will be the position X = 0 and Y = 0

   Actions actions = new Actions(this.session);
    int xPosition = this.session.FindElementsByAccessibilityId("GraphicView")[0].Size.Width - 530;
    int yPosition = this.session.FindElementsByAccessibilityId("GraphicView")[0].Size.Height- 150;
    actions.MoveToElement(this.xecuteClientSession.FindElementsByAccessibilityId("GraphicView")[0], xPosition, yPosition).ContextClick().Build().Perform();

Storyboard doesn't contain a view controller with identifier

Identity located in Identity Inspector tab named Storyboard ID for Xcode 6.3.2 and checked Use Storyboard ID option. enter image description here

How to exit a 'git status' list in a terminal?

Before pressing exit commands(q, etc..) check current input language: if it isn't English commands may not work.

Specify the date format in XMLGregorianCalendar

Much simpler using only SimpleDateFormat, without passing all the parameters individual:

    String FORMATER = "yyyy-MM-dd'T'HH:mm:ss'Z'";

    DateFormat format = new SimpleDateFormat(FORMATER);

    Date date = new Date();
    XMLGregorianCalendar gDateFormatted =
        DatatypeFactory.newInstance().newXMLGregorianCalendar(format.format(date));

Full example here.

Note: This is working only to remove the last 2 fields: milliseconds and timezone or to remove the entire time component using formatter yyyy-MM-dd.

Annotations from javax.validation.constraints not working

I come here some years after, and I could fix it thanks to atrain's comment above. In my case, I was missing @Valid in the API that receives the Object (a POJO in my case) that was annotated with @Size. It solved the issue.

I did not need to add any extra annotation, such as @Valid or @NotBlank to the variable annotated with @Size, just that constraint in the variable and what I mentioned in the API...

Pojo Class:

...
@Size(min = MIN_LENGTH, max = MAX_LENGTH);
private String exampleVar;
...

API Class:

...
public void exampleApiCall(@RequestBody @Valid PojoObject pojoObject){
  ...
}

Thanks and cheers

How to change color of Android ListView separator line?

using programetically

           // Set ListView divider color
            lv.setDivider(new ColorDrawable(Color.parseColor("#FF4A4D93")));

            // set ListView divider height
            lv.setDividerHeight(2);

using xml

<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">

  <ListView 
    android:id="@+id/android:list"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:divider="#44CC00"
    android:dividerHeight="4px"/>

</LinearLayout>

Python; urllib error: AttributeError: 'bytes' object has no attribute 'read'

Try this:

jsonResponse = json.loads(response.decode('utf-8'))

graphing an equation with matplotlib

This is because in line

graph(x**3+2*x-4, range(-10, 11))

x is not defined.

The easiest way is to pass the function you want to plot as a string and use eval to evaluate it as an expression.

So your code with minimal modifications will be

import numpy as np  
import matplotlib.pyplot as plt  
def graph(formula, x_range):  
    x = np.array(x_range)  
    y = eval(formula)
    plt.plot(x, y)  
    plt.show()

and you can call it as

graph('x**3+2*x-4', range(-10, 11))

Getting the difference between two sets

If you use Guava (former Google Collections) library there is a solution:

SetView<Number> difference = com.google.common.collect.Sets.difference(test2, test1);

The returned SetView is a Set, it is a live representation you can either make immutable or copy to another set. test1 and test2 are left intact.

How to move certain commits to be based on another branch in git?

This is a classic case of rebase --onto:

 # let's go to current master (X, where quickfix2 should begin)
 git checkout master

 # replay every commit *after* quickfix1 up to quickfix2 HEAD.
 git rebase --onto master quickfix1 quickfix2 

So you should go from

o-o-X (master HEAD)
     \ 
      q1a--q1b (quickfix1 HEAD)
              \
               q2a--q2b (quickfix2 HEAD)

to:

      q2a'--q2b' (new quickfix2 HEAD)
     /
o-o-X (master HEAD)
     \ 
      q1a--q1b (quickfix1 HEAD)

This is best done on a clean working tree.
See git config --global rebase.autostash true, especially after Git 2.10.

Bootstrap: how do I change the width of the container?

Add these piece of CSS in your css styling. Its better to add this after the bootstrap css file is added in order to overwrite the same.

html, body {
 height: 100%;
 max-width: 100%;
 overflow-x: hidden;
}`

What do Push and Pop mean for Stacks?

  • push = add to the stack
  • pop = remove from the stack

Returning a value from callback function in Node.js

Its undefined because, console.log(response) runs before doCall(urlToCall); is finished. You have to pass in a callback function aswell, that runs when your request is done.

First, your function. Pass it a callback:

function doCall(urlToCall, callback) {
    urllib.request(urlToCall, { wd: 'nodejs' }, function (err, data, response) {                              
        var statusCode = response.statusCode;
        finalData = getResponseJson(statusCode, data.toString());
        return callback(finalData);
    });
}

Now:

var urlToCall = "http://myUrlToCall";
doCall(urlToCall, function(response){
    // Here you have access to your variable
    console.log(response);
})

@Rodrigo, posted a good resource in the comments. Read about callbacks in node and how they work. Remember, it is asynchronous code.

Instance member cannot be used on type

Sometimes Xcode when overrides methods adds class func instead of just func. Then in static method you can't see instance properties. It is very easy to overlook it. That was my case.

enter image description here

How can I create keystore from an existing certificate (abc.crt) and abc.key files?

If the keystore is for tomcat then, after creating the keystore with the above answers, you must add a final step to create the "tomcat" alias for the key:

keytool -changealias -alias "1" -destalias "tomcat" -keystore keystore-file.jks

You can check the result with:

keytool -list -keystore keystore-file.jks -v

How can I autoformat/indent C code in vim?

I find that clang-format works well.

There are some example keybindings in the clang documentation

I prefer to use the equalprg binding in vim. This allows you to invoke clang-format with G=gg or other = indent options.

Just put the following in your .vimrc file:

autocmd FileType c,cpp setlocal equalprg=clang-format

IOException: Too many open files

Don't know the nature of your app, but I have seen this error manifested multiple times because of a connection pool leak, so that would be worth checking out. On Linux, socket connections consume file descriptors as well as file system files. Just a thought.

Best way to add Gradle support to IntelliJ Project

To add to other answers. For me it was helpful to delete .mvn directory and then add build.gradle. New versions of IntelliJ will then automatically notice that you use Gradle.

Visual Studio build fails: unable to copy exe-file from obj\debug to bin\debug

I also had a problem very similar to this and found the reason in my case was that I had made the bin\debug folder available as a shared folder under VMware and either VMware, Explorer under the VM guest, or maybe even an anti-virus program under the guest (though I don't think I had one installed) was holding a handle to the file(s).

Read input numbers separated by spaces

I would recommend reading in the line into a string, then splitting it based on the spaces. For this, you can use the getline(...) function. The trick is having a dynamic sized data structure to hold the strings once it's split. Probably the easiest to use would be a vector.

#include <string>
#include <vector>
...
  string rawInput;
  vector<String> numbers;
  while( getline( cin, rawInput, ' ' ) )
  {
    numbers.push_back(rawInput);
  }

So say the input looks like this:

Enter a number, or numbers separated by a space, between 1 and 1000.
10 5 20 1 200 7

You will now have a vector, numbers, that contains the elements: {"10","5","20","1","200","7"}.

Note that these are still strings, so not useful in arithmetic. To convert them to integers, we use a combination of the STL function, atoi(...), and because atoi requires a c-string instead of a c++ style string, we use the string class' c_str() member function.

while(!numbers.empty())
{
  string temp = numbers.pop_back();//removes the last element from the string
  num = atoi( temp.c_str() ); //re-used your 'num' variable from your code

  ...//do stuff
}

Now there's some problems with this code. Yes, it runs, but it is kind of clunky, and it puts the numbers out in reverse order. Lets re-write it so that it is a little more compact:

#include <string>
...
string rawInput;
cout << "Enter a number, or numbers separated by a space, between 1 and 1000." << endl;
while( getline( cin, rawInput, ' ') )
{
  num = atoi( rawInput.c_str() );
  ...//do your stuff
}

There's still lots of room for improvement with error handling (right now if you enter a non-number the program will crash), and there's infinitely more ways to actually handle the input to get it in a usable number form (the joys of programming!), but that should give you a comprehensive start. :)

Note: I had the reference pages as links, but I cannot post more than two since I have less than 15 posts :/

Edit: I was a little bit wrong about the atoi behavior; I confused it with Java's string->Integer conversions which throw a Not-A-Number exception when given a string that isn't a number, and then crashes the program if the exception isn't handled. atoi(), on the other hand, returns 0, which is not as helpful because what if 0 is the number they entered? Let's make use of the isdigit(...) function. An important thing to note here is that c++ style strings can be accessed like an array, meaning rawInput[0] is the first character in the string all the way up to rawInput[length - 1].

#include <string>
#include <ctype.h>
...
string rawInput;
cout << "Enter a number, or numbers separated by a space, between 1 and 1000." << endl;
while( getline( cin, rawInput, ' ') )
{
  bool isNum = true;
  for(int i = 0; i < rawInput.length() && isNum; ++i)
  {
    isNum = isdigit( rawInput[i]);
  }

  if(isNum)
  {
    num = atoi( rawInput.c_str() );
    ...//do your stuff
  }
  else
    cout << rawInput << " is not a number!" << endl;
}

The boolean (true/false or 1/0 respectively) is used as a flag for the for-loop, which steps through each character in the string and checks to see if it is a 0-9 digit. If any character in the string is not a digit, the loop will break during it's next execution when it gets to the condition "&& isNum" (assuming you've covered loops already). Then after the loop, isNum is used to determine whether to do your stuff, or to print the error message.

Jenkins pipeline if else not working

        if ( params.build_deploy == '1' ) {
            println "build_deploy ? ${params.build_deploy}"
              jobB = build job: 'k8s-core-user_deploy', propagate: false, wait: true, parameters: [
                         string(name:'environment', value: "${params.environment}"),
                         string(name:'branch_name', value: "${params.branch_name}"),
                         string(name:'service_name', value: "${params.service_name}"),                      
                     ]
            println jobB.getResult()
        }

get basic SQL Server table structure information

Name and datatype:

USE OurDatabaseName
GO

SELECT 
    sc.name AS [Columne Name], 
    st1.name AS [User Type],
    st2.name AS [Base Type]
FROM dbo.syscolumns sc
    INNER JOIN dbo.systypes st1 ON st1.xusertype = sc.xusertype
    INNER JOIN dbo.systypes st2 ON st2.xusertype = sc.xtype
-- STEP TWO: Change OurTableName to the table name
WHERE sc.id = OBJECT_ID('OurTableName')
ORDER BY sc.colid

Or:

SELECT COLUMN_NAME AS ColumnName, DATA_TYPE AS DataType, CHARACTER_MAXIMUM_LENGTH AS CharacterLength
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'OurTableName'

keycode and charcode

The property event.which is added when using jQuery to avoid browser differences. See docs.

The which property will be undefined if you are not using jQuery.

Char array declaration and initialization in C

Yes, this is a kind of inconsistency in the language.

The "=" in myarray = "abc"; is assignment (which won't work as the array is basically a kind of constant pointer), whereas in char myarray[4] = "abc"; it's an initialization of the array. There's no way for "late initialization".

You should just remember this rule.

A function to convert null to string

Convert.ToString(object) converts to string. If the object is null, Convert.ToString converts it to an empty string.

Calling .ToString() on an object with a null value throws a System.NullReferenceException.

EDIT:

Two exceptions to the rules:

1) ConvertToString(string) on a null string will always return null.

2) ToString(Nullable<T>) on a null value will return "" .

Code Sample:

// 1) Objects:

object obj = null;

//string valX1 = obj.ToString();           // throws System.NullReferenceException !!!
string val1 = Convert.ToString(obj);    

Console.WriteLine(val1 == ""); // True
Console.WriteLine(val1 == null); // False


// 2) Strings

String str = null;
//string valX2 = str.ToString();    // throws System.NullReferenceException !!!
string val2 = Convert.ToString(str); 

Console.WriteLine(val2 == ""); // False
Console.WriteLine(val2 == null); // True            


// 3) Nullable types:

long? num = null;
string val3 = num.ToString();  // ok, no error

Console.WriteLine(num == null); // True
Console.WriteLine(val3 == "");  // True
Console.WriteLine(val3 == null); // False 

val3 = Convert.ToString(num);  

Console.WriteLine(num == null);  // True
Console.WriteLine(val3 == "");  // True
Console.WriteLine(val3 == null); // False

Vertical Menu in Bootstrap

No, not in the current one. But you can take a look at the next version by downloading it from github. It has vertical pills and tabs. Maybe that will help? (be aware, it's under construction tho)

How to get client IP address using jQuery


<html lang="en">
<head>
    <title>Jquery - get ip address</title>
    <script type="text/javascript" src="//cdn.jsdelivr.net/jquery/1/jquery.min.js"></script>
</head>
<body>


<h1>Your Ip Address : <span class="ip"></span></h1>


<script type="text/javascript">
    $.getJSON("http://jsonip.com?callback=?", function (data) {
        $(".ip").text(data.ip);
    });
</script>


</body>
</html>

What's the difference between the Window.Loaded and Window.ContentRendered events

This is not about the difference between Window.ContentRendered and Window.Loaded but about what how the Window.Loaded event can be used:

I use it to avoid splash screens in all applications which need a long time to come up.

    // initializing my main window
    public MyAppMainWindow()
    {
        InitializeComponent();

        // Set the event
        this.ContentRendered += MyAppMainWindow_ContentRendered;
    }

    private void MyAppMainWindow_ContentRendered(object sender, EventArgs e)
    {
        // ... comes up quick when the controls are loaded and rendered

        // unset the event
        this.ContentRendered -= MyAppMainWindow_ContentRendered;

        // ... make the time comsuming init stuff here
    }

Keras, how do I predict after I trained a model?

Your can use your tokenizer and pad sequencing for a new piece of text. This is followed by model prediction. This will return the prediction as a numpy array plus the label itself.

For example:

new_complaint = ['Your service is not good']
seq = tokenizer.texts_to_sequences(new_complaint)
padded = pad_sequences(seq, maxlen=maxlen)
pred = model.predict(padded)
print(pred, labels[np.argmax(pred)])

How does "make" app know default target to build if no target is specified?

GNU Make also allows you to specify the default make target using a special variable called .DEFAULT_GOAL. You can even unset this variable in the middle of the Makefile, causing the next target in the file to become the default target.

Ref: The Gnu Make manual - Special Variables

MYSQL order by both Ascending and Descending sorting

I don't understand what the meaning of ordering with the same column ASC and DESC in the same ORDER BY, but this how you can do it: naam DESC, naam ASC like so:

ORDER BY `product_category_id` DESC,`naam` DESC, `naam` ASC

How do you delete a column by name in data.table?

I simply do it in the data frame kind of way:

DT$col = NULL

Works fast and as far as I could see doesn't cause any problems.

UPDATE: not the best method if your DT is very large, as using the $<- operator will lead to object copying. So better use:

DT[, col:=NULL]

Could not find or load main class with a Jar File

I had a similar problem which I could solve by granting execute-privilege for all parent folders in which the jar-file is located (on a linux system).

Example:

/folder1/folder2/folder3/executable.jar

all 3 folders (folder1, folder2 and folder3) as well as the executable.jar need execute-privilege for the current user, otherwise the error "Could not find or load main class ..." is returned.

How to change the interval time on bootstrap carousel?

You can use the options when initializing the carousel, like this:

// interval is in milliseconds. 1000 = 1 second -> so 1000 * 10 = 10 seconds
$('.carousel').carousel({
  interval: 1000 * 10
});

or you can use the interval attribute directly on the HTML tag, like this:

<div class="carousel" data-interval="10000">

The advantage of the latter approach is that you do not have to write any JS for it - while the advantage of the former is that you can compute the interval and initialize it with a variable value at run time.

Git submodule push

Note that since git1.7.11 ([ANNOUNCE] Git 1.7.11.rc1 and release note, June 2012) mentions:

"git push --recurse-submodules" learned to optionally look into the histories of submodules bound to the superproject and push them out.

Probably done after this patch and the --on-demand option:

recurse-submodules=<check|on-demand>::

Make sure all submodule commits used by the revisions to be pushed are available on a remote tracking branch.

  • If check is used, it will be checked that all submodule commits that changed in the revisions to be pushed are available on a remote.
    Otherwise the push will be aborted and exit with non-zero status.
  • If on-demand is used, all submodules that changed in the revisions to be pushed will be pushed.
    If on-demand was not able to push all necessary revisions it will also be aborted and exit with non-zero status.

So you could push everything in one go with (from the parent repo) a:

git push --recurse-submodules=on-demand

This option only works for one level of nesting. Changes to the submodule inside of another submodule will not be pushed.


With git 2.7 (January 2016), a simple git push will be enough to push the parent repo... and all its submodules.

See commit d34141c, commit f5c7cd9 (03 Dec 2015), commit f5c7cd9 (03 Dec 2015), and commit b33a15b (17 Nov 2015) by Mike Crowe (mikecrowe).
(Merged by Junio C Hamano -- gitster -- in commit 5d35d72, 21 Dec 2015)

push: add recurseSubmodules config option

The --recurse-submodules command line parameter has existed for some time but it has no config file equivalent.

Following the style of the corresponding parameter for git fetch, let's invent push.recurseSubmodules to provide a default for this parameter.
This also requires the addition of --recurse-submodules=no to allow the configuration to be overridden on the command line when required.

The most straightforward way to implement this appears to be to make push use code in submodule-config in a similar way to fetch.

The git config doc now include:

push.recurseSubmodules:

Make sure all submodule commits used by the revisions to be pushed are available on a remote-tracking branch.

  • If the value is 'check', then Git will verify that all submodule commits that changed in the revisions to be pushed are available on at least one remote of the submodule. If any commits are missing, the push will be aborted and exit with non-zero status.
  • If the value is 'on-demand' then all submodules that changed in the revisions to be pushed will be pushed. If on-demand was not able to push all necessary revisions it will also be aborted and exit with non-zero status. -
  • If the value is 'no' then default behavior of ignoring submodules when pushing is retained.

You may override this configuration at time of push by specifying '--recurse-submodules=check|on-demand|no'.

So:

git config push.recurseSubmodules on-demand
git push

Git 2.12 (Q1 2017)

git push --dry-run --recurse-submodules=on-demand will actually work.

See commit 0301c82, commit 1aa7365 (17 Nov 2016) by Brandon Williams (mbrandonw).
(Merged by Junio C Hamano -- gitster -- in commit 12cf113, 16 Dec 2016)

push run with --dry-run doesn't actually (Git 2.11 Dec. 2016 and lower/before) perform a dry-run when push is configured to push submodules on-demand.
Instead all submodules which need to be pushed are actually pushed to their remotes while any updates for the superproject are performed as a dry-run.
This is a bug and not the intended behaviour of a dry-run.

Teach push to respect the --dry-run option when configured to recursively push submodules 'on-demand'.
This is done by passing the --dry-run flag to the child process which performs a push for a submodules when performing a dry-run.


And still in Git 2.12, you now havea "--recurse-submodules=only" option to push submodules out without pushing the top-level superproject.

See commit 225e8bf, commit 6c656c3, commit 14c01bd (19 Dec 2016) by Brandon Williams (mbrandonw).
(Merged by Junio C Hamano -- gitster -- in commit 792e22e, 31 Jan 2017)

How to set max_connections in MySQL Programmatically

How to change max_connections

You can change max_connections while MySQL is running via SET:

mysql> SET GLOBAL max_connections = 5000;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE "max_connections";
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 5000  |
+-----------------+-------+
1 row in set (0.00 sec)

To OP

timeout related

I had never seen your error message before, so I googled. probably, you are using Connector/Net. Connector/Net Manual says there is max connection pool size. (default is 100) see table 22.21.

I suggest that you increase this value to 100k or disable connection pooling Pooling=false

UPDATED

he has two questions.

Q1 - what happens if I disable pooling Slow down making DB connection. connection pooling is a mechanism that use already made DB connection. cost of Making new connection is high. http://en.wikipedia.org/wiki/Connection_pool

Q2 - Can the value of pooling be increased or the maximum is 100?

you can increase but I'm sure what is MAX value, maybe max_connections in my.cnf

My suggestion is that do not turn off Pooling, increase value by 100 until there is no connection error.

If you have Stress Test tool like JMeter you can test youself.

How to disable and then enable onclick event on <div> with javascript

You can use the CSS property pointer-events to disable the click event on any element:

https://developer.mozilla.org/en-US/docs/Web/CSS/pointer-events

// To disable:    
document.getElementById('id').style.pointerEvents = 'none';
// To re-enable:
document.getElementById('id').style.pointerEvents = 'auto'; 
// Use '' if you want to allow CSS rules to set the value

Here is a JsBin: http://jsbin.com/oyAhuRI/1/edit

How to set variables in HIVE scripts

Have you tried using the dollar sign and brackets like this:

SELECT * 
FROM foo 
WHERE day >= '${CURRENT_DATE}';

How to hide "Showing 1 of N Entries" with the dataTables.js library

If you also need to disable the drop-down (not to hide the text) then set the lengthChange option to false

$('#datatable').dataTable( {
  "lengthChange": false
} );

Works for DataTables 1.10+

Read more in the official documentation

How to Delete a topic in apache kafka

Deletion of a topic has been supported since 0.8.2.x version. You have to enable topic deletion (setting delete.topic.enable to true) on all brokers first.

Note: Ever since 1.0.x, the functionality being stable, delete.topic.enable is by default true.

Follow this step by step process for manual deletion of topics

  1. Stop Kafka server
  2. Delete the topic directory, on each broker (as defined in the logs.dirs and log.dir properties) with rm -rf command
  3. Connect to Zookeeper instance: zookeeper-shell.sh host:port
  4. From within the Zookeeper instance:
    1. List the topics using: ls /brokers/topics
    2. Remove the topic folder from ZooKeeper using: rmr /brokers/topics/yourtopic
    3. Exit the Zookeeper instance (Ctrl+C)
  5. Restart Kafka server
  6. Confirm if it was deleted or not by using this command kafka-topics.sh --list --zookeeper host:port

How to call execl() in C with the proper arguments?

If you need just to execute your VLC playback process and only give control back to your application process when it is done and nothing more complex, then i suppose you can use just:

system("The same thing you type into console");

Python Pandas User Warning: Sorting because non-concatenation axis is not aligned

tl;dr:

concat and append currently sort the non-concatenation index (e.g. columns if you're adding rows) if the columns don't match. In pandas 0.23 this started generating a warning; pass the parameter sort=True to silence it. In the future the default will change to not sort, so it's best to specify either sort=True or False now, or better yet ensure that your non-concatenation indices match.


The warning is new in pandas 0.23.0:

In a future version of pandas pandas.concat() and DataFrame.append() will no longer sort the non-concatenation axis when it is not already aligned. The current behavior is the same as the previous (sorting), but now a warning is issued when sort is not specified and the non-concatenation axis is not aligned, link.

More information from linked very old github issue, comment by smcinerney :

When concat'ing DataFrames, the column names get alphanumerically sorted if there are any differences between them. If they're identical across DataFrames, they don't get sorted.

This sort is undocumented and unwanted. Certainly the default behavior should be no-sort.

After some time the parameter sort was implemented in pandas.concat and DataFrame.append:

sort : boolean, default None

Sort non-concatenation axis if it is not already aligned when join is 'outer'. The current default of sorting is deprecated and will change to not-sorting in a future version of pandas.

Explicitly pass sort=True to silence the warning and sort. Explicitly pass sort=False to silence the warning and not sort.

This has no effect when join='inner', which already preserves the order of the non-concatenation axis.

So if both DataFrames have the same columns in the same order, there is no warning and no sorting:

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['a', 'b'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['a', 'b'])

print (pd.concat([df1, df2]))
   a  b
0  1  0
1  2  8
0  4  7
1  5  3

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['b', 'a'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['b', 'a'])

print (pd.concat([df1, df2]))
   b  a
0  0  1
1  8  2
0  7  4
1  3  5

But if the DataFrames have different columns, or the same columns in a different order, pandas returns a warning if no parameter sort is explicitly set (sort=None is the default value):

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8]}, columns=['b', 'a'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3]}, columns=['a', 'b'])

print (pd.concat([df1, df2]))

FutureWarning: Sorting because non-concatenation axis is not aligned.

   a  b
0  1  0
1  2  8
0  4  7
1  5  3

print (pd.concat([df1, df2], sort=True))
   a  b
0  1  0
1  2  8
0  4  7
1  5  3

print (pd.concat([df1, df2], sort=False))
   b  a
0  0  1
1  8  2
0  7  4
1  3  5

If the DataFrames have different columns, but the first columns are aligned - they will be correctly assigned to each other (columns a and b from df1 with a and b from df2 in the example below) because they exist in both. For other columns that exist in one but not both DataFrames, missing values are created.

Lastly, if you pass sort=True, columns are sorted alphanumerically. If sort=False and the second DafaFrame has columns that are not in the first, they are appended to the end with no sorting:

df1 = pd.DataFrame({"a": [1, 2], "b": [0, 8], 'e':[5, 0]}, 
                    columns=['b', 'a','e'])
df2 = pd.DataFrame({"a": [4, 5], "b": [7, 3], 'c':[2, 8], 'd':[7, 0]}, 
                    columns=['c','b','a','d'])

print (pd.concat([df1, df2]))

FutureWarning: Sorting because non-concatenation axis is not aligned.

   a  b    c    d    e
0  1  0  NaN  NaN  5.0
1  2  8  NaN  NaN  0.0
0  4  7  2.0  7.0  NaN
1  5  3  8.0  0.0  NaN

print (pd.concat([df1, df2], sort=True))
   a  b    c    d    e
0  1  0  NaN  NaN  5.0
1  2  8  NaN  NaN  0.0
0  4  7  2.0  7.0  NaN
1  5  3  8.0  0.0  NaN

print (pd.concat([df1, df2], sort=False))

   b  a    e    c    d
0  0  1  5.0  NaN  NaN
1  8  2  0.0  NaN  NaN
0  7  4  NaN  2.0  7.0
1  3  5  NaN  8.0  0.0

In your code:

placement_by_video_summary = placement_by_video_summary.drop(placement_by_video_summary_new.index)
                                                       .append(placement_by_video_summary_new, sort=True)
                                                       .sort_index()

How to _really_ programmatically change primary and accent color in Android Lollipop?

USE A TOOLBAR

You can set a custom toolbar item color dynamically by creating a custom toolbar class:

package view;

import android.app.Activity;
import android.content.Context;
import android.graphics.ColorFilter;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.support.v7.internal.view.menu.ActionMenuItemView;
import android.support.v7.widget.ActionMenuView;
import android.support.v7.widget.Toolbar;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AutoCompleteTextView;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;

public class CustomToolbar extends Toolbar{

    public CustomToolbar(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        // TODO Auto-generated constructor stub
    }

    public CustomToolbar(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

    public CustomToolbar(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        ctxt = context;
    }

    int itemColor;
    Context ctxt;

    @Override 
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        Log.d("LL", "onLayout");
        super.onLayout(changed, l, t, r, b);
        colorizeToolbar(this, itemColor, (Activity) ctxt);
    } 

    public void setItemColor(int color){
        itemColor = color;
        colorizeToolbar(this, itemColor, (Activity) ctxt);
    }



    /**
     * Use this method to colorize toolbar icons to the desired target color
     * @param toolbarView toolbar view being colored
     * @param toolbarIconsColor the target color of toolbar icons
     * @param activity reference to activity needed to register observers
     */
    public static void colorizeToolbar(Toolbar toolbarView, int toolbarIconsColor, Activity activity) {
        final PorterDuffColorFilter colorFilter
                = new PorterDuffColorFilter(toolbarIconsColor, PorterDuff.Mode.SRC_IN);

        for(int i = 0; i < toolbarView.getChildCount(); i++) {
            final View v = toolbarView.getChildAt(i);

            doColorizing(v, colorFilter, toolbarIconsColor);
        }

      //Step 3: Changing the color of title and subtitle.
        toolbarView.setTitleTextColor(toolbarIconsColor);
        toolbarView.setSubtitleTextColor(toolbarIconsColor);
    }

    public static void doColorizing(View v, final ColorFilter colorFilter, int toolbarIconsColor){
        if(v instanceof ImageButton) {
            ((ImageButton)v).getDrawable().setAlpha(255);
            ((ImageButton)v).getDrawable().setColorFilter(colorFilter);
        }

        if(v instanceof ImageView) {
            ((ImageView)v).getDrawable().setAlpha(255);
            ((ImageView)v).getDrawable().setColorFilter(colorFilter);
        }

        if(v instanceof AutoCompleteTextView) {
            ((AutoCompleteTextView)v).setTextColor(toolbarIconsColor);
        }

        if(v instanceof TextView) {
            ((TextView)v).setTextColor(toolbarIconsColor);
        }

        if(v instanceof EditText) {
            ((EditText)v).setTextColor(toolbarIconsColor);
        }

        if (v instanceof ViewGroup){
            for (int lli =0; lli< ((ViewGroup)v).getChildCount(); lli ++){
                doColorizing(((ViewGroup)v).getChildAt(lli), colorFilter, toolbarIconsColor);
            }
        }

        if(v instanceof ActionMenuView) {
            for(int j = 0; j < ((ActionMenuView)v).getChildCount(); j++) {

                //Step 2: Changing the color of any ActionMenuViews - icons that
                //are not back button, nor text, nor overflow menu icon.
                final View innerView = ((ActionMenuView)v).getChildAt(j);

                if(innerView instanceof ActionMenuItemView) {
                    int drawablesCount = ((ActionMenuItemView)innerView).getCompoundDrawables().length;
                    for(int k = 0; k < drawablesCount; k++) {
                        if(((ActionMenuItemView)innerView).getCompoundDrawables()[k] != null) {
                            final int finalK = k;

                            //Important to set the color filter in seperate thread, 
                            //by adding it to the message queue
                            //Won't work otherwise. 
                            //Works fine for my case but needs more testing

                            ((ActionMenuItemView) innerView).getCompoundDrawables()[finalK].setColorFilter(colorFilter);

//                              innerView.post(new Runnable() {
//                                  @Override
//                                  public void run() {
//                                      ((ActionMenuItemView) innerView).getCompoundDrawables()[finalK].setColorFilter(colorFilter);
//                                  }
//                              });
                        }
                    }
                }
            }
        }
    }



}

then refer to it in your layout file. Now you can set a custom color using

toolbar.setItemColor(Color.Red);

Sources:

I found the information to do this here: How to dynamicaly change Android Toolbar icons color

and then I edited it, improved upon it, and posted it here: GitHub:AndroidDynamicToolbarItemColor

MomentJS getting JavaScript Date in UTC

Or simply:

Date.now

From MDN documentation:

The Date.now() method returns the number of milliseconds elapsed since January 1, 1970

Available since ECMAScript 5.1

It's the same as was mentioned above (new Date().getTime()), but more shortcutted version.

ReferenceError: event is not defined error in Firefox

It is because you forgot to pass in event into the click function:

$('.menuOption').on('click', function (e) { // <-- the "e" for event

    e.preventDefault(); // now it'll work

    var categories = $(this).attr('rel');
    $('.pages').hide();
    $(categories).fadeIn();
});

On a side note, e is more commonly used as opposed to the word event since Event is a global variable in most browsers.

jQuery: selecting each td in a tr

expanding on the answer above the 'each' function will return you the table-cell html object. wrapping that in $() will then allow you to perform jquery actions on it.

$(this).find('td').each (function( column, td) {
  $(td).blah
});  

Access denied for user 'root'@'localhost' (using password: YES) (Mysql::Error)

This error happens if you did not set the password on install, in this case the mysql using unix-socket plugin.

But if delete the plugin link from settings (table mysql.user) will other problem. This does not fix the problem and creates another problem. To fix the deleted link and set password ("PWD") do:

1) Run with --skip-grant-tables as said above.

If it doesnt works then add the string skip-grant-tables in section [mysqld] of /etc/mysql/mysql.conf.d/mysqld.cnf. Then do sudo service mysql restart.

2) Run mysql -u root -p, then (change "PWD"):

update mysql.user 
    set authentication_string=PASSWORD("PWD"), plugin="mysql_native_password" 
    where User='root' and Host='localhost';    
flush privileges;

quit
then sudo service mysql restart. Check: mysql -u root -p.

Before restart remove that string from file mysqld.cnf, if you set it there.

@bl79 is the author of this answer, i've just reposted it, because it does help!

unable to install pg gem

On Mac brew install postgres THEN bundle install

When should I use semicolons in SQL Server?

Note: This answers the question as written, but not the problem as stated. Adding it here, since people will be searching for it

Semicolon is also used before WITH in recursive CTE statements:

;WITH Numbers AS
(
    SELECT n = 1
    UNION ALL
    SELECT n + 1
    FROM Numbers
    WHERE n+1 <= 10
)
SELECT n
FROM Numbers

This query will generate a CTE called Numbers that consists of integers [1..10]. It is done by creating a table with the value 1 only, and then recursing until you reach 10.

Detecting Enter keypress on VB.NET

I see this has been answered, but it seems like you could avoid all of this 'remapping' of the enter key by simply hooking your validation into the AcceptButton on a form. ie. you have 3 textboxes (txtA,txtB,txtC) and an 'OK' button set to be AcceptButton (and TabOrder set properly). So, if in txtA and you hit enter, if the data is invalid, your focus will stay in txtA, but if it is valid, assuming the other txts need input, validation will just put you into the next txt that needs valid input thus simulating TAB behaviour... once all txts have valid input, pressing enter will fire a succsessful validation and close form (or whatever...) Make sense?

How do you programmatically update query params in react-router?

From DimitriDushkin on GitHub:

import { browserHistory } from 'react-router';

/**
 * @param {Object} query
 */
export const addQuery = (query) => {
  const location = Object.assign({}, browserHistory.getCurrentLocation());

  Object.assign(location.query, query);
  // or simple replace location.query if you want to completely change params

  browserHistory.push(location);
};

/**
 * @param {...String} queryNames
 */
export const removeQuery = (...queryNames) => {
  const location = Object.assign({}, browserHistory.getCurrentLocation());
  queryNames.forEach(q => delete location.query[q]);
  browserHistory.push(location);
};

or

import { withRouter } from 'react-router';
import { addQuery, removeQuery } from '../../utils/utils-router';

function SomeComponent({ location }) {
  return <div style={{ backgroundColor: location.query.paintRed ? '#f00' : '#fff' }}>
    <button onClick={ () => addQuery({ paintRed: 1 })}>Paint red</button>
    <button onClick={ () => removeQuery('paintRed')}>Paint white</button>
  </div>;
}

export default withRouter(SomeComponent);

Multiple arguments to function called by pthread_create()?

struct arg_struct *args = (struct arg_struct *)args;

--> this assignment is wrong, I mean the variable argument should be used in this context. Cheers!!!

How do I remove whitespace from the end of a string in Python?

>>> "    xyz     ".rstrip()
'    xyz'

There is more about rstrip in the documentation.

Reading data from DataGridView in C#

Code Example : Reading data from DataGridView and storing it in an array

int[,] n = new int[3, 19];
for (int i = 0; i < (StartDataView.Rows.Count - 1); i++)
{
    for (int j = 0; j < StartDataView.Columns.Count; j++)
    {
        if(this.StartDataView.Rows[i].Cells[j].Value.ToString() != string.Empty)
        {
            try
            {
                n[i, j] = int.Parse(this.StartDataView.Rows[i].Cells[j].Value.ToString());
            }
            catch (Exception Ee)
            { //get exception of "null"
                MessageBox.Show(Ee.ToString());
            }
        }
    }
}

Calculating Page Table Size

In 32 bit virtual address system we can have 2^32 unique address, since the page size given is 4KB = 2^12, we will need (2^32/2^12 = 2^20) entries in the page table, if each entry is 4Bytes then total size of the page table = 4 * 2^20 Bytes = 4MB

Function ereg_replace() is deprecated - How to clear this bug?

Switch to preg_replaceDocs and update the expression to use preg syntax (PCRE) instead of ereg syntax (POSIX) where there are differencesDocs (just as it says to do in the manual for ereg_replaceDocs).

How many bytes in a JavaScript string?

Try this combination with using unescape js function:

const byteAmount = unescape(encodeURIComponent(yourString)).length

Full encode proccess example:

const s  = "1 a ? ? @ ®"; // length is 11
const s2 = encodeURIComponent(s); // length is 41
const s3 = unescape(s2); // length is 15 [1-1,a-1,?-2,?-3,@-1,®-2]
const s4 = escape(s3); // length is 39
const s5 = decodeURIComponent(s4); // length is 11

Converting a double to an int in Javascript without rounding

Just use parseInt() and be sure to include the radix so you get predictable results:

parseInt(d, 10);

Why does "return list.sort()" return None, not the list?

Python has two kinds of sorts: a sort method (or "member function") and a sort function. The sort method operates on the contents of the object named -- think of it as an action that the object is taking to re-order itself. The sort function is an operation over the data represented by an object and returns a new object with the same contents in a sorted order.

Given a list of integers named l the list itself will be reordered if we call l.sort():

>>> l = [1, 5, 2341, 467, 213, 123]
>>> l.sort()
>>> l
[1, 5, 123, 213, 467, 2341]

This method has no return value. But what if we try to assign the result of l.sort()?

>>> l = [1, 5, 2341, 467, 213, 123]
>>> r = l.sort()
>>> print(r)
None

r now equals actually nothing. This is one of those weird, somewhat annoying details that a programmer is likely to forget about after a period of absence from Python (which is why I am writing this, so I don't forget again).

The function sorted(), on the other hand, will not do anything to the contents of l, but will return a new, sorted list with the same contents as l:

>>> l = [1, 5, 2341, 467, 213, 123]
>>> r = sorted(l)
>>> l
[1, 5, 2341, 467, 213, 123]
>>> r
[1, 5, 123, 213, 467, 2341]

Be aware that the returned value is not a deep copy, so be cautious about side-effecty operations over elements contained within the list as usual:

>>> spam = [8, 2, 4, 7]
>>> eggs = [3, 1, 4, 5]
>>> l = [spam, eggs]
>>> r = sorted(l)
>>> l
[[8, 2, 4, 7], [3, 1, 4, 5]]
>>> r
[[3, 1, 4, 5], [8, 2, 4, 7]]
>>> spam.sort()
>>> eggs.sort()
>>> l
[[2, 4, 7, 8], [1, 3, 4, 5]]
>>> r
[[1, 3, 4, 5], [2, 4, 7, 8]]

Python TypeError: not enough arguments for format string

Note that the % syntax for formatting strings is becoming outdated. If your version of Python supports it, you should write:

instr = "'{0}', '{1}', '{2}', '{3}', '{4}', '{5}', '{6}'".format(softname, procversion, int(percent), exe, description, company, procurl)

This also fixes the error that you happened to have.

SQL Server: Get table primary key using sql query

The code I'll give you works and retrieves not only keys, but a lot of data from a table in SQL Server. Is tested in SQL Server 2k5/2k8, dunno about 2k. Enjoy!

SELECT DISTINCT
    sys.tables.object_id AS TableId,
    sys.columns.column_id AS ColumnId,
    sys.columns.name AS ColumnName,
    sys.types.name AS TypeName,
    sys.columns.precision AS NumericPrecision,
    sys.columns.scale AS NumericScale,
    sys.columns.is_nullable AS IsNullable,
    (   SELECT 
            COUNT(column_name)
        FROM 
            INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE 
        WHERE
            TABLE_NAME = sys.tables.name AND
            CONSTRAINT_NAME =
                (   SELECT
                    constraint_name
                    FROM 
                        INFORMATION_SCHEMA.TABLE_CONSTRAINTS
                    WHERE
                        TABLE_NAME = sys.tables.name AND                    
                        constraint_type = 'PRIMARY KEY' AND
                        COLUMN_NAME = sys.columns.name
                )
    ) AS IsPrimaryKey,
    sys.columns.max_length / 2 AS CharMaxLength /*BUG*/
FROM 
    sys.columns, sys.types, sys.tables 
WHERE
    sys.tables.object_id = sys.columns.object_id AND
    sys.types.system_type_id = sys.columns.system_type_id AND
    sys.types.user_type_id = sys.columns.user_type_id AND
    sys.tables.name = 'TABLE'
ORDER BY 
    IsPrimaryKey

You can use only the primary key part, but I think that the rest might become handy. Best regards, David

Using jquery to delete all elements with a given id

You should be using a class for multiple elements as an id is meant to be only a single element. To answer your question on the .each() syntax though, this is what it would look like:

$('#myID').each(function() {
    $(this).remove();
});

Official JQuery documentation here.

How can I change the text inside my <span> with jQuery?

Try this

$("#abc").html('<span class = "xyz"> SAMPLE TEXT</span>');

Handle all the css relevant to that span within xyz

List Directories and get the name of the Directory

You seem to be using Python as if it were the shell. Whenever I've needed to do something like what you're doing, I've used os.walk()

For example, as explained here: [x[0] for x in os.walk(directory)] should give you all of the subdirectories, recursively.

Checking if an input field is required using jQuery

A little bit of a more complete answer, inspired by the accepted answer:

$( '#form_id' ).submit( function( event ) {
        event.preventDefault();

        //validate fields
        var fail = false;
        var fail_log = '';
        var name;
        $( '#form_id' ).find( 'select, textarea, input' ).each(function(){
            if( ! $( this ).prop( 'required' )){

            } else {
                if ( ! $( this ).val() ) {
                    fail = true;
                    name = $( this ).attr( 'name' );
                    fail_log += name + " is required \n";
                }

            }
        });

        //submit if fail never got set to true
        if ( ! fail ) {
            //process form here.
        } else {
            alert( fail_log );
        }

});

In this case we loop all types of inputs and if they are required, we check if they have a value, and if not, a notice that they are required is added to the alert that will run.

Note that this, example assumes the form will be proceed inside the positive conditional via AJAX or similar. If you are submitting via traditional methods, move the second line, event.preventDefault(); to inside the negative conditional.

How to List All Redis Databases?

you can use redis-cli INFO keyspace

localhost:8000> INFO keyspace
# Keyspace
db0:keys=7,expires=0,avg_ttl=0
db1:keys=1,expires=0,avg_ttl=0
db2:keys=1,expires=0,avg_ttl=0
db11:keys=1,expires=0,avg_ttl=0

Selecting fields from JSON output

Assume you stored that dictionary in a variable called values. To get id in to a variable, do:

idValue = values['criteria'][0]['id']

If that json is in a file, do the following to load it:

import json
jsonFile = open('your_filename.json', 'r')
values = json.load(jsonFile)
jsonFile.close()

If that json is from a URL, do the following to load it:

import urllib, json
f = urllib.urlopen("http://domain/path/jsonPage")
values = json.load(f)
f.close()

To print ALL of the criteria, you could:

for criteria in values['criteria']:
    for key, value in criteria.iteritems():
        print key, 'is:', value
    print ''

Object Library Not Registered When Adding Windows Common Controls 6.0

...and on my 64 bit W7 machine, with VB6 installed... in DOS, as Admin, this worked to solve an OCX problem I was having with a VB6 App:

cd C:\Windows\SysWOW64
regsvr32 mscomctl.ocx
regtlib msdatsrc.tlb

YES! This solution solved the problem I had using MSCAL.OCX (The Microsoft Calendar Control) in VB6.

Thank you guys! :-)

How do check if a PHP session is empty?

I would use isset and empty:

session_start();
if(isset($_SESSION['blah']) && !empty($_SESSION['blah'])) {
   echo 'Set and not empty, and no undefined index error!';
}

array_key_exists is a nice alternative to using isset to check for keys:

session_start();
if(array_key_exists('blah',$_SESSION) && !empty($_SESSION['blah'])) {
    echo 'Set and not empty, and no undefined index error!';
}

Make sure you're calling session_start before reading from or writing to the session array.

Msg 102, Level 15, State 1, Line 1 Incorrect syntax near ' '

For the OP's command:

select compid,2, convert(datetime, '01/01/' + CONVERT(char(4),cal_yr) ,101) ,0,  Update_dt, th1, th2, th3_pc , Update_id, Update_dt,1
from  #tmp_CTF** 

I get this error:

Msg 102, Level 15, State 1, Line 2
Incorrect syntax near '*'.

when debugging something like this split the long line up so you'll get a better row number:

select compid
,2
, convert(datetime
, '01/01/' 
+ CONVERT(char(4)
,cal_yr) 
,101) 
,0
,  Update_dt
, th1
, th2
, th3_pc 
, Update_id
, Update_dt
,1
from  #tmp_CTF** 

this now results in:

Msg 102, Level 15, State 1, Line 16
Incorrect syntax near '*'.

which is probably just from the OP not putting the entire command in the question, or use [ ] braces to signify the table name:

from [#tmp_CTF**]

if that is the table name.

How to set a default value in react-select

  1. Create a state property for the default option text in the constructor
    • Don't worry about the default option value
  2. Add an option tag to the render function. Only show using state and ternary expression
  3. Create a function to handle when an option was selected
  4. Change the state of the default option value in this event handler function to null

    Class MySelect extends React.Component
    {
        constructor()
        {
            super()
            this.handleChange = this.handleChange.bind(this);
            this.state = {
                selectDefault: "Select An Option"
            }
        }
        handleChange(event)
        {
            const selectedValue = event.target.value;
            //do something with selectedValue
            this.setState({
                selectDefault: null
            });
        }
        render()
        {
            return (
            <select name="selectInput" id="selectInput" onChange={this.handleChange} value= 
                {this.selectedValue}>
             {this.state.selectDefault ? <option>{this.state.selectDefault}</option> : ''}
                {'map list or static list of options here'}
            </select>
            )
        }
    }
    

Why does Eclipse automatically add appcompat v7 library support whenever I create a new project?

Create a new Android Application Project and uncheck Create activity in step two (Configure project).

Extracting columns from text file with different delimiters in Linux

If the command should work with both tabs and spaces as the delimiter I would use awk:

awk '{print $100,$101,$102,$103,$104,$105}' myfile > outfile

As long as you just need to specify 5 fields it is imo ok to just type them, for longer ranges you can use a for loop:

awk '{for(i=100;i<=105;i++)print $i}' myfile > outfile

If you want to use cut, you need to use the -f option:

cut -f100-105 myfile > outfile

If the field delimiter is different from TAB you need to specify it using -d:

cut -d' ' -f100-105 myfile > outfile

Check the man page for more info on the cut command.

When should I use "this" in a class?

There are a lot of good answers, but there is another very minor reason to put this everywhere. If you have tried opening your source codes from a normal text editor (e.g. notepad etc), using this will make it a whole lot clearer to read.

Imagine this:

public class Hello {
    private String foo;

    // Some 10k lines of codes

    private String getStringFromSomewhere() {
        // ....
    }

    // More codes

    public class World {
        private String bar;

        // Another 10k lines of codes

        public void doSomething() {
            // More codes
            foo = "FOO";
            // More codes
            String s = getStringFromSomewhere();
            // More codes
            bar = s;
        }
    }
}

This is very clear to read with any modern IDE, but this will be a total nightmare to read with a regular text editor.

You will struggle to find out where foo resides, until you use the editor's "find" function. Then you will scream at getStringFromSomewhere() for the same reason. Lastly, after you have forgotten what s is, that bar = s is going to give you the final blow.

Compare it to this:

public void doSomething() {
    // More codes
    Hello.this.foo = "FOO";
    // More codes
    String s = Hello.this.getStringFromSomewhere();
    // More codes
    this.bar = s;
}
  1. You know foo is a variable declared in outer class Hello.
  2. You know getStringFromSomewhere() is a method declared in outer class as well.
  3. You know that bar belongs to World class, and s is a local variable declared in that method.

Of course, whenever you design something, you create rules. So while designing your API or project, if your rules include "if someone opens all these source codes with a notepad, he or she should shoot him/herself in the head," then you are totally fine not to do this.

Python FileNotFound

try block should be around open. Not around prompt.

while True:
    prompt = input("\n Hello to Sudoku valitator,"
    "\n \n Please type in the path to your file and press 'Enter': ")
    try:
        sudoku = open(prompt, 'r').readlines()
    except FileNotFoundError:
        print("Wrong file or file path")
    else:
        break

How to print binary tree diagram?

Print a [large] tree by lines.

output example:

z
+-- c
¦   +-- a
¦   +-- b
+-- d
+-- e
¦   +-- asdf
+-- f

code:

public class TreeNode {

    final String name;
    final List<TreeNode> children;

    public TreeNode(String name, List<TreeNode> children) {
        this.name = name;
        this.children = children;
    }

    public String toString() {
        StringBuilder buffer = new StringBuilder(50);
        print(buffer, "", "");
        return buffer.toString();
    }

    private void print(StringBuilder buffer, String prefix, String childrenPrefix) {
        buffer.append(prefix);
        buffer.append(name);
        buffer.append('\n');
        for (Iterator<TreeNode> it = children.iterator(); it.hasNext();) {
            TreeNode next = it.next();
            if (it.hasNext()) {
                next.print(buffer, childrenPrefix + "+-- ", childrenPrefix + "¦   ");
            } else {
                next.print(buffer, childrenPrefix + "+-- ", childrenPrefix + "    ");
            }
        }
    }
}

P.S. This answer doesn't exactly focus on "binary" trees -- instead, it prints all kinds of trees. Solution is inspired by the "tree" command in linux.

Java: Difference between the setPreferredSize() and setSize() methods in components

setSize() or setBounds() can be used when no layout manager is being used.

However, if you are using a layout manager you can provide hints to the layout manager using the setXXXSize() methods like setPreferredSize() and setMinimumSize() etc.

And be sure that the component's container uses a layout manager that respects the requested size. The FlowLayout, GridBagLayout, and SpringLayout managers use the component's preferred size (the latter two depending on the constraints you set), but BorderLayout and GridLayout usually don't.If you specify new size hints for a component that's already visible, you need to invoke the revalidate method on it to make sure that its containment hierarchy is laid out again. Then invoke the repaint method.

How to extract 1 screenshot for a video with ffmpeg at a given time?

Use the -ss option:

ffmpeg -ss 01:23:45 -i input -vframes 1 -q:v 2 output.jpg
  • For JPEG output use -q:v to control output quality. Full range is a linear scale of 1-31 where a lower value results in a higher quality. 2-5 is a good range to try.

  • The select filter provides an alternative method for more complex needs such as selecting only certain frame types, or 1 per 100, etc.

  • Placing -ss before the input will be faster. See FFmpeg Wiki: Seeking and this excerpt from the ffmpeg cli tool documentation:

-ss position (input/output)

When used as an input option (before -i), seeks in this input file to position. Note the in most formats it is not possible to seek exactly, so ffmpeg will seek to the closest seek point before position. When transcoding and -accurate_seek is enabled (the default), this extra segment between the seek point and position will be decoded and discarded. When doing stream copy or when -noaccurate_seek is used, it will be preserved.

When used as an output option (before an output filename), decodes but discards input until the timestamps reach position.

position may be either in seconds or in hh:mm:ss[.xxx] form.

How to change the Eclipse default workspace?

I took this question to mean how can you change the Default workspace so that when Eclipse boots up the workspace you want is automatically loaded:

  • Go under preferences then type "workspace" in the search box provided to filter the list. Alternatively you can go to General>Startup and Shutdown>Workspaces.
  • There you can set a flag to make Eclipse prompt you to select a workspace at startup by checking the "Prompt for workspace at startup" checkbox.
  • You can set the number of previous workspaces to remember also. Finally there is a list of recent workspaces. If you just remove all but the one you want Eclipse will automatically startup with that workspace.

Push existing project into Github

Git has been the version-control system of choice since its inception in 2005. About 87% of the developers use Git as their version-control system.

But if you have a project that is already existing and you want to push to Git in the remote server, follow along the below steps:

  1. Go to the terminal of your project directory

  2. You need to initialize your project git using git init

  3. Create a .gitignore file and it is actually a text file that tells Git which files or folders to ignore in a project.

  4. Stage your files using git add .

  5. Commit your changes to your local repository with an appropriate commit message: git commit -m "my first commit"

  6. In this step, you just need to create a repository in any one of the distributed version control systems like GitHub or Bitbucket

  7. Use this Git command to link your local repository with that of the remote: git remote add <your-remote-name> <your-remote-url>

So, if your GitHub repo-url is https://github.com/your-github-username/new-repository.git, then the Git command becomes:

git remote add origin https://github.com/<your-github-username>/new-repository.git
  1. Push your code to remote GitHub repository

    git push origin master

Note: The git push command requires two parameters: the name of the remote repository (origin) and the branch to push to (here master is the default branch for every repository).

Refer this blog for detailed information.

Html ordered list 1.1, 1.2 (Nested counters and scope) not working

This is a great solution! With a few additional CSS rules you can format it just like an MS Word outline list with a hanging first line indent:

OL { 
  counter-reset: item; 
}
LI { 
  display: block; 
}
LI:before { 
  content: counters(item, ".") "."; 
  counter-increment: item; 
  padding-right:10px; 
  margin-left:-20px;
}

How can I declare and use Boolean variables in a shell script?

I found the existing answers confusing.

Personally, I just want to have something which looks and works like C.

This snippet works many times a day in production:

snapshotEvents=true

if ($snapshotEvents)
then
    # Do stuff if true
fi

and to keep everyone happy, I tested:

snapshotEvents=false

if !($snapshotEvents)
then
    # Do stuff if false
fi

Which also worked fine.

The $snapshotEvents evaluates the contents of value of the variable. So you need the $.

You don't really need the parentheses, I just find them helpful.

Quadratic and cubic regression in Excel

The LINEST function described in a previous answer is the way to go, but an easier way to show the 3 coefficients of the output is to additionally use the INDEX function. In one cell, type: =INDEX(LINEST(B2:B21,A2:A21^{1,2},TRUE,FALSE),1) (by the way, the B2:B21 and A2:A21 I used are just the same values the first poster who answered this used... of course you'd change these ranges appropriately to match your data). This gives the X^2 coefficient. In an adjacent cell, type the same formula again but change the final 1 to a 2... this gives the X^1 coefficient. Lastly, in the next cell over, again type the same formula but change the last number to a 3... this gives the constant. I did notice that the three coefficients are very close but not quite identical to those derived by using the graphical trendline feature under the charts tab. Also, I discovered that LINEST only seems to work if the X and Y data are in columns (not rows), with no empty cells within the range, so be aware of that if you get a #VALUE error.

Elasticsearch: Failed to connect to localhost port 9200 - Connection refused

By default it should bind to all local addresses. So, assuming you don't have a network layer issue with firewalls, the only ES setting I can think to check is network.bind_host and make sure it is either not set or is set to 0.0.0.0 or ::0 or to the correct IP address for your network.

Update: per comments in ES 2.3 you should set network.host instead.

How to get the last row of an Oracle a table

$sql = "INSERT INTO table_name( field1, field2 )  VALUES ('foo','bar') 
        RETURNING ID INTO :mylastid";
$stmt = oci_parse($db, $sql);
oci_bind_by_name($stmt, "mylastid", $last_id, 8, SQLT_INT);
oci_execute($stmt);

echo "last inserted id is:".$last_id;

Tip: you have to use your id column name in {your_id_col_name} below...

"RETURNING {your_id_col_name} INTO :mylastid"

WPF Application that only has a tray icon

I recently had this same problem. Unfortunately, NotifyIcon is only a Windows.Forms control at the moment, if you want to use it you are going to have to include that part of the framework. I guess that depends how much of a WPF purist you are.

If you want a quick and easy way of getting started check out this WPF NotifyIcon control on the Code Project which does not rely on the WinForms NotifyIcon at all. A more recent version seems to be available on the author's website and as a NuGet package. This seems like the best and cleanest way to me so far.

  • Rich ToolTips rather than text
  • WPF context menus and popups
  • Command support and routed events
  • Flexible data binding
  • Rich balloon messages rather than the default messages provides by the OS

Check it out. It comes with an amazing sample app too, very easy to use, and you can have great looking Windows Live Messenger style WPF popups, tooltips, and context menus. Perfect for displaying an RSS feed, I am using it for a similar purpose.

How to check if directory exist using C++ and winAPI

This code might work:

//if the directory exists
 DWORD dwAttr = GetFileAttributes(str);
 if(dwAttr != 0xffffffff && (dwAttr & FILE_ATTRIBUTE_DIRECTORY))