Programs & Examples On #Usb flash drive

A USB flash drive is a data storage device that includes flash memory with an integrated Universal Serial Bus (USB) interface.

How to mount a single file in a volume

I have same issue on my Windows 8.1

It turned out that it was due to case-sensitivity of path. I called docker-compose up from directory cd /c/users/alex/ and inside container a file was turned into directory.

But when I did cd /c/Users/alex/ (not Users capitalized) and called docker-compose up from there, it worked.

In my system both Users dir and Alex dir are capitalized, though it seems like only Users dir matter.

Git pull a certain branch from GitHub

you may also do

git pull -r origin master

fix merge conflicts if any

git rebase --continue

-r is for rebase. This will make you branch structure from

        v  master       
          ^ other branch


        v  master       
              ^ other branch

This will lead to a cleaner history. Note: In case you have already pushed your other-branch to origin( or any other remote), you may have to force push your branch after rebase.

git push -f origin other-branch

Can jQuery get all CSS styles associated with an element?

I had tried many different solutions. This was the only one that worked for me in that it was able to pick up on styles applied at class level and at style as directly attributed on the element. So a font set at css file level and one as a style attribute; it returned the correct font.

It is simple! (Sorry, can't find where I originally found it)

//-- html object
var element = htmlObject; //e.g document.getElementById
//-- or jquery object
var element = htmlObject[0]; //e.g $(selector)

var stylearray = document.defaultView.getComputedStyle(element, null);
var font = stylearray["font-family"]

Alternatively you can list all the style by cycling through the array

for (var key in stylearray) {
console.log(key + ': ' + stylearray[key];

How to get json response using in c#?

Some APIs want you to supply the appropriate "Accept" header in the request to get the wanted response type.

For example if an API can return data in XML and JSON and you want the JSON result, you would need to set the HttpWebRequest.Accept property to "application/json".

HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(requestUri);
httpWebRequest.Method = WebRequestMethods.Http.Get;
httpWebRequest.Accept = "application/json";

Max length UITextField

Beware of the undo bug for UITextField mentioned in this post: Set the maximum character length of a UITextField

here is how you fix it in swift

if(range.length + range.location > count(textField.text)) {
        return false;

PHP Get Site URL Protocol - http vs https

$protocal = 'http';
if ($_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https' || $_SERVER['HTTPS'] == 'on') {$protocal = 'https';}

echo $protocal;

Hexadecimal To Decimal in Shell Script

I have this handy script on my $PATH to filter 0x1337-like; 1337; or "0x1337" lines of input into decimal strings (expanded for clarity):

#!/usr/bin/env bash

while read data; do
  withoutQuotes=`echo ${data} | sed s/\"//g`
  without0x=`echo ${withoutQuotes} | sed s/0x//g`
  echo $((16#${clean}))

How can I discard remote changes and mark a file as "resolved"?

git checkout has the --ours option to check out the version of the file that you had locally (as opposed to --theirs, which is the version that you pulled in). You can pass . to git checkout to tell it to check out everything in the tree. Then you need to mark the conflicts as resolved, which you can do with git add, and commit your work once done:

git checkout --ours .  # checkout our local version of all files
git add -u             # mark all conflicted files as merged
git commit             # commit the merge

Note the . in the git checkout command. That's very important, and easy to miss. git checkout has two modes; one in which it switches branches, and one in which it checks files out of the index into the working copy (sometimes pulling them into the index from another revision first). The way it distinguishes is by whether you've passed a filename in; if you haven't passed in a filename, it tries switching branches (though if you don't pass in a branch either, it will just try checking out the current branch again), but it refuses to do so if there are modified files that that would effect. So, if you want a behavior that will overwrite existing files, you need to pass in . or a filename in order to get the second behavior from git checkout.

It's also a good habit to have, when passing in a filename, to offset it with --, such as git checkout --ours -- <filename>. If you don't do this, and the filename happens to match the name of a branch or tag, Git will think that you want to check that revision out, instead of checking that filename out, and so use the first form of the checkout command.

I'll expand a bit on how conflicts and merging work in Git. When you merge in someone else's code (which also happens during a pull; a pull is essentially a fetch followed by a merge), there are few possible situations.

The simplest is that you're on the same revision. In this case, you're "already up to date", and nothing happens.

Another possibility is that their revision is simply a descendent of yours, in which case you will by default have a "fast-forward merge", in which your HEAD is just updated to their commit, with no merging happening (this can be disabled if you really want to record a merge, using --no-ff).

Then you get into the situations in which you actually need to merge two revisions. In this case, there are two possible outcomes. One is that the merge happens cleanly; all of the changes are in different files, or are in the same files but far enough apart that both sets of changes can be applied without problems. By default, when a clean merge happens, it is automatically committed, though you can disable this with --no-commit if you need to edit it beforehand (for instance, if you rename function foo to bar, and someone else adds new code that calls foo, it will merge cleanly, but produce a broken tree, so you may want to clean that up as part of the merge commit in order to avoid having any broken commits).

The final possibility is that there's a real merge, and there are conflicts. In this case, Git will do as much of the merge as it can, and produce files with conflict markers (<<<<<<<, =======, and >>>>>>>) in your working copy. In the index (also known as the "staging area"; the place where files are stored by git add before committing them), you will have 3 versions of each file with conflicts; there is the original version of the file from the ancestor of the two branches you are merging, the version from HEAD (your side of the merge), and the version from the remote branch.

In order to resolve the conflict, you can either edit the file that is in your working copy, removing the conflict markers and fixing the code up so that it works. Or, you can check out the version from one or the other sides of the merge, using git checkout --ours or git checkout --theirs. Once you have put the file into the state you want it, you indicate that you are done merging the file and it is ready to commit using git add, and then you can commit the merge with git commit.

How do I add slashes to a string in Javascript?

var myNewString = myOldString.replace(/'/g, "\\'");

Escape sequence \f - form feed - what exactly is it?

It comes from the era of Line Printers and green-striped fan-fold paper.

Trust me, you ain't gonna need it...

Remove Item from ArrayList

 public void DeleteUserIMP(UserIMP useriamp) {
       synchronized (ListUserIMP) {
            if (ListUserIMP.isEmpty()) {
            System.out.println("user is empty");
        }  else {
            Iterator<UserIMP> it = ListUserIMP.iterator();
            while (it.hasNext()) {
                UserIMP user =;
                if (useriamp.getMoblieNumber().equals(user.getMoblieNumber())) {
                    System.out.println("remove it");
            // ListUserIMP.remove(useriamp);

            System.out.println(" this user removed");
        Constants.RESULT_FOR_REGISTRATION = Constants.MESSAGE_OK;
        // System.out.println("This user Deleted " + Constants.MESSAGE_OK);


Postgres FOR LOOP

I find it more convenient to make a connection using a procedural programming language (like Python) and do these types of queries.

import psycopg2
connection_psql = psycopg2.connect( user="admin_user"
                                  , password="***"
                                  , port="5432"
                                  , database="myDB"
                                  , host="[ENDPOINT]")
cursor_psql = connection_psql.cursor()

myList = [...]
for item in myList:
    -- The query goes here


SQL Joins Vs SQL Subqueries (Performance)?

The performance should be the same; it's much more important to have the correct indexes and clustering applied on your tables (there exist some good resources on that topic).

(Edited to reflect the updated question)

How do I get the absolute directory of a file in bash?

To get the full path use:

readlink -f relative/path/to/file

To get the directory of a file:

dirname relative/path/to/file

You can also combine the two:

dirname $(readlink -f relative/path/to/file)

If readlink -f is not available on your system you can use this*:

function myreadlink() {
  cd "$(dirname $1)"         # or  cd "${1%/*}"
  echo "$PWD/$(basename $1)" # or  echo "$PWD/${1##*/}"

Note that if you only need to move to a directory of a file specified as a relative path, you don't need to know the absolute path, a relative path is perfectly legal, so just use:

cd $(dirname relative/path/to/file)

if you wish to go back (while the script is running) to the original path, use pushd instead of cd, and popd when you are done.

* While myreadlink above is good enough in the context of this question, it has some limitation relative to the readlink tool suggested above. For example it doesn't correctly follow a link to a file with different basename.

iTunes Connect Screenshots Sizes for all iOS (iPhone/iPad/Apple Watch) devices

This answer is updated for Xcode 11.

App Store Connect currently asks for images in the following categories:

enter image description here

iPhone 6.5" Display

This is 1242 x 2688 pixels. You can create this size image using the iPhone 11 Pro Max simulator.

iPhone 5.5" Display

This is 1242 x 2208 pixels. You can create this size image using the iPhone 8 Plus simulator.

iPad Pro (3rd gen) 12.9" Display

That is 2048 x 2732 pixels. You can create this size image using the iPad Pro (12.9-inch) (3rd generation) simulator.

iPad Pro (2nd gen) 12.9" Display

That is 2048 x 2732 pixels. This is the exact same size as the iPad Pro (12.9-inch) (3rd generation), so most people can use the same screenshots here. But see this.


  • Use File > New Screen Shot (Command+S) in the simulator to save a screenshot to the desktop. On a real device press Sleep/Wake+Home on the iPhone/iPad (images available in Photo app)
  • The pixel dimensions above are the full screen portrait orientation sizes. You shouldn't include the status bar, so you can either paste background color over the status bar text and icons or crop them out and scale the image back up.
  • See this link for more details.

Mocking HttpClient in unit tests

DO NOT have a wrapper that creates a new instance of HttpClient. If you do that, you will run out of sockets at runtime (even though you are disposing the HttpClient object).

If using MOQ, the correct way to do this is to add using Moq.Protected; to your test and then write code like the following:

var response = new HttpResponseMessage(HttpStatusCode.OK)
    Content = new StringContent("It worked!")
var mockHttpMessageHandler = new Mock<HttpMessageHandler>();
    .ReturnsAsync(() => response);

var httpClient = new HttpClient(mockHttpMessageHandler.Object);

How to set minDate to current date in jQuery UI Datepicker?

minDate property for current date works on for both -> minDate:"yy-mm-dd" or minDate:0

How to use GROUP_CONCAT in a CONCAT in MySQL

SELECT id, Group_concat(column) FROM (SELECT id, Concat(name, ':', Group_concat(value)) AS column FROM mytbl GROUP BY id, name) tbl GROUP BY id;

DB2 Timestamp select statement

You might want to use TRUNC function on your column when comparing with string format, so it compares only till seconds, not milliseconds.

SELECT * FROM <table_name> WHERE id = 1 
AND TRUNC(usagetime, 'SS') = '2012-09-03 08:03:06';

If you wanted to truncate upto minutes, hours, etc. that is also possible, just use appropriate notation instead of 'SS':

hour ('HH'), minute('MI'), year('YEAR' or 'YYYY'), month('MONTH' or 'MM'), Day ('DD')

Removing trailing newline character from fgets() input

The steps to remove the newline character in the perhaps most obvious way:

  1. Determine the length of the string inside NAME by using strlen(), header string.h. Note that strlen() does not count the terminating \0.
size_t sl = strlen(NAME);

  1. Look if the string begins with or only includes one \0 character (empty string). In this case sl would be 0 since strlen() as I said above doesn´t count the \0 and stops at the first occurrence of it:
if(sl == 0)
   // Skip the newline replacement process.

  1. Check if the last character of the proper string is a newline character '\n'. If this is the case, replace \n with a \0. Note that index counts start at 0 so we will need to do NAME[sl - 1]:
if(NAME[sl - 1] == '\n')
   NAME[sl - 1] = '\0';

Note if you only pressed Enter at the fgets() string request (the string content was only consisted of a newline character) the string in NAME will be an empty string thereafter.

  1. We can combine step 2. and 3. together in just one if-statement by using the logic operator &&:
if(sl > 0 && NAME[sl - 1] == '\n')
   NAME[sl - 1] = '\0';

  1. The finished code:
size_t sl = strlen(NAME);
if(sl > 0 && NAME[sl - 1] == '\n')
   NAME[sl - 1] = '\0';

If you rather like a function for use this technique by handling fgets output strings in general without retyping each and every time, here is fgets_newline_kill:

void fgets_newline_kill(char a[])
    size_t sl = strlen(a);

    if(sl > 0 && a[sl - 1] == '\n')
       a[sl - 1] = '\0';

In your provided example, it would be:

printf("Enter your Name: ");

if (fgets(Name, sizeof Name, stdin) == NULL) {
    fprintf(stderr, "Error reading Name.\n");
else {

Note that this method does not work if the input string has embedded \0s in it. If that would be the case strlen() would only return the amount of characters until the first \0. But this isn´t quite a common approach, since the most string-reading functions usually stop at the first \0 and take the string until that null character.

Aside from the question on its own. Try to avoid double negations that make your code unclearer: if (!(fgets(Name, sizeof Name, stdin) != NULL) {}. You can simply do if (fgets(Name, sizeof Name, stdin) == NULL) {}.

When is a timestamp (auto) updated?

Give the command SHOW CREATE TABLE whatever

Then look at the table definition.

It probably has a line like this


in it. DEFAULT CURRENT_TIMESTAMP means that any INSERT without an explicit time stamp setting uses the current time. Likewise, ON UPDATE CURRENT_TIMESTAMP means that any update without an explicit timestamp results in an update to the current timestamp value.

You can control this default behavior when creating your table.

Or, if the timestamp column wasn't created correctly in the first place, you can change it.

ALTER TABLE whatevertable
     CHANGE whatevercolumn 
            whatevercolumn TIMESTAMP NOT NULL
                           DEFAULT CURRENT_TIMESTAMP 
                           ON UPDATE CURRENT_TIMESTAMP;

This will cause both INSERT and UPDATE operations on the table automatically to update your timestamp column. If you want to update whatevertable without changing the timestamp, that is,

To prevent the column from updating when other columns change

then you need to issue this kind of update.

UPDATE whatevertable
   SET something = 'newvalue',
       whatevercolumn = whatevercolumn
 WHERE someindex = 'indexvalue'

This works with TIMESTAMP and DATETIME columns. (Prior to MySQL version 5.6.5 it only worked with TIMESTAMPs) When you use TIMESTAMPs, time zones are accounted for: on a correctly configured server machine, those values are always stored in UTC and translated to local time upon retrieval.

Form inline inside a form horizontal in twitter bootstrap?

For bootstrap 3 example above works but is overcomplicated, rather than using form-group use form-inline for the fields you want inline.


<div class="form-group">
     <input type="text" size="4" class="form-control" />

<div class="form-inline">
      <label>Expiration (MM/YYYY)</label><br>
      <input type="text" size="2" class="form-control" /> / <input type="text" size="4" class="form-control" />

How to group dataframe rows into list in pandas groupby

To solve this for several columns of a dataframe:

In [5]: df = pd.DataFrame( {'a':['A','A','B','B','B','C'], 'b':[1,2,5,5,4,6],'c'
   ...: :[3,3,3,4,4,4]})

In [6]: df
   a  b  c
0  A  1  3
1  A  2  3
2  B  5  3
3  B  5  4
4  B  4  4
5  C  6  4

In [7]: df.groupby('a').agg(lambda x: list(x))
           b          c
A     [1, 2]     [3, 3]
B  [5, 5, 4]  [3, 4, 4]
C        [6]        [4]

This answer was inspired from Anamika Modi's answer. Thank you!

Get current domain

I know this might not be entirely on the subject, but in my experience, I find storing WWW-ness of current URL in a variable useful.

Edit: In addition, please see my comment below, to see what this is getting at.

This is important when determining whether to dispatch Ajax calls with "www", or without:

$.ajax("url" : "", ...

$.ajax("url" : "", ...

When dispatching an Ajax call the domain name must match that of in the browser's address bar, otherwise you will have Uncaught SecurityError in console.

So I came up with this solution to address the issue:

    substr($_SERVER['SERVER_NAME'], 0, 3) == "www" ? $WWW = true : $WWW = false;

    if ($WWW) {
        /* We have */
    } else {
        /* We have */

Then, based on whether $WWW is true, or false run the proper Ajax call.

I know this might sound trivial, but this is such a common problem that is easy to trip over.

Vertical align middle with Bootstrap responsive grid

Add !important rule to display: table of your .v-center class.

.v-center {
    display:table !important;
    border:2px solid gray;

Your display property is being overridden by bootstrap to display: block.


www-data permissions?

As stated in an article by Slicehost:

User setup

So let's start by adding the main user to the Apache user group:

sudo usermod -a -G www-data demo

That adds the user 'demo' to the 'www-data' group. Do ensure you use both the -a and the -G options with the usermod command shown above.

You will need to log out and log back in again to enable the group change.

Check the groups now:

# demo www-data

So now I am a member of two groups: My own (demo) and the Apache group (www-data).

Folder setup

Now we need to ensure the public_html folder is owned by the main user (demo) and is part of the Apache group (www-data).

Let's set that up:

sudo chgrp -R www-data /home/demo/public_html

As we are talking about permissions I'll add a quick note regarding the sudo command: It's a good habit to use absolute paths (/home/demo/public_html) as shown above rather than relative paths (~/public_html). It ensures sudo is being used in the correct location.

If you have a public_html folder with symlinks in place then be careful with that command as it will follow the symlinks. In those cases of a working public_html folder, change each folder by hand.


Good so far, but remember the command we just gave only affects existing folders. What about anything new?

We can set the ownership so anything new is also in the 'www-data' group.

The first command will change the permissions for the public_html directory to include the "setgid" bit:

sudo chmod 2750 /home/demo/public_html

That will ensure that any new files are given the group 'www-data'. If you have subdirectories, you'll want to run that command for each subdirectory (this type of permission doesn't work with '-R'). Fortunately new subdirectories will be created with the 'setgid' bit set automatically.

If we need to allow write access to Apache, to an uploads directory for example, then set the permissions for that directory like so:

sudo chmod 2770 /home/demo/public_html/

The permissions only need to be set once as new files will automatically be assigned the correct ownership.

How can I make a countdown with NSTimer?

Variable for your timer

var timer = 60

NSTimer with 1.0 as interval

var clock = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: "countdown", userInfo: nil, repeats: true)

Here you can decrease the timer

func countdown() {

Git log to get commits only for a specific branch

You could try something like this:


    target="$(git rev-parse $1)"
    echo "$target --not"
    git for-each-ref --shell --format="ref=%(refname)" refs/heads | \
    while read entry
        eval "$entry"

        test "$ref" != "$target" && echo "$ref"

git log $(all_but $1)

Or, borrowing from the recipe in the Git User's Manual:

git log $1 --not $( git show-ref --heads | cut -d' ' -f2 | grep -v "^$1" )

how does array[100] = {0} set the entire array to 0?

It's not magic.

The behavior of this code in C is described in section of the C specification (online draft of C spec): for the elements that don't have a specified value, the compiler initializes pointers to NULL and arithmetic types to zero (and recursively applies this to aggregates).

The behavior of this code in C++ is described in section of the C++ specification (online draft of C++ spec): the compiler aggregate-initializes the elements that don't have a specified value.

Also, note that in C++ (but not C), you can use an empty initializer list, causing the compiler to aggregate-initialize all of the elements of the array:

char array[100] = {};

As for what sort of code the compiler might generate when you do this, take a look at this question: Strange assembly from array 0-initialization

How to read multiple text files into a single RDD?

You can specify whole directories, use wildcards and even CSV of directories and wildcards. E.g.:


As Nick Chammas points out this is an exposure of Hadoop's FileInputFormat and therefore this also works with Hadoop (and Scalding).

How can I find where I will be redirected using cURL?

You can use:

$redirectURL = curl_getinfo($ch,CURLINFO_REDIRECT_URL);

How to sum the values of a JavaScript object?

Sum the object key value by parse Integer. Converting string format to integer and summing the values

var obj = {
  pay: 22
var x = parseInt(;
console.log(x + 20);

How to put a component inside another component in Angular2?

I think in your Angular-2 version directives are not supported in Component decorator, hence you have to register directive same as other component in @NgModule and then import in component as below and also remove directives: [ChildComponent] from decorator.

import {myDirective} from './myDirective';

When do I have to use interfaces instead of abstract classes?

From Java How to Program about abstract classes:

Because they’re used only as superclasses in inheritance hierarchies, we refer to them as abstract superclasses. These classes cannot be used to instantiate objects, because abstract classes are incomplete. Subclasses must declare the “missing pieces” to become “concrete” classes, from which you can instantiate objects. Otherwise, these subclasses, too, will be abstract.

To answer your question "What is the reason to use interfaces?":

An abstract class’s purpose is to provide an appropriate superclass from which other classes can inherit and thus share a common design.

As opposed to an interface:

An interface describes a set of methods that can be called on an object, but does not provide concrete implementations for all the methods... Once a class implements an interface, all objects of that class have an is-a relationship with the interface type, and all objects of the class are guaranteed to provide the functionality described by the interface. This is true of all subclasses of that class as well.

So, to answer your question "I was wondering when I should use interfaces", I think you should use interfaces when you want a full implementation and use abstract classes when you want partial pieces for your design (for reusability)

Fatal error: Out of memory, but I do have plenty of memory (PHP)

I know it's an old thread, but here's my experience getting it resolved.

My server is a hosted service running Apache.

My script crashed with out of memory at 6Mb, when my limit Was 256Mb - crazy, yeah?

It is being called synchronously via an http callback, from javascript running on my client, and crashed after around 550 calls. After much time wasted with incompetent "Escalated Support" guys, my script now magically runs.

They said all they did was to reset php.ini, but I checked the differences: enter image description here

No changes there that I can see that could have a bearing on an Out of Memory error.

I suspect a memory leak in the web server which my "Escalated Support" guy is hiding under the guise of resetting the php.ini. And, really, I'm not a conspiracy theorist.

Entity framework left join

adapted from MSDN, how to left join using EF 4

var query = from u in usergroups
            join p in UsergroupPrices on u.UsergroupID equals p.UsergroupID into gj
            from x in gj.DefaultIfEmpty()
            select new { 
                UsergroupID = u.UsergroupID,
                UsergroupName = u.UsergroupName,
                Price = (x == null ? String.Empty : x.Price) 

How to connect access database in c#

Try this code,

public void ConnectToAccess()
    System.Data.OleDb.OleDbConnection conn = new 
    // TODO: Modify the connection string and include any
    // additional required properties for your database.
    conn.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;" +
        @"Data source= C:\Documents and Settings\username\" +
        @"My Documents\AccessFile.mdb";
        // Insert code to process data.
        catch (Exception ex)
        MessageBox.Show("Failed to connect to data source");

Numpy matrix to array

First, Mv = numpy.asarray(M.T), which gives you a 4x1 but 2D array.

Then, perform A = Mv[0,:], which gives you what you want. You could put them together, as numpy.asarray(M.T)[0,:].

How to enable MySQL Query Log?

You can disable or enable the general query log (which logs all queries) with

SET GLOBAL general_log = 1 # (or 0 to disable)

How to compare two dates in Objective-C

NSDate *today = [NSDate date]; // it will give you current date
NSDate *newDate = [NSDate dateWithString:@"xxxxxx"]; // your date 

NSComparisonResult result; 
//has three possible values: NSOrderedSame,NSOrderedDescending, NSOrderedAscending

result = [today compare:newDate]; // comparing two dates

    NSLog(@"today is less");
else if(result==NSOrderedDescending)
    NSLog(@"newDate is less");
    NSLog(@"Both dates are same");

There are other ways that you may use to compare an NSDate objects. Each of the methods will be more efficient at certain tasks. I have chosen the compare method because it will handle most of your basic date comparison needs.

How do I break a string in YAML over multiple lines?

To preserve newlines use |, for example:

  This is a very long sentence
  that spans several lines in the YAML
  but which will be rendered as a string
  with newlines preserved.

is translated to "This is a very long sentence?\n that spans several lines in the YAML?\n but which will be rendered as a string?\n with newlines preserved.\n"

Identify duplicate values in a list in Python

These answers are O(n), so a little more code than using mylist.count() but much more efficient as mylist gets longer

If you just want to know the duplicates, use collections.Counter

from collections import Counter
mylist = [20, 30, 25, 20]
[k for k,v in Counter(mylist).items() if v>1]

If you need to know the indices,

from collections import defaultdict
D = defaultdict(list)
for i,item in enumerate(mylist):
D = {k:v for k,v in D.items() if len(v)>1}

Understanding MongoDB BSON Document size limit

Many in the community would prefer no limit with warnings about performance, see this comment for a well reasoned argument:

My take, the lead developers are stubborn about this issue because they decided it was an important "feature" early on. They're not going to change it anytime soon because their feelings are hurt that anyone questioned it. Another example of personality and politics detracting from a product in open source communities but this is not really a crippling issue.

changing permission for files and folder recursively using shell command in mac

The issue is that the * is getting interpreted by your shell and is expanding to a file named TEST_FILE that happens to be in your current working directory, so you're telling find to execute the command named TEST_FILE which doesn't exist. I'm not sure what you're trying to accomplish with that *, you should just remove it.

Furthermore, you should use the idiom -exec program '{}' \+ instead of -exec program '{}' \; so that find doesn't fork a new process for each file. With ;, a new process is forked for each file, whereas with +, it only forks one process and passes all of the files on a single command line, which for simple programs like chmod is much more efficient.

Lastly, chmod can do recursive changes on its own with the -R flag, so unless you need to search for specific files, just do this:

chmod -R 777 /Users/Test/Desktop/PATH

How can I get my Android device country code without using GPS?

You shouldn't be passing anything in to getCountry(). Remove Locale.getDefault():

String locale = context.getResources().getConfiguration().locale.getCountry();

The client and server cannot communicate, because they do not possess a common algorithm - ASP.NET C# IIS TLS 1.0 / 1.1 / 1.2 - Win32Exception

There are two possible scenario, in my case I used 2nd point.

  1. If you are facing this issue in production environment and you can easily deploy new code to the production then you can use of below solution.

    You can add below line of code before making api call,

    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12; // .NET 4.5

  2. If you cannot deploy new code and you want to resolve with the same code which is present in the production, then this issue can be done by changing some configuration setting file. You can add either of one in your config file.

    <AppContextSwitchOverrides value="Switch.System.Net.DontEnableSchUseStrongCrypto=false"/>


  <AppContextSwitchOverrides value="Switch.System.Net.DontEnableSystemDefaultTlsVersions=false"

how to parse xml to java object?

JAXB is a reliable choice as it does xml to java classes mapping smoothely. But there are other frameworks available, here is one such:

explicit casting from super class to subclass

The code generates a compilation error because your instance type is an Animal:

Animal animal=new Animal();

Downcasting is not allowed in Java for several reasons. See here for details.

onchange equivalent in angular2

@Mark Rajcok gave a great solution for ion projects that include a range type input.

In any other case of non ion projects I will suggest this:


<input type="text" name="points" #points maxlength="8" [(ngModel)]="range" (ngModelChange)="range=saverange($event, points)">


    onChangeAchievement(eventStr: string, eRef): string {

      //Do something (some manipulations) on input and than return it to be saved:

       //In case you need to force of modifing the Element-Reference value on-focus of input:
       var eventStrToReplace = eventStr.replace(/[^0-9,eE\.\+]+/g, "");
       if (eventStr != eventStrToReplace) {
           eRef.value = eventStrToReplace;

      return this.getNumberOnChange(eventStr);


The idea here:

  1. Letting the (ngModelChange) method to do the Setter job:

    (ngModelChange)="range=saverange($event, points)

  2. Enabling direct access to the native Dom element using this call:

    eRef.value = eventStrToReplace;

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

An explanation of the following error:

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


You opened up more than the allowed limit of connections to the database. You ran something like this: Connection conn = myconn.Open(); inside of a loop, and forgot to run conn.close();. Just because your class is destroyed and garbage collected does not release the connection to the database. The quickest fix to this is to make sure you have the following code with whatever class that creates a connection:

protected void finalize() throws Throwable  
    try { your_connection.close(); } 
    catch (SQLException e) { 

Place that code in any class where you create a Connection. Then when your class is garbage collected, your connection will be released.

Run this SQL to see postgresql max connections allowed:

show max_connections;

The default is 100. PostgreSQL on good hardware can support a few hundred connections at a time. If you want to have thousands, you should consider using connection pooling software to reduce the connection overhead.

Take a look at exactly who/what/when/where is holding open your connections:

SELECT * FROM pg_stat_activity;

The number of connections currently used is:

SELECT COUNT(*) from pg_stat_activity;

Debugging strategy

  1. You could give different usernames/passwords to the programs that might not be releasing the connections to find out which one it is, and then look in pg_stat_activity to find out which one is not cleaning up after itself.

  2. Do a full exception stack trace when the connections could not be created and follow the code back up to where you create a new Connection, make sure every code line where you create a connection ends with a connection.close();

How to set the max_connections higher:

max_connections in the postgresql.conf sets the maximum number of concurrent connections to the database server.

  1. First find your postgresql.conf file
  2. If you don't know where it is, query the database with the sql: SHOW config_file;
  3. Mine is in: /var/lib/pgsql/data/postgresql.conf
  4. Login as root and edit that file.
  5. Search for the string: "max_connections".
  6. You'll see a line that says max_connections=100.
  7. Set that number bigger, check the limit for your postgresql version.
  8. Restart the postgresql database for the changes to take effect.

What's the maximum max_connections?

Use this query:

select min_val, max_val from pg_settings where name='max_connections';

I get the value 8388607, in theory that's the most you are allowed to have, but then a runaway process can eat up thousands of connections, and surprise, your database is unresponsive until reboot. If you had a sensible max_connections like 100. The offending program would be denied a new connection.

How to compare LocalDate instances Java 8

I believe this snippet will also be helpful in a situation where the dates comparison spans more than two entries.

static final int COMPARE_EARLIEST = 0;

static final int COMPARE_MOST_RECENT = 1;

public LocalDate getTargetDate(List<LocalDate> datesList, int comparatorType) { 
   LocalDate refDate = null;
       case COMPARE_EARLIEST:         
       //returns the most earliest of the date entries
          refDate = (LocalDate) -> 

          //returns the most recent of the date entries 
          refDate = (LocalDate) -> 

   return refDate;

Is there a pretty print for PHP?

The best I found yet is this:

echo "<pre>";
echo "</pre>";

And if you want it more detailed:

echo "<pre>";
echo "</pre>";

Adding a <pre> HTML tag in a web development environment will respect the newlines \n of the print function correctly, without having to add some html <br>

XML Document to String

First you need to get rid of all newline characters in all your text nodes. Then you can use an identity transform to output your DOM tree. Look at the javadoc for TransformerFactory#newTransformer().

canvas.toDataURL() SecurityError

Unless google serves this image with the correct Access-Control-Allow-Origin header, then you wont be able to use their image in canvas. This is due to not having CORS approval. You can read more about this here, but it essentially means:

Although you can use images without CORS approval in your canvas, doing so taints the canvas. Once a canvas has been tainted, you can no longer pull data back out of the canvas. For example, you can no longer use the canvas toBlob(), toDataURL(), or getImageData() methods; doing so will throw a security error.

This protects users from having private data exposed by using images to pull information from remote web sites without permission.

I suggest just passing the URL to your server-side language and using curl to download the image. Be careful to sanitise this though!


As this answer is still the accepted answer, you should check out @shadyshrif's answer, which is to use:

var img = new Image();
img.setAttribute('crossOrigin', 'anonymous');
img.src = url;

This will only work if you have the correct permissions, but will at least allow you to do what you want.

docker : invalid reference format

For others come to here:
If you happen to put your docker command in a file, say, check your line separator. In Linux, it should be LR, otherwise you would get the same error.

java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference

in your baseadapter class constructor try to initialize LayoutInflater, normally i preferred this way,

public ClassBaseAdapter(Context context,ArrayList<Integer> listLoanAmount) {
    this.context = context;
    this.listLoanAmount = listLoanAmount;
    this.layoutInflater = LayoutInflater.from(context);

at the top of the class create LayoutInflater variable, hope this will help you

Effective method to hide email from spam bots

If you have php support, you can do something like this:

<img src="scriptname.php">

And the scriptname.php:

header("Content-type: image/png");
// Your email address which will be shown in the image
$email    =    "[email protected]";
$length    =    (strlen($email)*8);
$im = @ImageCreate ($length, 20)
     or die ("Kann keinen neuen GD-Bild-Stream erzeugen");
$background_color = ImageColorAllocate ($im, 255, 255, 255); // White: 255,255,255
$text_color = ImageColorAllocate ($im, 55, 103, 122);
imagestring($im, 3,5,2,$email, $text_color);
imagepng ($im);

How to copy to clipboard using Access/VBA?

VB 6 provides a Clipboard object that makes all of this extremely simple and convenient, but unfortunately that's not available from VBA.

If it were me, I'd go the API route. There's no reason to be scared of calling native APIs; the language provides you with the ability to do that for a reason.

However, a simpler alternative is to use the DataObject class, which is part of the Forms library. I would only recommend going this route if you are already using functionality from the Forms library in your app. Adding a reference to this library only to use the clipboard seems a bit silly.

For example, to place some text on the clipboard, you could use the following code:

Dim clipboard As MSForms.DataObject
Set clipboard = New MSForms.DataObject
clipboard.SetText "A string value"

Or, to copy text from the clipboard into a string variable:

Dim clipboard As MSForms.DataObject
Dim strContents As String

Set clipboard = New MSForms.DataObject
strContents = clipboard.GetText

Rewrite left outer join involving multiple tables from Informix to Oracle

Write one table per join, like this:

select tab1.a,tab2.b,tab3.c,tab4.d 
  table1 tab1
  inner join table2 tab2 on tab2.fg = tab1.fg
  left join table3 tab3 on = and tab3.desc = "XYZ"
  left join table4 tab4 on tab4.xya = tab3.xya and =
  left join table5 tab5 on tab5.dd = tab3.dd and tab5.kk = tab4.kk

Note that while my query contains actual left join, your query apparently doesn't. Since the conditions are in the where, your query should behave like inner joins. (Although I admit I don't know Informix, so maybe I'm wrong there).

The specfific Informix extension used in the question works a bit differently with regards to left joins. Apart from the exact syntax of the join itself, this is mainly in the fact that in Informix, you can specify a list of outer joined tables. These will be left outer joined, and the join conditions can be put in the where clause. Note that this is a specific extension to SQL. Informix also supports 'normal' left joins, but you can't combine the two in one query, it seems.

In Oracle this extension doesn't exist, and you can't put outer join conditions in the where clause, since the conditions will be executed regardless.

So look what happens when you move conditions to the where clause:

select tab1.a,tab2.b,tab3.c,tab4.d 
  table1 tab1
  inner join table2 tab2 on tab2.fg = tab1.fg
  left join table3 tab3 on =
  left join table4 tab4 on tab4.xya = tab3.xya
  left join table5 tab5 on tab5.dd = tab3.dd and tab5.kk = tab4.kk
  tab3.desc = "XYZ" and =

Now, only rows will be returned for which those two conditions are true. They cannot be true when no row is found, so if there is no matching row in table3 and/or table4, or if ss is null in either of the two, one of these conditions is going to return false, and no row is returned. This effectively changed your outer join to an inner join, and as such changes the behavior significantly.

PS: left join and left outer join are the same. It means that you optionally join the second table to the first (the left one). Rows are returned if there is only data in the 'left' part of the join. In Oracle you can also right [outer] join to make not the left, but the right table the leading table. And there is and even full [outer] join to return a row if there is data in either table.

File opens instead of downloading in internet explorer in a href link

This must be a matter of http headers.

see here: HTTP Headers for File Downloads

The server should tell your browser to download the file by sending

Content-Type: application/octet-stream; 
Content-Disposition: attachment;

in the headers

Using routes in Express-js

No one should ever have to keep writing app.use('/someRoute', require('someFile')) until it forms a heap of code.

It just doesn't make sense at all to be spending time invoking/defining routings. Even if you do need custom control, it's probably only for some of the time, and for the most bit you want to be able to just create a standard file structure of routings and have a module do it automatically.

Try Route Magic

As you scale your app, the routing invocations will start to form a giant heap of code that serves no purpose. You want to do just 2 lines of code to handle all the app.use routing invocations with Route Magic like this:

const magic = require('express-routemagic')
magic.use(app, __dirname, '[your route directory]')

For those you want to handle manually, just don't use pass the directory to Magic.

Flash CS4 refuses to let go

What if you compile it using another machine? A fresh installed one would be lovely. I hope your machine is not jealous.

Efficient way to rotate a list in python

What is the use case? Often, we don't actually need a fully shifted array --we just need to access a handful of elements in the shifted array.

Getting Python slices is runtime O(k) where k is the slice, so a sliced rotation is runtime N. The deque rotation command is also O(k). Can we do better?

Consider an array that is extremely large (let's say, so large it would be computationally slow to slice it). An alternative solution would be to leave the original array alone and simply calculate the index of the item that would have existed in our desired index after a shift of some kind.

Accessing a shifted element thus becomes O(1).

def get_shifted_element(original_list, shift_to_left, index_in_shifted):
    # back calculate the original index by reversing the left shift
    idx_original = (index_in_shifted + shift_to_left) % len(original_list)
    return original_list[idx_original]

my_list = [1, 2, 3, 4, 5]

print get_shifted_element(my_list, 1, 2) ----> outputs 4

print get_shifted_element(my_list, -2, 3) -----> outputs 2 

Call javascript from MVC controller action

For those that just used a standard form submit (non-AJAX), there's another way to fire some Javascript/JQuery code upon completion of your action.

First, create a string property on your Model.

public class MyModel 
    public string JavascriptToRun { get; set;}

Now, bind to your new model property in the Javascript of your view:

<script type="text/javascript">

Now, also in your view, create a Javascript function that does whatever you need to do:

<script type="text/javascript">

     function ShowErrorPopup() {
          alert('Sorry, we could not process your order.');


Finally, in your controller action, you need to call this new Javascript function:

public ActionResult PurchaseCart(MyModel model)
    // Do something useful

    if (success == false)
        model.JavascriptToRun= "ShowErrorPopup()";
        return View(model);
        return RedirectToAction("Success");

How can I explicitly free memory in Python?

Unfortunately (depending on your version and release of Python) some types of objects use "free lists" which are a neat local optimization but may cause memory fragmentation, specifically by making more and more memory "earmarked" for only objects of a certain type and thereby unavailable to the "general fund".

The only really reliable way to ensure that a large but temporary use of memory DOES return all resources to the system when it's done, is to have that use happen in a subprocess, which does the memory-hungry work then terminates. Under such conditions, the operating system WILL do its job, and gladly recycle all the resources the subprocess may have gobbled up. Fortunately, the multiprocessing module makes this kind of operation (which used to be rather a pain) not too bad in modern versions of Python.

In your use case, it seems that the best way for the subprocesses to accumulate some results and yet ensure those results are available to the main process is to use semi-temporary files (by semi-temporary I mean, NOT the kind of files that automatically go away when closed, just ordinary files that you explicitly delete when you're all done with them).

Example: Communication between Activity and Service using Messaging

Seems to me you could've saved some memory by declaring your activity with "implements Handler.Callback"

"Primary Filegroup is Full" in SQL Server 2008 Standard for no apparent reason

I found that this happens because:

SQL Server only releases all the pages that a heap table uses when the following conditions are true: A deletion on this table occurs. A table-level lock is being held. Note A heap table is any table that is not associated with a clustered index.

If pages are not deallocated, other objects in the database cannot reuse the pages.

However, when you enable a row versioning-based isolation level in a SQL Server 2005 database, pages cannot be released even if a table-level lock is being held.

Microsoft's solution:

To work around this problem, use one of the following methods: Include a TABLOCK hint in the DELETE statement if a row versioning-based isolation level is not enabled. For example, use a statement that is similar to the following:


Note represents the name of the table. Use the TRUNCATE TABLE statement if you want to delete all the records in the table. For example, use a statement that is similar to the following:


Create a clustered index on a column of the table. For more information about how to create a clustered index on a table, see the "Creating a Clustered Index" topic in SQL

You'll notice at the bottom of the link that it is NOT noted that it applies to SQL Server 2008 but I think it does

Importing data from a JSON file into R

jsonlite will import the JSON into a data frame. It can optionally flatten nested objects. Nested arrays will be data frames.

> library(jsonlite)
> winners <- fromJSON("winners.json", flatten=TRUE)
> colnames(winners)
[1] "winner" "votes" "startPrice" "lastVote.timestamp" "" "lastVote.user.user_id"
> winners[,c("winner","startPrice","")]
    winner startPrice
1 68694999          0              Lamur
> winners[,c("votes")]
                            ts user.user_id
1 Thu Mar 25 03:13:01 UTC 2010     Lamur     68694999
2 Thu Mar 25 03:13:08 UTC 2010     Lamur     68694999

Is there a way to perform "if" in python's lambda

Probably the worst python line I've written so far:

f = lambda x: sys.stdout.write(["2\n",][2*(x==2)-2])

If x == 2 you print,

if x != 2 you raise.

App not setup: This app is still in development mode


I have done successfully Login with Facebook by doing below things. Now it is working fine.

As per described by George Mano

Visit Facebook Apps Page and select your application.

Go to Settings -> Basic.

Add a 1 Contact Email, 2 Privacy Policy URL, 3 User Data Deletion and choose 4 Category and Last 5. Live your application

The Privacy Policy URL should be a webpage where you have hosted the terms and conditions of your application and data used.

The General Data Protection Regulation (GDPR) requires developers to provide a way for people to request that their data be deleted. To be compliant with these requirements, you must provide either a data deletion request callback or instructions to inform people how to delete their data from your app or website

Toggle the button in the top of the screen, as seen below, in order to switch from Development to Live.

enter image description here

How can I scroll up more (increase the scroll buffer) in iTerm2?

There is an option “unlimited scrollback buffer” which you can find under Preferences > Profiles > Terminal or you can just pump up number of lines that you want to have in history in the same place.

In SQL, how can you "group by" in ranges?

An alternative approach would involve storing the ranges in a table, instead of embedding them in the query. You would end up with a table, call it Ranges, that looks like this:

LowerLimit   UpperLimit   Range 
0              9          '0-9'
10            19          '10-19'
20            29          '20-29'
30            39          '30-39'

And a query that looks like this:

   Range as [Score Range],
   Count(*) as [Number of Occurences]
   Ranges r inner join Scores s on s.Score between r.LowerLimit and r.UpperLimit
group by Range

This does mean setting up a table, but it would be easy to maintain when the desired ranges change. No code changes necessary!

Pretty-print a Map in Java

Since java 8 there is easy way to do it with Lambda:

yourMap.keySet().forEach(key -> {
    Object obj = yourMap.get(key);
    System.out.println( obj);

Can I exclude some concrete urls from <url-pattern> inside <filter-mapping>?

I used an approach described by Eric Daugherty: I created a special servlet that always answers with 403 code and put its mapping before the general one.

Mapping fragment:


And the servlet class:

public class SpecialServlet extends HttpServlet {
    public SpecialServlet() {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

What are the most common naming conventions in C?

There could be many, mainly IDEs dictate some trends and C++ conventions are also pushing. For C commonly:

  • UNDERSCORED_UPPER_CASE (macro definitions, constants, enum members)
  • underscored_lower_case (variables, functions)
  • CamelCase (custom types: structs, enums, unions)
  • uncappedCamelCase (oppa Java style)
  • UnderScored_CamelCase (variables, functions under kind of namespaces)

Hungarian notation for globals are fine but not for types. And even for trivial names, please use at least two characters.

How to check if a given directory exists in Ruby

You can also use Dir::exist? like so:

Dir.exist?('Directory Name')

Returns true if the 'Directory Name' is a directory, false otherwise.1

EOFError: end of file reached issue with Net::HTTP

I had a similar problem with a request to a non-SSL service.

This blog suggested vaguely to try URI encoding the URL that is passed to 'get':

I took a shot at it, based on desperation, and in my limiting testing this seems to have fixed it for me. My new code is:

@http ='')  
@http = @http.start    
url = ''
req =
req.basic_auth USERNAME, API_KEY
res = @http.request(req) 

Note that I use @http.start as I want to maintain the HTTP session over multiple requests. Other than that, you might like to try the most relevant part which is: URI.encode(url) inside the get call

VBA - Run Time Error 1004 'Application Defined or Object Defined Error'

Solution #1: Your statement

.Range(Cells(RangeStartRow, RangeStartColumn), Cells(RangeEndRow, RangeEndColumn)).PasteSpecial xlValues

does not refer to a proper Range to act upon. Instead,

.Range(.Cells(RangeStartRow, RangeStartColumn), .Cells(RangeEndRow, RangeEndColumn)).PasteSpecial xlValues

does (and similarly in some other cases).

Solution #2: Activate Worksheets("Cable Cards") prior to using its cells.

Explanation: Cells(RangeStartRow, RangeStartColumn) (e.g.) gives you a Range, that would be ok, and that is why you often see Cells used in this way. But since it is not applied to a specific object, it applies to the ActiveSheet. Thus, your code attempts using .Range(rng1, rng2), where .Range is a method of one Worksheet object and rng1 and rng2 are in a different Worksheet.

There are two checks that you can do to make this quite evident:

  1. Activate your Worksheets("Cable Cards") prior to executing your Sub and it will start working (now you have well-formed references to Ranges). For the code you posted, adding .Activate right after With... would indeed be a solution, although you might have a similar problem somewhere else in your code when referring to a Range in another Worksheet.

  2. With a sheet other than Worksheets("Cable Cards") active, set a breakpoint at the line throwing the error, start your Sub, and when execution breaks, write at the immediate window

    Debug.Print Cells(RangeStartRow, RangeStartColumn).Address(external:=True)

    Debug.Print .Cells(RangeStartRow, RangeStartColumn).Address(external:=True)

    and see the different outcomes.

Conclusion: Using Cells or Range without a specified object (e.g., Worksheet, or Range) might be dangerous, especially when working with more than one Sheet, unless one is quite sure about what Sheet is active.

Make an html number input always display 2 decimal places

An even simpler solution would be this (IF you are targeting ALL number inputs in a particular form):

//limit number input decimal places to two
     this.value = parseFloat(this.value).toFixed(2);

Android - Pulling SQlite database android device

A common way to achieve what you desire is to use the ADB pull command.

Another way I prefer in most cases is to copy the database by code to SD card:

try {
    File sd = Environment.getExternalStorageDirectory();

    if (sd.canWrite()) {
        String currentDBPath = "/data/data/" + getPackageName() + "/databases/yourdatabasename";
        String backupDBPath = "backupname.db";
        File currentDB = new File(currentDBPath);
        File backupDB = new File(sd, backupDBPath);

        if (currentDB.exists()) {
            FileChannel src = new FileInputStream(currentDB).getChannel();
            FileChannel dst = new FileOutputStream(backupDB).getChannel();
            dst.transferFrom(src, 0, src.size());
} catch (Exception e) {


Don't forget to set the permission to write on SD in your manifest, like below.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Set Encoding of File to UTF8 With BOM in Sublime Text 3

Into the Preferences > Setting - Default

You will have the next by default:

// Display file encoding in the status bar
    "show_encoding": false

You could change it or like cdesmetz said set your user settings.

Find all special characters in a column in SQL Server 2008

The following transact SQL script works for all languages (international). The solution is not to check for alphanumeric but to check for not containing special characters.

DECLARE @teststring nvarchar(max)
SET @teststring = 'Test''Me'
SELECT 'IS ALPHANUMERIC: ' + @teststring
WHERE @teststring NOT LIKE '%[-!#%&+,./:;<=>@`{|}~"()*\\\_\^\?\[\]\'']%' {ESCAPE '\'}

Select top 10 records for each category

I do it this way:

SELECT a.* FROM articles AS a
  LEFT JOIN articles AS a2 
    ON a.section = a2.section AND a.article_date <= a2.article_date
GROUP BY a.article_id
HAVING COUNT(*) <= 10;

update: This example of GROUP BY works in MySQL and SQLite only, because those databases are more permissive than standard SQL regarding GROUP BY. Most SQL implementations require that all columns in the select-list that aren't part of an aggregate expression are also in the GROUP BY.

How do I reference a local image in React?

You need to wrap you image source path within {}

<img src={'path/to/one.jpeg'} />

You need to use require if using webpack

<img src={require('path/to/one.jpeg')} />

how to get selected row value in the KendoUI

One way is to use the Grid's select() and dataItem() methods.

In single selection case, select() will return a single row which can be passed to dataItem()

var entityGrid = $("#EntitesGrid").data("kendoGrid");
var selectedItem = entityGrid.dataItem(;
// selectedItem has EntityVersionId and the rest of your model

For multiple row selection select() will return an array of rows. You can then iterate through the array and the individual rows can be passed into the grid's dataItem().

var entityGrid = $("#EntitesGrid").data("kendoGrid");
var rows =;
rows.each(function(index, row) {
  var selectedItem = entityGrid.dataItem(row);
  // selectedItem has EntityVersionId and the rest of your model

PHPExcel auto size column width

$col = 'A';
    $tempCol = $col++;
    if($tempCol == $objPHPExcel->getActiveSheet()->getHighestDataColumn()){

Get list of certificates from the certificate store in C#

X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine);


foreach (X509Certificate2 certificate in store.Certificates){

Crystal Reports - Adding a parameter to a 'Command' query

The solution I came up with was as follows:

  1. Create the SQL query in your favorite query dev tool
  2. In Crystal Reports, within the main report, create parameter to pass to the subreport
  3. Create sub report, using the 'Add Command' option in the 'Data' portion of the 'Report Creation Wizard' and the SQL query from #1.
  4. Once the subreport is added to the main report, right click on the subreport, choose 'Change Subreport Links...', select the link field, and uncheck 'Select data in subreport based on field:'

    NOTE: You may have to initially add the parameter with the 'Select data in subreport based on field:' checked, then go back to 'Change Subreport Links ' and uncheck it after the subreport has been created.

  5. In the subreport, click the 'Report' menu, 'Select Expert', use the 'Formula Editor', set the SQL column from #1 either equal to or like the parameter(s) selected in #4.

                    (Subreport SQL Column)  (Parameter from Main Report)
            Example:  {Command.Project} like {?Pm-?Proj_Name}

Check existence of input argument in a Bash shell script

It is:

if [ $# -eq 0 ]
    echo "No arguments supplied"

The $# variable will tell you the number of input arguments the script was passed.

Or you can check if an argument is an empty string or not like:

if [ -z "$1" ]
    echo "No argument supplied"

The -z switch will test if the expansion of "$1" is a null string or not. If it is a null string then the body is executed.

What's the longest possible worldwide phone number I should consider in SQL varchar(length) for phone

Assuming you don't store things like the '+', '()', '-', spaces and what-have-yous (and why would you, they are presentational concerns which would vary based on local customs and the network distributions anyways), the ITU-T recommendation E.164 for the international telephone network (which most national networks are connected via) specifies that the entire number (including country code, but not including prefixes such as the international calling prefix necessary for dialling out, which varies from country to country, nor including suffixes, such as PBX extension numbers) be at most 15 characters.

Call prefixes depend on the caller, not the callee, and thus shouldn't (in many circumstances) be stored with a phone number. If the database stores data for a personal address book (in which case storing the international call prefix makes sense), the longest international prefixes you'd have to deal with (according to Wikipedia) are currently 5 digits, in Finland.

As for suffixes, some PBXs support up to 11 digit extensions (again, according to Wikipedia). Since PBX extension numbers are part of a different dialing plan (PBXs are separate from phone companies' exchanges), extension numbers need to be distinguishable from phone numbers, either with a separator character or by storing them in a different column.

Get text from DataGridView selected cells

DataGridView.SelectedCells is a collection of cells, so it's not as simple as calling ToString() on it. You have to loop through each cell in the collection and get each cell's value instead.

The following will create a comma-delimited list of all selected cells' values.


TextBox1.Text = "";
bool FirstValue = true;
foreach(DataGridViewCell cell in DataGridView1.SelectedCells)
        TextBox1.Text += ", ";
    TextBox1.Text += cell.Value.ToString();
    FirstValue = false;

VB.NET (Translated from the code above)

TextBox1.Text = ""
Dim FirstValue As Boolean =  True 
Dim cell As DataGridViewCell
For Each cell In DataGridView1.SelectedCells
    If Not FirstValue Then
        TextBox1.Text += ", "
    End If
    TextBox1.Text += cell.Value.ToString()
    FirstValue = False

What does <T> (angle brackets) mean in Java?

Generic classes are a type of class that takes in a data type as a parameter when it's created. This type parameter is specified using angle brackets and the type can change each time a new instance of the class is instantiated. For instance, let's create an ArrayList for Employee objects and another for Company objects

ArrayList<Employee> employees = new ArrayList<Employee>();
ArrayList<Company> companies = new ArrayList<Company>();

You'll notice that we're using the same ArrayList class to create both lists and we pass in the Employee or Company type using angle brackets. Having one generic class be able to handle multiple types of data cuts down on having a lot of classes that perform similar tasks. Generics also help to cut down on bugs by giving everything a strong type which helps the compiler point out errors. By specifying a type for ArrayList, the compiler will throw an error if you try to add an Employee to the Company list or vice versa.

Android; Check if file exists without creating a new one

Your chunk of code does not create a new one, it only checks if its already there and nothing else.

File file = new File(filePath);
//Do something
// Do something else.

Java Synchronized list

It will give consistent behavior for add/remove operations. But while iterating you have to explicitly synchronized. Refer this link

Laravel PDOException SQLSTATE[HY000] [1049] Unknown database 'forge'

Sounds like you have an environment-specific config file somewhere that overrides the default database settings. Possibly app/config/local/database.php.

What is Common Gateway Interface (CGI)?

CGI is an interface which tells the webserver how to pass data to and from an application. More specifically, it describes how request information is passed in environment variables (such as request type, remote IP address), how the request body is passed in via standard input, and how the response is passed out via standard output. You can refer to the CGI specification for details.

To use your image:

user (client) request for page ---> webserver ---[CGI]----> Server side Program ---> MySQL Server.

Most if not all, webservers can be configured to execute a program as a 'CGI'. This means that the webserver, upon receiving a request, will forward the data to a specific program, setting some environment variables and marshalling the parameters via standard input and standard output so the program can know where and what to look for.

The main benefit is that you can run ANY executable code from the web, given that both the webserver and the program know how CGI works. That's why you could write web programs in C or Bash with a regular CGI-enabled webserver. That, and that most programming environments can easily use standard input, standard output and environment variables.

In your case you most likely used another, specific for PHP, means of communication between your scripts and the webserver, this, as you well mention in your question, is an embedded interpreter called mod_php.

So, answering your questions:

What exactly is CGI?

See above.

Whats the big deal with /cgi-bin/*.cgi? Whats up with this? I don't know what is this cgi-bin directory on the server for. I don't know why they have *.cgi extensions.

That's the traditional place for cgi programs, many webservers come with this directory pre configured to execute all binaries there as CGI programs. The .cgi extension denotes an executable that is expected to work through the CGI.

Why does Perl always comes in the way. CGI & Perl (language). I also don't know whats up with these two. Almost all the time I keep hearing these two in combination "CGI & Perl". This book is another great example CGI Programming with Perl Why not "CGI Programming with PHP/JSP/ASP". I never saw such things.

Because Perl is ancient (older than PHP, JSP and ASP which all came to being when CGI was already old, Perl existed when CGI was new) and became fairly famous for being a very good language to serve dynamic webpages via the CGI. Nowadays there are other alternatives to run Perl in a webserver, mainly mod_perl.

CGI Programming in C this confuses me a lot. in C?? Seriously?? I don't know what to say. I"m just confused. "in C"?? This changes everything. Program needs to be compiled and executed. This entirely changes my view of web programming. When do I compile? How does the program gets executed (because it will be a machine code, so it must execute as a independent process). How does it communicate with the web server? IPC? and interfacing with all the servers (in my example MATLAB & MySQL) using socket programming? I'm lost!!

You compile the executable once, the webserver executes the program and passes the data in the request to the program and outputs the received response. CGI specifies that one program instance will be launched per each request. This is why CGI is inefficient and kind of obsolete nowadays.

They say that CGI is deprecated. Its no more in use. Is it so? What is its latest update?

CGI is still used when performance is not paramount and a simple means of executing code is required. It is inefficient for the previously stated reasons and there are more modern means of executing any program in a web enviroment. Currently the most famous is FastCGI.

Filter object properties by key in ES6

I'm surprised how nobody has suggested this yet. It's super clean and very explicit about which keys you want to keep.

const unfilteredObj = {a: ..., b:..., c:..., x:..., y:...}

const filterObject = ({a,b,c}) => ({a,b,c})
const filteredObject = filterObject(unfilteredObject)

Or if you want a dirty one liner:

const unfilteredObj = {a: ..., b:..., c:..., x:..., y:...}

const filteredObject = (({a,b,c})=>({a,b,c}))(unfilteredObject);

Initialize 2D array

Easy to read/type.

  table = new char[][] {
    , "abcdefghij".toCharArray()

What is the difference between . (dot) and $ (dollar sign)?

I think a short example of where you would use . and not $ would help clarify things.

double x = x * 2
triple x = x * 3
times6 = double . triple

:i times6
times6 :: Num c => c -> c

Note that times6 is a function that is created from function composition.

How to clear browsing history using JavaScript?

Ok. This is an ancient history, but may be my solution could be useful for you or another developers. If I don't want an user press back key in a page (lets say page B called from an page A) and go back to last page (page A), I do next steps:

First, on page A, instead call next page using window.location.href or window.location.replace, I make a call using two commands: and window.close example on page A:

<a href="#"
      Page B</a>;

All modifiers on window open are just to make up the resulting page. This will open a new window (popWindow) without posibilities of use the back key, and will close the caller page (Page A)

Second: On page B you can use the same proccess if you want this page do the same thing.

Well. This needs the user accept you can open popup windows, but in a controlled system, as if you are programming pages for your work or client, this is easily recommended for the users. Just accept the site as trusted.

What's "tools:context" in Android layout files?

tools:context=".MainActivity" thisline is used in xml file which indicate that which java source file is used to access this xml file. it means show this xml preview for perticular java files.

How to create a sub array from another array in Java?

Use copyOfRange method from java.util.Arrays class:

int[] newArray = Arrays.copyOfRange(oldArray, startIndex, endIndex);

For more details:

Link to similar question

.NET Events - What are object sender & EventArgs e?

sender refers to the object that invoked the event that fired the event handler. This is useful if you have many objects using the same event handler.

EventArgs is something of a dummy base class. In and of itself it's more or less useless, but if you derive from it, you can add whatever data you need to pass to your event handlers.

When you implement your own events, use an EventHandler or EventHandler<T> as their type. This guarantees that you'll have exactly these two parameters for all your events (which is a good thing).

Accessing an SQLite Database in Swift


func createDatabase()
    var path:Array=NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
    let directory:String=path[0]
    let DBpath=(directory as NSString).appendingPathComponent("Food.sqlite")


    if (FileManager.default.fileExists(atPath: DBpath))
        print("Successfull database create")
        let pathfrom:String=(Bundle.main.resourcePath! as NSString).appendingPathComponent("Food.sqlite")

        var success:Bool
        do {
            try FileManager.default.copyItem(atPath: pathfrom, toPath: DBpath)
            success = true
        } catch _ {
            success = false

        if !success
            print("database not create ")
            print("Successfull database new create")


import UIKit

class database: NSObject
func databasePath() -> NSString
    var path:Array=NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)
    let directory:String=path[0] 
    let DBpath=(directory as NSString).appendingPathComponent("Food.sqlite")

    if (FileManager.default.fileExists(atPath: DBpath))
        return DBpath as NSString
    return DBpath as NSString

func ExecuteQuery(_ str:String) -> Bool
    var result:Bool=false
    let DBpath:String=self.databasePath() as String

    var db: OpaquePointer? = nil
    var stmt:OpaquePointer? = nil

    let strExec=str.cString(using: String.Encoding.utf8)

    if (sqlite3_open(DBpath, &db)==SQLITE_OK)
        if (sqlite3_prepare_v2(db, strExec! , -1, &stmt, nil) == SQLITE_OK)
            if (sqlite3_step(stmt) == SQLITE_DONE)

    return result

func SelectQuery(_ str:String) -> Array<Dictionary<String,String>>
    var result:Array<Dictionary<String,String>>=[]
    let DBpath:String=self.databasePath() as String

    var db: OpaquePointer? = nil
    var stmt:OpaquePointer? = nil

    let strExec=str.cString(using: String.Encoding.utf8)

    if ( sqlite3_open(DBpath,&db) == SQLITE_OK)
        if (sqlite3_prepare_v2(db, strExec! , -1, &stmt, nil) == SQLITE_OK)
            while (sqlite3_step(stmt) == SQLITE_ROW)
                var i:Int32=0
                let icount:Int32=sqlite3_column_count(stmt)

                var dict=Dictionary<String, String>()

                while i < icount
                    let strF=sqlite3_column_name(stmt, i)
                    let strV = sqlite3_column_text(stmt, i)

                    let rFiled:String=String(cString: strF!)
                    let rValue:String=String(cString: strV!)
                    //let rValue=String(cString: UnsafePointer<Int8>(strV!))

                    dict[rFiled] = rValue

                    i += 1
                result.insert(dict, at: result.count)

    return result

func AllSelectQuery(_ str:String) -> Array<Model>
    var result:Array<Model>=[]
    let DBpath:String=self.databasePath() as String

    var db: OpaquePointer? = nil
    var stmt:OpaquePointer? = nil

    let strExec=str.cString(using: String.Encoding.utf8)

    if ( sqlite3_open(DBpath,&db) == SQLITE_OK)
        if (sqlite3_prepare_v2(db, strExec! , -1, &stmt, nil) == SQLITE_OK)
            while (sqlite3_step(stmt) == SQLITE_ROW)
                let mod=Model()

       sqlite3_column_text(stmt, 0))
                mod.image=String(cString: sqlite3_column_text(stmt, 1))
       sqlite3_column_text(stmt, 2))
                mod.foodtype=String(cString: sqlite3_column_text(stmt, 3))
                mod.vegtype=String(cString: sqlite3_column_text(stmt, 4))
                mod.details=String(cString: sqlite3_column_text(stmt, 5))

                result.insert(mod, at: result.count)
    return result



import UIKit

class Model: NSObject
var uid:Int = 0
var id:String = ""
var image:String = ""
var name:String = ""
var foodtype:String = ""
var vegtype:String = ""
var details:String = ""
var mealtype:String = ""
var date:String = ""

Access database :

let DB=database()
var mod=Model()

database Query fire :

var DailyResult:Array<Model> = DB.AllSelectQuery("select * from food where foodtype == 'Sea Food' ORDER BY name ASC")

jquery how to use multiple ajax calls one after the end of the other

You could also use jquery when and then functions. for example

 $.when( $.ajax( "test.aspx" ) ).then(function( data, textStatus, jqXHR ) {
  //another ajax call

jquery function val() is not equivalent to "$(this).value="?

You want:

this.value = ''; // straight JS, no jQuery


$(this).val(''); // jQuery

With $(this).value = '' you're assigning an empty string as the value property of the jQuery object that wraps this -- not the value of this itself.

IIS sc-win32-status codes

Here's the list of all Win32 error codes. You can use this page to lookup the error code mentioned in IIS logs:

You can also use command line utility net to find information about a Win32 error code. The syntax would be:
net helpmsg Win32_Status_Code

Can I run Keras model on gpu?

2.0 Compatible Answer: While above mentioned answer explain in detail on how to use GPU on Keras Model, I want to explain how it can be done for Tensorflow Version 2.0.

To know how many GPUs are available, we can use the below code:

print("Num GPUs Available: ", len(tf.config.experimental.list_physical_devices('GPU')))

To find out which devices your operations and tensors are assigned to, put tf.debugging.set_log_device_placement(True) as the first statement of your program.

Enabling device placement logging causes any Tensor allocations or operations to be printed. For example, running the below code:


# Create some tensors
a = tf.constant([[1.0, 2.0, 3.0], [4.0, 5.0, 6.0]])
b = tf.constant([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]])
c = tf.matmul(a, b)


gives the Output shown below:

Executing op MatMul in device /job:localhost/replica:0/task:0/device:GPU:0 tf.Tensor( [[22. 28.] [49. 64.]], shape=(2, 2), dtype=float32)

For more information, refer this link

What is the correct way to create a single-instance WPF application?

So many answers to such a seemingly simple question. Just to shake things up a little bit here is my solution to this problem.

Creating a Mutex can be troublesome because the JIT-er only sees you using it for a small portion of your code and wants to mark it as ready for garbage collection. It pretty much wants to out-smart you thinking you are not going to be using that Mutex for that long. In reality you want to hang onto this Mutex for as long as your application is running. The best way to tell the garbage collector to leave you Mutex alone is to tell it to keep it alive though out the different generations of garage collection. Example:

var m = new Mutex(...);

I lifted the idea from this page:

How do I ignore a directory with SVN?

After losing a lot of time looking for how to do this simple activity, I decided to post it was not hard to find a decent explanation.

First let the sample structure

$ svn st ? project/trunk/target ? project/trunk/myfile.x

1 – first configure the editor,in mycase vim export SVN_EDITOR=vim

2 – “svn propedit svn:ignore project/trunk/” will open a new file and you can add your files and subdirectory in us case type “target” save and close file and works

$ svn st ? project/trunk/myfile.x


Python mysqldb: Library not loaded: libmysqlclient.18.dylib

I solved the problem by creating a symbolic link to the library. I.e.

The actual library resides in


And then I created a symbolic link in


Using the command:

sudo ln -s /usr/local/mysql/lib/libmysqlclient.18.dylib /usr/lib/libmysqlclient.18.dylib

so that I have the following mapping:

ls -l libmysqlclient.18.dylib 
lrwxr-xr-x  1 root  wheel  44 16 Jul 14:01 libmysqlclient.18.dylib -> /usr/local/mysql/lib/libmysqlclient.18.dylib

That was it. After that everything worked fine.


Notice, that since MacOS El Capitan the System Integrity Protection (SIP, also known as "rootless") will prevent you from creating links in /usr/lib/. You could disable SIP by following these instructions, but you can create a link in /usr/local/lib/ instead:

sudo ln -s /usr/local/mysql/lib/libmysqlclient.18.dylib /usr/local/lib/libmysqlclient.18.dylib

Export data from R to Excel

I have been trying out the different packages including the function:

install.packages ("prettyR") 

library (prettyR)

delimit.table (Corrvar,"Name the csv.csv") ## Corrvar is a name of an object from an output I had on scaled variables to run a regression.

However I tried this same code for an output from another analysis (occupancy models model selection output) and it did not work. And after many attempts and exploration I:

  • copied the output from R (Ctrl+c)
  • in Excel sheet I pasted it (Ctrl+V)
  • Select the first column where the data is
  • In the "Data" vignette, click on "Text to column"

  • Select Delimited option, click next

  • Tick space box in "Separator", click next

  • Click Finalize (End)

Your output now should be in a form you can manipulate easy in excel. So perhaps not the fanciest option but it does the trick if you just want to explore your data in another way.

PS. If the labels in excel are not the exact one it is because Im translating the lables from my spanish excel.

How can I strip first and last double quotes?

IMPORTANT: I'm extending the question/answer to strip either single or double quotes. And I interpret the question to mean that BOTH quotes must be present, and matching, to perform the strip. Otherwise, the string is returned unchanged.

To "dequote" a string representation, that might have either single or double quotes around it (this is an extension of @tgray's answer):

def dequote(s):
    If a string has single or double quotes around it, remove them.
    Make sure the pair of quotes match.
    If a matching pair of quotes is not found, return the string unchanged.
    if (s[0] == s[-1]) and s.startswith(("'", '"')):
        return s[1:-1]
    return s


startswith can take a tuple, to match any of several alternatives. The reason for the DOUBLED parentheses (( and )) is so that we pass ONE parameter ("'", '"') to startswith(), to specify the permitted prefixes, rather than TWO parameters "'" and '"', which would be interpreted as a prefix and an (invalid) start position.

s[-1] is the last character in the string.


print( dequote("\"he\"l'lo\"") )
print( dequote("'he\"l'lo'") )
print( dequote("he\"l'lo") )
print( dequote("'he\"l'lo\"") )



(For me, regex expressions are non-obvious to read, so I didn't try to extend @Alex's answer.)

python 3.2 UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 9629: character maps to <undefined>

Maybe a little late to reply. I happen to run into the same problem today. I find that on Windows you can change the console encoder to utf-8 or other encoder that can represent your data. Then you can print it to sys.stdout.

First, run following code in the console:

chcp 65001

Then, start python do anything you want.

how to create a list of lists

Just came across the same issue today...

In order to create a list of lists you will have firstly to store your data, array, or other type of variable into a list. Then, create a new empty list and append to it the lists that you just created. At the end you should end up with a list of lists:

listoflists = []

How to make asynchronous HTTP requests in PHP

As of 2018, Guzzle has become the defacto standard library for HTTP requests, used in several modern frameworks. It's written in pure PHP and does not require installing any custom extensions.

It can do asynchronous HTTP calls very nicely, and even pool them such as when you need to make 100 HTTP calls, but don't want to run more than 5 at a time.

Concurrent request example

use GuzzleHttp\Client;
use GuzzleHttp\Promise;

$client = new Client(['base_uri' => '']);

// Initiate each request but do not block
$promises = [
    'image' => $client->getAsync('/image'),
    'png'   => $client->getAsync('/image/png'),
    'jpeg'  => $client->getAsync('/image/jpeg'),
    'webp'  => $client->getAsync('/image/webp')

// Wait on all of the requests to complete. Throws a ConnectException
// if any of the requests fail
$results = Promise\unwrap($promises);

// Wait for the requests to complete, even if some of them fail
$results = Promise\settle($promises)->wait();

// You can access each result using the key provided to the unwrap
// function.
echo $results['image']['value']->getHeader('Content-Length')[0]
echo $results['png']['value']->getHeader('Content-Length')[0]


PHP removing a character in a string

While a regexp would suit here just fine, I'll present you with an alternative method. It might be a tad faster than the equivalent regexp, but life's all about choices (...or something).

$length = strlen($urlString);
for ($i=0; $i<$length; i++) {
  if ($urlString[$i] === '?') {
    $urlString[$i+1] = '';

Weird, I know.

calling javascript function on OnClientClick event of a Submit button

<asp:Button ID="btnGet" runat="server" Text="Get" OnClick="btnGet_Click" OnClientClick="retun callMethod();" />
<script type="text/javascript">
    function callMethod() {
        //your logic should be here and make sure your logic code note returing function
        return false;

Invalid default value for 'create_date' timestamp field

That is because of server SQL Mode - NO_ZERO_DATE.

From the reference: NO_ZERO_DATE - In strict mode, don't allow '0000-00-00' as a valid date. You can still insert zero dates with the IGNORE option. When not in strict mode, the date is accepted but a warning is generated.

Best way to store data locally in .NET (C#)

The first thing I'd look at is a database. However, serialization is an option. If you go for binary serialization, then I would avoid BinaryFormatter - it has a tendency to get angry between versions if you change fields etc. Xml via XmlSerialzier would be fine, and can be side-by-side compatible (i.e. with the same class definitions) with protobuf-net if you want to try contract-based binary serialization (giving you a flat file serializer without any effort).

Meaning of Choreographer messages in Logcat

Choreographer lets apps to connect themselves to the vsync, and properly time things to improve performance.

Android view animations internally uses Choreographer for the same purpose: to properly time the animations and possibly improve performance.

Since Choreographer is told about every vsync events, it can tell if one of the Runnables passed along by the* apis doesn't finish in one frame's time, causing frames to be skipped.

In my understanding Choreographer can only detect the frame skipping. It has no way of telling why this happens.

The message "The application may be doing too much work on its main thread." could be misleading.

Store an array in HashMap

HashMap<String, List<Integer>> map = new HashMap<String, List<Integer>>();
HashMap<String, int[]> map = new HashMap<String, int[]>();

pick one, for example

HashMap<String, List<Integer>> map = new HashMap<String, List<Integer>>();
map.put("Something", new ArrayList<Integer>());
for (int i=0;i<numarulDeCopii; i++) {

or just

HashMap<String, int[]> map = new HashMap<String, int[]>();
map.put("Something", coeficientUzura);

Create a one to many relationship using SQL Server

  1. Define two tables (example A and B), with their own primary key
  2. Define a column in Table A as having a Foreign key relationship based on the primary key of Table B

This means that Table A can have one or more records relating to a single record in Table B.

If you already have the tables in place, use the ALTER TABLE statement to create the foreign key constraint:

ALTER TABLE A ADD CONSTRAINT fk_b FOREIGN KEY (b_id) references b(id) 
  • fk_b: Name of the foreign key constraint, must be unique to the database
  • b_id: Name of column in Table A you are creating the foreign key relationship on
  • b: Name of table, in this case b
  • id: Name of column in Table B

X11/Xlib.h not found in Ubuntu

Presume he's using the tutorial from along with premake4.3 :-)

sudo apt-get install libx11-dev ................. for X11/Xlib.h
sudo apt-get install mesa-common-dev........ for GL/glx.h
sudo apt-get install libglu1-mesa-dev ..... for GL/glu.h
sudo apt-get install libxrandr-dev ........... for X11/extensions/Xrandr.h
sudo apt-get install libxi-dev ................... for X11/extensions/XInput.h

After which I could build glsdk_0.4.4 and examples without further issue.

Is it possible to run .APK/Android apps on iPad/iPhone devices?

The app can't be run natively, but it could be run on an emulator. You can use ManyMo to embed them in a website and make users add your app to their home screen. This link should be useful for making the app more realistic. Users could then only press the share button and add the app to their home screen. All data will be deleted when the "app" is closed in their iOS devices so you should use the Internet/cloud for storage. It can't access camera or multi touch, but it may be useful.

Send JSON data via POST (ajax) and receive json response from Controller (MVC)

Your PersonSheets has a property int Id, Id isn't in the post, so modelbinding fails. Make Id nullable (int?) or send atleast Id = 0 with the POst .

C++ inheritance - inaccessible base?

By default, inheritance is private. You have to explicitly use public:

class Bar : public Foo

How do I generate a list with a specified increment step?

You can use scalar multiplication to modify each element in your vector.

> r <- 0:10 
> r <- r * 2
> r 
 [1]  0  2  4  6  8 10 12 14 16 18 20


> r <- 0:10 * 2 
> r 
 [1]  0  2  4  6  8 10 12 14 16 18 20

Excel VBA If cell.Value =... then

You can use the Like operator with a wildcard to determine whether a given substring exists in a string, for example:

If cell.Value Like "*Word1*" Then
ElseIf cell.Value Like "*Word2*" Then
End If

In this example the * character in "*Word1*" is a wildcard character which matches zero or more characters.

NOTE: The Like operator is case-sensitive, so "Word1" Like "word1" is false, more information can be found on this MSDN page.

System.Data.SqlClient.SqlException: Invalid object name 'dbo.Projects'

Try to do this way

protected override void OnModelCreating(DbModelBuilder modelBuilder) 

or if you use .net core try it

protected override void OnModelCreating(ModelBuilder modelBuilder)

Replace Usuario for your Entity Name, like a DbSet<<EntityName>> Entities without Plural

Is iterating ConcurrentHashMap values thread safe?

What does it mean?

That means that each iterator you obtain from a ConcurrentHashMap is designed to be used by a single thread and should not be passed around. This includes the syntactic sugar that the for-each loop provides.

What happens if I try to iterate the map with two threads at the same time?

It will work as expected if each of the threads uses it's own iterator.

What happens if I put or remove a value from the map while iterating it?

It is guaranteed that things will not break if you do this (that's part of what the "concurrent" in ConcurrentHashMap means). However, there is no guarantee that one thread will see the changes to the map that the other thread performs (without obtaining a new iterator from the map). The iterator is guaranteed to reflect the state of the map at the time of it's creation. Futher changes may be reflected in the iterator, but they do not have to be.

In conclusion, a statement like

for (Object o : someConcurrentHashMap.entrySet()) {
    // ...

will be fine (or at least safe) almost every time you see it.

Omitting all xsi and xsd namespaces when serializing an object in .NET?

After reading Microsoft's documentation and several solutions online, I have discovered the solution to this problem. It works with both the built-in XmlSerializer and custom XML serialization via IXmlSerialiazble.

To wit, I'll use the same MyTypeWithNamespaces XML sample that's been used in the answers to this question so far.

[XmlRoot("MyTypeWithNamespaces", Namespace="urn:Abracadabra", IsNullable=false)]
public class MyTypeWithNamespaces
    // As noted below, per Microsoft's documentation, if the class exposes a public
    // member of type XmlSerializerNamespaces decorated with the 
    // XmlNamespacesDeclarationAttribute, then the XmlSerializer will utilize those
    // namespaces during serialization.
    public MyTypeWithNamespaces( )
        this._namespaces = new XmlSerializerNamespaces(new XmlQualifiedName[] {
            // Don't do this!! Microsoft's documentation explicitly says it's not supported.
            // It doesn't throw any exceptions, but in my testing, it didn't always work.

            // new XmlQualifiedName(string.Empty, string.Empty),  // And don't do this:
            // new XmlQualifiedName("", "")

            // DO THIS:
            new XmlQualifiedName(string.Empty, "urn:Abracadabra") // Default Namespace
            // Add any other namespaces, with prefixes, here.

    // If you have other constructors, make sure to call the default constructor.
    public MyTypeWithNamespaces(string label, int epoch) : this( )
        this._label = label;
        this._epoch = epoch;

    // An element with a declared namespace different than the namespace
    // of the enclosing type.
    public string Label
        get { return this._label; }
        set { this._label = value; }
    private string _label;

    // An element whose tag will be the same name as the property name.
    // Also, this element will inherit the namespace of the enclosing type.
    public int Epoch
        get { return this._epoch; }
        set { this._epoch = value; }
    private int _epoch;

    // Per Microsoft's documentation, you can add some public member that
    // returns a XmlSerializerNamespaces object. They use a public field,
    // but that's sloppy. So I'll use a private backed-field with a public
    // getter property. Also, per the documentation, for this to work with
    // the XmlSerializer, decorate it with the XmlNamespaceDeclarations
    // attribute.
    public XmlSerializerNamespaces Namespaces
        get { return this._namespaces; }
    private XmlSerializerNamespaces _namespaces;

That's all to this class. Now, some objected to having an XmlSerializerNamespaces object somewhere within their classes; but as you can see, I neatly tucked it away in the default constructor and exposed a public property to return the namespaces.

Now, when it comes time to serialize the class, you would use the following code:

MyTypeWithNamespaces myType = new MyTypeWithNamespaces("myLabel", 42);

   OK, I just figured I could do this to make the code shorter, so I commented out the
   below and replaced it with what follows:

// You have to use this constructor in order for the root element to have the right namespaces.
// If you need to do custom serialization of inner objects, you can use a shortened constructor.
XmlSerializer xs = new XmlSerializer(typeof(MyTypeWithNamespaces), new XmlAttributeOverrides(),
    new Type[]{}, new XmlRootAttribute("MyTypeWithNamespaces"), "urn:Abracadabra");

XmlSerializer xs = new XmlSerializer(typeof(MyTypeWithNamespaces),
    new XmlRootAttribute("MyTypeWithNamespaces") { Namespace="urn:Abracadabra" });

// I'll use a MemoryStream as my backing store.
MemoryStream ms = new MemoryStream();

// This is extra! If you want to change the settings for the XmlSerializer, you have to create
// a separate XmlWriterSettings object and use the XmlTextWriter.Create(...) factory method.
// So, in this case, I want to omit the XML declaration.
XmlWriterSettings xws = new XmlWriterSettings();
xws.OmitXmlDeclaration = true;
xws.Encoding = Encoding.UTF8; // This is probably the default
// You could use the XmlWriterSetting to set indenting and new line options, but the
// XmlTextWriter class has a much easier method to accomplish that.

// The factory method returns a XmlWriter, not a XmlTextWriter, so cast it.
XmlTextWriter xtw = (XmlTextWriter)XmlTextWriter.Create(ms, xws);
// Then we can set our indenting options (this is, of course, optional).
xtw.Formatting = Formatting.Indented;

// Now serialize our object.
xs.Serialize(xtw, myType, myType.Namespaces);

Once you have done this, you should get the following output:

    <Label xmlns="urn:Whoohoo">myLabel</Label>

I have successfully used this method in a recent project with a deep hierachy of classes that are serialized to XML for web service calls. Microsoft's documentation is not very clear about what to do with the publicly accesible XmlSerializerNamespaces member once you've created it, and so many think it's useless. But by following their documentation and using it in the manner shown above, you can customize how the XmlSerializer generates XML for your classes without resorting to unsupported behavior or "rolling your own" serialization by implementing IXmlSerializable.

It is my hope that this answer will put to rest, once and for all, how to get rid of the standard xsi and xsd namespaces generated by the XmlSerializer.

UPDATE: I just want to make sure I answered the OP's question about removing all namespaces. My code above will work for this; let me show you how. Now, in the example above, you really can't get rid of all namespaces (because there are two namespaces in use). Somewhere in your XML document, you're going to need to have something like xmlns="urn:Abracadabra" xmlns:w="urn:Whoohoo. If the class in the example is part of a larger document, then somewhere above a namespace must be declared for either one of (or both) Abracadbra and Whoohoo. If not, then the element in one or both of the namespaces must be decorated with a prefix of some sort (you can't have two default namespaces, right?). So, for this example, Abracadabra is the defalt namespace. I could inside my MyTypeWithNamespaces class add a namespace prefix for the Whoohoo namespace like so:

public MyTypeWithNamespaces
    this._namespaces = new XmlSerializerNamespaces(new XmlQualifiedName[] {
        new XmlQualifiedName(string.Empty, "urn:Abracadabra"), // Default Namespace
        new XmlQualifiedName("w", "urn:Whoohoo")

Now, in my class definition, I indicated that the <Label/> element is in the namespace "urn:Whoohoo", so I don't need to do anything further. When I now serialize the class using my above serialization code unchanged, this is the output:

<MyTypeWithNamespaces xmlns:w="urn:Whoohoo">

Because <Label> is in a different namespace from the rest of the document, it must, in someway, be "decorated" with a namespace. Notice that there are still no xsi and xsd namespaces.

How to render a PDF file in Android

public class MyPdfViewActivity extends Activity {

  protected void onCreate(Bundle savedInstanceState) {
    WebView mWebView=new WebView(MyPdfViewActivity.this);

Youtube autoplay not working on mobile devices with embedded HTML5 player

There is a way to make youtube autoplay, and complete playlists play through. Get Adblock browser for Android, and then go to the youtube website, and and configure it for the desktop version of the page, close Adblock browser out, and then reopen, and you will have the desktop version, where autoplay will work.

Using the desktop version will also mean that AdBlock will work. The mobile version invokes the standalone YouTube player, which is why you want the desktop version of the page, so that autoplay will work, and so ad blocking will work.

What is the best way to remove accents (normalize) in a Python unicode string?


import unicodedata
from random import choice

import perfplot
import regex
import text_unidecode

def remove_accent_chars_regex(x: str):
    return regex.sub(r'\p{Mn}', '', unicodedata.normalize('NFKD', x))

def remove_accent_chars_join(x: str):
    # answer by MiniQuark
    return u"".join([c for c in unicodedata.normalize('NFKD', x) if not unicodedata.combining(c)])
    setup=lambda n: ''.join([choice('Málaga François Phút Hon ??') for i in range(n)]),
    labels=['regex', 'join', 'unidecode'],
    n_range=[2 ** k for k in range(22)],
    equality_check=None, relative_to=0, xlabel='str len'

How to get the last N rows of a pandas DataFrame?

This is because of using integer indices (ix selects those by label over -3 rather than position, and this is by design: see integer indexing in pandas "gotchas"*).

*In newer versions of pandas prefer loc or iloc to remove the ambiguity of ix as position or label:


see the docs.

As Wes points out, in this specific case you should just use tail!

Multiplying Two Columns in SQL Server

select InitialPayment * MonthlyRate as MultiplyingCalculation, InitialPayment - MonthlyRate as SubtractingCalculation from Payment

What is the difference between Bootstrap .container and .container-fluid classes?

Quick version: .container has one fixed width for each screen size in bootstrap (xs,sm,md,lg); .container-fluid expands to fill the available width.

The difference between container and container-fluid comes from these lines of CSS:

@media (min-width: 568px) {
  .container {
    width: 550px;
@media (min-width: 992px) {
  .container {
    width: 970px;
@media (min-width: 1200px) {
  .container {
    width: 1170px;

Depending on the width of the viewport that the webpage is being viewed on, the container class gives its div a specific fixed width. These lines don't exist in any form for container-fluid, so its width changes every time the viewport width changes.

So for example, say your browser window is 1000px wide. As it's greater than the min-width of 992px, your .container element will have a width of 970px. You then slowly widen your browser window. The width of your .container won't change until you get to 1200px, at which it will jump to 1170px wide and stay that way for any larger browser widths.

Your .container-fluid element, on the other hand, will constantly resize as you make even the smallest changes to your browser width.

Closing database connections in Java

When you are done with using your Connection, you need to explicitly close it by calling its close() method in order to release any other database resources (cursors, handles, etc.) the connection may be holding on to.

Actually, the safe pattern in Java is to close your ResultSet, Statement, and Connection (in that order) in a finally block when you are done with them. Something like this:

Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;

try {
    // Do stuff

} catch (SQLException ex) {
    // Exception handling stuff
} finally {
    if (rs != null) {
        try {
        } catch (SQLException e) { /* Ignored */}
    if (ps != null) {
        try {
        } catch (SQLException e) { /* Ignored */}
    if (conn != null) {
        try {
        } catch (SQLException e) { /* Ignored */}

The finally block can be slightly improved into (to avoid the null check):

} finally {
    try { rs.close(); } catch (Exception e) { /* Ignored */ }
    try { ps.close(); } catch (Exception e) { /* Ignored */ }
    try { conn.close(); } catch (Exception e) { /* Ignored */ }

But, still, this is extremely verbose so you generally end up using an helper class to close the objects in null-safe helper methods and the finally block becomes something like this:

} finally {

And, actually, the Apache Commons DbUtils has a DbUtils class which is precisely doing that, so there isn't any need to write your own.

Android studio 3.0: Unable to resolve dependency for :app@dexOptions/compileClasspath': Could not resolve project :animators

I found two type of solutions :

  1. Solution with the old g??radle-3.3 :

    As first and temporary solution to make the project run with android studio 3.0 , I maintain the old config of my previous of Android Studio 2.3

    distributionUrl= , compileSdkVersion 25** and **buildToolsVersion "25.0.3" and classpath '

  2. Solution with the new g??radle-4.1 :

    To work with the new features of gradle 4.1 and the classpath' , I followed this link . So, Those are my implementations :

In the file :

distributionPath=wrapper/dists zipStoreBase=GRADLE_USER_HOME

In the file build.gradle of the project :

buildscript {
    repositories {
    dependencies {
        classpath ''
        //classpath 'me.tatarka:gradle-retrolambda:3.3.1' remove this line

allprojects {
    repositories {

task clean(type: Delete) {
    delete rootProject.buildDir

In the file build.gradle of the app :

apply plugin: ''
//apply plugin: 'me.tatarka.retrolambda' remove this line

repositories {
    maven {
        url ""
    maven { url "" }

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.2"
    defaultConfig {
        applicationId "com.imennmn.myprojectid"
        minSdkVersion 21
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner ""
         * Enabling multidex support.
        multiDexEnabled true
        missingDimensionStrategy 'minApi' , 'minApi24'

        javaCompileOptions {
            annotationProcessorOptions {
                includeCompileClasspath true

        dexOptions {
            javaMaxHeapSize "4g"
            preDexLibraries = false

    buildTypes {
        release {
            shrinkResources false
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'

    lintOptions {
        checkReleaseBuilds false
        abortOnError false

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8

    configurations.all {
        resolutionStrategy.force ''

     * Solve the problem when using multiple free source libs
     * NOTICE or LICENSE files cause duplicates
    packagingOptions {
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/DEPENDENCIES.txt'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/DEPENDENCIES'
        //exclude duplicate butterknife and parceler libs
        exclude 'META-INF/services/javax.annotation.processing.Processor'
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/'



dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation files('libs/motwin-android-sdk-3.2.0-RELEASE-TLS.jar')
    implementation files('libs/notifmanager-android-lib-3.1.0-RELEASE.jar')
    implementation files('libs/commons-lang-2.4.jar')
    androidTestImplementation('', {
        exclude group: '', module: 'support-annotations'
    implementation ''
    implementation ''
    implementation ''
    implementation ''
    api 'com.jakewharton:butterknife:7.0.1'
    implementation 'de.hdodenhof:circleimageview:2.1.0'
    implementation ''
    implementation ''
    implementation 'com.github.bumptech.glide:glide:3.7.0'
    implementation ''
    testImplementation 'junit:junit:4.12'
    implementation 'com.facebook.rebound:rebound:0.3.8'
    implementation ''
    implementation 'io.reactivex.rxjava2:rxjava:2.1.1'
    implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'

    implementation project(':animators')

    // Retrofit2 & XmlConverter
    implementation 'com.squareup.retrofit2:retrofit:2.3.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.1.0'
    implementation 'com.squareup.retrofit2:adapter-rxjava:2.1.0'

    implementation('com.squareup.retrofit2:converter-simplexml:2.3.0') {
        exclude group: 'xpp3', module: 'xpp3'
        exclude group: 'stax', module: 'stax-api'
        exclude group: 'stax', module: 'stax'

    implementation 'com.squareup.okhttp3:okhttp:3.4.1'
    implementation 'com.squareup.okhttp3:logging-interceptor:3.4.1'

    //Library to reports crash
    implementation('ch.acra:acra:4.5.0') {
        exclude group: 'org.json'

    implementation 'com.github.kenglxn.QRGen:android:2.3.0'


In the build.gradle of the library animator I upgrade targetSdkVersion to 26 :

apply plugin: ''

android {
  compileSdkVersion 26
  buildToolsVersion '26.0.2'

  defaultConfig {
    minSdkVersion 21
    targetSdkVersion 26
    versionCode 1
    versionName "1.0"

dependencies {
  implementation ""
  implementation ""
  implementation ""

jQuery - trapping tab select event

This post shows a complete working HTML file as an example of triggering code to run when a tab is clicked. The .on() method is now the way that jQuery suggests that you handle events.

jQuery development history

To make something happen when the user clicks a tab can be done by giving the list element an id.

<li id="list">

Then referring to the id.

$("#list").on("click", function() {
 alert("Tab Clicked!");

Make sure that you are using a current version of the jQuery api. Referencing the jQuery api from Google, you can get the link here:

Here is a complete working copy of a tabbed page that triggers an alert when the horizontal tab 1 is clicked.

<!-- This HTML doc is modified from an example by:  -->
<!-- -->

<meta charset="utf-8">

<link rel="stylesheet" href="">

pre {
clear: none;
div.showCode {
margin-left: 8em;
.tabs {
margin-top: 0.5em;
.ui-tabs { 
padding: 0.2em; 
background: url( repeat-x scroll 50% top #F5F3E5; 
border-width: 1px; 
.ui-tabs .ui-tabs-nav { 
padding-left: 0.2em; 
background: url( repeat-x scroll 50% 50% #ECE8DA; 
border: 1px solid #D4CCB0;
-moz-border-radius: 6px; 
-webkit-border-radius: 6px; 
border-radius: 6px; 
.ui-tabs-nav .ui-state-active {
border-color: #D4CCB0;
.ui-tabs .ui-tabs-panel { 
background: transparent; 
border-width: 0px; 
.ui-tabs-panel p {
margin-top: 0em;
#minImage {
margin-left: 6.5em;
#minImage img {
padding: 2px;
border: 2px solid #448844;
vertical-align: bottom;

#tabs-nested > .ui-tabs-panel {
padding: 0em;
#tabs-nested-left {
position: relative;
padding-left: 6.5em;
#tabs-nested-left .ui-tabs-nav {
position: absolute;
left: 0.25em;
top: 0.25em;
bottom: 0.25em;
width: 6em;
padding: 0.2em 0 0.2em 0.2em;
#tabs-nested-left .ui-tabs-nav li {
right: 1px;
width: 100%;
border-right: none;
border-bottom-width: 1px !important;
-moz-border-radius: 4px 0px 0px 4px;
-webkit-border-radius: 4px 0px 0px 4px;
border-radius: 4px 0px 0px 4px;
overflow: hidden;
#tabs-nested-left .ui-tabs-nav li.ui-tabs-selected,
#tabs-nested-left .ui-tabs-nav li.ui-state-active {
border-right: 1px solid transparent;
#tabs-nested-left .ui-tabs-nav li a {
float: right;
width: 100%;
text-align: right;
#tabs-nested-left > div {
height: 10em;
overflow: auto;


<script src=""></script>
<script src=""></script>

    $(function() {

<header role="banner">
    <h1>jQuery UI Tabs Styling</h1>


<article id="tabs-nested" class="tabs">
    $("#ForClick").on("click", function() {
        alert("Tab Clicked!");
    <li id="ForClick"><a href="#tabs-nested-1">First</a></li>
    <li><a href="#tabs-nested-2">Second</a></li>
    <li><a href="#tabs-nested-3">Third</a></li>
<div id="tabs-nested-1">
    <article id="tabs-nested-left" class="tabs">
            <li><a href="#tabs-nested-left-1">First</a></li>
            <li><a href="#tabs-nested-left-2">Second</a></li>
            <li><a href="#tabs-nested-left-3">Third</a></li>
        <div id="tabs-nested-left-1">
            <p>Nested tabs, horizontal then vertical.</p>

<form action="/sign" method="post">
  <div><textarea name="content" rows="5" cols="100"></textarea></div>
  <div><input type="submit" value="Sign Guestbook"></div>
        <div id="tabs-nested-left-2">
            <p>Nested Left Two</p>
        <div id="tabs-nested-left-3">
            <p>Nested Left Three</p>
<div id="tabs-nested-2">
    <p>Tab Two Main</p>
<div id="tabs-nested-3">
    <p>Tab Three Main</p>



What do parentheses surrounding an object/function/class declaration mean?

Andy Hume pretty much gave the answer, I just want to add a few more details.

With this construct you are creating an anonymous function with its own evaluation environment or closure, and then you immediately evaluate it. The nice thing about this is that you can access the variables declared before the anonymous function, and you can use local variables inside this function without accidentally overwriting an existing variable.

The use of the var keyword is very important, because in JavaScript every variable is global by default, but with the keyword you create a new, lexically scoped variable, that is, it is visible by the code between the two braces. In your example, you are essentially creating short aliases to the objects in the YUI library, but it has more powerful uses.

I don't want to leave you without a code example, so I'll put here a simple example to illustrate a closure:

var add_gen = function(n) {
  return function(x) {
    return n + x;
var add2 = add_gen(2);
add2(3); // result is 5

What is going on here? In the function add_gen you are creating an another function which will simply add the number n to its argument. The trick is that in the variables defined in the function parameter list act as lexically scoped variables, like the ones defined with var.

The returned function is defined between the braces of the add_gen function so it will have access to the value of n even after add_gen function has finished executing, that is why you will get 5 when executing the last line of the example.

With the help of function parameters being lexically scoped, you can work around the "problems" arising from using loop variables in anonymous functions. Take a simple example:

for(var i=0; i<5; i++) {
  setTimeout(function(){alert(i)}, 10);

The "expected" result could be the numbers from zero to four, but you get four instances of fives instead. This happens because the anonymous function in setTimeout and the for loop are using the very same i variable, so by the time the functions get evaluated, i will be 5.

You can get the naively expected result by using the technique in your question and the fact, that function parameters are lexically scoped. (I've used this approach in an other answer)

for(var i=0; i<5; i++) {
     (function(j) {
       return function(){alert(j)};
     })(i), 10);

With the immediate evaluation of the outer function you are creating a completely independent variable named j in each iteration, and the current value of i will be copied in to this variable, so you will get the result what was naively expected from the first try.

I suggest you to try to understand the excellent tutorial at to understand closures better, that is where I learnt very-very much.

Convert Word doc, docx and Excel xls, xlsx to PDF with PHP

The easiest way to do this in my experience is with the Cloudmersive free native PHP library, just call convertDocumentDocxToPdf:

require_once(__DIR__ . '/vendor/autoload.php');

// Configure API key authorization: Apikey
$config = Swagger\Client\Configuration::getDefaultConfiguration()->setApiKey('Apikey', 'YOUR_API_KEY');

$apiInstance = new Swagger\Client\Api\ConvertDocumentApi(

    new GuzzleHttp\Client(),
$input_file = "/path/to/file.txt"; // \SplFileObject | Input file to perform the operation on.

try {
    $result = $apiInstance->convertDocumentDocxToPdf($input_file);
} catch (Exception $e) {
    echo 'Exception when calling ConvertDocumentApi->convertDocumentDocxToPdf: ', $e->getMessage(), PHP_EOL;

Be sure to replace $input_file with the appropriate file path. You can also configure it to use a byte array if you prefer to do it that way. The result will be the bytes of the converted PDF file.

Need a query that returns every field that contains a specified letter

where somefield like '%a%' or somefield like '%b%'

Pylint "unresolved import" error in Visual Studio Code

I have resolved import error by Ctrl + Shift + P. Type "Preferences settings" and select the option Preferences Open Settings (JSON)

And add the line "python.pythonPath": "/usr/bin/"

So the JSON content should look like:

    "python.pythonPath": "/usr/bin/"

Keep other configuration lines if they are present. This should import all modules that you have installed using PIP for autocomplete.

Bundling data files with PyInstaller (--onefile)

Perhaps i missed a step or did something wrong but the methods which are above, didn't bundle data files with PyInstaller into one exe file. Let me share the steps what i have done.

  1. step:Write one of the above methods into your py file with importing sys and os modules. I tried both of them. The last one is:

    def resource_path(relative_path):
    """ Get absolute path to resource, works for dev and for PyInstaller """
        base_path = getattr(sys, '_MEIPASS', os.path.dirname(os.path.abspath(__file__)))
        return os.path.join(base_path, relative_path)
  2. step: Write, pyi-makespec, to the console, to create a file.spec file.

  3. step: Open, file.spec with Notepad++ to add the data files like below:

    a = Analysis(['C:\\Users\\TCK\\Desktop\\Projeler\\'],
    #Add the file like the below example
    a.datas += [('Converter-GUI.ico', 'C:\\Users\\TCK\\Desktop\\Projeler\\Converter-GUI.ico', 'DATA')]
    pyz = PYZ(a.pure, a.zipped_data,
    exe = EXE(pyz,
              #Turn the console option False if you don't want to see the console while executing the program.
              #Add an icon to the program.
    coll = COLLECT(exe,
  4. step: I followed the above steps, then saved the spec file. At last opened the console and write, pyinstaller file.spec (in my case, file=Converter-GUI).

Conclusion: There's still more than one file in the dist folder.

Note: I'm using Python 3.5.

EDIT: Finally it works with Jonathan Reinhart's method.

  1. step: Add the below codes to your python file with importing sys and os.

    def resource_path(relative_path):
    """ Get absolute path to resource, works for dev and for PyInstaller """
        base_path = getattr(sys, '_MEIPASS', os.path.dirname(os.path.abspath(__file__)))
        return os.path.join(base_path, relative_path)
  2. step: Call the above function with adding the path of your file:

    image_path = resource_path("Converter-GUI.ico")
  3. step: Write the above variable that call the function to where your codes need the path. In my case it's:

  4. step: Open the console in the same directory of your python file, write the codes like below:

        pyinstaller --onefile
  5. step: Open the .spec file of the python file and append the a.datas array and add the icon to the exe class, which was given above before the edit in 3'rd step.
  6. step: Save and exit the path file. Go to your folder which include the spec and py file. Open again the console window and type the below command:

        pyinstaller your_file.spec

After the 6. step your one file is ready to use.

How can I remove jenkins completely from linux

On Centos7, It is important to note that while you remove jenkins using following command: sudo yum remove jenkins

it will not remove your users and other information. For that you will have to do following: sudo rm -r /var/lib/jenkins

How to part DATE and TIME from DATETIME in MySQL

per the mysql documentation, the DATE() function will pull the date part of a datetime feild, and TIME() for the time portion. so I would try:

select DATE(dateTimeField) as Date, TIME(dateTimeField) as Time, col2, col3, FROM Table1 ...

How can I see normal print output created during pytest run?

When running the test use the -s option. All print statements in would get printed on the console when test is run.

py.test -s

Formatting a Date String in React Native

There is no need to include a bulky library such as Moment.js to fix such a simple issue.

The issue you are facing is not with formatting, but with parsing.

As John Shammas mentions in another answer, the Date constructor (and Date.parse) are picky about the input. Your 2016-01-04 10:34:23 may work in one JavaScript implementation, but not necessarily in the other.

According to the specification of ECMAScript 5.1, Date.parse supports (a simplification of) ISO 8601. That's good news, because your date is already very ISO 8601-like.

All you have to do is change the input format just a little. Swap the space for a T: 2016-01-04T10:34:23; and optionally add a time zone (2016-01-04T10:34:23+01:00), otherwise UTC is assumed.

mysqli::mysqli(): (HY000/2002): Can't connect to local MySQL server through socket 'MySQL' (2)

When you use just "localhost" the MySQL client library tries to use a Unix domain socket for the connection instead of a TCP/IP connection. The error is telling you that the socket, called MySQL, cannot be used to make the connection, probably because it does not exist (error number 2).

From the MySQL Documentation:

On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option.

There are a few ways to solve this problem.

  1. You can just use TCP/IP instead of the Unix socket. You would do this by using instead of localhost when you connect. The Unix socket might by faster and safer to use, though.
  2. You can change the socket in php.ini: open the MySQL configuration file my.cnf to find where MySQL creates the socket, and set PHP's mysqli.default_socket to that path. On my system it's /var/run/mysqld/mysqld.sock.
  3. Configure the socket directly in the PHP script when opening the connection. For example:

    $db = new MySQLi('localhost', 'kamil', '***', '', 0, 

Android WSDL/SOAP service client

Icesoap, which I found yesterday, looks promising. It worked on a basic test, but it lacks more examples.

All possible array initialization syntaxes

hi just to add another way: from this page :

you can use this form If you want to Generates a sequence of integral numbers within a specified range strat 0 to 9:

using System.Linq
public int[] arrayName = Enumerable.Range(0, 9).ToArray();

Using sendmail from bash script for multiple recipients

Try doing this :

recipients="[email protected],[email protected],[email protected]"

And another approach, using shell here-doc :

/usr/sbin/sendmail "$recipients" <<EOF

Example Message

Be sure to separate the headers from the body with a blank line as per RFC 822.

HTTP GET with request body

You have a list of options which are far better than using a request body with GET.

Let' assume you have categories and items for each category. Both to be identified by an id ("catid" / "itemid" for the sake of this example). You want to sort according to another parameter "sortby" in a specific "order". You want to pass parameters for "sortby" and "order":

You can:

  1. Use query strings, e.g.{catid}/item/{itemid}?sortby=itemname&order=asc
  2. Use mod_rewrite (or similar) for paths:{catid}/item/{itemid}/{sortby}/{order}
  3. Use individual HTTP headers you pass with the request
  4. Use a different method, e.g. POST, to retrieve a resource.

All have their downsides, but are far better than using a GET with a body.

Argparse optional positional arguments?

As an extension to @VinaySajip answer. There are additional nargs worth mentioning.

  1. parser.add_argument('dir', nargs=1, default=os.getcwd())

N (an integer). N arguments from the command line will be gathered together into a list

  1. parser.add_argument('dir', nargs='*', default=os.getcwd())

'*'. All command-line arguments present are gathered into a list. Note that it generally doesn't make much sense to have more than one positional argument with nargs='*', but multiple optional arguments with nargs='*' is possible.

  1. parser.add_argument('dir', nargs='+', default=os.getcwd())

'+'. Just like '*', all command-line args present are gathered into a list. Additionally, an error message will be generated if there wasn’t at least one command-line argument present.

  1. parser.add_argument('dir', nargs=argparse.REMAINDER, default=os.getcwd())

argparse.REMAINDER. All the remaining command-line arguments are gathered into a list. This is commonly useful for command line utilities that dispatch to other command line utilities

If the nargs keyword argument is not provided, the number of arguments consumed is determined by the action. Generally this means a single command-line argument will be consumed and a single item (not a list) will be produced.

Edit (copied from a comment by @Acumenus) nargs='?' The docs say: '?'. One argument will be consumed from the command line if possible and produced as a single item. If no command-line argument is present, the value from default will be produced.

How to retrieve the current version of a MySQL database management system (DBMS)?

MySQL Server version

shell> mysqld --version

MySQL Client version

shell> mysql --version

shell> mysql -V 

How to insert element as a first child?

parentNode.insertBefore(newChild, refChild)

Inserts the node newChild as a child of parentNode before the existing child node refChild. (Returns newChild.)

If refChild is null, newChild is added at the end of the list of children. Equivalently, and more readably, use parentNode.appendChild(newChild).

How do I remove the space between inline/inline-block elements?

I found a pure CSS solution that worked for me very well in all browsers:

span {
    display: table-cell;

Android: How to Programmatically set the size of a Layout

You can get the actual height of called layout with this code:

public int getLayoutSize() {
// Get the layout id
    final LinearLayout root = (LinearLayout) findViewById(;
    final AtomicInteger layoutHeight = new AtomicInteger(); Runnable() { 
    public void run() { 
        Rect rect = new Rect(); 
        Window win = getWindow();  // Get the Window

                // Get the height of Status Bar
                int statusBarHeight =;

                // Get the height occupied by the decoration contents 
                int contentViewTop = win.findViewById(Window.ID_ANDROID_CONTENT).getTop();

                // Calculate titleBarHeight by deducting statusBarHeight from contentViewTop  
                int titleBarHeight = contentViewTop - statusBarHeight; 
                Log.i("MY", "titleHeight = " + titleBarHeight + " statusHeight = " + statusBarHeight + " contentViewTop = " + contentViewTop); 

                // By now we got the height of titleBar & statusBar
                // Now lets get the screen size
                DisplayMetrics metrics = new DisplayMetrics();
                int screenHeight = metrics.heightPixels;
                int screenWidth = metrics.widthPixels;
                Log.i("MY", "Actual Screen Height = " + screenHeight + " Width = " + screenWidth);   

                // Now calculate the height that our layout can be set
                // If you know that your application doesn't have statusBar added, then don't add here also. Same applies to application bar also 
                layoutHeight.set(screenHeight - (titleBarHeight + statusBarHeight));
                Log.i("MY", "Layout Height = " + layoutHeight);   

            // Lastly, set the height of the layout       
            FrameLayout.LayoutParams rootParams = (FrameLayout.LayoutParams)root.getLayoutParams();
            rootParams.height = layoutHeight.get();

return layoutHeight.get();

Resolve promises one after another (i.e. in sequence)?

Most of the answers dont include the results of ALL promises individually, so in case someone is looking for this particular behaviour, this is a possible solution using recursion.

It follows the style of Promise.all:

  • Returns the array of results in the .then() callback.

  • If some promise fails, its returned immediately in the .catch() callback.

const promiseEach = (arrayOfTasks) => {_x000D_
  let results = []_x000D_
  return new Promise((resolve, reject) => {_x000D_
    const resolveNext = (arrayOfTasks) => {_x000D_
      // If all tasks are already resolved, return the final array of results_x000D_
      if (arrayOfTasks.length === 0) return resolve(results)_x000D_
      // Extract first promise and solve it_x000D_
      const first = arrayOfTasks.shift()_x000D_
      first().then((res) => {_x000D_
      }).catch((err) => {_x000D_
// Lets try it _x000D_
const promise = (time, shouldThrowError) => new Promise((resolve, reject) => {_x000D_
  const timeInMs = time * 1000_x000D_
    console.log(`Waited ${time} secs`)_x000D_
    if (shouldThrowError) reject(new Error('Promise failed'))_x000D_
  }, timeInMs)_x000D_
const tasks = [() => promise(1), () => promise(2)]_x000D_
  .then((res) => {_x000D_
    console.log(res) // [1, 2]_x000D_
  // Oops some promise failed_x000D_
  .catch((error) => {_x000D_

Note about the tasks array declaration:

In this case is not possible to use the following notation like Promise.all would use:

const tasks = [promise(1), promise(2)]

And we have to use:

const tasks = [() => promise(1), () => promise(2)]

The reason is that JavaScript starts executing the promise immediatelly after its declared. If we use methods like Promise.all, it just checks that the state of all of them is fulfilled or rejected, but doesnt start the exection itself. Using () => promise() we stop the execution until its called.

Check whether an input string contains a number in javascript

You can also try lodash:

const isNumeric = number => 
  _.isFinite(_.parseInt(number)) && !_.isNaN(_.parseInt(number))

Mockito verify order / sequence of method calls

Note that you can also use the InOrder class to verify that various methods are called in order on a single mock, not just on two or more mocks.

Suppose I have two classes Foo and Bar:

public class Foo {
  public void first() {}
  public void second() {}

public class Bar {
  public void firstThenSecond(Foo foo) {

I can then add a test class to test that Bar's firstThenSecond() method actually calls first(), then second(), and not second(), then first(). See the following test code:

public class BarTest {
  public void testFirstThenSecond() {
    Bar bar = new Bar();
    Foo mockFoo = Mockito.mock(Foo.class);

    InOrder orderVerifier = Mockito.inOrder(mockFoo);
    // These lines will PASS

    // These lines will FAIL
    // orderVerifier.verify(mockFoo).second();
    // orderVerifier.verify(mockFoo).first();

Why is my method undefined for the type object?

It should be like that

public static void main(String[] args) {
        EchoServer0 e = new EchoServer0();
        // TODO Auto-generated method stub

Your variable of type Object truly doesn't have such a method, but the type EchoServer0 you define above certainly has.

HTML-encoding lost when attribute read from input field

You shouldn't have to escape/encode values in order to shuttle them from one input field to another.

 <input id="button" type="button" value="Click me">
 <input type="hidden" id="hiddenId" name="hiddenId" value="I like cheese">
 <input type="text" id="output" name="output">
    $(document).ready(function(e) {
        $('#button').click(function(e) {

JS doesn't go inserting raw HTML or anything; it just tells the DOM to set the value property (or attribute; not sure). Either way, the DOM handles any encoding issues for you. Unless you're doing something odd like using document.write or eval, HTML-encoding will be effectively transparent.

If you're talking about generating a new textbox to hold the's still as easy. Just pass the static part of the HTML to jQuery, and then set the rest of the properties/attributes on the object it returns to you.

$box = $('<input type="text" name="whatever">').val($('#hiddenId').val());

How to simplify a null-safe compareTo() implementation?

You can extract method:

public int cmp(String txt, String otherTxt)
    if ( txt == null )
        return otjerTxt == null ? 0 : 1;

    if ( otherTxt == null )
          return 1;

    return txt.compareToIgnoreCase(otherTxt);

public int compareTo(Metadata other) {
   int result = cmp( name,; 
   if ( result != 0 )  return result;
   return cmp( value, other.value); 


setTimeout in React Native

Write a new function for settimeout. Pls try this.

class CowtanApp extends Component {
  this.state = {
  timePassed: false

componentDidMount() {
  this.setTimeout( () => {

setTimePassed() {
   this.setState({timePassed: true});

render() {

if (!this.state.timePassed){
  return <LoadingPage/>;
  return (
      style = {styles.container}
      initialRoute = {{
        component: LoginPage,
        title: 'Sign In',

CSS customized scroll bar in div

Webkit browsers (such as Chrome, Safari and Opera) supports the non-standard ::-webkit-scrollbar pseudo element, which allows us to modify the look of the browser's scrollbar.

Note: The ::-webkit-scrollbar is not supported by Firefox or IE and Edge.

* {_x000D_
  box-sizing: border-box;_x000D_
  font-family: sans-serif;_x000D_
div {_x000D_
  width: 15rem;_x000D_
  height: 8rem;_x000D_
  padding: .5rem;_x000D_
  border: 1px solid #aaa;_x000D_
  margin-bottom: 1rem;_x000D_
  overflow: auto;_x000D_
.box::-webkit-scrollbar {_x000D_
  width: .8em;_x000D_
.box::-webkit-scrollbar-track {_x000D_
  box-shadow: inset 0 0 6px rgba(0, 0, 0, .3);_x000D_
.box::-webkit-scrollbar-thumb {_x000D_
  background-color: dodgerblue;_x000D_
<div class="box">_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate</p>_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate</p>_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate</p>_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate</p>_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate</p>_x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate</p>_x000D_

Reference: How To Create a Custom Scrollbar

Are there any worse sorting algorithms than Bogosort (a.k.a Monkey Sort)?

The "what would you like it to be?" sort

  1. Note the system time.
  2. Sort using Quicksort (or anything else reasonably sensible), omitting the very last swap.
  3. Note the system time.
  4. Calculate the required time. Extended precision arithmetic is a requirement.
  5. Wait the required time.
  6. Perform the last swap.

Not only can it implement any conceivable O(x) value short of infinity, the time taken is provably correct (if you can wait that long).

How to disable Home and other system buttons in Android?

You can't disable Home button from ICS onwords but can disable other buttons as follows

public boolean dispatchKeyEvent(KeyEvent keyEvent){
   return true;

Limit on the WHERE col IN (...) condition

Parameterize the query and pass the ids in using a Table Valued Parameter.

For example, define the following type:


Along with the following stored procedure:

CREATE PROCEDURE sp__Procedure_Name
    @OrderIDs IdTable READONLY,

    SELECT *
    FROM table

How do I make case-insensitive queries on Mongodb?

To find case-insensitive literals string:

Using regex (recommended)

    name: {
        $regex: new RegExp('^' + name.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&') + '$', 'i')

Using lower-case index (faster)

    name_lower: name.toLowerCase()

Regular expressions are slower than literal string matching. However, an additional lowercase field will increase your code complexity. When in doubt, use regular expressions. I would suggest to only use an explicitly lower-case field if it can replace your field, that is, you don't care about the case in the first place.

Note that you will need to escape the name prior to regex. If you want user-input wildcards, prefer appending .replace(/%/g, '.*') after escaping so that you can match "a%" to find all names starting with 'a'.

How to find the path of Flutter SDK

If you have the flutter SDK installed.


flutter doctor -v

The first line will show the install path..

(if you don't have it installed go to the documentation)

How to find an available port?

It may not help you much, but on my (Ubuntu) machine I have a file /etc/services in which at least the ports used/reserved by some of the apps are given. These are the standard ports for those apps.

No guarantees that these are running, just the default ports these apps use (so you should not use them if possible).

There are slightly more than 500 ports defined, about half UDP and half TCP.

The files are made using information by IANA, see IANA Assigned port numbers.

Including external HTML file to another HTML file

You can use jquery load for that.

<script type="text/javascript">
$(document).ready(function(e) {

Don't forget to include jquery library befor above code.

Object creation on the stack/heap?

The two forms are the same with one exception: temporarily, the new (Object *) has an undefined value when the creation and assignment are separate. The compiler may combine them back together, since the undefined pointer is not particularly useful. This does not relate to global variables (unless the declaration is global, in which case it's still true for both forms).

Including external jar-files in a new jar-file build with Ant

Cheesle is right. There's no way for the classloader to find the embedded jars. If you put enough debug commands on the command line you should be able to see the 'java' command failing to add the jars to a classpath

What you want to make is sometimes called an 'uberjar'. I found one-jar as a tool to help make them, but I haven't tried it. Sure there's many other approaches.

Android Canvas: drawing too large bitmap

For this error was like others said a big image(1800px X 900px) which was in drawable directory, I edited the image and reduced the size proportionally using photoshop and it worked...!!

Return value of x = os.system(..)

os.system('command') returns a 16 bit number, which first 8 bits from left(lsb) talks about signal used by os to close the command, Next 8 bits talks about return code of command.

Refer my answer for more detail in What is the return value of os.system() in Python?

Python 3.6 install win32api?

Information provided by @Gord

As of September 2019 pywin32 is now available from PyPI and installs the latest version (currently version 224). This is done via the pip command

pip install pywin32

If you wish to get an older version the sourceforge link below would probably have the desired version, if not you can use the command, where xxx is the version you require, e.g. 224

pip install pywin32==xxx

This differs to the pip command below as that one uses pypiwin32 which currently installs an older (namely 223)

Browsing the docs I see no reason for these commands to work for all python3.x versions, I am unsure on python2.7 and below so you would have to try them and if they do not work then the solutions below will work.

Probably now undesirable solutions but certainly still valid as of September 2019

There is no version of specific version ofwin32api. You have to get the pywin32module which currently cannot be installed via pip. It is only available from this link at the moment.

The install does not take long and it pretty much all done for you. Just make sure to get the right version of it depending on your python version :)


Since I posted my answer there are other alternatives to downloading the win32api module.

It is now available to download through pip using this command;

pip install pypiwin32

Also it can be installed from this GitHub repository as provided in comments by @Heath

'console' is undefined error for Internet Explorer

Encountered similar problem running console.log in child windows in IE9, created by function.

It seems that in this case console is defined only in parent window and is undefined in child windows until you refresh them. Same applies to children of child windows.

I deal with this issue by wrapping log in next function (below is fragment of module)

getConsole: function()
        if (typeof console !== 'undefined') return console;

        var searchDepthMax = 5,
            searchDepth = 0,
            context = window.opener;

        while (!!context && searchDepth < searchDepthMax)
            if (typeof context.console !== 'undefined') return context.console;

            context = context.opener;

        return null;
    log: function(message){
        var _console = this.getConsole();
        if (!!_console) _console.log(message);

Non-numeric Argument to Binary Operator Error in R

Because your question is phrased regarding your error message and not whatever your function is trying to accomplish, I will address the error.

- is the 'binary operator' your error is referencing, and either CurrentDay or MA (or both) are non-numeric.

A binary operation is a calculation that takes two values (operands) and produces another value (see wikipedia for more). + is one such operator: "1 + 1" takes two operands (1 and 1) and produces another value (2). Note that the produced value isn't necessarily different from the operands (e.g., 1 + 0 = 1).

R only knows how to apply + (and other binary operators, such as -) to numeric arguments:

> 1 + 1
[1] 2
> 1 + 'one'
Error in 1 + "one" : non-numeric argument to binary operator

When you see that error message, it means that you are (or the function you're calling is) trying to perform a binary operation with something that isn't a number.


Your error lies in the use of [ instead of [[. Because Day is a list, subsetting with [ will return a list, not a numeric vector. [[, however, returns an object of the class of the item contained in the list:

> Day <- Transaction(1, 2)["b"]
> class(Day)
[1] "list"
> Day + 1
Error in Day + 1 : non-numeric argument to binary operator

> Day2 <- Transaction(1, 2)[["b"]]
> class(Day2)
[1] "numeric"
> Day2 + 1
[1] 3

Transaction, as you've defined it, returns a list of two vectors. Above, Day is a list contain one vector. Day2, however, is simply a vector.

How to set session variable in jquery?

You could try using HTML5s sessionStorage it lasts for the duration on the page session. A page session lasts for as long as the browser is open and survives over page reloads and restores. Opening a page in a new tab or window will cause a new session to be initiated.

sessionStorage.setItem("username", "John");

Browser Compatibility compatible with every A-grade browser, included iPhone or Android.

NUnit Unit tests not showing in Test Explorer with Test Adapter installed

Make sure your tests are properly marked with the Test attribute. If all of the tests are marked with only the Explicit attribute, the TestAdapter doesn't recognize the fixture.

Can you disable tabs in Bootstrap?

No Need Any Jquery, Just One Line CSS

.nav-tabs li.disabled a {
    pointer-events: none;

Concatenating date with a string in Excel

Thanks for the solution !

It works, but in a french Excel environment, you should apply something like


to get the date preserved as it is displayed in F2 cell, after concatenation. Best Regards

jQuery - Add ID instead of Class

Keep in mind this overwrites any ID that the element already has:


The reason why addClass exists is because an element can have multiple classes, so you wouldn't want to necessarily overwrite the classes already set. But with most attributes, there is only one value allowed at any given time.

Split string with multiple delimiters in Python

This is how the regex look like:

import re
# "semicolon or (a comma followed by a space)"
pattern = re.compile(r";|, ")

# "(semicolon or a comma) followed by a space"
pattern = re.compile(r"[;,] ")

print pattern.split(text)

Android translate animation - permanently move View to new position using AnimationListener

I usually prefer to work with deltas in translate animation, since it avoids a lot of confusion.

Try this out, see if it works for you:

TranslateAnimation anim = new TranslateAnimation(0, amountToMoveRight, 0, amountToMoveDown);

anim.setAnimationListener(new TranslateAnimation.AnimationListener() {

    public void onAnimationStart(Animation animation) { }

    public void onAnimationRepeat(Animation animation) { }

    public void onAnimationEnd(Animation animation) 
        FrameLayout.LayoutParams params = (FrameLayout.LayoutParams)view.getLayoutParams();
        params.topMargin += amountToMoveDown;
        params.leftMargin += amountToMoveRight;


Make sure to make amountToMoveRight / amountToMoveDown final

Hope this helps :)

How to download image using requests

How about this, a quick solution.

import requests

url = ""
response = requests.get(url)
if response.status_code == 200:
    with open("/Users/apple/Desktop/sample.jpg", 'wb') as f:

Python add item to the tuple

You need to make the second element a 1-tuple, eg:

a = ('2',)
b = 'z'
new = a + (b,)

setState(...): Can only update a mounted or mounting component. This usually means you called setState() on an unmounted component. This is a no-op

Having named method in place of the anonymous function in audioNode.addEventListener 's callback should eliminate the subject warning:

    componentDidMount(prevProps, prevState, prevContext) {
    let [audioNode, songLen] = [, List.length-1];

    audioNode.addEventListener('ended', () => {
        this._endedPlay(songLen, () => {

    audioNode.addEventListener('timeupdate', this.callbackMethod );

callBackMethod = () => {
    let [remainTime, remainTimeMin, remainTimeSec, remainTimeInfo] = [];

    if(!isNaN(audioNode.duration)) {
        remainTime = audioNode.duration - audioNode.currentTime;
        remainTimeMin = parseInt(remainTime/60);  // ???
        remainTimeSec = parseInt(remainTime%60);  // ???

        if(remainTimeSec < 10) {
            remainTimeSec = '0'+remainTimeSec;
        remainTimeInfo = remainTimeMin + ':' + remainTimeSec;
        this.setState({'time': remainTimeInfo});

And yes, named method is needed anyways because removeEventListener won't work with anonymous callbacks, as mentioned above several times.

Excel Define a range based on a cell value

Say you have number 1,2,3,4,5,6, in cell A1,A2,A3,A4,A5,A6 respectively. in cell A7 we calculate the sum of A1:Ax. x is specified in cell B1 (in this case, x can be any number from 1 to 6). in cell A7, you can write the following formular:


CONCATENATE will give you the index of the cell Ax(if you put 3 in B1, CONCATENATE("A",B1)) gives A3).

INDIRECT convert "A3" to a index.

see this link Using the value in a cell as a cell reference in a formula?

How can I view an old version of a file with Git?

You can use git show with a path from the root of the repository (./ or ../ for relative pathing):

$ git show REVISION:path/to/file

Replace REVISION with your actual revision (could be a Git commit SHA, a tag name, a branch name, a relative commit name, or any other way of identifying a commit in Git)

For example, to view the version of file <repository-root>/src/main.c from 4 commits ago, use:

$ git show HEAD~4:src/main.c

Git for Windows requires forward slashes even in paths relative to the current directory. For more information, check out the man page for git-show.

Sorting a vector in descending order

What about this?

std::sort(numbers.begin(), numbers.end());
std::reverse(numbers.begin(), numbers.end());

How do I iterate through lines in an external file with shell?

You'll be wanting to use the 'read' command

while read name
    echo "$name"
done < names.txt

Note that "$name" is quoted -- if it's not, it will be split using the characters in $IFS as delimiters. This probably won't be noticed if you're just echoing the variable, but if your file contains a list of file names which you want to copy, those will get broken down by $IFS if the variable is unquoted, which is not what you want or expect.

If you want to use Mike Clark's approach (loading into a variable rather than using read), you can do it without the use of cat:

NAMES="$(< scripts/names.txt)" #names from names.txt file
for NAME in $NAMES; do
    echo "$NAME"

The problem with this is that it loads the whole file into $NAMES, when you read it back out, you can either get the whole file (if quoted) or the file broken down by $IFS, if not quoted. By default, this will give you individual words, not individual lines. So if the name "Mary Jane" appeared on a line, you would get "Mary" and "Jane" as two separate names. Using read will get around this... although you could also change the value of $IFS

Fixed positioning in Mobile Safari

Here you can see what (mobile) browsers support css position fixed + there version.