Programs & Examples On #Codeigniter url

By default, URLs in CodeIgniter are designed to be search-engine and human friendly. Rather than using the standard "query string" approach to URLs that is synonymous with dynamic systems, CodeIgniter uses a segment-based approach: example.com/news/article/my_article

How to get a random number between a float range?

random.uniform(a, b) appears to be what your looking for. From the docs:

Return a random floating point number N such that a <= N <= b for a <= b and b <= N <= a for b < a.

See here.

Sockets - How to find out what port and address I'm assigned

The comment in your code is wrong. INADDR_ANY doesn't put server's IP automatically'. It essentially puts 0.0.0.0, for the reasons explained in mark4o's answer.

Multiple left-hand assignment with JavaScript

var var1 = 1, var2 = 1, var3 = 1;

In this case var keyword is applicable to all the three variables.

var var1 = 1,
    var2 = 1,
    var3 = 1;

which is not equivalent to this:

var var1 = var2 = var3 = 1;

In this case behind the screens var keyword is only applicable to var1 due to variable hoisting and rest of the expression is evaluated normally so the variables var2, var3 are becoming globals

Javascript treats this code in this order:

/*
var 1 is local to the particular scope because of var keyword
var2 and var3 will become globals because they've used without var keyword
*/

var var1;   //only variable declarations will be hoisted.

var1= var2= var3 = 1; 

Running a simple shell script as a cronjob

The easiest way would be to use a GUI:

For Gnome use gnome-schedule (universe)

sudo apt-get install gnome-schedule 

For KDE use kde-config-cron

It should be pre installed on Kubuntu

But if you use a headless linux or don´t want GUI´s you may use:

crontab -e

If you type it into Terminal you´ll get a table.
You have to insert your cronjobs now.
Format a job like this:

*     *     *     *     *  YOURCOMMAND
-     -     -     -     -
|     |     |     |     |
|     |     |     |     +----- Day in Week (0 to 7) (Sunday is 0 and 7)
|     |     |     +------- Month (1 to 12)
|     |     +--------- Day in Month (1 to 31)
|     +----------- Hour (0 to 23)
+------------- Minute (0 to 59)

There are some shorts, too (if you don´t want the *):

@reboot --> only once at startup
@daily ---> once a day
@midnight --> once a day at midnight
@hourly --> once a hour
@weekly --> once a week
@monthly --> once a month
@annually --> once a year
@yearly --> once a year

If you want to use the shorts as cron (because they don´t work or so):

@daily --> 0 0 * * *
@midnight --> 0 0 * * *
@hourly --> 0 * * * *
@weekly --> 0 0 * * 0
@monthly --> 0 0 1 * *
@annually --> 0 0 1 1 *
@yearly --> 0 0 1 1 *

Attempt to write a readonly database - Django w/ SELinux error

You can change the owner of your database file and it's folder to django:

chown django:django /home/django/mysite
chown django:django /home/django/mysite/my_db.sqlite3

This work for DigitalOcean's 1-Click Django Droplet

How to increment datetime by custom months in python without using library

Here's my salt :

current = datetime.datetime(mydate.year, mydate.month, 1)
next_month = datetime.datetime(mydate.year + int(mydate.month / 12), ((mydate.month % 12) + 1), 1)

Quick and easy :)

Extracting Ajax return data in jQuery

You may also use the jQuery context parameter. Link to docs

Selector Context

By default, selectors perform their searches within the DOM starting at the document root. However, an alternate context can be given for the search by using the optional second parameter to the $() function

Therefore you could also have:

success: function(data){
    var oneval = $('#one',data).text();
    var subval = $('#sub',data).text();
}

How to insert a new line in strings in Android

Try:

String str = "my string \n my other string";

When printed you will get:

my string
my other string

Laravel Eloquent compare date from datetime field

You can get the all record of the date '2016-07-14' by using it

 whereDate('date','=','2016-07-14')

Or use the another code for dynamic date

whereDate('date',$date)

Bootstrap: Open Another Modal in Modal

For someone who use bootstrap 4 https://jsfiddle.net/helloroy/tmm9juoh/

_x000D_
_x000D_
var modal_lv = 0;_x000D_
$('.modal').on('shown.bs.modal', function (e) {_x000D_
    $('.modal-backdrop:last').css('zIndex',1051+modal_lv);_x000D_
    $(e.currentTarget).css('zIndex',1052+modal_lv);_x000D_
    modal_lv++_x000D_
});_x000D_
_x000D_
$('.modal').on('hidden.bs.modal', function (e) {_x000D_
    modal_lv--_x000D_
});
_x000D_
<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js"></script>_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#modal-a">_x000D_
  Launch demo modal a_x000D_
</button>_x000D_
_x000D_
<div class="modal fade" id="modal-a" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">_x000D_
  <div class="modal-dialog" role="document">_x000D_
    <div class="modal-content">_x000D_
      <div class="modal-header">_x000D_
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>_x000D_
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">_x000D_
          <span aria-hidden="true">&times;</span>_x000D_
        </button>_x000D_
      </div>_x000D_
      <div class="modal-body">_x000D_
        <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#modal-b">_x000D_
  Launch another demo modal b_x000D_
</button>_x000D_
<p class="my-3">_x000D_
Not good for fade In._x000D_
</p>_x000D_
<p class="my-3">_x000D_
who help to improve?_x000D_
</p>_x000D_
      </div>_x000D_
      <div class="modal-footer">_x000D_
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>_x000D_
        <button type="button" class="btn btn-primary">Save changes</button>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>_x000D_
_x000D_
<div class="modal fade" id="modal-b" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">_x000D_
  <div class="modal-dialog" role="document">_x000D_
    <div class="modal-content">_x000D_
      <div class="modal-header">_x000D_
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>_x000D_
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">_x000D_
          <span aria-hidden="true">&times;</span>_x000D_
        </button>_x000D_
      </div>_x000D_
      <div class="modal-body">_x000D_
        <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#modal-c">_x000D_
  Launch another demo modal c_x000D_
</button>_x000D_
<p class="my-3">_x000D_
But good enough for static modal_x000D_
</p>_x000D_
      </div>_x000D_
      <div class="modal-footer">_x000D_
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>_x000D_
        <button type="button" class="btn btn-primary">Save changes</button>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>_x000D_
_x000D_
_x000D_
<div class="modal" id="modal-c" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">_x000D_
  <div class="modal-dialog" role="document">_x000D_
    <div class="modal-content">_x000D_
      <div class="modal-header">_x000D_
        <h5 class="modal-title" id="exampleModalLabel">Modal title</h5>_x000D_
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">_x000D_
          <span aria-hidden="true">&times;</span>_x000D_
        </button>_x000D_
      </div>_x000D_
      <div class="modal-body">_x000D_
<p class="my-3">That's all.</p>_x000D_
      </div>_x000D_
      <div class="modal-footer">_x000D_
        <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>_x000D_
        <button type="button" class="btn btn-primary">Save changes</button>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

java.lang.NoClassDefFoundError: org/apache/http/client/HttpClient

If its a maven project, add the below dependency in your pom file

    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.3.4</version>
    </dependency>

python dataframe pandas drop column using int

Drop multiple columns like this:

cols = [1,2,4,5,12]
df.drop(df.columns[cols],axis=1,inplace=True)

inplace=True is used to make the changes in the dataframe itself without doing the column dropping on a copy of the data frame. If you need to keep your original intact, use:

df_after_dropping = df.drop(df.columns[cols],axis=1)

Add characters to a string in Javascript

You can also keep adding strings to an existing string like so:

var myString = "Hello ";
myString += "World";
myString += "!";

the result would be -> Hello World!

Create a new txt file using VB.NET

You can try writing into the Documents folder. Here is a "debug" function I did for the debugging needs of my project:

Private Sub writeDebug(ByVal x As String)
    Dim path As String = System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)
    Dim FILE_NAME As String = path & "\mydebug.txt"
    MsgBox(FILE_NAME)
    If System.IO.File.Exists(FILE_NAME) = False Then
        System.IO.File.Create(FILE_NAME).Dispose()
    End If
    Dim objWriter As New System.IO.StreamWriter(FILE_NAME, True)
    objWriter.WriteLine(x)
    objWriter.Close()
End Sub

There are more standard folders you can access through the "SpecialFolder" object.

What does \0 stand for?

The null character '\0' (also null terminator), abbreviated NUL, is a control character with the value zero. Its the same in C and objective C

The character has much more significance in C and it serves as a reserved character used to signify the end of a string,often called a null-terminated string

The length of a C string (an array containing the characters and terminated with a '\0' character) is found by searching for the (first) NUL byte.

How do you attach and detach from Docker's process?

I think this should depend on the situation.Take the following container as an example:

# docker run -it -d ubuntu
91262536f7c9a3060641448120bda7af5ca812b0beb8f3c9fe72811a61db07fc
# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
91262536f7c9        ubuntu              "/bin/bash"         5 seconds ago       Up 4 seconds                            serene_goldstine

(1) Use "docker attach" to attach the container:

Since "docker attach" will not allocate a new tty, but reuse the original running tty, so if you run exit command, it will cause the running container exit:

# docker attach 91262536f7c9
exit
exit
# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
91262536f7c9        ubuntu              "/bin/bash"         39 minutes ago      Exited (0) 3 seconds ago                       serene_goldstine

So unless you really want to make running container exit, you should use Ctrl+p + Ctrl+q.

(2) Use "docker exec"

Since "docker exec" will allocate a new tty, so I think you should use exit instead of Ctrl+p + Ctrl+q.

The following is executing Ctrl+p + Ctrl+q to quit the container:

# docker exec -it 91262536f7c9 bash
root@91262536f7c9:/# ps -aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0  18160  1908 ?        Ss+  04:03   0:00 /bin/bash
root        15  0.0  0.0  18164  1892 ?        Ss   04:03   0:00 bash
root        28  0.0  0.0  15564  1148 ?        R+   04:03   0:00 ps -aux
root@91262536f7c9:/# echo $$
15

Then login container again, you will see the bash process in preavious docker exec command is still alive (PID is 15):

# docker exec -it 91262536f7c9 bash
root@91262536f7c9:/# ps -aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0  18160  1908 ?        Ss+  04:03   0:00 /bin/bash
root        15  0.0  0.0  18164  1892 ?        Ss+  04:03   0:00 bash
root        29  0.0  0.0  18164  1888 ?        Ss   04:04   0:00 bash
root        42  0.0  0.0  15564  1148 ?        R+   04:04   0:00 ps -aux
root@91262536f7c9:/# echo $$
29

Notepad++ incrementally replace

I was looking for the same feature today but couldn't do this in Notepad++. However, we have TextPad to our rescue. It worked for me.

In TextPad's replace dialog, turn on regex; then you could try replacing

<row id="1"/>

by

<row id="\i"/>

Have a look at this link for further amazing replace features of TextPad - http://sublimetext.userecho.com/topic/106519-generate-a-sequence-of-numbers-increment-replace/

How to do a SOAP Web Service call from Java class?

I understand your problem boils down to how to call a SOAP (JAX-WS) web service from Java and get its returning object. In that case, you have two possible approaches:

  1. Generate the Java classes through wsimport and use them; or
  2. Create a SOAP client that:
    1. Serializes the service's parameters to XML;
    2. Calls the web method through HTTP manipulation; and
    3. Parse the returning XML response back into an object.


About the first approach (using wsimport):

I see you already have the services' (entities or other) business classes, and it's a fact that the wsimport generates a whole new set of classes (that are somehow duplicates of the classes you already have).

I'm afraid, though, in this scenario, you can only either:

  • Adapt (edit) the wsimport generated code to make it use your business classes (this is difficult and somehow not worth it - bear in mind everytime the WSDL changes, you'll have to regenerate and readapt the code); or
  • Give up and use the wsimport generated classes. (In this solution, you business code could "use" the generated classes as a service from another architectural layer.)

About the second approach (create your custom SOAP client):

In order to implement the second approach, you'll have to:

  1. Make the call:
    • Use the SAAJ (SOAP with Attachments API for Java) framework (see below, it's shipped with Java SE 1.6 or above) to make the calls; or
    • You can also do it through java.net.HttpUrlconnection (and some java.io handling).
  2. Turn the objects into and back from XML:
    • Use an OXM (Object to XML Mapping) framework such as JAXB to serialize/deserialize the XML from/into objects
    • Or, if you must, manually create/parse the XML (this can be the best solution if the received object is only a little bit differente from the sent one).

Creating a SOAP client using classic java.net.HttpUrlConnection is not that hard (but not that simple either), and you can find in this link a very good starting code.

I recommend you use the SAAJ framework:

SOAP with Attachments API for Java (SAAJ) is mainly used for dealing directly with SOAP Request/Response messages which happens behind the scenes in any Web Service API. It allows the developers to directly send and receive soap messages instead of using JAX-WS.

See below a working example (run it!) of a SOAP web service call using SAAJ. It calls this web service.

import javax.xml.soap.*;

public class SOAPClientSAAJ {

    // SAAJ - SOAP Client Testing
    public static void main(String args[]) {
        /*
            The example below requests from the Web Service at:
             https://www.w3schools.com/xml/tempconvert.asmx?op=CelsiusToFahrenheit


            To call other WS, change the parameters below, which are:
             - the SOAP Endpoint URL (that is, where the service is responding from)
             - the SOAP Action

            Also change the contents of the method createSoapEnvelope() in this class. It constructs
             the inner part of the SOAP envelope that is actually sent.
         */
        String soapEndpointUrl = "https://www.w3schools.com/xml/tempconvert.asmx";
        String soapAction = "https://www.w3schools.com/xml/CelsiusToFahrenheit";

        callSoapWebService(soapEndpointUrl, soapAction);
    }

    private static void createSoapEnvelope(SOAPMessage soapMessage) throws SOAPException {
        SOAPPart soapPart = soapMessage.getSOAPPart();

        String myNamespace = "myNamespace";
        String myNamespaceURI = "https://www.w3schools.com/xml/";

        // SOAP Envelope
        SOAPEnvelope envelope = soapPart.getEnvelope();
        envelope.addNamespaceDeclaration(myNamespace, myNamespaceURI);

            /*
            Constructed SOAP Request Message:
            <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:myNamespace="https://www.w3schools.com/xml/">
                <SOAP-ENV:Header/>
                <SOAP-ENV:Body>
                    <myNamespace:CelsiusToFahrenheit>
                        <myNamespace:Celsius>100</myNamespace:Celsius>
                    </myNamespace:CelsiusToFahrenheit>
                </SOAP-ENV:Body>
            </SOAP-ENV:Envelope>
            */

        // SOAP Body
        SOAPBody soapBody = envelope.getBody();
        SOAPElement soapBodyElem = soapBody.addChildElement("CelsiusToFahrenheit", myNamespace);
        SOAPElement soapBodyElem1 = soapBodyElem.addChildElement("Celsius", myNamespace);
        soapBodyElem1.addTextNode("100");
    }

    private static void callSoapWebService(String soapEndpointUrl, String soapAction) {
        try {
            // Create SOAP Connection
            SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
            SOAPConnection soapConnection = soapConnectionFactory.createConnection();

            // Send SOAP Message to SOAP Server
            SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(soapAction), soapEndpointUrl);

            // Print the SOAP Response
            System.out.println("Response SOAP Message:");
            soapResponse.writeTo(System.out);
            System.out.println();

            soapConnection.close();
        } catch (Exception e) {
            System.err.println("\nError occurred while sending SOAP Request to Server!\nMake sure you have the correct endpoint URL and SOAPAction!\n");
            e.printStackTrace();
        }
    }

    private static SOAPMessage createSOAPRequest(String soapAction) throws Exception {
        MessageFactory messageFactory = MessageFactory.newInstance();
        SOAPMessage soapMessage = messageFactory.createMessage();

        createSoapEnvelope(soapMessage);

        MimeHeaders headers = soapMessage.getMimeHeaders();
        headers.addHeader("SOAPAction", soapAction);

        soapMessage.saveChanges();

        /* Print the request message, just for debugging purposes */
        System.out.println("Request SOAP Message:");
        soapMessage.writeTo(System.out);
        System.out.println("\n");

        return soapMessage;
    }

}

About using JAXB for serializing/deserializing, it is very easy to find information about it. You can start here: http://www.mkyong.com/java/jaxb-hello-world-example/.

How to create an empty file at the command line in Windows?

You can use the old command

copy con file_name.ext

don't type anything, just press F6 to save it, however it will print "File copied", but when you open the file, it will be empty

Copying files from one directory to another in Java

Spring Framework has many similar util classes like Apache Commons Lang. So there is org.springframework.util.FileSystemUtils

File src = new File("/home/user/src");
File dest = new File("/home/user/dest");
FileSystemUtils.copyRecursively(src, dest);

How to get first and last element in an array in java?

Getting first and last elements in an array in Java

int[] a = new int[]{1, 8, 5, 9, 4};

First Element: a[0]

Last Element: a[a.length-1]

How to remove a directory from git repository?

I usually use git add --all to remove files / folders from remote repositories

rm -r folder_name
git add --all
git commit -m "some comment"
git push origin master

master can be replaced by any other branch of the repository.

Subtracting two lists in Python

list(set([x for x in a if x not in b]))
  • Leaves a and b untouched.
  • Is a unique set of "a - b".
  • Done.

Error java.lang.OutOfMemoryError: GC overhead limit exceeded

For me, the following steps worked:

  1. Open the eclipse.ini file
  2. Change

    -Xms40m
    -Xmx512m
    

    to

    -Xms512m
    -Xmx1024m
    
  3. Restart Eclipse

See here

What is the difference between VFAT and FAT32 file systems?

Copied from http://technet.microsoft.com/en-us/library/cc750354.aspx

What's FAT?

FAT may sound like a strange name for a file system, but it's actually an acronym for File Allocation Table. Introduced in 1981, FAT is ancient in computer terms. Because of its age, most operating systems, including Microsoft Windows NT®, Windows 98, the Macintosh OS, and some versions of UNIX, offer support for FAT.

The FAT file system limits filenames to the 8.3 naming convention, meaning that a filename can have no more than eight characters before the period and no more than three after. Filenames in a FAT file system must also begin with a letter or number, and they can't contain spaces. Filenames aren't case sensitive.

What About VFAT?

Perhaps you've also heard of a file system called VFAT. VFAT is an extension of the FAT file system and was introduced with Windows 95. VFAT maintains backward compatibility with FAT but relaxes the rules. For example, VFAT filenames can contain up to 255 characters, spaces, and multiple periods. Although VFAT preserves the case of filenames, it's not considered case sensitive.

When you create a long filename (longer than 8.3) with VFAT, the file system actually creates two different filenames. One is the actual long filename. This name is visible to Windows 95, Windows 98, and Windows NT (4.0 and later). The second filename is called an MS-DOS® alias. An MS-DOS alias is an abbreviated form of the long filename. The file system creates the MS-DOS alias by taking the first six characters of the long filename (not counting spaces), followed by the tilde [~] and a numeric trailer. For example, the filename Brien's Document.txt would have an alias of BRIEN'~1.txt.

An interesting side effect results from the way VFAT stores its long filenames. When you create a long filename with VFAT, it uses one directory entry for the MS-DOS alias and another entry for every 13 characters of the long filename. In theory, a single long filename could occupy up to 21 directory entries. The root directory has a limit of 512 files, but if you were to use the maximum length long filenames in the root directory, you could cut this limit to a mere 24 files. Therefore, you should use long filenames very sparingly in the root directory. Other directories aren't affected by this limit.

You may be wondering why we're discussing VFAT. The reason is it's becoming more common than FAT, but aside from the differences I mentioned above, VFAT has the same limitations. When you tell Windows NT to format a partition as FAT, it actually formats the partition as VFAT. The only time you'll have a true FAT partition under Windows NT 4.0 is when you use another operating system, such as MS-DOS, to format the partition.

FAT32

FAT32 is actually an extension of FAT and VFAT, first introduced with Windows 95 OEM Service Release 2 (OSR2). FAT32 greatly enhances the VFAT file system but it does have its drawbacks.

The greatest advantage to FAT32 is that it dramatically increases the amount of free hard disk space. To illustrate this point, consider that a FAT partition (also known as a FAT16 partition) allows only a certain number of clusters per partition. Therefore, as your partition size increases, the cluster size must also increase. For example, a 512-MB FAT partition has a cluster size of 8K, while a 2-GB partition has a cluster size of 32K.

This may not sound like a big deal until you consider that the FAT file system only works in single cluster increments. For example, on a 2-GB partition, a 1-byte file will occupy the entire cluster, thereby consuming 32K, or roughly 32,000 times the amount of space that the file should consume. This rule applies to every file on your hard disk, so you can see how much space can be wasted.

Converting a partition to FAT32 reduces the cluster size (and overcomes the 2-GB partition size limit). For partitions 8 GB and smaller, the cluster size is reduced to a mere 4K. As you can imagine, it's not uncommon to gain back hundreds of megabytes by converting a partition to FAT32, especially if the partition contains a lot of small files.

Note: This section of the quote/ article (1999) is out of date. Updated info quote below.

As I mentioned, FAT32 does have limitations. Unfortunately, it isn't compatible with any operating system other than Windows 98 and the OSR2 version of Windows 95. However, Windows 2000 will be able to read FAT32 partitions.

The other disadvantage is that your disk utilities and antivirus software must be FAT32-aware. Otherwise, they could interpret the new file structure as an error and try to correct it, thus destroying data in the process.

Finally, I should mention that converting to FAT32 is a one-way process. Once you've converted to FAT32, you can't convert the partition back to FAT16. Therefore, before converting to FAT32, you need to consider whether the computer will ever be used in a dual-boot environment. I should also point out that although other operating systems such as Windows NT can't directly read a FAT32 partition, they can read it across the network. Therefore, it's no problem to share information stored on a FAT32 partition with other computers on a network that run older operating systems.

Updated mentioned in comment by Doktor-J (assimilated to update out of date answer in case comment is ever lost):

I'd just like to point out that most modern operating systems (WinXP/Vista/7/8, MacOS X, most if not all Linux variants) can read FAT32, contrary to what the second-to-last paragraph suggests.

The original article was written in 1999, and being posted on a Microsoft website, probably wasn't concerned with non-Microsoft operating systems anyways.

The operating systems "excluded" by that paragraph are probably the original Windows 95, Windows NT 4.0, Windows 3.1, DOS, etc.

Why is C so fast, and why aren't other languages as fast or faster?

what's to stop other languages from being able to compile down to binary that runs every bit as fast as C?

Nothing. Modern languages like Java or .NET langs are oriented more on programmer productivity rather than performance. Hardware is cheap now days. Also compilation to intermediate representation gives a lot of bonuses such as security, portability etc. .NET CLR can take advantage of different hardware - for example you don't need to manually optimize/recompile program to use SSE instructions set.

Error QApplication: no such file or directory

Make sure you have qmake in your path (which qmake), and that it works (qmake -v) (IF you have to kill it with ctr-c then there is something wrong with your environment).

Then follow this: http://developer.qt.nokia.com/doc/qt-4.8/gettingstartedqt.html

How to trigger click on page load?

try this,

$("document").ready(function(){

$("your id here").trigger("click");
});

Correct way to initialize HashMap and can HashMap hold different value types?

This is a change made with Java 1.5. What you list first is the old way, the second is the new way.

By using HashMap you can do things like:

HashMap<String, Doohickey> ourMap = new HashMap<String, Doohickey>();

....

Doohickey result = ourMap.get("bob");

If you didn't have the types on the map, you'd have to do this:

Doohickey result = (Doohickey) ourMap.get("bob");

It's really very useful. It helps you catch bugs and avoid writing all sorts of extra casts. It was one of my favorite features of 1.5 (and newer).

You can still put multiple things in the map, just specify it as Map, then you can put any object in (a String, another Map, and Integer, and three MyObjects if you are so inclined).

jquery json to string?

Most browsers have a native JSON object these days, which includes parse and stringify methods. So just try JSON.stringify({}) and see if you get "{}". You can even pass in parameters to filter out keys or to do pretty-printing, e.g. JSON.stringify({a:1,b:2}, null, 2) puts a newline and 2 spaces in front of each key.

JSON.stringify({a:1,b:2}, null, 2)

gives

"{\n  \"a\": 1,\n  \"b\": 2\n}"

which prints as

{
  "a": 1,
  "b": 2
}

As for the messing around part of your question, use the second parameter. From http://www.javascriptkit.com/jsref/json.shtml :

The replacer parameter can either be a function or an array of String/Numbers. It steps through each member within the JSON object to let you decide what value each member should be changed to. As a function it can return:

  • A number, string, or Boolean, which replaces the property's original value with the returned one.
  • An object, which is serialized then returned. Object methods or functions are not allowed, and are removed instead.
  • Null, which causes the property to be removed.

As an array, the values defined inside it corresponds to the names of the properties inside the JSON object that should be retained when converted into a JSON object.

get the selected index value of <select> tag in php

Your form is valid. Only thing that comes to my mind is, after seeing your full html, is that you're passing your "default" value (which is not set!) instead of selecting something. Try as suggested by @Vina in the comment, i.e. giving it a selected option, or writing a default value

<select name="gender">
<option value="default">Select </option>    
<option value="male">   Male   </option>
<option value="female"> Female </option>
</select>

OR

<select name="gender">
<option value="male" selected="selected">   Male   </option>
<option value="female"> Female </option>
</select>

When you get your $_POST vars, check for them being set; you can assign a default value, or just an empty string in case they're not there.

Most important thing, AVOID SQL INJECTIONS:

//....
$fname   = isset($_POST["fname"]) ? mysql_real_escape_string($_POST['fname']) : '';
$lname   = isset($_POST['lname']) ? mysql_real_escape_string($_POST['lname']) : '';
$email   = isset($_POST['email']) ? mysql_real_escape_string($_POST['email']) : '';
you might also want to validate e-mail:
if($mail = filter_var($_POST['email'], FILTER_VALIDATE_EMAIL))
{
  $email = mysql_real_escape_string($_POST['email']);
}
else
{
  //die ('invalid email address');
  // or whatever, a default value? $email = '';
}
$paswod  = isset($_POST["paswod"]) ? mysql_real_escape_string($_POST['paswod']) : '';
$gender  = isset($_POST['gender']) ? mysql_real_escape_string($_POST['gender']) : '';

$query = mysql_query("SELECT Email FROM users WHERE Email = '".$email."')";
if(mysql_num_rows($query)> 0)
{
  echo 'userid is already there';
}
else
{
 $sql = "INSERT INTO users (FirstName, LastName, Email, Password, Gender)
         VALUES ('".$fname."','".$lname."','".$email."','".paswod."','".$gender."')";
$res = mysql_query($sql) or die('Error:'.mysql_error());
echo 'created';

Angular 6: saving data to local storage

you can use localStorage for storing the json data:

the example is given below:-

let JSONDatas = [
    {"id": "Open"},
    {"id": "OpenNew", "label": "Open New"},
    {"id": "ZoomIn", "label": "Zoom In"},
    {"id": "ZoomOut", "label": "Zoom Out"},
    {"id": "Find", "label": "Find..."},
    {"id": "FindAgain", "label": "Find Again"},
    {"id": "Copy"},
    {"id": "CopyAgain", "label": "Copy Again"},
    {"id": "CopySVG", "label": "Copy SVG"},
    {"id": "ViewSVG", "label": "View SVG"}
]

localStorage.setItem("datas", JSON.stringify(JSONDatas));

let data = JSON.parse(localStorage.getItem("datas"));

console.log(data);

Proxy with express.js

Ok, here's a ready-to-copy-paste answer using the require('request') npm module and an environment variable *instead of an hardcoded proxy):

coffeescript

app.use (req, res, next) ->                                                 
  r = false
  method = req.method.toLowerCase().replace(/delete/, 'del')
  switch method
    when 'get', 'post', 'del', 'put'
      r = request[method](
        uri: process.env.PROXY_URL + req.url
        json: req.body)
    else
      return res.send('invalid method')
  req.pipe(r).pipe res

javascript:

app.use(function(req, res, next) {
  var method, r;
  method = req.method.toLowerCase().replace(/delete/,"del");
  switch (method) {
    case "get":
    case "post":
    case "del":
    case "put":
      r = request[method]({
        uri: process.env.PROXY_URL + req.url,
        json: req.body
      });
      break;
    default:
      return res.send("invalid method");
  }
  return req.pipe(r).pipe(res);
});

What is the right way to write my script 'src' url for a local development environment?

This is an old post but...

You can reference the working directory (the folder the .html file is located in) with ./, and the directory above that with ../

Example directory structure:

/html/public/
- index.html
- script2.js
- js/
   - script.js

To load script.js from inside index.html:

<script type="text/javascript" src="./js/script.js">

This goes to the current working directory (location of index.html) and then to the js folder, and then finds the script.

You could also specify ../ to go one directory above the working directory, to load things from there. But that is unusual.

Pass Hidden parameters using response.sendRedirect()

Using session, I successfully passed a parameter (name) from servlet #1 to servlet #2, using response.sendRedirect in servlet #1. Servlet #1 code:

protected void doPost(HttpServletRequest request, HttpServletResponse response) {
    String name = request.getParameter("name");
    String password = request.getParameter("password");
    ...
    request.getSession().setAttribute("name", name);
    response.sendRedirect("/todo.do");

In Servlet #2, you don't need to get name back. It's already connected to the session. You could do String name = (String) request.getSession().getAttribute("name"); ---but you don't need this.

If Servlet #2 calls a JSP, you can show name this way on the JSP webpage:

<h1>Welcome ${name}</h1>

How do you overcome the svn 'out of date' error?

If you're using the github svn bridge, it is likely because something changed on github's side of things. The solution is simple, you just have to run svn switch, which lets it properly find itself, then update and everything will work. Just run the following from the root of your checkout

svn info | grep Relative 
svn switch path_from_previous_command
svn update

or

svn switch `svn info | grep Relative | sed 's_.*: __'`
svn update

The basis for this solution comes from Lee Preimesberger's blog

IN vs ANY operator in PostgreSQL

(Neither IN nor ANY is an "operator". A "construct" or "syntax element".)

Logically, quoting the manual:

IN is equivalent to = ANY.

But there are two syntax variants of IN and two variants of ANY. Details:

IN taking a set is equivalent to = ANY taking a set, as demonstrated here:

But the second variant of each is not equivalent to the other. The second variant of the ANY construct takes an array (must be an actual array type), while the second variant of IN takes a comma-separated list of values. This leads to different restrictions in passing values and can also lead to different query plans in special cases:

ANY is more versatile

The ANY construct is far more versatile, as it can be combined with various operators, not just =. Example:

SELECT 'foo' LIKE ANY('{FOO,bar,%oo%}');

For a big number of values, providing a set scales better for each:

Related:

Inversion / opposite / exclusion

"Find rows where id is in the given array":

SELECT * FROM tbl WHERE id = ANY (ARRAY[1, 2]);

Inversion: "Find rows where id is not in the array":

SELECT * FROM tbl WHERE id <> ALL (ARRAY[1, 2]);
SELECT * FROM tbl WHERE id <> ALL ('{1, 2}');  -- equivalent array literal
SELECT * FROM tbl WHERE NOT (id = ANY ('{1, 2}'));

All three equivalent. The first with array constructor, the other two with array literal. The data type can be derived from context unambiguously. Else, an explicit cast may be required, like '{1,2}'::int[].

Rows with id IS NULL do not pass either of these expressions. To include NULL values additionally:

SELECT * FROM tbl WHERE (id = ANY ('{1, 2}')) IS NOT TRUE;

How to convert float number to Binary?

The float value is stored in IEEE 754 format so we can't convert it directly like integer, char to binary.

But we can convert float to binary through a pointer.

#include <stdio.h>

int main()
{
    float a = 7.5;
    int i;
    int * p;

    p = &a;
    for (i = sizeof(int) * 8 - 1; i >= 0; i--)
    {   
        printf("%d", (*p) >> i & 1); 
    }   

    return 0;
}

Output

0 10000001 11100000000000000000000

Spaces added for clarification, they are not included as part of the program.

How to convert a string of bytes into an int?

I use the following function to convert data between int, hex and bytes.

def bytes2int(str):
 return int(str.encode('hex'), 16)

def bytes2hex(str):
 return '0x'+str.encode('hex')

def int2bytes(i):
 h = int2hex(i)
 return hex2bytes(h)

def int2hex(i):
 return hex(i)

def hex2int(h):
 if len(h) > 1 and h[0:2] == '0x':
  h = h[2:]

 if len(h) % 2:
  h = "0" + h

 return int(h, 16)

def hex2bytes(h):
 if len(h) > 1 and h[0:2] == '0x':
  h = h[2:]

 if len(h) % 2:
  h = "0" + h

 return h.decode('hex')

Source: http://opentechnotes.blogspot.com.au/2014/04/convert-values-to-from-integer-hex.html

Converting an object to a string

1.

JSON.stringify(o);

Item: {"a":"1", "b":"2"}

2.

var o = {a:1, b:2};
var b=[]; Object.keys(o).forEach(function(k){b.push(k+":"+o[k]);});
b="{"+b.join(', ')+"}";
console.log('Item: ' + b);

Item: {a:1, b:2}

How to make Twitter bootstrap modal full screen

I've came up with a "responsive" solution for fullscreen modals:

Fullscreen Modals that can be enabled only on certain breakpoints. In this way the modal will display "normal" on wider (desktop) screens and fullscreen on smaller (tablet or mobile) screens, giving it the feeling of a native app.

Implemented for Bootstrap 3 and Bootstrap 4. Included by default in Bootstrap 5.


Bootstrap v5

Fullscreen modals are included by default in Bootstrap 5: https://getbootstrap.com/docs/5.0/components/modal/#fullscreen-modal


Bootstrap v4

The following generic code should work:

.modal {
  padding: 0 !important; // override inline padding-right added from js
}
.modal .modal-dialog {
  width: 100%;
  max-width: none;
  height: 100%;
  margin: 0;
}
.modal .modal-content {
  height: 100%;
  border: 0;
  border-radius: 0;
}
.modal .modal-body {
  overflow-y: auto;
}

By including the scss code below, it generates the following classes that need to be added to the .modal element:

+---------------+---------+---------+---------+---------+---------+
|               |   xs    |   sm    |   md    |   lg    |   xl    | 
|               | <576px  | =576px  | =768px  | =992px  | =1200px |
+---------------+---------+---------+---------+---------+---------+
|.fullscreen    |  100%   | default | default | default | default | 
+---------------+---------+---------+---------+---------+---------+
|.fullscreen-sm |  100%   |  100%   | default | default | default | 
+---------------+---------+---------+---------+---------+---------+
|.fullscreen-md |  100%   |  100%   |  100%   | default | default |
+---------------+---------+---------+---------+---------+---------+
|.fullscreen-lg |  100%   |  100%   |  100%   |  100%   | default |
+---------------+---------+---------+---------+---------+---------+
|.fullscreen-xl |  100%   |  100%   |  100%   |  100%   |  100%   |
+---------------+---------+---------+---------+---------+---------+

The scss code is:

@mixin modal-fullscreen() {
  padding: 0 !important; // override inline padding-right added from js

  .modal-dialog {
    width: 100%;
    max-width: none;
    height: 100%;
    margin: 0;
  }

  .modal-content {
    height: 100%;
    border: 0;
    border-radius: 0;
  }

  .modal-body {
    overflow-y: auto;
  }

}

@each $breakpoint in map-keys($grid-breakpoints) {
  @include media-breakpoint-down($breakpoint) {
    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);

    .modal-fullscreen#{$infix} {
      @include modal-fullscreen();
    }
  }
}

Demo on Codepen: https://codepen.io/andreivictor/full/MWYNPBV/


Bootstrap v3

Based on previous responses to this topic (@Chris J, @kkarli), the following generic code should work:

.modal {
  padding: 0 !important; // override inline padding-right added from js
}

.modal .modal-dialog {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
}

.modal .modal-content {
  height: auto;
  min-height: 100%;
  border: 0 none;
  border-radius: 0;
  box-shadow: none;
}

If you want to use responsive fullscreen modals, use the following classes that need to be added to .modal element:

  • .modal-fullscreen-md-down - the modal is fullscreen for screens smaller than 1200px.
  • .modal-fullscreen-sm-down - the modal is fullscreen for screens smaller than 922px.
  • .modal-fullscreen-xs-down - the modal is fullscreen for screen smaller than 768px.

Take a look at the following code:

/* Extra small devices (less than 768px) */
@media (max-width: 767px) {
  .modal-fullscreen-xs-down {
    padding: 0 !important;
  }
  .modal-fullscreen-xs-down .modal-dialog {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }
  .modal-fullscreen-xs-down .modal-content {
    height: auto;
    min-height: 100%;
    border: 0 none;
    border-radius: 0;
    box-shadow: none;
  } 
}

/* Small devices (less than 992px) */
@media (max-width: 991px) {
  .modal-fullscreen-sm-down {
    padding: 0 !important;
  }
  .modal-fullscreen-sm-down .modal-dialog {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }
  .modal-fullscreen-sm-down .modal-content {
    height: auto;
    min-height: 100%;
    border: 0 none;
    border-radius: 0;
    box-shadow: none;
  }
}

/* Medium devices (less than 1200px) */
@media (max-width: 1199px) {
  .modal-fullscreen-md-down {
    padding: 0 !important;
  }
  .modal-fullscreen-md-down .modal-dialog {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }
  .modal-fullscreen-md-down .modal-content {
    height: auto;
    min-height: 100%;
    border: 0 none;
    border-radius: 0;
    box-shadow: none;
  }
}

Demo is available on Codepen: https://codepen.io/andreivictor/full/KXNdoO.

Those who use Sass as a preprocessor can take advantage of the following mixin:

@mixin modal-fullscreen() {
  padding: 0 !important; // override inline padding-right added from js

  .modal-dialog {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }

  .modal-content {
    height: auto;
    min-height: 100%;
    border: 0 none;
    border-radius: 0;
    box-shadow: none;
  }

}

How do I view the list of functions a Linux shared library is exporting?

Among other already mentioned tools you can use also readelf (manual). It is similar to objdump but goes more into detail. See this for the difference explanation.

$ readelf -sW /lib/liblzma.so.5 |head -n10

Symbol table '.dynsym' contains 128 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 FUNC    GLOBAL DEFAULT  UND pthread_mutex_unlock@GLIBC_2.0 (4)
     2: 00000000     0 FUNC    GLOBAL DEFAULT  UND pthread_mutex_destroy@GLIBC_2.0 (4)
     3: 00000000     0 NOTYPE  WEAK   DEFAULT  UND _ITM_deregisterTMCloneTable
     4: 00000000     0 FUNC    GLOBAL DEFAULT  UND memmove@GLIBC_2.0 (5)
     5: 00000000     0 FUNC    GLOBAL DEFAULT  UND free@GLIBC_2.0 (5)
     6: 00000000     0 FUNC    GLOBAL DEFAULT  UND memcpy@GLIBC_2.0 (5)

How can I enable Assembly binding logging?

Just create a new DWORD(32) under the Fusion key. Name the DWORD to EnableLog, and set it to value 1. Then restart IIS, refresh the page giving errors, and the assembly bind logs will show in the error message.

Use of PUT vs PATCH methods in REST API real life scenarios

TLDR - Dumbed Down Version

PUT => Set all new attributes for an existing resource.

PATCH => Partially update an existing resource (not all attributes required).

How to error handle 1004 Error with WorksheetFunction.VLookup?

There is a way to skip the errors inside the code and go on with the loop anyway, hope it helps:

Sub new1()

Dim wsFunc As WorksheetFunction: Set wsFunc = Application.WorksheetFunction
Dim ws As Worksheet: Set ws = Sheets(1)
Dim rngLook As Range: Set rngLook = ws.Range("A:M")

currName = "Example"
On Error Resume Next ''if error, the code will go on anyway
cellNum = wsFunc.VLookup(currName, rngLook, 13, 0)

If Err.Number <> 0 Then
''error appeared
    MsgBox "currName not found" ''optional, no need to do anything
End If

On Error GoTo 0 ''no error, coming back to default conditions

End Sub

Build fat static library (device + simulator) using Xcode and SDK 4+

I've made an XCode 4 project template that lets you make a universal framework as easily as making a regular library.

Microsoft.ReportViewer.Common Version=12.0.0.0

In My cases, After installing Sql server data tools by Visual Studio 2015 installer, problem has been resolved

Here is the screenshot for installing data tools

Apache 13 permission denied in user's home directory

selinux is cause for that problem.....

TException: Error: TSocket: Could not connect to localhost:9160 (Permission denied [13]) To resolve it, you need to change an SELinux boolean value (which will automatically persist across reboots). You may also want to restart httpd to reset the proxy worker, although this isn't strictly required.

setsebool -P httpd_can_network_connect 1

or

(13) Permission Denied

Error 13 indicates a filesystem permissions problem. That is, Apache was denied access to a file or directory due to incorrect permissions. It does not, in general, imply a problem in the Apache configuration files.

In order to serve files, Apache must have the proper permission granted by the operating system to access those files. In particular, the User or Group specified in httpd.conf must be able to read all files that will be served and search the directory containing those files, along with all parent directories up to the root of the filesystem.

Typical permissions on a unix-like system for resources not owned by the User or Group specified in httpd.conf would be 644 -rw-r--r-- for ordinary files and 755 drwxr-x-r-x for directories or CGI scripts. You may also need to check extended permissions (such as SELinux permissions) on operating systems that support them.

An Example

Lets say that you received the Permission Denied error when accessing the file /usr/local/apache2/htdocs/foo/bar.html on a unix-like system.

First check the existing permissions on the file:

cd /usr/local/apache2/htdocs/foo ls -l bar.htm

Fix them if necessary:

chmod 644 bar.html

Then do the same for the directory and each parent directory (/usr/local/apache2/htdocs/foo, /usr/local/apache2/htdocs, /usr/local/apache2, /usr/local, /usr):

ls -la chmod +x . cd ..

repeat up to the root

On some systems, the utility namei can be used to help find permissions problems by listing the permissions along each component of the path:

namei -m /usr/local/apache2/htdocs/foo/bar.html

If all the standard permissions are correct and you still get a Permission Denied error, you should check for extended-permissions. For example you can use the command setenforce 0 to turn off SELinux and check to see if the problem goes away. If so, ls -alZ can be used to view SELinux permission and chcon to fix them.

In rare cases, this can be caused by other issues, such as a file permissions problem elsewhere in your apache2.conf file. For example, a WSGIScriptAlias directive not mapping to an actual file. The error message may not be accurate about which file was unreadable.

DO NOT set files or directories to mode 777, even "just to test", even if "it's just a test server". The purpose of a test server is to get things right in a safe environment, not to get away with doing it wrong. All it will tell you is if the problem is with files that actually exist.

C - gettimeofday for computing time?

To subtract timevals:

gettimeofday(&t0, 0);
/* ... */
gettimeofday(&t1, 0);
long elapsed = (t1.tv_sec-t0.tv_sec)*1000000 + t1.tv_usec-t0.tv_usec;

This is assuming you'll be working with intervals shorter than ~2000 seconds, at which point the arithmetic may overflow depending on the types used. If you need to work with longer intervals just change the last line to:

long long elapsed = (t1.tv_sec-t0.tv_sec)*1000000LL + t1.tv_usec-t0.tv_usec;

Pass a JavaScript function as parameter

You can also use eval() to do the same thing.

//A function to call
function needToBeCalled(p1, p2)
{
    alert(p1+"="+p2);
}

//A function where needToBeCalled passed as an argument with necessary params
//Here params is comma separated string
function callAnotherFunction(aFunction, params)
{
    eval(aFunction + "("+params+")");
}

//A function Call
callAnotherFunction("needToBeCalled", "10,20");

That's it. I was also looking for this solution and tried solutions provided in other answers but finally got it work from above example.

How to get PHP $_GET array?

The usual way to do this in PHP is to put id[] in your URL instead of just id:

http://link/foo.php?id[]=1&id[]=2&id[]=3

Then $_GET['id'] will be an array of those values. It's not especially pretty, but it works out of the box.

Evaluating a mathematical expression in a string

Pyparsing can be used to parse mathematical expressions. In particular, fourFn.py shows how to parse basic arithmetic expressions. Below, I've rewrapped fourFn into a numeric parser class for easier reuse.

from __future__ import division
from pyparsing import (Literal, CaselessLiteral, Word, Combine, Group, Optional,
                       ZeroOrMore, Forward, nums, alphas, oneOf)
import math
import operator

__author__ = 'Paul McGuire'
__version__ = '$Revision: 0.0 $'
__date__ = '$Date: 2009-03-20 $'
__source__ = '''http://pyparsing.wikispaces.com/file/view/fourFn.py
http://pyparsing.wikispaces.com/message/view/home/15549426
'''
__note__ = '''
All I've done is rewrap Paul McGuire's fourFn.py as a class, so I can use it
more easily in other places.
'''


class NumericStringParser(object):
    '''
    Most of this code comes from the fourFn.py pyparsing example

    '''

    def pushFirst(self, strg, loc, toks):
        self.exprStack.append(toks[0])

    def pushUMinus(self, strg, loc, toks):
        if toks and toks[0] == '-':
            self.exprStack.append('unary -')

    def __init__(self):
        """
        expop   :: '^'
        multop  :: '*' | '/'
        addop   :: '+' | '-'
        integer :: ['+' | '-'] '0'..'9'+
        atom    :: PI | E | real | fn '(' expr ')' | '(' expr ')'
        factor  :: atom [ expop factor ]*
        term    :: factor [ multop factor ]*
        expr    :: term [ addop term ]*
        """
        point = Literal(".")
        e = CaselessLiteral("E")
        fnumber = Combine(Word("+-" + nums, nums) +
                          Optional(point + Optional(Word(nums))) +
                          Optional(e + Word("+-" + nums, nums)))
        ident = Word(alphas, alphas + nums + "_$")
        plus = Literal("+")
        minus = Literal("-")
        mult = Literal("*")
        div = Literal("/")
        lpar = Literal("(").suppress()
        rpar = Literal(")").suppress()
        addop = plus | minus
        multop = mult | div
        expop = Literal("^")
        pi = CaselessLiteral("PI")
        expr = Forward()
        atom = ((Optional(oneOf("- +")) +
                 (ident + lpar + expr + rpar | pi | e | fnumber).setParseAction(self.pushFirst))
                | Optional(oneOf("- +")) + Group(lpar + expr + rpar)
                ).setParseAction(self.pushUMinus)
        # by defining exponentiation as "atom [ ^ factor ]..." instead of
        # "atom [ ^ atom ]...", we get right-to-left exponents, instead of left-to-right
        # that is, 2^3^2 = 2^(3^2), not (2^3)^2.
        factor = Forward()
        factor << atom + \
            ZeroOrMore((expop + factor).setParseAction(self.pushFirst))
        term = factor + \
            ZeroOrMore((multop + factor).setParseAction(self.pushFirst))
        expr << term + \
            ZeroOrMore((addop + term).setParseAction(self.pushFirst))
        # addop_term = ( addop + term ).setParseAction( self.pushFirst )
        # general_term = term + ZeroOrMore( addop_term ) | OneOrMore( addop_term)
        # expr <<  general_term
        self.bnf = expr
        # map operator symbols to corresponding arithmetic operations
        epsilon = 1e-12
        self.opn = {"+": operator.add,
                    "-": operator.sub,
                    "*": operator.mul,
                    "/": operator.truediv,
                    "^": operator.pow}
        self.fn = {"sin": math.sin,
                   "cos": math.cos,
                   "tan": math.tan,
                   "exp": math.exp,
                   "abs": abs,
                   "trunc": lambda a: int(a),
                   "round": round,
                   "sgn": lambda a: abs(a) > epsilon and cmp(a, 0) or 0}

    def evaluateStack(self, s):
        op = s.pop()
        if op == 'unary -':
            return -self.evaluateStack(s)
        if op in "+-*/^":
            op2 = self.evaluateStack(s)
            op1 = self.evaluateStack(s)
            return self.opn[op](op1, op2)
        elif op == "PI":
            return math.pi  # 3.1415926535
        elif op == "E":
            return math.e  # 2.718281828
        elif op in self.fn:
            return self.fn[op](self.evaluateStack(s))
        elif op[0].isalpha():
            return 0
        else:
            return float(op)

    def eval(self, num_string, parseAll=True):
        self.exprStack = []
        results = self.bnf.parseString(num_string, parseAll)
        val = self.evaluateStack(self.exprStack[:])
        return val

You can use it like this

nsp = NumericStringParser()
result = nsp.eval('2^4')
print(result)
# 16.0

result = nsp.eval('exp(2^4)')
print(result)
# 8886110.520507872

ERROR 1115 (42000): Unknown character set: 'utf8mb4'

maybe whole database + tables + fields should have the same charset??!

i.e.

CREATE TABLE `politicas` (
  `ID` int(11) NOT NULL AUTO_INCREMENT,
  `Nombre` varchar(250) CHARACTER SET utf8 NOT NULL,
  -------------------------------------^here!!!!!!!!!!!
  PRIMARY KEY (`ID`)
) ENGINE=MyISAM AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
  -------------------------------------------------^here!!!!!!!!!

How to update the value of a key in a dictionary in Python?

n = eval(input('Num books: '))
books = {}
for i in range(n):
    titlez = input("Enter Title: ")
    copy = eval(input("Num of copies: "))
    books[titlez] = copy

prob = input('Sell a book; enter YES or NO: ')
if prob == 'YES' or 'yes':
    choice = input('Enter book title: ')
    if choice in books:
        init_num = books[choice]
        init_num -= 1
        books[choice] = init_num
        print(books)

Remove table row after clicking table row delete button

Using pure Javascript:

Don't need to pass this to the SomeDeleteRowFunction():

<td><input type="button" value="Delete Row" onclick="SomeDeleteRowFunction()"></td>

The onclick function:

function SomeDeleteRowFunction() {
      // event.target will be the input element.
      var td = event.target.parentNode; 
      var tr = td.parentNode; // the row to be removed
      tr.parentNode.removeChild(tr);
}

Convert categorical data in pandas dataframe

One of the simplest ways to convert the categorical variable into dummy/indicator variables is to use get_dummies provided by pandas. Say for example we have data in which sex is a categorical value (male & female) and you need to convert it into a dummy/indicator here is how to do it.

_x000D_
_x000D_
tranning_data = pd.read_csv("../titanic/train.csv")
features = ["Age", "Sex", ] //here sex is catagorical value
X_train = pd.get_dummies(tranning_data[features])
print(X_train)

Age Sex_female Sex_male
20    0          1
33    1          0
40    1          0
22    1          0
54    0          1
_x000D_
_x000D_
_x000D_

Remove rows not .isin('X')

All you have to do is create a subset of your dataframe where the isin method evaluates to False:

df = df[df['Column Name'].isin(['Value']) == False]

How to resize image (Bitmap) to a given size?

 Bitmap yourBitmap;
 Bitmap resized = Bitmap.createScaledBitmap(yourBitmap, newWidth, newHeight, true);

or:

 resized = Bitmap.createScaledBitmap(yourBitmap,(int)(yourBitmap.getWidth()*0.8), (int)(yourBitmap.getHeight()*0.8), true);

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

There's always the Bogobogosort (Bogoception!). It performs Bogosort on increasingly large subsets of the list, and then starts all over again if the list is ever not sorted.

for (int n=1; n<sizeof(list); ++n) {
  while (!isInOrder(list, 0, n)) {
    shuffle(list, 0, n);
  }
  if (!isInOrder(list, 0, n+1)) { n=0; }
}

COPY with docker but with exclusion

FOR A ONE LINER SOLUTION, type the following in Command prompt or Terminal at project root.

echo node_modules > .dockerignore

This creates the extension-less . prefixed file without any issue. Replace node_modules with the folder you want to exclude.

What's the difference between process.cwd() vs __dirname?

Knowing the scope of each can make things easier to remember.

process is node's global object, and .cwd() returns where node is running.

__dirname is module's property, and represents the file path of the module. In node, one module resides in one file.

Similarly, __filename is another module's property, which holds the file name of the module.

Find commit by hash SHA in Git

There are two ways to do this.

1. providing the SHA of the commit you want to see to git log

git log -p a2c25061

Where -p is short for patch

2. use git show

git show a2c25061

The output for both commands will be:

  • the commit
  • the author
  • the date
  • the commit message
  • the patch information

Javascript replace all "%20" with a space

If you want to use jQuery you can use .replaceAll()

Why a function checking if a string is empty always returns true?

You got an answer but in your case you can use

return empty($input);

or

return is_string($input);

What's the "Content-Length" field in HTTP header?

One octet is 8 bits. Content-length is the number of octets that the message body represents.

How can I create C header files

  1. Open your favorite text editor
  2. Create a new file named whatever.h
  3. Put your function prototypes in it

DONE.

Example whatever.h

#ifndef WHATEVER_H_INCLUDED
#define WHATEVER_H_INCLUDED
int f(int a);
#endif

Note: include guards (preprocessor commands) added thanks to luke. They avoid including the same header file twice in the same compilation. Another possibility (also mentioned on the comments) is to add #pragma once but it is not guaranteed to be supported on every compiler.

Example whatever.c

#include "whatever.h"

int f(int a) { return a + 1; }

And then you can include "whatever.h" into any other .c file, and link it with whatever.c's object file.

Like this:

sample.c

#include "whatever.h"

int main(int argc, char **argv)
{
    printf("%d\n", f(2)); /* prints 3 */
    return 0;
}

To compile it (if you use GCC):

$ gcc -c whatever.c -o whatever.o
$ gcc -c sample.c -o sample.o

To link the files to create an executable file:

$ gcc sample.o whatever.o -o sample

You can test sample:

$ ./sample
3
$

Is there a way to automatically build the package.json file for Node.js projects

Command line:

npm init

will create package.json file

To install , update and uninstall packages under dependencies into package.json file:

Command line :

npm install <pkg>@* --save 

will automatically add the latest version for the package under dependencies into package.json file

EX:

npm install node-markdown@* --save

Command line:

npm install <pkg> --save

also will automatically add the latest version for the package under dependencies into package.json file

if you need specific version for a package use this Command line:

npm install <pkg>@<version> --save

will automatically add specific version of package under dependencies into package.json file

EX:

npm install [email protected] --save

if you need specific range of version for a package use this Command line:

npm install <pkg>@<version range>

will automatically add the latest version for the package between range of version under dependencies into package.json file

EX:

npm install koa-views@">1.0.0 <1.2.0" --save

For more details about how to write version for package npm Doc

Command line:

npm update --save

will update packages into package.json file and will automatically add updated version for all packages under dependencies into package.json file

Command line:

npm uninstall <pkg> --save

will automatically remove package from dependencies into package.json file and remove package from node_module folder

How to simulate a touch event in Android?

MotionEvent is generated only by touching the screen.

unexpected T_ENCAPSED_AND_WHITESPACE, expecting T_STRING or T_VARIABLE or T_NUM_STRING error

In my case, heredoc caused the issue. There is no problem with PHP version 7.3 up. Howerver, it error with PHP 7.0.33 if you use heredoc with space.

My example code

$rexpenditure = <<<Expenditure
                  <tr>
                      <td>$row->payment_referencenumber</td>
                      <td>$row->payment_requestdate</td>
                      <td>$row->payment_description</td>
                      <td>$row->payment_fundingsource</td>
                      <td>$row->payment_agencyulo</td>
                      <td>$row->payment_agencyproject</td>
                      <td>$$row->payment_disbustment</td>
                      <td>$row->payment_payeename</td>
                      <td>$row->payment_processpayment</td>
                  </tr>
Expenditure;

It will error if there is a space on PHP 7.0.33.

Combine two tables for one output

You'll need to use UNION to combine the results of two queries. In your case:

SELECT ChargeNum, CategoryID, SUM(Hours)
FROM KnownHours
GROUP BY ChargeNum, CategoryID
UNION ALL
SELECT ChargeNum, 'Unknown' AS CategoryID, SUM(Hours)
FROM UnknownHours
GROUP BY ChargeNum

Note - If you use UNION ALL as in above, it's no slower than running the two queries separately as it does no duplicate-checking.

How to create a temporary directory/folder in Java?

As you can see in the other answers, no standard approach has arisen. Hence you already mentioned Apache Commons, I propose the following approach using FileUtils from Apache Commons IO:

/**
 * Creates a temporary subdirectory in the standard temporary directory.
 * This will be automatically deleted upon exit.
 * 
 * @param prefix
 *            the prefix used to create the directory, completed by a
 *            current timestamp. Use for instance your application's name
 * @return the directory
 */
public static File createTempDirectory(String prefix) {

    final File tmp = new File(FileUtils.getTempDirectory().getAbsolutePath()
            + "/" + prefix + System.currentTimeMillis());
    tmp.mkdir();
    Runtime.getRuntime().addShutdownHook(new Thread() {

        @Override
        public void run() {

            try {
                FileUtils.deleteDirectory(tmp);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    });
    return tmp;

}

This is preferred since apache commons the library that comes as closest to the asked "standard" and works with both JDK 7 and older versions. This also returns an "old" File instance (which is stream based) and not a "new" Path instance (which is buffer based and would be the result of JDK7's getTemporaryDirectory() method) -> Therefore it returns what most people need when they want to create a temporary directory.

Git push failed, "Non-fast forward updates were rejected"

You can add --force-with-lease to the command, it will works.

git push --force-with-lease

--force is destructive because it unconditionally overwrites the remote repository with whatever you have locally. But --force-with-lease ensure you don't overwrite other's work.

See more info here.

Saving and loading objects and using pickle

You didn't open the file in binary mode.

open("Fruits.obj",'rb')

Should work.

For your second error, the file is most likely empty, which mean you inadvertently emptied it or used the wrong filename or something.

(This is assuming you really did close your session. If not, then it's because you didn't close the file between the write and the read).

I tested your code, and it works.

How to enable multidexing with the new Android Multidex support library

First you should try with Proguard (This clean all code unused)

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"

    defaultConfig {
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

converting a javascript string to a html object

If the browser that you are planning to use is Mozilla (Addon development) (not sure of chrome) you can use the following method in Javascript

function DOM( string )
{
    var {Cc, Ci} = require("chrome");
    var parser = Cc["@mozilla.org/xmlextras/domparser;1"].createInstance(Ci.nsIDOMParser);
    console.log("PARSING OF DOM COMPLETED ...");
    return (parser.parseFromString(string, "text/html"));
};

Hope this helps

Not equal string

Try this:

if(myString != "-1")

The opperand is != and not =!

You can also use Equals

if(!myString.Equals("-1"))

Note the ! before myString

When to use std::size_t?

A good rule of thumb is for anything that you need to compare in the loop condition against something that is naturally a std::size_t itself.

std::size_t is the type of any sizeof expression and as is guaranteed to be able to express the maximum size of any object (including any array) in C++. By extension it is also guaranteed to be big enough for any array index so it is a natural type for a loop by index over an array.

If you are just counting up to a number then it may be more natural to use either the type of the variable that holds that number or an int or unsigned int (if large enough) as these should be a natural size for the machine.

Cannot import the keyfile 'blah.pfx' - error 'The keyfile may be password protected'

My problem was that the TFS Build Controller was running as a network service and for some reason I didn't understand why the Visual Studio Build Host service certificates were not being used. I changed the identity of the Visual Studio Build service to something more manageable, made sure it had rights on the TFS server, and manually added the certificates using the MMC.

The problem was also that MSBuild can't add the password protected certificates to the store.

No Android SDK found - Android Studio

Here is the solution just copy your SDK Manager.exe file at the root folder of your android studio's installation, Sync your project and cheers... here is the link for details. running Android Studio on Windows 7 fails, no Android SDK found

How do I use Node.js Crypto to create a HMAC-SHA1 hash?

A few years ago it was said that update() and digest() were legacy methods and the new streaming API approach was introduced. Now the docs say that either method can be used. For example:

var crypto    = require('crypto');
var text      = 'I love cupcakes';
var secret    = 'abcdeg'; //make this your secret!!
var algorithm = 'sha1';   //consider using sha256
var hash, hmac;

// Method 1 - Writing to a stream
hmac = crypto.createHmac(algorithm, secret);    
hmac.write(text); // write in to the stream
hmac.end();       // can't read from the stream until you call end()
hash = hmac.read().toString('hex');    // read out hmac digest
console.log("Method 1: ", hash);

// Method 2 - Using update and digest:
hmac = crypto.createHmac(algorithm, secret);
hmac.update(text);
hash = hmac.digest('hex');
console.log("Method 2: ", hash);

Tested on node v6.2.2 and v7.7.2

See https://nodejs.org/api/crypto.html#crypto_class_hmac. Gives more examples for using the streaming approach.

Unsupported major.minor version 52.0 in my app

Gradle Scripts >> build.gradle (Module app)

Change buildToolsVersion "24.0.0" to buildToolsVersion "23.0.3"

source : experience

Cursor inside cursor

Do you do any more fetches? You should show those as well. You're only showing us half the code.

It should look like:

FETCH NEXT FROM @Outer INTO ...
WHILE @@FETCH_STATUS = 0
BEGIN
  DECLARE @Inner...
  OPEN @Inner
  FETCH NEXT FROM @Inner INTO ...
  WHILE @@FETCH_STATUS = 0
  BEGIN
  ...
    FETCH NEXT FROM @Inner INTO ...
  END
  CLOSE @Inner
  DEALLOCATE @Inner
  FETCH NEXT FROM @Outer INTO ...
END
CLOSE @Outer
DEALLOCATE @Outer

Also, make sure you do not name the cursors the same... and any code (check your triggers) that gets called does not use a cursor that is named the same. I've seen odd behavior from people using 'theCursor' in multiple layers of the stack.

Showing/Hiding Table Rows with Javascript - can do with ID - how to do with Class?

You can change the class of the entire table and use the cascade in the CSS: http://jsbin.com/oyunuy/1/

What is the Oracle equivalent of SQL Server's IsNull() function?

You can use the condition if x is not null then.... It's not a function. There's also the NVL() function, a good example of usage here: NVL function ref.

fastest way to export blobs from table into individual files

I came here looking for exporting blob into file with least effort. CLR functions is not something what I'd call least effort. Here described lazier one, using OLE Automation:

declare @init int
declare @file varbinary(max) = CONVERT(varbinary(max), N'your blob here')
declare @filepath nvarchar(4000) = N'c:\temp\you file name here.txt'

EXEC sp_OACreate 'ADODB.Stream', @init OUTPUT; -- An instace created
EXEC sp_OASetProperty @init, 'Type', 1; 
EXEC sp_OAMethod @init, 'Open'; -- Calling a method
EXEC sp_OAMethod @init, 'Write', NULL, @file; -- Calling a method
EXEC sp_OAMethod @init, 'SaveToFile', NULL, @filepath, 2; -- Calling a method
EXEC sp_OAMethod @init, 'Close'; -- Calling a method
EXEC sp_OADestroy @init; -- Closed the resources

You'll potentially need to allow to run OA stored procedures on server (and then turn it off, when you're done):

sp_configure 'show advanced options', 1;  
GO  
RECONFIGURE;  
GO  
sp_configure 'Ole Automation Procedures', 1;  
GO  
RECONFIGURE;  
GO

How to convert a string to ASCII

You can do it by using LINQ-expression.

  public static List<int> StringToAscii(string value)
  {
        if (string.IsNullOrEmpty(value))
            throw new ArgumentException("Value cannot be null or empty.", nameof(value));

        return value.Select(System.Convert.ToInt32).ToList();
  } 

Uncaught syntaxerror: unexpected identifier?

There are errors here :

var formTag = document.getElementsByTagName("form"), // form tag is an array
selectListItem = $('select'),
makeSelect = document.createElement('select'),
makeSelect.setAttribute("id", "groups");

The code must change to:

var formTag = document.getElementsByTagName("form");
var selectListItem = $('select');
var makeSelect = document.createElement('select');
makeSelect.setAttribute("id", "groups");

By the way, there is another error at line 129 :

var createLi.appendChild(createSubList);

Replace it with:

createLi.appendChild(createSubList);

How can I tell if I'm running in 64-bit JVM or 32-bit JVM (from within a program)?

Under Windows 7 in the "Control Panel" under "Programs | Programs and Features" the 64-bit variants of JRE & JDK are listed with "64-bit" in parentheses (e.g. "Java SE Development Kit 7 Update 65 (64-Bit)"), while for the 32-bit variants the variant is not mentioned in parentheses (e.g. just "Java SE Development Kit 8 Update 60").

Meaning of ${project.basedir} in pom.xml

There are a set of available properties to all Maven projects.

From Introduction to the POM:

project.basedir: The directory that the current project resides in.

This means this points to where your Maven projects resides on your system. It corresponds to the location of the pom.xml file. If your POM is located inside /path/to/project/pom.xml then this property will evaluate to /path/to/project.

Some properties are also inherited from the Super POM, which is the case for project.build.directory. It is the value inside the <project><build><directory> element of the POM. You can get a description of all those values by looking at the Maven model. For project.build.directory, it is:

The directory where all files generated by the build are placed. The default value is target.

This is the directory that will hold every generated file by the build.

Checking if a key exists in a JS object

var obj = {
    "key1" : "k1",
    "key2" : "k2",
    "key3" : "k3"
};

if ("key1" in obj)
    console.log("has key1 in obj");

=========================================================================

To access a child key of another key

var obj = {
    "key1": "k1",
    "key2": "k2",
    "key3": "k3",
    "key4": {
        "keyF": "kf"
    }
};

if ("keyF" in obj.key4)
    console.log("has keyF in obj");

Git blame -- prior commits?

Building on the previous answer, this bash one-liner should give you what you're looking for. It displays the git blame history for a particular line of a particular file, through the last 5 revisions:

LINE=10 FILE=src/options.cpp REVS=5; for commit in $(git rev-list -n $REVS HEAD $FILE); do git blame -n -L$LINE,+1 $commit -- $FILE; done

In the output of this command, you might see the content of the line change, or the line number displayed might even change, for a particular commit.

This often indicates that the line was added for the first time, after that particular commit. It could also indicate the line was moved from another part of the file.

for loop in Python

Try using this:

for k in range(1,c+1,2):

Fragment transaction animation: slide in and slide out

I have same issue, i used simple solution

1)create sliding_out_right.xml in anim folder

  <?xml version="1.0" encoding="utf-8"?>
    <set xmlns:android="http://schemas.android.com/apk/res/android">
        <translate android:fromXDelta="0" android:toXDelta="-50%p"
            android:duration="@android:integer/config_mediumAnimTime"/>
        <alpha android:fromAlpha="1.0" android:toAlpha="0.0"
            android:duration="@android:integer/config_mediumAnimTime" />
    </set>

2) create sliding_in_left.xml in anim folder

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate android:fromXDelta="50%p" android:toXDelta="0"
        android:duration="@android:integer/config_mediumAnimTime"/>
    <alpha android:fromAlpha="0.0" android:toAlpha="1.0"
        android:duration="@android:integer/config_mediumAnimTime" />
</set>

3) simply using fragment transaction setCustomeAnimations() with two custom xml and two default xml for animation as follows :-

 fragmentTransaction.setCustomAnimations(R.anim.sliding_in_left, R.anim.sliding_out_right, android.R.anim.slide_in_left, android.R.anim.slide_out_right );

Getting the last element of a list

In Python, how do you get the last element of a list?

To just get the last element,

  • without modifying the list, and
  • assuming you know the list has a last element (i.e. it is nonempty)

pass -1 to the subscript notation:

>>> a_list = ['zero', 'one', 'two', 'three']
>>> a_list[-1]
'three'

Explanation

Indexes and slices can take negative integers as arguments.

I have modified an example from the documentation to indicate which item in a sequence each index references, in this case, in the string "Python", -1 references the last element, the character, 'n':

 +---+---+---+---+---+---+
 | P | y | t | h | o | n |
 +---+---+---+---+---+---+
   0   1   2   3   4   5 
  -6  -5  -4  -3  -2  -1

>>> p = 'Python'
>>> p[-1]
'n'

Assignment via iterable unpacking

This method may unnecessarily materialize a second list for the purposes of just getting the last element, but for the sake of completeness (and since it supports any iterable - not just lists):

>>> *head, last = a_list
>>> last
'three'

The variable name, head is bound to the unnecessary newly created list:

>>> head
['zero', 'one', 'two']

If you intend to do nothing with that list, this would be more apropos:

*_, last = a_list

Or, really, if you know it's a list (or at least accepts subscript notation):

last = a_list[-1]

In a function

A commenter said:

I wish Python had a function for first() and last() like Lisp does... it would get rid of a lot of unnecessary lambda functions.

These would be quite simple to define:

def last(a_list):
    return a_list[-1]

def first(a_list):
    return a_list[0]

Or use operator.itemgetter:

>>> import operator
>>> last = operator.itemgetter(-1)
>>> first = operator.itemgetter(0)

In either case:

>>> last(a_list)
'three'
>>> first(a_list)
'zero'

Special cases

If you're doing something more complicated, you may find it more performant to get the last element in slightly different ways.

If you're new to programming, you should avoid this section, because it couples otherwise semantically different parts of algorithms together. If you change your algorithm in one place, it may have an unintended impact on another line of code.

I try to provide caveats and conditions as completely as I can, but I may have missed something. Please comment if you think I'm leaving a caveat out.

Slicing

A slice of a list returns a new list - so we can slice from -1 to the end if we are going to want the element in a new list:

>>> a_slice = a_list[-1:]
>>> a_slice
['three']

This has the upside of not failing if the list is empty:

>>> empty_list = []
>>> tail = empty_list[-1:]
>>> if tail:
...     do_something(tail)

Whereas attempting to access by index raises an IndexError which would need to be handled:

>>> empty_list[-1]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IndexError: list index out of range

But again, slicing for this purpose should only be done if you need:

  • a new list created
  • and the new list to be empty if the prior list was empty.

for loops

As a feature of Python, there is no inner scoping in a for loop.

If you're performing a complete iteration over the list already, the last element will still be referenced by the variable name assigned in the loop:

>>> def do_something(arg): pass
>>> for item in a_list:
...     do_something(item)
...     
>>> item
'three'

This is not semantically the last thing in the list. This is semantically the last thing that the name, item, was bound to.

>>> def do_something(arg): raise Exception
>>> for item in a_list:
...     do_something(item)
...
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "<stdin>", line 1, in do_something
Exception
>>> item
'zero'

Thus this should only be used to get the last element if you

  • are already looping, and
  • you know the loop will finish (not break or exit due to errors), otherwise it will point to the last element referenced by the loop.

Getting and removing it

We can also mutate our original list by removing and returning the last element:

>>> a_list.pop(-1)
'three'
>>> a_list
['zero', 'one', 'two']

But now the original list is modified.

(-1 is actually the default argument, so list.pop can be used without an index argument):

>>> a_list.pop()
'two'

Only do this if

  • you know the list has elements in it, or are prepared to handle the exception if it is empty, and
  • you do intend to remove the last element from the list, treating it like a stack.

These are valid use-cases, but not very common.

Saving the rest of the reverse for later:

I don't know why you'd do it, but for completeness, since reversed returns an iterator (which supports the iterator protocol) you can pass its result to next:

>>> next(reversed([1,2,3]))
3

So it's like doing the reverse of this:

>>> next(iter([1,2,3]))
1

But I can't think of a good reason to do this, unless you'll need the rest of the reverse iterator later, which would probably look more like this:

reverse_iterator = reversed([1,2,3])
last_element = next(reverse_iterator)

use_later = list(reverse_iterator)

and now:

>>> use_later
[2, 1]
>>> last_element
3

Does List<T> guarantee insertion order?

If you will change the order of operations, you will avoid the strange behavior: First insert the value to the right place in the list, and then delete it from his first position. Make sure you delete it by his index, because if you will delete it by reference, you might delete them both...

What is the difference between #import and #include in Objective-C?

If you are familiar with C++ and macros, then

#import "Class.h" 

is similar to

{
#pragma once

#include "class.h"
}

which means that your Class will be loaded only once when your app runs.

Alternative to itoa() for converting integer to string C++?

You can actually convert anything to a string with one cleverly written template function. This code example uses a loop to create subdirectories in a Win-32 system. The string concatenation operator, operator+, is used to concatenate a root with a suffix to generate directory names. The suffix is created by converting the loop control variable, i, to a C++ string, using the template function, and concatenating that with another string.

//Mark Renslow, Globe University, Minnesota School of Business, Utah Career College
//C++ instructor and Network Dean of Information Technology

#include <cstdlib>
#include <iostream>
#include <string>
#include <sstream> // string stream
#include <direct.h>

using namespace std;

string intToString(int x)
{
/**************************************/
/* This function is similar to itoa() */
/* "integer to alpha", a non-standard */
/* C language function. It takes an   */
/* integer as input and as output,    */
/* returns a C++ string.              */
/* itoa()  returned a C-string (null- */
/* terminated)                        */
/* This function is not needed because*/
/* the following template function    */
/* does it all                        */
/**************************************/   
       string r;
       stringstream s;

       s << x;
       r = s.str();

       return r;

}

template <class T>
string toString( T argument)
{
/**************************************/
/* This template shows the power of   */
/* C++ templates. This function will  */
/* convert anything to a string!      */
/* Precondition:                      */
/* operator<< is defined for type T    */
/**************************************/
       string r;
       stringstream s;

       s << argument;
       r = s.str();

       return r;

}

int main( )
{
    string s;

    cout << "What directory would you like me to make?";

    cin >> s;

    try
    {
      mkdir(s.c_str());
    }
    catch (exception& e) 
    {
      cerr << e.what( ) << endl;
    }

    chdir(s.c_str());

    //Using a loop and string concatenation to make several sub-directories
    for(int i = 0; i < 10; i++)
    {
        s = "Dir_";
        s = s + toString(i);
        mkdir(s.c_str());
    }
    system("PAUSE");
    return EXIT_SUCCESS;
}

Attaching click to anchor tag in angular

I have examined all the above answer's, We just need to implement two things to work it as expected.

Step - 1: Add the (click) event in the anchor tag in the HTML page and remove the href=" " as its explicitly for navigating to external links, Instead use routerLink = " " which helps in navigating views.

<ul>
  <li><a routerLink="" (click)="hitAnchor1($event)"><p>Click One</p></a></li>
  <li><a routerLink="" (click)="hitAnchor2($event)"><p>Click Two</p></a></li>
</ul>

Step - 2: Call the above function to attach the click event to anchor tags (coming from ajax) in the .ts file,

  hitAnchor1(e){
      console.log("Events", e);
      alert("You have clicked the anchor-1 tag");
   }
  hitAnchor2(e){
      console.log("Events", e);
      alert("You have clicked the anchor-2 tag");
   }

That's all. It work's as expected. I created the example below, You can have a look:-

https://stackblitz.com/edit/angular-yn6q6t

Laravel update model with unique validation rule for attribute

Append the id of the instance currently being updated to the validator.

  1. Pass the id of your instance to ignore the unique validator.

  2. In the validator, use a parameter to detect if you are updating or creating the resource.

If updating, force the unique rule to ignore a given id:

//rules
'email' => 'unique:users,email_address,' . $userId,

If creating, proceed as usual:

//rules
'email' => 'unique:users,email_address',

file_get_contents() Breaks Up UTF-8 Characters

Exemple :

$string = file_get_contents(".../File.txt");
$string = mb_convert_encoding($string, 'UTF-8', "ISO-8859-1");
echo $string;

How does BitLocker affect performance?

I am talking here from a theoretical point of view; I have not tried BitLocker.

BitLocker uses AES encryption with a 128-bit key. On a Core2 machine, clocked at 2.53 GHz, encryption speed should be about 110 MB/s, using one core. The two cores could process about 220 MB/s, assuming perfect data transfer and core synchronization with no overhead, and that nothing requires the CPU in the same time (that one hell of an assumption, actually). The X25-M G2 is announced at 250 MB/s read bandwidth (that's what the specs say), so, in "ideal" conditions, BitLocker necessarily involves a bit of a slowdown.

However read bandwidth is not that important. It matters when you copy huge files, which is not something that you do very often. In everyday work, access time is much more important: as a developer, you create, write, read and delete many files, but they are all small (most of them are much smaller than one megabyte). This is what makes SSD "snappy". Encryption does not impact access time. So my guess is that any performance degradation will be negligible(*).

(*) Here I assume that Microsoft's developers did their job properly.

tkinter: how to use after method

You need to give a function to be called after the time delay as the second argument to after:

after(delay_ms, callback=None, *args)

Registers an alarm callback that is called after a given time.

So what you really want to do is this:

tiles_letter = ['a', 'b', 'c', 'd', 'e']

def add_letter():
    rand = random.choice(tiles_letter)
    tile_frame = Label(frame, text=rand)
    tile_frame.pack()
    root.after(500, add_letter)
    tiles_letter.remove(rand)  # remove that tile from list of tiles


root.after(0, add_letter)  # add_letter will run as soon as the mainloop starts.
root.mainloop()

You also need to schedule the function to be called again by repeating the call to after inside the callback function, since after only executes the given function once. This is also noted in the documentation:

The callback is only called once for each call to this method. To keep calling the callback, you need to reregister the callback inside itself

Note that your example will throw an exception as soon as you've exhausted all the entries in tiles_letter, so you need to change your logic to handle that case whichever way you want. The simplest thing would be to add a check at the beginning of add_letter to make sure the list isn't empty, and just return if it is:

def add_letter():
    if not tiles_letter:
        return
    rand = random.choice(tiles_letter)
    tile_frame = Label(frame, text=rand)
    tile_frame.pack()
    root.after(500, add_letter)
    tiles_letter.remove(rand)  # remove that tile from list of tiles

Live-Demo: repl.it

Java: Check the date format of current string is according to required format or not

You can try this to simple date format valdation

 public Date validateDateFormat(String dateToValdate) {

    SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HHmmss");
    //To make strict date format validation
    formatter.setLenient(false);
    Date parsedDate = null;
    try {
        parsedDate = formatter.parse(dateToValdate);
        System.out.println("++validated DATE TIME ++"+formatter.format(parsedDate));

    } catch (ParseException e) {
        //Handle exception
    }
    return parsedDate;
}

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required?

If you are in a test environment and do not want to set security settings you have to allow less secure apps via. this link in Gmail.

https://myaccount.google.com/lesssecureapps

How do you set the max number of characters for an EditText in Android?

It is working for me.

    etMsgDescription.setFilters(new InputFilter[] {new InputFilter.LengthFilter(maximum_character)});

    etMsgDescription.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

            tvCharacterLimite.setText(" "+String.valueOf(maximum_character - etMsgDescription.getText().length()));
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });

Get the Year/Month/Day from a datetime in php?

Use DateTime with DateTime::format()

$datetime = new DateTime($dateTimeString);
echo $datetime->format('w');

Type Checking: typeof, GetType, or is?

1.

Type t = typeof(obj1);
if (t == typeof(int))

This is illegal, because typeof only works on types, not on variables. I assume obj1 is a variable. So, in this way typeof is static, and does its work at compile time instead of runtime.

2.

if (obj1.GetType() == typeof(int))

This is true if obj1 is exactly of type int. If obj1 derives from int, the if condition will be false.

3.

if (obj1 is int)

This is true if obj1 is an int, or if it derives from a class called int, or if it implements an interface called int.

How to change the status bar color in Android?

This is what worked for me in KitKat and with good results.

public static void setTaskBarColored(Activity context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT)
        {
            Window w = context.getWindow();
            w.setFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
            //status bar height
            int statusBarHeight = Utilities.getStatusBarHeight(context);

            View view = new View(context);
            view.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
            view.getLayoutParams().height = statusBarHeight;
            ((ViewGroup) w.getDecorView()).addView(view);
            view.setBackgroundColor(context.getResources().getColor(R.color.colorPrimaryTaskBar));
        }
    }

How to sort by column in descending order in Spark SQL?

import org.apache.spark.sql.functions.desc

df.orderBy(desc("columnname1"),desc("columnname2"),asc("columnname3"))

Notify ObservableCollection when Item changes

One simple solution to this is to replace the item being changed in the ObservableCollection which notifies the collection of the changed item. In the sample code snippet below Artists is the ObservableCollection and artist is an item of the type in the ObservableCollection:

    var index = Artists.IndexOf(artist);
    Artists.RemoveAt(index);
    artist.IsFollowed = true; // change something in the item
    Artists.Insert(index, artist);

Implements vs extends: When to use? What's the difference?

As shown in the figure given below, a class extends another class, an interface extends another interface but a class implements an interface. enter image description here

For more details

Python locale error: unsupported locale setting

More permanent solution would be to fill the missing values, in the output shown by command: locale

Output from locale is:

 $ locale
LANG=en_US.utf8
LANGUAGE=
LC_CTYPE="en_US.utf8"
LC_NUMERIC=es_ES.utf8
LC_TIME=es_ES.utf8
LC_COLLATE="en_US.utf8"
LC_MONETARY=es_ES.utf8
LC_MESSAGES="en_US.utf8"
LC_PAPER=es_ES.utf8
LC_NAME="en_US.utf8"
LC_ADDRESS="en_US.utf8"
LC_TELEPHONE="en_US.utf8"
LC_MEASUREMENT=es_ES.utf8
LC_IDENTIFICATION="en_US.utf8"
LC_ALL=

To Fill the missing values edit ~/.bashrc :

 $ vim ~/.bashrc

Add the following lines after the above command (suppose you want en_US.UTF-8 to be your language):

export LANGUAGE="en_US.UTF-8"
export LC_ALL="en_US.UTF-8"

If this file is ReadOnly you would be needing to follow the steps mentioned by The GeekyBoy. The answer given by Dr Beco in Superuser has details relating to saving readonly files.

After saving the file do:

$ source ~/.bashrc

Now you wont be facing the same problem anymore.

SQL Server 2008 R2 Express permissions -- cannot create database or modify users

In SSMS 2012, you'll have to use:

To enable single-user mode, in SQL instance properties, DO NOT go to "Advance" tag, there is already a "Startup Parameters" tag.

  1. Add "-m;" into parameters;
  2. Restart the service and logon this SQL instance by using windows authentication;
  3. The rest steps are same as above. Change your windows user account permission in security or reset SA account password.
  4. Last, remove "-m" parameter from "startup parameters";

Using FolderBrowserDialog in WPF application

You need to add a reference to System.Windows.Forms.dll, then use the System.Windows.Forms.FolderBrowserDialog class.

Adding using WinForms = System.Windows.Forms; will be helpful.

Half circle with CSS (border, outline only)

Below is a minimal code to achieve the effect.

This also works responsively since the border-radius is in percentage.

_x000D_
_x000D_
.semi-circle{_x000D_
width: 200px;_x000D_
height: 100px;_x000D_
border-radius: 50% 50% 0 0 / 100% 100% 0 0;_x000D_
border: 10px solid #000;_x000D_
border-bottom: 0;_x000D_
}
_x000D_
<div class="semi-circle"></div>
_x000D_
_x000D_
_x000D_

How to draw lines in Java

I understand you are using Java AWT API for drawing. The paint method is invoked when the control needs repainting. And I'm pretty sure it provides in the Graphics argument what rectangle is the one who needs repainting (to avoid redrawing all).

So if you are presenting a fixed image you just draw whatever you need in that method.

If you are animating I assume you can invalidate some region and the paint method will be invoked automagically. So you can modify state, call invalidate, and it will be called again.

Difference between an API and SDK

I'm not sure there's any official definition of these two terms. I understand an API to be a set of documented programmable libraries and supporting source such as headers or IDL files. SDKs usually contain APIs but often often add compilers, tools, and samples to the mix.

Do Java arrays have a maximum size?

Haven't seen the right answer, even though it's very easy to test.

In a recent HotSpot VM, the correct answer is Integer.MAX_VALUE - 5. Once you go beyond that:

public class Foo {
  public static void main(String[] args) {
    Object[] array = new Object[Integer.MAX_VALUE - 4];
  }
}

You get:

Exception in thread "main" java.lang.OutOfMemoryError:
  Requested array size exceeds VM limit

Capturing standard out and error with Start-Process

IMPORTANT:

We have been using the function as provided above by LPG.

However, this contains a bug you might encounter when you start a process that generates a lot of output. Due to this you might end up with a deadlock when using this function. Instead use the adapted version below:

Function Execute-Command ($commandTitle, $commandPath, $commandArguments)
{
  Try {
    $pinfo = New-Object System.Diagnostics.ProcessStartInfo
    $pinfo.FileName = $commandPath
    $pinfo.RedirectStandardError = $true
    $pinfo.RedirectStandardOutput = $true
    $pinfo.UseShellExecute = $false
    $pinfo.Arguments = $commandArguments
    $p = New-Object System.Diagnostics.Process
    $p.StartInfo = $pinfo
    $p.Start() | Out-Null
    [pscustomobject]@{
        commandTitle = $commandTitle
        stdout = $p.StandardOutput.ReadToEnd()
        stderr = $p.StandardError.ReadToEnd()
        ExitCode = $p.ExitCode
    }
    $p.WaitForExit()
  }
  Catch {
     exit
  }
}

Further information on this issue can be found at MSDN:

A deadlock condition can result if the parent process calls p.WaitForExit before p.StandardError.ReadToEnd and the child process writes enough text to fill the redirected stream. The parent process would wait indefinitely for the child process to exit. The child process would wait indefinitely for the parent to read from the full StandardError stream.

How do I change TextView Value inside Java Code?

I presume that this question is a continuation of this one.

What are you trying to do? Do you really want to dynamically change the text in your TextView objects when the user clicks a button? You can certainly do that, if you have a reason, but, if the text is static, it is usually set in the main.xml file, like this:

<TextView  
android:id="@+id/rate"
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
android:text="@string/rate"
/>

The string "@string/rate" refers to an entry in your strings.xml file that looks like this:

<string name="rate">Rate</string>

If you really want to change this text later, you can do so by using Nikolay's example - you'd get a reference to the TextView by utilizing the id defined for it within main.xml, like this:


final TextView textViewToChange = (TextView) findViewById(R.id.rate);
textViewToChange.setText(
    "The new text that I'd like to display now that the user has pushed a button.");

Create boolean column in MySQL with false as default value?

Use ENUM in MySQL for true / false it gives and accepts the true / false values without any extra code.

ALTER TABLE `itemcategory` ADD `aaa` ENUM('false', 'true') NOT NULL DEFAULT 'false'

How to use ArrayAdapter<myClass>

I think this is the best approach. Using generic ArrayAdapter class and extends your own Object adapter is as simple as follows:

public abstract class GenericArrayAdapter<T> extends ArrayAdapter<T> {

  // Vars
  private LayoutInflater mInflater;

  public GenericArrayAdapter(Context context, ArrayList<T> objects) {
    super(context, 0, objects);
    init(context);
  }

  // Headers
  public abstract void drawText(TextView textView, T object);

  private void init(Context context) {
    this.mInflater = LayoutInflater.from(context);
  }

  @Override public View getView(int position, View convertView, ViewGroup parent) {
    final ViewHolder vh;
    if (convertView == null) {
      convertView = mInflater.inflate(android.R.layout.simple_list_item_1, parent, false);
      vh = new ViewHolder(convertView);
      convertView.setTag(vh);
    } else {
      vh = (ViewHolder) convertView.getTag();
    }

    drawText(vh.textView, getItem(position));

    return convertView;
  }

  static class ViewHolder {

    TextView textView;

    private ViewHolder(View rootView) {
      textView = (TextView) rootView.findViewById(android.R.id.text1);
    }
  }
}

and here your adapter (example):

public class SizeArrayAdapter extends GenericArrayAdapter<Size> {

  public SizeArrayAdapter(Context context, ArrayList<Size> objects) {
    super(context, objects);
  }

  @Override public void drawText(TextView textView, Size object) {
    textView.setText(object.getName());
  }

}

and finally, how to initialize it:

ArrayList<Size> sizes = getArguments().getParcelableArrayList(Constants.ARG_PRODUCT_SIZES);
SizeArrayAdapter sizeArrayAdapter = new SizeArrayAdapter(getActivity(), sizes);
listView.setAdapter(sizeArrayAdapter);

I've created a Gist with TextView layout gravity customizable ArrayAdapter:

https://gist.github.com/m3n0R/8822803

Check if string matches pattern

  
import re

ab = re.compile("^([A-Z]{1}[0-9]{1})+$")
ab.match(string)
  


I believe that should work for an uppercase, number pattern.

How can I "disable" zoom on a mobile web page?

document.addEventListener('dblclick', (event) => {
    event.preventDefault()
}, { passive: false });

How to view file diff in git before commit

To check for local differences:

git diff myfile.txt

or you can use a diff tool (in case you'd like to revert some changes):

git difftool myfile.txt

To use git difftool more efficiently, install and use your favourite GUI tool such as Meld, DiffMerge or OpenDiff.

Note: You can also use . (instead of filename) to see current dir changes.

In order to check changes per each line, use: git blame which will display which line was commited in which commit.


To view the actual file before the commit (where master is your branch), run:

git show master:path/my_file

How to get the type of T from a member of a generic class or method?

That's work for me. Where myList is some unknown kind of list.

IEnumerable myEnum = myList as IEnumerable;
Type entryType = myEnum.AsQueryable().ElementType;

How to display custom view in ActionBar?

For example, you can define a layout file which contains a EditText element.

<?xml version="1.0" encoding="utf-8"?>
<EditText xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/searchfield"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:inputType="textFilter" >

</EditText> 

you can do

public class MainActivity extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ActionBar actionBar = getActionBar();
    // add the custom view to the action bar
    actionBar.setCustomView(R.layout.actionbar_view);
    EditText search = (EditText) actionBar.getCustomView().findViewById(R.id.searchfield);
    search.setOnEditorActionListener(new OnEditorActionListener() {

      @Override
      public boolean onEditorAction(TextView v, int actionId,
          KeyEvent event) {
        Toast.makeText(MainActivity.this, "Search triggered",
            Toast.LENGTH_LONG).show();
        return false;
      }
    });
    actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM
        | ActionBar.DISPLAY_SHOW_HOME);


    }

How to make an executable JAR file?

It's too late to answer for this question. But if someone is searching for this answer now I've made it to run with no errors.

First of all make sure to download and add maven to path. [ mvn --version ] will give you version specifications of it if you have added to the path correctly.

Now , add following code to the maven project [ pom.xml ] , in the following code replace with your own main file entry point for eg [ com.example.test.Test ].

      <plugin>
            <!-- Build an executable JAR -->
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.4</version>
            <configuration>
                <archive>
                    <manifest>
                    <mainClass>
            your_package_to_class_that_contains_main_file .MainFileName</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>

Now go to the command line [CMD] in your project and type mvn package and it will generate a jar file as something like ProjectName-0.0.1-SNAPSHOT.jar under target directory.

Now navigate to the target directory by cd target.

Finally type java -jar jar-file-name.jar and yes this should work successfully if you don't have any errors in your program.

How to get ER model of database from server with Workbench

I want to enhance Mr. Kamran Ali's answer with pictorial view.

Pictorial View is given step by step:

  1. Go to "Database" Menu option
  2. Select the "Reverse Engineer" option.

enter image description here

  1. A wizard will come. Select from "Stored Connection" and press "Next" button.

enter image description here

  1. Then "Next"..to.."Finish"

Enjoy :)

How can I copy a file from a remote server to using Putty in Windows?

One of the putty tools is pscp.exe; it will allow you to copy files from your remote host.

Using JQuery to check if no radio button in a group has been checked

var len = $('#your_form_id input:radio:checked').length;
      if (!len) {
        alert("None checked");
      };
      alert("checked: "+ len);

How do I install the Nuget provider for PowerShell on a unconnected machine so I can install a nuget package from the PS command line?

The provider is bundled with PowerShell>=6.0.

If all you need is a way to install a package from a file, just grab the .msi installer for the latest version from the github releases page, copy it over to the machine, install it and use it.

PHP foreach with Nested Array?

Both syntaxes are correct. But the result would be Array. You probably want to do something like this:

foreach ($tmpArray[1] as $value) {
  echo $value[0];
  foreach($value[1] as $val){
    echo $val;
  }
}

This will print out the string "two" ($value[0]) and the integers 4, 5 and 6 from the array ($value[1]).

How to set width of a div in percent in JavaScript?

Yes, it is:

<div id="myid">Some Content........</div>

document.getElementById('#myid').style.width = '50%';

How to query a MS-Access Table from MS-Excel (2010) using VBA

Sub Button1_Click()
Dim cn As Object
    Dim rs As Object
    Dim strSql As String
    Dim strConnection As String
    Set cn = CreateObject("ADODB.Connection")
    strConnection = "Provider=Microsoft.ACE.OLEDB.12.0;" & _
        "Data Source=C:\Documents and Settings\XXXXXX\My Documents\my_access_table.accdb"
    strSql = "SELECT Count(*) FROM mytable;"
    cn.Open strConnection
    Set rs = cn.Execute(strSql)
    MsgBox rs.Fields(0) & " rows in MyTable"

    rs.Close
    Set rs = Nothing
    cn.Close
    Set cn = Nothing

End Sub

How can I get the behavior of GNU's readlink -f on a Mac?

Truely platform-indpendent would be also this R-onliner

readlink(){ RScript -e "cat(normalizePath(commandArgs(T)[1]))" "$1";}

To actually mimic readlink -f <path>, $2 instead of $1 would need to be used.

Sql query to insert datetime in SQL Server

I encounter into a more generic problem: getting different (and not necessarily known) datetime formats and insert them into datetime column. I've solved it using this statement, which was finally became a scalar function (relevant for ODBC canonical, american, ANSI and british\franch date style - can be expanded):

insert into <tableName>(<dateTime column>) values(coalesce 
(TRY_CONVERT(datetime, <DateString, 121), TRY_CONVERT(datetime, <DateString>, 
101), TRY_CONVERT(datetime, <DateString>, 102), TRY_CONVERT(datetime, 
<DateString>, 103))) 

Concatenate rows of two dataframes in pandas

call concat and pass param axis=1 to concatenate column-wise:

In [5]:

pd.concat([df_a,df_b], axis=1)
Out[5]:
        AAseq Biorep  Techrep Treatment     mz      AAseq1 Biorep1  Techrep1  \
0  ELVISLIVES      A        1         C  500.0  ELVISLIVES       A         1   
1  ELVISLIVES      A        1         C  500.5  ELVISLIVES       A         1   
2  ELVISLIVES      A        1         C  501.0  ELVISLIVES       A         1   

  Treatment1  inte1  
0          C   1100  
1          C   1050  
2          C   1010  

There is a useful guide to the various methods of merging, joining and concatenating online.

For example, as you have no clashing columns you can merge and use the indices as they have the same number of rows:

In [6]:

df_a.merge(df_b, left_index=True, right_index=True)
Out[6]:
        AAseq Biorep  Techrep Treatment     mz      AAseq1 Biorep1  Techrep1  \
0  ELVISLIVES      A        1         C  500.0  ELVISLIVES       A         1   
1  ELVISLIVES      A        1         C  500.5  ELVISLIVES       A         1   
2  ELVISLIVES      A        1         C  501.0  ELVISLIVES       A         1   

  Treatment1  inte1  
0          C   1100  
1          C   1050  
2          C   1010  

And for the same reasons as above a simple join works too:

In [7]:

df_a.join(df_b)
Out[7]:
        AAseq Biorep  Techrep Treatment     mz      AAseq1 Biorep1  Techrep1  \
0  ELVISLIVES      A        1         C  500.0  ELVISLIVES       A         1   
1  ELVISLIVES      A        1         C  500.5  ELVISLIVES       A         1   
2  ELVISLIVES      A        1         C  501.0  ELVISLIVES       A         1   

  Treatment1  inte1  
0          C   1100  
1          C   1050  
2          C   1010  

Google Maps Android API v2 Authorization failure

I had the same issue. After about two hours of googling, retries, regenerating API Key many times, etc. i discovered that i enabled the wrong service in the Google APis Console. I enabled Google Maps API v2 Service, but for Android Apps you have to use Google Maps Android API v2. After enabling the right service all started working.

How can I submit a POST form using the <a href="..."> tag?

In case you use MVC to accomplish it - you will have to do something like this

 <form action="/ControllerName/ActionName" method="post">
        <a href="javascript:;" onclick="parentNode.submit();"><%=n%></a>
        <input type="hidden" name="mess" value=<%=n%>/>
    </form>

I just went through some examples here and did not see the MVC one figured it won't hurt to post it.

Then on your Action in the Controller I would just put <HTTPPost> On the top of it. I believe if you don't have <HTTPGET> on the top of it it would still work but explicitly putting it there feels a bit safer.

How to get current page URL in MVC 3

One thing that isn't mentioned in other answers is case sensitivity, if it is going to be referenced in multiple places (which it isn't in the original question but is worth taking into consideration as this question appears in a lot of similar searches). Based on other answers I found the following worked for me initially:

Request.Url.AbsoluteUri.ToString()

But in order to be more reliable this then became:

Request.Url.AbsoluteUri.ToString().ToLower()

And then for my requirements (checking what domain name the site is being accessed from and showing the relevant content):

Request.Url.AbsoluteUri.ToString().ToLower().Contains("xxxx")

HTTP Headers for File Downloads

As explained by Alex's link you're probably missing the header Content-Disposition on top of Content-Type.

So something like this:

Content-Disposition: attachment; filename="MyFileName.ext"

Does Arduino use C or C++?

Arduino sketches are written in C++.

Here is a typical construct you'll encounter:

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
...
lcd.begin(16, 2);
lcd.print("Hello, World!");

That's C++, not C.

Hence do yourself a favor and learn C++. There are plenty of books and online resources available.

How can I find the number of arguments of a Python function?

someMethod.func_code.co_argcount

or, if the current function name is undetermined:

import sys

sys._getframe().func_code.co_argcount

What is MATLAB good for? Why is it so used by universities? When is it better than Python?

MATLAB, as mentioned by others, is great at matrix manipulation, and was originally built as an extension of the well-known BLAS and LAPACK libraries used for linear algebra. It interfaces well with other languages like Java, and is well favored by engineering and scientific companies for its well developed and documented libraries. From what I know of Python and NumPy, while they share many of the fundamental capabilities of MATLAB, they don't have the full breadth and depth of capabilities with their libraries.

Personally, I use MATLAB because that's what I learned in my internship, that's what I used in grad school, and that's what I used in my first job. I don't have anything against Python (or any other language). It's just what I'm used too.

Also, there is another free version in addition to scilab mentioned by @Jim C from gnu called Octave.

Upload Image using POST form data in Python-requests

From wechat api doc:

curl -F [email protected] "http://file.api.wechat.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE"

Translate the command above to python:

import requests
url = 'http://file.api.wechat.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE'
files = {'media': open('test.jpg', 'rb')}
requests.post(url, files=files)

How do CSS triangles work?

CSS Triangles: A Tragedy in Five Acts

As alex said, borders of equal width butt up against each other at 45 degree angles:

borders meet at 45 degree angles, content in middle

When you have no top border, it looks like this:

no top border

Then you give it a width of 0...

no width

...and a height of 0...

no height either

...and finally, you make the two side borders transparent:

transparent side borders

That results in a triangle.

How do I get specific properties with Get-AdUser

using select-object for example:

Get-ADUser -Filter * -SearchBase 'OU=Users & Computers, DC=aaaaaaa, DC=com' -Properties DisplayName | select -expand displayname | Export-CSV "ADUsers.csv" 

Break a previous commit into multiple commits

A quick reference of the necessary commands, because I basically know what to do but always forget the right syntax:

git rebase -i <sha1_before_split>
# mark the targeted commit with 'edit'
git reset HEAD^
git add ...
git commit -m "First part"
git add ...
git commit -m "Second part"
git rebase --continue

Credits to Emmanuel Bernard's blog post.

What is the difference between HTTP_HOST and SERVER_NAME in PHP?

Please note that if you want to use IPv6, you probably want to use HTTP_HOST rather than SERVER_NAME . If you enter http://[::1]/ the environment variables will be the following:

HTTP_HOST = [::1]
SERVER_NAME = ::1

This means, that if you do a mod_rewrite for example, you might get a nasty result. Example for a SSL redirect:

# SERVER_NAME will NOT work - Redirection to https://::1/
RewriteRule .* https://%{SERVER_NAME}/

# HTTP_HOST will work - Redirection to https://[::1]/
RewriteRule .* https://%{HTTP_HOST}/

This applies ONLY if you access the server without an hostname.

Sanitizing user input before adding it to the DOM in Javascript

You need to take extra precautions when using user supplied data in HTML attributes. Because attributes has many more attack vectors than output inside HTML tags.

The only way to avoid XSS attacks is to encode everything except alphanumeric characters. Escape all characters with ASCII values less than 256 with the &#xHH; format. Which unfortunately may cause problems in your scenario, if you are using CSS classes and javascript to fetch those elements.

OWASP has a good description of how to mitigate HTML attribute XSS:

http://www.owasp.org/index.php/XSS_(Cross_Site_Scripting)_Prevention_Cheat_Sheet#RULE_.233_-_JavaScript_Escape_Before_Inserting_Untrusted_Data_into_HTML_JavaScript_Data_Values

How to make war file in Eclipse

File -> Export -> Web -> WAR file

OR in Kepler follow as shown below :

enter image description here

What is the behavior of integer division?

Where the result is negative, C truncates towards 0 rather than flooring - I learnt this reading about why Python integer division always floors here: Why Python's Integer Division Floors

Connection string using Windows Authentication

This is shorter and works

<connectionStrings>      
<add name="DBConnection"
             connectionString="data source=SERVER\INSTANCE;
       Initial Catalog=MyDB;Integrated Security=SSPI;"
             providerName="System.Data.SqlClient" />
</connectionStrings> 

Persist Security Info not needed

Ways to save enums in database

If saving enums as strings in the database, you can create utility methods to (de)serialize any enum:

   public static String getSerializedForm(Enum<?> enumVal) {
        String name = enumVal.name();
        // possibly quote value?
        return name;
    }

    public static <E extends Enum<E>> E deserialize(Class<E> enumType, String dbVal) {
        // possibly handle unknown values, below throws IllegalArgEx
        return Enum.valueOf(enumType, dbVal.trim());
    }

    // Sample use:
    String dbVal = getSerializedForm(Suit.SPADE);
    // save dbVal to db in larger insert/update ...
    Suit suit = deserialize(Suit.class, dbVal);

Using Google maps API v3 how do I get LatLng with a given address?

I don't think location.LatLng is working, however this works:

results[0].geometry.location.lat(), results[0].geometry.location.lng()

Found it while exploring Get Lat Lon source code.

Convert JavaScript String to be all lower case?

you can use the in built .toLowerCase() method on javascript strings. ex: var x = "Hello"; x.toLowerCase();

Plotting categorical data with pandas and matplotlib

To plot multiple categorical features as bar charts on the same plot, I would suggest:

import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame(
    {
        "colour": ["red", "blue", "green", "red", "red", "yellow", "blue"],
        "direction": ["up", "up", "down", "left", "right", "down", "down"],
    }
)

categorical_features = ["colour", "direction"]
fig, ax = plt.subplots(1, len(categorical_features))
for i, categorical_feature in enumerate(df[categorical_features]):
    df[categorical_feature].value_counts().plot("bar", ax=ax[i]).set_title(categorical_feature)
fig.show()

enter image description here

Rebasing a Git merge commit

Given that I just lost a day trying to figure this out and actually found a solution with the help of a coworker, I thought I should chime in.

We have a large code base and we have to deal with 2 branch heavily being modified at the same time. There is a main branch and a secondary branch if you which.

While I merge the secondary branch into the main branch, work continues in the main branch and by the time i'm done, I can't push my changes because they are incompatible.

I therefore need to "rebase" my "merge".

This is how we finally did it :

1) make note of the SHA. ex.: c4a924d458ea0629c0d694f1b9e9576a3ecf506b

git log -1

2) Create the proper history but this will break the merge.

git rebase -s ours --preserve-merges origin/master

3) make note of the SHA. ex.: 29dd8101d78

git log -1

4) Now reset to where you were before

git reset c4a924d458ea0629c0d694f1b9e9576a3ecf506b --hard

5) Now merge the current master into your working branch

git merge origin/master
git mergetool
git commit -m"correct files

6) Now that you have the right files, but the wrong history, get the right history on top of your change with :

git reset 29dd8101d78 --soft

7) And then --amend the results in your original merge commit

git commit --amend

Voila!

How to export JSON from MongoDB using Robomongo

Robomongo's shell functionality will solve the problem. In my case I needed couple of columns as CSV format.

var cursor = db.getCollection('Member_details').find({Category: 'CUST'},{CustomerId :1,Name :1,_id:0})

while (cursor.hasNext()) {
    var record = cursor.next();   
    print(record.CustomerID + "," + record.Name)
}

Output : -------

334, Harison
433, Rechard
453, Michel
533, Pal

Serializing enums with Jackson

Here is my solution. I want transform enum to {id: ..., name: ...} form.

With Jackson 1.x:

pom.xml:

<properties>
    <jackson.version>1.9.13</jackson.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-core-asl</artifactId>
        <version>${jackson.version}</version>
    </dependency>
    <dependency>
        <groupId>org.codehaus.jackson</groupId>
        <artifactId>jackson-mapper-asl</artifactId>
        <version>${jackson.version}</version>
    </dependency>
</dependencies>

Rule.java:

import org.codehaus.jackson.map.annotate.JsonSerialize;
import my.NamedEnumJsonSerializer;
import my.NamedEnum;

@Entity
@Table(name = "RULE")
public class Rule {
    @Column(name = "STATUS", nullable = false, updatable = true)
    @Enumerated(EnumType.STRING)
    @JsonSerialize(using = NamedEnumJsonSerializer.class)
    private Status status;
    public Status getStatus() { return status; }
    public void setStatus(Status status) { this.status = status; }

    public static enum Status implements NamedEnum {
        OPEN("open rule"),
        CLOSED("closed rule"),
        WORKING("rule in work");

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

NamedEnum.java:

package my;

public interface NamedEnum {
    String name();
    String getName();
}

NamedEnumJsonSerializer.java:

package my;

import my.NamedEnum;
import java.io.IOException;
import java.util.*;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.JsonSerializer;
import org.codehaus.jackson.map.SerializerProvider;

public class NamedEnumJsonSerializer extends JsonSerializer<NamedEnum> {
    @Override
    public void serialize(NamedEnum value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
        Map<String, String> map = new HashMap<>();
        map.put("id", value.name());
        map.put("name", value.getName());
        jgen.writeObject(map);
    }
}

With Jackson 2.x:

pom.xml:

<properties>
    <jackson.version>2.3.3</jackson.version>
</properties>

<dependencies>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>${jackson.version}</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>${jackson.version}</version>
    </dependency>
</dependencies>

Rule.java:

import com.fasterxml.jackson.annotation.JsonFormat;

@Entity
@Table(name = "RULE")
public class Rule {
    @Column(name = "STATUS", nullable = false, updatable = true)
    @Enumerated(EnumType.STRING)
    private Status status;
    public Status getStatus() { return status; }
    public void setStatus(Status status) { this.status = status; }

    @JsonFormat(shape = JsonFormat.Shape.OBJECT)
    public static enum Status {
        OPEN("open rule"),
        CLOSED("closed rule"),
        WORKING("rule in work");

        private String name;
        Status(String name) { this.name = name; }
        public String getName() { return this.name; }
        public String getId() { return this.name(); }
    };
}

Rule.Status.CLOSED translated to {id: "CLOSED", name: "closed rule"}.

GC overhead limit exceeded

From Java SE 6 HotSpot[tm] Virtual Machine Garbage Collection Tuning

the following

Excessive GC Time and OutOfMemoryError

The concurrent collector will throw an OutOfMemoryError if too much time is being spent in garbage collection: if more than 98% of the total time is spent in garbage collection and less than 2% of the heap is recovered, an OutOfMemoryError will be thrown. This feature is designed to prevent applications from running for an extended period of time while making little or no progress because the heap is too small. If necessary, this feature can be disabled by adding the option -XX:-UseGCOverheadLimit to the command line.

The policy is the same as that in the parallel collector, except that time spent performing concurrent collections is not counted toward the 98% time limit. In other words, only collections performed while the application is stopped count toward excessive GC time. Such collections are typically due to a concurrent mode failure or an explicit collection request (e.g., a call to System.gc()).

in conjunction with a passage further down

One of the most commonly encountered uses of explicit garbage collection occurs with RMIs distributed garbage collection (DGC). Applications using RMI refer to objects in other virtual machines. Garbage cannot be collected in these distributed applications without occasionally collection the local heap, so RMI forces full collections periodically. The frequency of these collections can be controlled with properties. For example,

java -Dsun.rmi.dgc.client.gcInterval=3600000

-Dsun.rmi.dgc.server.gcInterval=3600000 specifies explicit collection once per hour instead of the default rate of once per minute. However, this may also cause some objects to take much longer to be reclaimed. These properties can be set as high as Long.MAX_VALUE to make the time between explicit collections effectively infinite, if there is no desire for an upper bound on the timeliness of DGC activity.

Seems to imply that the evaluation period for determining the 98% is one minute long, but it might be configurable on Sun's JVM with the correct define.

Of course, other interpretations are possible.

Line break in HTML with '\n'

You can use CSS white-space property for \n. You can also preserve the tabs as in \t.

For line break \n:

white-space: pre-line;

For line break \n and tabs \t:

white-space: pre-wrap;

_x000D_
_x000D_
document.getElementById('just-line-break').innerHTML = 'Testing 1\nTesting 2\n\tNo tab';_x000D_
_x000D_
document.getElementById('line-break-and-tab').innerHTML = 'Testing 1\nTesting 2\n\tWith tab';
_x000D_
#just-line-break {_x000D_
  white-space: pre-line;_x000D_
}_x000D_
_x000D_
#line-break-and-tab {_x000D_
  white-space: pre-wrap;_x000D_
}
_x000D_
<div id="just-line-break"></div>_x000D_
_x000D_
<br/>_x000D_
_x000D_
<div id="line-break-and-tab"></div>
_x000D_
_x000D_
_x000D_

Heroku deployment error H10 (App crashed)

I had the same problem, I did the following

heroku run rails c

It identified a syntax error and missing comma within a controller permitted params. As mentioned above the Heroku logs did not provide sufficient information to problem solve the problem.

I have not seen the application crashed message on Heroku previously.

How to convert signed to unsigned integer in python

Python doesn't have builtin unsigned types. You can use mathematical operations to compute a new int representing the value you would get in C, but there is no "unsigned value" of a Python int. The Python int is an abstraction of an integer value, not a direct access to a fixed-byte-size integer.

How to check if a given directory exists in Ruby

You could use Kernel#test:

test ?d, 'some directory'

it gets it's origins from https://ss64.com/bash/test.html you will notice bash test has this flag -d to test if a directory exists -d file True if file is a Directory. [[ -d demofile ]]

Using Jquery Ajax to retrieve data from Mysql

Please make sure your $row[1] , $row[2] contains correct value, we do assume here that 1 = Name , and 2 here is your Address field ?

Assuming you have correctly fetched your records from your Records.php, You can do something like this:

$(document).ready(function()
{
    $('#getRecords').click(function()
    {
        var response = '';
        $.ajax({ type: 'POST',   
                 url: "Records.php",   
                 async: false,
                 success : function(text){
                               $('#table1').html(text);
                           }
           });
    });

}

In your HTML

<table id="table1"> 
    //Let jQuery AJAX Change This Text  
</table>
<button id='getRecords'>Get Records</button>

A little note:

Try learing PDO http://php.net/manual/en/class.pdo.php since mysql_* functions are no longer encouraged..

Text-align class for inside a table

You can use this CSS below:

.text-right {text-align: right} /* For right align */
.text-left {text-align: left} /* For left align */
.text-center {text-align: center} /* For center align */

SQL select join: is it possible to prefix all columns as 'prefix.*'?

The only database I know that does this is SQLite, depending on the settings you configure with PRAGMA full_column_names and PRAGMA short_column_names. See http://www.sqlite.org/pragma.html

Otherwise all I can recommend is to fetch columns in a result set by ordinal position rather than by column name, if it's too much trouble for you to type the names of the columns in your query.

This is a good example of why it's bad practice to use SELECT * -- because eventually you'll have a need to type out all the column names anyway.

I understand the need to support columns that may change name or position, but using wildcards makes that harder, not easier.

Hive insert query like SQL

To insert entire data of table2 in table1. Below is a query:

INSERT INTO TABLE table1 SELECT * FROM table2; 

Python - Extracting and Saving Video Frames

After a lot of research on how to convert frames to video I have created this function hope this helps. We require opencv for this:

import cv2
import numpy as np
import os

def frames_to_video(inputpath,outputpath,fps):
   image_array = []
   files = [f for f in os.listdir(inputpath) if isfile(join(inputpath, f))]
   files.sort(key = lambda x: int(x[5:-4]))
   for i in range(len(files)):
       img = cv2.imread(inputpath + files[i])
       size =  (img.shape[1],img.shape[0])
       img = cv2.resize(img,size)
       image_array.append(img)
   fourcc = cv2.VideoWriter_fourcc('D', 'I', 'V', 'X')
   out = cv2.VideoWriter(outputpath,fourcc, fps, size)
   for i in range(len(image_array)):
       out.write(image_array[i])
   out.release()


inputpath = 'folder path'
outpath =  'video file path/video.mp4'
fps = 29
frames_to_video(inputpath,outpath,fps)

change the value of fps(frames per second),input folder path and output folder path according to your own local locations

(413) Request Entity Too Large | uploadReadAheadSize

This helped me to resolve the problem (one line - split for readability / copy-ability):

C:\Windows\System32\inetsrv\appcmd  set config "YOUR_WEBSITE_NAME" 
     -section:system.webServer/serverRuntime /uploadReadAheadSize:"2147483647" 
     /commit:apphost

Double free or corruption after queue::push

You can also try to check null before delete such that

if(myArray) { delete[] myArray; myArray = NULL; }

or you can define all delete operations ina safe manner like this:

#ifndef SAFE_DELETE
#define SAFE_DELETE(p) { if(p) { delete (p); (p) = NULL; } }
#endif

#ifndef SAFE_DELETE_ARRAY
#define SAFE_DELETE_ARRAY(p) { if(p) { delete[] (p); (p) = NULL; } }
#endif

and then use

SAFE_DELETE_ARRAY(myArray);

How to add spacing between UITableViewCell

The way I achieve adding spacing between cells is to make numberOfSections = "Your array count" and make each section contains only one row. And then define headerView and its height.

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return yourArry.count;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 1;
}

-(CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    return cellSpacingHeight;
}

-(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    UIView *v = [UIView new];
    [v setBackgroundColor:[UIColor clearColor]];
    return v;
}

Oracle select most recent date record

you can't use aliases from select list inside the WHERE clause (because of the Order of Evaluation of a SELECT statement)

also you cannot use OVER clause inside WHERE clause - "You can specify analytic functions with this clause in the select list or ORDER BY clause." (citation from docs.oracle.com)

select *
from (select
  staff_id, site_id, pay_level, date, 
  max(date) over (partition by staff_id) max_date
  from owner.table
  where end_enrollment_date is null
)
where date = max_date

Is there a Sleep/Pause/Wait function in JavaScript?

You need to re-factor the code into pieces. This doesn't stop execution, it just puts a delay in between the parts.

function partA() {
  ...
  window.setTimeout(partB,1000);
}

function partB() {
   ...
}

How to remove non-alphanumeric characters?

here's a really simple regex for that:

\W|_

and used as you need it (with a forward / slash delimiter).

preg_replace("/\W|_/", '', $string);

Test it here with this great tool that explains what the regex is doing:

http://www.regexr.com/

How to divide two columns?

Presumably, those columns are integer columns - which will be the reason as the result of the calculation will be of the same type.

e.g. if you do this:

SELECT 1 / 2

you will get 0, which is obviously not the real answer. So, convert the values to e.g. decimal and do the calculation based on that datatype instead.

e.g.

SELECT CAST(1 AS DECIMAL) / 2

gives 0.500000

what is Array.any? for javascript

JavaScript has the Array.prototype.some() method:

[1, 2, 3].some((num) => num % 2 === 0);  

returns true because there's (at least) one even number in the array.

In general, the Array class in JavaScript's standard library is quite poor compared to Ruby's Enumerable. There's no isEmpty method and .some() requires that you pass in a function or you'll get an undefined is not a function error. You can define your own .isEmpty() as well as a .any() that is closer to Ruby's like this:

Array.prototype.isEmpty = function() {
    return this.length === 0;
}

Array.prototype.any = function(func) {
   return this.some(func || function(x) { return x });
}

Libraries like underscore.js and lodash provide helper methods like these, if you're used to Ruby's collection methods, it might make sense to include them in your project.

Use of document.getElementById in JavaScript

document.getElementById("demo").innerHTML = voteable finds the element with the id demo and then places the voteable value into it; either too young or old enough.

So effectively <p id="demo"></p> becomes for example <p id="demo">Old Enough</p>

Animate a custom Dialog

I've been struggling with Dialog animation today, finally got it working using styles, so here is an example.

To start with, the most important thing — I probably had it working 5 different ways today but couldn't tell because... If your devices animation settings are set to "No Animations" (Settings ? Display ? Animation) then the dialogs won't be animated no matter what you do!

The following is a stripped down version of my styles.xml. Hopefully it is self-explanatory. This should be located in res/values.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="PauseDialog" parent="@android:style/Theme.Dialog">
        <item name="android:windowAnimationStyle">@style/PauseDialogAnimation</item>
    </style>

    <style name="PauseDialogAnimation">
        <item name="android:windowEnterAnimation">@anim/spin_in</item>
        <item name="android:windowExitAnimation">@android:anim/slide_out_right</item>
    </style>
</resources>

The windowEnterAnimation is one of my animations and is located in res\anim. The windowExitAnimation is one of the animations that is part of the Android SDK.

Then when I create the Dialog in my activities onCreateDialog(int id) method I do the following.

Dialog dialog = new Dialog(this, R.style.PauseDialog);

// Setting the title and layout for the dialog
dialog.setTitle(R.string.pause_menu_label);
dialog.setContentView(R.layout.pause_menu);

Alternatively you could set the animations the following way instead of using the Dialog constructor that takes a theme.

Dialog dialog = new Dialog(this);
dialog.getWindow().getAttributes().windowAnimations = R.style.PauseDialogAnimation;

How to remove unused imports in Intellij IDEA on commit?

If you are using IntelliJ IDEA or Android Studio:

Android optimize imports

Go to Settings > Editor > General >Auto Import and check the Optimize imports on the fly checkbox.

CSS background image URL failing to load

Source location should be the URL (relative to the css file or full web location), not a file system full path, for example:

background: url("http://localhost/media/css/static/img/sprites/buttons-v3-10.png");
background: url("static/img/sprites/buttons-v3-10.png");

Alternatively, you can try to use file:/// protocol prefix.

"You may need an appropriate loader to handle this file type" with Webpack and Babel

BABEL TEAM UPDATE:

We're super excited that you're trying to use ES2015 syntax, but instead of continuing yearly presets, the team recommends using babel-preset-env. By default, it has the same behavior as previous presets to compile ES2015+ to ES5

If you are using Babel version 7 you will need to run npm install @babel/preset-env and have "presets": ["@babel/preset-env"] in your .babelrc configuration.

This will compile all latest features to es5 transpiled code:

Prerequisites:

  1. Webpack 4+
  2. Babel 7+

Step-1:: npm install --save-dev @babel/preset-env

Step-2: In order to compile JSX code to es5 babel provides @babel/preset-react package to convert reactjsx extension file to native browser understandable code.

Step-3: npm install --save-dev @babel/preset-react

Step-4: create .babelrc file inside root path path of your project where webpack.config.js exists.

{
  "presets": ["@babel/preset-env", "@babel/preset-react"]
}

Step-5: webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
    mode: 'development',
    entry: path.resolve(__dirname, 'src/index.js'),
    output: {
        path: path.resolve(__dirname, 'output'),
        filename: 'bundle.js'
    },
    resolve: {
        extensions: ['.js', '.jsx']
    },
    module: {
        rules: [{
                test: /\.(js|jsx)$/,
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader'
                }
            },
            {
                test: /\.css$/i,
                use: ['style-loader', 'css-loader'],
            }
        ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: "./public/index.html",
            filename: "./index.html"
         })
    ]
}

Finding longest string in array

If your string is already split into an array, you'll not need the split part.

function findLongestWord(str) {
  str = str.split(' ');
  var longest = 0;

  for(var i = 0; i < str.length; i++) {
     if(str[i].length >= longest) {
       longest = str[i].length;
        } 
     }
  return longest;
}
findLongestWord("The quick brown fox jumped over the lazy dog");

How npm start runs a server on port 8000

You can change the port in the console by running the following on Windows:

SET PORT=8000

For Mac, Linux or Windows WSL use the following:

export PORT=8000

The export sets the environment variable for the current shell and all child processes like npm that might use it.

If you want the environment variable to be set just for the npm process, precede the command with the environment variable like this (on Mac and Linux and Windows WSL):

PORT=8000 npm run start

How to remove the first and the last character of a string

You could regex it:

"string".replace(/^\/?|\/?$/, "")
"/installers/services/".replace(/^\/?|\/?$/, "") // -> installers/services

The regex explained:
- Optional first slash: ^/?, escaped -> ^\/? (the ^ means beginning of string)
- The pipe ( | ) can be read as or
- Than the option slash at the end -> /?$, escaped -> \/?$ ( the $ means end of string)

Combined it would be ^/?|/$ without escaping. Optional first slash OR optional last slash

bootstrap 4 file input doesn't show the file name

This works with Bootstrap 4.1.3:

<script>
    $("input[type=file]").change(function () {
        var fieldVal = $(this).val();

        // Change the node's value by removing the fake path (Chrome)
        fieldVal = fieldVal.replace("C:\\fakepath\\", "");

        if (fieldVal != undefined || fieldVal != "") {
            $(this).next(".custom-file-label").attr('data-content', fieldVal);
            $(this).next(".custom-file-label").text(fieldVal);
        }
    });
</script>

How to force reloading php.ini file?

TL;DR; If you're still having trouble after restarting apache or nginx, also try restarting the php-fpm service.

The answers here don't always satisfy the requirement to force a reload of the php.ini file. On numerous occasions I've taken these steps to be rewarded with no update, only to find the solution I need after also restarting the php-fpm service. So if restarting apache or nginx doesn't trigger a php.ini update although you know the files are updated, try restarting php-fpm as well.

To restart the service:

Note: prepend sudo if not root

Using SysV Init scripts directly:

/etc/init.d/php-fpm restart        # typical
/etc/init.d/php5-fpm restart       # debian-style
/etc/init.d/php7.0-fpm restart     # debian-style PHP 7

Using service wrapper script

service php-fpm restart        # typical
service php5-fpm restart       # debian-style
service php7.0-fpm restart.    # debian-style PHP 7

Using Upstart (e.g. ubuntu):

restart php7.0-fpm         # typical (ubuntu is debian-based) PHP 7
restart php5-fpm           # typical (ubuntu is debian-based)
restart php-fpm            # uncommon

Using systemd (newer servers):

systemctl restart php-fpm.service        # typical
systemctl restart php5-fpm.service       # uncommon
systemctl restart php7.0-fpm.service     # uncommon PHP 7

Or whatever the equivalent is on your system.

The above commands taken directly from this server fault answer

SQL get the last date time record

SELECT TOP 1 * FROM foo ORDER BY Dates DESC

Will return one result with the latest date.

SELECT * FROM foo WHERE foo.Dates = (SELECT MAX(Dates) FROM foo)

Will return all results that have the same maximum date, to the milissecond.

This is for SQL Server. I'll leave it up to you to use the DATEPART function if you want to use dates but not times.

JPA or JDBC, how are they different?

JDBC is the predecessor of JPA.

JDBC is a bridge between the Java world and the databases world. In JDBC you need to expose all dirty details needed for CRUD operations, such as table names, column names, while in JPA (which is using JDBC underneath), you also specify those details of database metadata, but with the use of Java annotations.

So JPA creates update queries for you and manages the entities that you looked up or created/updated (it does more as well).

If you want to do JPA without a Java EE container, then Spring and its libraries may be used with the very same Java annotations.

Decimal or numeric values in regular expression validation

A digit in the range 1-9 followed by zero or more other digits:

^[1-9]\d*$

To allow numbers with an optional decimal point followed by digits. A digit in the range 1-9 followed by zero or more other digits then optionally followed by a decimal point followed by at least 1 digit:

^[1-9]\d*(\.\d+)?$

Notes:

  • The ^ and $ anchor to the start and end basically saying that the whole string must match the pattern

  • ()? matches 0 or 1 of the whole thing between the brackets

Update to handle commas:

In regular expressions . has a special meaning - match any single character. To match literally a . in a string you need to escape the . using \. This is the meaning of the \. in the regexp above. So if you want to use comma instead the pattern is simply:

^[1-9]\d*(,\d+)?$

Further update to handle commas and full stops

If you want to allow a . between groups of digits and a , between the integral and the fractional parts then try:

^[1-9]\d{0,2}(\.\d{3})*(,\d+)?$

i.e. this is a digit in the range 1-9 followed by up to 2 other digits then zero or more groups of a full stop followed by 3 digits then optionally your comma and digits as before.

If you want to allow a . anywhere between the digits then try:

^[1-9][\.\d]*(,\d+)?$

i.e. a digit 1-9 followed by zero or more digits or full stops optionally followed by a comma and one or more digits.

Can I clear cell contents without changing styling?

You should use the ClearContents method if you want to clear the content but preserve the formatting.

Worksheets("Sheet1").Range("A1:G37").ClearContents

How to search if dictionary value contains certain string with Python

Klaus solution has less overhead, on the other hand this one may be more readable

myDict = {'age': ['12'], 'address': ['34 Main Street, 212 First Avenue'],
          'firstName': ['Alan', 'Mary-Ann'], 'lastName': ['Stone', 'Lee']}

def search(myDict, lookup):
    for key, value in myDict.items():
        for v in value:
            if lookup in v:
                return key

search(myDict, 'Mary')

Leave out quotes when copying from cell

If you try pasting into Word-Pad, Notepad++ or Word you wouldn't have this issue. To copy the cell value as pure text, to achieve what you describe you have to use a macro:

In the workbook where you want this to apply (or in your Personal.xls if you want to use across several workbooks), place the following code in a standard module:

Code:

Sub CopyCellContents()
'create a reference in the VBE to Microsft Forms 2.0 Lib
' do this by (in VBA editor) clicking tools - > references and then ticking "Microsoft Forms 2.0 Library"
Dim objData As New DataObject
Dim strTemp As String
strTemp = ActiveCell.Value
objData.SetText (strTemp)
objData.PutInClipboard
End Sub

To add a standard module to your project (workbook), open up the VBE with Alt+F11 and then right-click on your workbook in the top left Project Window and select Insert>Module. Paste the code into the code module window which will open on the right.

Back in Excel, go Tools>Macro>Macros and select the macro called "CopyCellContents" and then choose Options from the dialog. Here you can assign the macro to a shortcut key (eg like CTRL+C for normal copy) - I used CTRL+Q.

Then, when you want to copy a single cell over to Notepad/wherever, just do Ctrl+q (or whatever you chose) and then do a CTRL+V or Edit>Paste in your chosen destination.

My answer is copied (with a few additions) from: here

EDIT: (from comments)

If you don't find Microsoft Forms 2.0 Library in the references list, You can try

  • looking for FM20.DLL instead (thanks @Peter Smallwood)
  • clicking Browse and selecting C:\Windows\System32\FM20.dll (32 bit Windows) (thanks @JWhy)
  • clicking Browse and selecting C:\Windows\SysWOW64\FM20.dll (on 64-bit)

How to parse a CSV in a Bash script?

In a CSV file, each field is separated by a comma. The problem is, a field itself might have an embedded comma:

Name,Phone
"Woo, John",425-555-1212

You really need a library package that offer robust CSV support instead of relying on using comma as a field separator. I know that scripting languages such as Python has such support. However, I am comfortable with the Tcl scripting language so that is what I use. Here is a simple Tcl script which does what you are asking for:

#!/usr/bin/env tclsh

package require csv 
package require Tclx

# Parse the command line parameters
lassign $argv fileName columnNumber expectedValue

# Subtract 1 from columnNumber because Tcl's list index starts with a
# zero instead of a one
incr columnNumber -1

for_file line $fileName {
    set columns [csv::split $line]
    set columnValue [lindex $columns $columnNumber]
    if {$columnValue == $expectedValue} {
        puts $line
    }   
}

Save this script to a file called csv.tcl and invoke it as:

$ tclsh csv.tcl filename indexNumber expectedValue

Explanation

The script reads the CSV file line by line and store the line in the variable $line, then it split each line into a list of columns (variable $columns). Next, it picks out the specified column and assigned it to the $columnValue variable. If there is a match, print out the original line.

Remove HTML Tags in Javascript with Regex

<html>
<head>
<script type="text/javascript">
function striptag(){
var html = /(<([^>]+)>)/gi;
for (i=0; i < arguments.length; i++)
arguments[i].value=arguments[i].value.replace(html, "")
}
</script>
</head> 
<body>
       <form name="myform">
<textarea class="comment" title="comment" name=comment rows=4 cols=40></textarea><br>
<input type="button" value="Remove HTML Tags" onClick="striptag(this.form.comment)">
</form>
</body>
</html>

Need a row count after SELECT statement: what's the optimal SQL approach?

Here are some ideas:

  • Go with Approach #1 and resize the array to hold additional results or use a type that automatically resizes as neccessary (you don't mention what language you are using so I can't be more specific).
  • You could execute both statements in Approach #1 within a transaction to guarantee the counts are the same both times if your database supports this.
  • I'm not sure what you are doing with the data but if it is possible to process the results without storing all of them first this might be the best method.