Programs & Examples On #Publisher

My eclipse won't open, i download the bundle pack it keeps saying error log

Make sure you have the prerequisite, a JVM (http://wiki.eclipse.org/Eclipse/Installation#Install_a_JVM) installed.

This will be a JRE and JDK package.

There are a number of sources which includes: http://www.oracle.com/technetwork/java/javase/downloads/index.html.

Removing space from dataframe columns in pandas

  • To remove white spaces:

1) To remove white space everywhere:

df.columns = df.columns.str.replace(' ', '')

2) To remove white space at the beginning of string:

df.columns = df.columns.str.lstrip()

3) To remove white space at the end of string:

df.columns = df.columns.str.rstrip()

4) To remove white space at both ends:

df.columns = df.columns.str.strip()
  • To replace white spaces with other characters (underscore for instance):

5) To replace white space everywhere

df.columns = df.columns.str.replace(' ', '_')

6) To replace white space at the beginning:

df.columns = df.columns.str.replace('^ +', '_')

7) To replace white space at the end:

df.columns = df.columns.str.replace(' +$', '_')

8) To replace white space at both ends:

df.columns = df.columns.str.replace('^ +| +$', '_')

All above applies to a specific column as well, assume you have a column named col, then just do:

df[col] = df[col].str.strip()  # or .replace as above

Android Studio Error: Error:CreateProcess error=216, This version of %1 is not compatible with the version of Windows you're running

Don't worry... Its much easy to solve your problem. Just SET you SDK-LOCATION and JDK-LOCATION.

  • Click on Configure ( As Soon Android studio open )
  • Click Project Default
  • Click Project Structure
  • Clik Android Sdk Location

  • Select & Browse your Android SDK Location (Like: C:\Android\sdk)

  • Uncheck USE EMBEDDED JDK LOCATION

  • Set & Browse JDK Location, Like C:\Program Files\Java\jdk1.8.0_121

failed to load ad : 3

I hadn't published a version of my app with ads yet.

I was seeing error code 3: ERROR_CODE_NO_FILL after I switched from emulators with a debug version to a real device with the release version (installed through adb shell commands).

I waited 12+ hours and I could see ad requests on the AdMob portal, but no matches (match rate of 0%). I went to the Play Console > Store Presence > Pricing & distribution and switched the radio button for Contains ads to Yes, it has ads. I even tried uploading my app bundle (without publishing) to the Play Console. Neither of these worked.

Various AdMob help articles (including the one linked below) mention that if you've been seeing test ads (ads labeled with "Test Ad"), then your code is working and real ads should work as expected (once they build up inventory).

With that in mind, I went ahead and published my app to the Play Store and once the update was live, I downloaded it via the Play Store app on my real phone and the ads loaded no problem and my match rate is now sitting at 66% on AdMob. From the AdMob FAQ article, it sounds like it typically takes a few hours and could have taken up to 24 hours for ads to start showing.

ad mob FAQ re: how long does it take ads to show

Source: https://support.google.com/admob/answer/2993019?hl=en

IIS Manager in Windows 10

Thanks to @SLaks comment above I was able to turn on IIS and bring the manager back.

Press the Windows Key and type Windows Features, select the first entry Turn Windows Features On or Off.

Make sure the box next to IIS is checked.

enter image description here

If it is not checked, check it. This might take a few minutes, but this will install everything you need to use IIS.

When it is done, IIS should have returned to Control Panel > Administrative Tools

enter image description here

Django: OperationalError No Such Table

I'm using Django 1.9, SQLite3 and DjangoCMS 3.2 and had the same issue. I solved it by running python manage.py makemigrations. This was followed by a prompt stating that the database contained non-null value types but did not have a default value set. It gave me two options: 1) select a one off value now or 2) exit and change the default setting in models.py. I selected the first option and gave the default value of 1. Repeated this four or five times until the prompt said it was finished. I then ran python manage.py migrate. Now it works just fine. Remember, by running python manage.py makemigrations first, a revised copy of the database is created (mine was 0004) and you can always revert back to a previous database state.

Joining Multiple Tables - Oracle

I recommend that you get in the habit, right now, of using ANSI-style joins, meaning you should use the INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, FULL OUTER JOIN, and CROSS JOIN elements in your SQL statements rather than using the "old-style" joins where all the tables are named together in the FROM clause and all the join conditions are put in the the WHERE clause. ANSI-style joins are easier to understand and less likely to be miswritten and/or misinterpreted than "old-style" joins.

I'd rewrite your query as:

SELECT bc.firstname,
       bc.lastname,
       b.title,
       TO_CHAR(bo.orderdate, 'MM/DD/YYYY') "Order Date",
       p.publishername
FROM BOOK_CUSTOMER bc
INNER JOIN books b
  ON b.BOOK_ID = bc.BOOK_ID
INNER JOIN  book_order bo
  ON bo.BOOK_ID = b.BOOK_ID
INNER JOIN publisher p
  ON p.PUBLISHER_ID = b.PUBLISHER_ID
WHERE p.publishername = 'PRINTING IS US';

Share and enjoy.

How to check if a row exists in MySQL? (i.e. check if an email exists in MySQL)

After validation and before INSERT check if username already exists, using mysqli(procedural). This works:

//check if username already exists
       include 'phpscript/connect.php'; //connect to your database

       $sql = "SELECT username FROM users WHERE username = '$username'";
       $result = $conn->query($sql);

       if($result->num_rows > 0) {
           $usernameErr =  "username already taken"; //takes'em back to form
       } else { // go on to INSERT new record

Error 1920 service failed to start. Verify that you have sufficient privileges to start system services

Check service dependencies if they are disabled.

Set those dependencies to Automatic, Start them and it should work.

How to push changes to github after jenkins build completes?

I followed the below Steps. It worked for me.

In Jenkins execute shell under Build, creating a file and trying to push that file from Jenkins workspace to GitHub.

enter image description here

Download Git Publisher Plugin and Configure as shown below snapshot.

enter image description here

Click on Save and Build. Now you can check your git repository whether the file was pushed successfully or not.

How to sort an array of objects in Java?

Sometimes you want to sort an array of objects on an arbitrary value. Since compareTo() always uses the same information about the instance, you might want to use a different technique. One way is to use a standard sorting algorithm. Let's say you have an array of books and you want to sort them on their height, which is stored as an int and accessible through the method getHeight(). Here's how you could sort the books in your array. (If you don't want to change the original array, simply make a copy and sort that.)

`int tallest; // the index of tallest book found thus far
 Book temp; // used in the swap
 for(int a = 0; a < booksArray.length - 1; a++) {
   tallest = a; // reset tallest to current index
   // start inner loop at next index
   for(int b = a + 1; b < booksArray.length; b++)
     // check if the book at this index is taller than the
     // tallest found thus far
     if(booksArray[b].getHeight() > booksArray[tallest].getHeight())
       tallest = b;
   // once inner loop is complete, swap the tallest book found with
   // the one at the current index of the outer loop
   temp = booksArray[a];
   booksArray[a] = booksArray[tallest];
   booksArray[tallest] = temp;
 }`

When this code is done, the array of Book object will be sorted by height in descending order--an interior designer's dream!

There are no primary or candidate keys in the referenced table that match the referencing column list in the foreign key

Another thing is - if your keys are very complicated sometimes you need to replace the places of the fields and it helps :

if this dosent work:

foreign key (ISBN, Title) references BookTitle (ISBN, Title)

Then this might work (not for this specific example but in general) :

foreign key (Title,ISBN) references BookTitle (Title,ISBN)

How can I enable Assembly binding logging?

  1. Create a new Application Pool

  2. Go to the Advanced Settings of this application pool

  3. Set the Enable 32-Bit Application to True

  4. Point your web application to use this new Pool

Screenshot (IIS-ApplicationPool)

An Authentication object was not found in the SecurityContext - Spring 3.2.2

This could also happens if you put a @PreAuthorize or @PostAuthorize in a Bean in creation. I would recommend to move such annotations to methods of interest.

IFrame: This content cannot be displayed in a frame

use <meta http-equiv="X-Frame-Options" content="allow"> in the one to show in the iframe to allow it.

How to make Sonar ignore some classes for codeCoverage metric?

When using sonar-scanner for swift, use sonar.coverage.exclusions in your sonar-project.properties to exclude any file for only code coverage. If you want to exclude files from analysis as well, you can use sonar.exclusions. This has worked for me in swift

sonar.coverage.exclusions=**/*ViewController.swift,**/*Cell.swift,**/*View.swift

How to maintain page scroll position after a jquery event is carried out?

Try the code below to prevent the default behaviour scrolling back to the top of the page

$(document).ready(function() {   
  $('.galleryicon').live("click", function(e) {  // the (e) represent the event
    $('#mainImage').hide();     
    $('#cakebox').css('background-image', "url('ajax-loader.gif')");     
    var i = $('<img />').attr('src',this.href).load(function() {         
      $('#mainImage').attr('src', i.attr('src'));         
      $('#cakebox').css('background-image', 'none');         
      $('#mainImage').fadeIn();     
    });
  e.preventDefault(); //Prevent default click action which is causing the 
  return false;       //page to scroll back to the top
  });  
});

For more information on event.preventDefault() have a look here at the official documentation.

Why is my locally-created script not allowed to run under the RemoteSigned execution policy?

What works for me was right-click on the .ps1 file and then properties. Click the "UNBLOCK" button. Works great fir me after spending hours trying to change the policies.

The source was not found, but some or all event logs could not be searched

Launch Developer command line "As an Administrator". This account has full access to Security log

What precisely does 'Run as administrator' do?

UPDATE

"Run as Aministrator" is just a command, enabling the program to continue some operations that require the Administrator privileges, without displaying the UAC alerts.

Even if your user is a member of administrators group, some applications like yours need the Administrator privileges to continue running, because the application is considered not safe, if it is doing some special operation, like editing a system file or something else. This is the reason why Windows needs the Administrator privilege to execute the application and it notifies you with a UAC alert. Not all applications need an Amnistrator account to run, and some applications, like yours, need the Administrator privileges.

If you execute the application with 'run as administrator' command, you are notifying the system that your application is safe and doing something that requires the administrator privileges, with your confirm.

If you want to avoid this, just disable the UAC on Control Panel.

If you want to go further, read the question Difference between "Run as Administrator" and Windows 7 Administrators Group on Microsoft forum or this SuperUser question.

How do I detect whether 32-bit Java is installed on x64 Windows, only looking at the filesystem and registry?

If it is not Oracle's Java, you may not be able to tell. When I install Oracle Java 64-bit, the files go into C:\Program Files\Java, but when I install a 32-bit version, they default to C:\Program Files (x86)\Java instead. Of course, the person who installed Java could have overridden those defaults.

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

That method was added in Servlet 2.5.

So this problem can have at least 3 causes:

  1. The servlet container does not support Servlet 2.5.
  2. The web.xml is not declared conform Servlet 2.5 or newer.
  3. The webapp's runtime classpath is littered with servlet container specific JAR files of a different servlet container make/version which does not support Servlet 2.5.

To solve it,

  1. Make sure that your servlet container supports at least Servlet 2.5. That are at least Tomcat 6, Glassfish 2, JBoss AS 4.1, etcetera. Tomcat 5.5 for example supports at highest Servlet 2.4. If you can't upgrade Tomcat, then you'd need to downgrade Spring to a Servlet 2.4 compatible version.
  2. Make sure that the root declaration of web.xml complies Servlet 2.5 (or newer, at least the highest whatever your target runtime supports). For an example, see also somewhere halfway our servlets wiki page.
  3. Make sure that you don't have any servlet container specific libraries like servlet-api.jar or j2ee.jar in /WEB-INF/lib or even worse, the JRE/lib or JRE/lib/ext. They do not belong there. This is a pretty common beginner's mistake in an attempt to circumvent compilation errors in an IDE, see also How do I import the javax.servlet API in my Eclipse project?.

How to mark a build unstable in Jenkins when running shell scripts

In my job script, I have the following statements (this job only runs on the Jenkins master):

# This is the condition test I use to set the build status as UNSTABLE
if [ ${PERCENTAGE} -gt 80 -a ${PERCENTAGE} -lt 90 ]; then
  echo WARNING: disc usage percentage above 80%

  # Download the Jenkins CLI JAR:
  curl -o jenkins-cli.jar ${JENKINS_URL}/jnlpJars/jenkins-cli.jar

  # Set build status to unstable
  java -jar jenkins-cli.jar -s ${JENKINS_URL}/ set-build-result unstable

fi

You can see this and a lot more information about setting build statuses on the Jenkins wiki: https://wiki.jenkins-ci.org/display/JENKINS/Jenkins+CLI

Multiple SQL joins

 SELECT
 B.Title, B.Edition, B.Year, B.Pages, B.Rating     --from Books
, C.Category                                        --from Categories
, P.Publisher                                       --from Publishers
, W.LastName                                        --from Writers

FROM Books B

JOIN Categories_Books CB ON B._ISBN = CB._Books_ISBN
JOIN Categories_Books CB ON CB.__Categories_Category_ID = C._CategoryID
JOIN Publishers P ON B.PublisherID = P._Publisherid
JOIN Writers_Books WB ON B._ISBN = WB._Books_ISBN
JOIN Writers W ON WB._Writers_WriterID = W._WriterID

Could not resolve Spring property placeholder

I still believe its to do with the props file not being located by spring. Do a quick test by passing the params as jvm params. i.e -Didm.url=....

MSBUILD : error MSB1008: Only one project can be specified

SOLUTION
Remove the Quotes around the /p:PublishDir setting

i.e.
Instead of quotes

/p:PublishDir="\\BSIIS3\c$\DATA\WEBSITES\benesys.net\benesys.net\TotalEducationTest\"  

Use no quotes

/p:PublishDir=\\BSIIS3\c$\DATA\WEBSITES\benesys.net\benesys.net\TotalEducationTest\  

I am sorry I did not post my finding sooner. I actually had to research again to see what needed to be changed. Who would have thought removing quotes would have worked? I discovered this when viewing a coworkers build for another solution and noticed it did not have quotes.

XSLT string replace

Here is the XSLT function which will work similar to the String.Replace() function of C#.

This template has the 3 Parameters as below

text :- your main string

replace :- the string which you want to replace

by :- the string which will reply by new string

Below are the Template

<xsl:template name="string-replace-all">
  <xsl:param name="text" />
  <xsl:param name="replace" />
  <xsl:param name="by" />
  <xsl:choose>
    <xsl:when test="contains($text, $replace)">
      <xsl:value-of select="substring-before($text,$replace)" />
      <xsl:value-of select="$by" />
      <xsl:call-template name="string-replace-all">
        <xsl:with-param name="text" select="substring-after($text,$replace)" />
        <xsl:with-param name="replace" select="$replace" />
        <xsl:with-param name="by" select="$by" />
      </xsl:call-template>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$text" />
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

Below sample shows how to call it

<xsl:variable name="myVariable ">
  <xsl:call-template name="string-replace-all">
    <xsl:with-param name="text" select="'This is a {old} text'" />
    <xsl:with-param name="replace" select="'{old}'" />
    <xsl:with-param name="by" select="'New'" />
  </xsl:call-template>
</xsl:variable>

You can also refer the below URL for the details.

Signing a Windows EXE file

I had the same scenario in my job and here are our findings

The first thing you have to do is get the certificate and install it on your computer, you can either buy one from a Certificate Authority or generate one using makecert.

Here are the pros and cons of the 2 options

Buy a certificate

Generate a certificate using Makecert

  • Pros:
    • The steps are easy and you can share the certificate with the end users
  • Cons:
    • End users will have to manually install the certificate on their machines and depending on your clients that might not be an option
    • Certificates generated with makecert are normally used for development and testing, not production

Sign the executable file

There are two ways of signing the file you want:

  • Using a certificate installed on the computer

    signtool.exe sign /a /s MY /sha1 sha1_thumbprint_value /t http://timestamp.verisign.com/scripts/timstamp.dll /v "C:\filename.dll"

    • In this example we are using a certificate stored on the Personal folder with a SHA1 thumbprint (This thumbprint comes from the certificate) to sign the file located at C:\filename.dll
  • Using a certificate file

    signtool sign /tr http://timestamp.digicert.com /td sha256 /fd sha256 /f "c:\path\to\mycert.pfx" /p pfxpassword "c:\path\to\file.exe"

    • In this example we are using the certificate c:\path\to\mycert.pfx with the password pfxpassword to sign the file c:\path\to\file.exe

Test Your Signature

  • Method 1: Using signtool

    Go to: Start > Run
    Type CMD > click OK
    At the command prompt, enter the directory where signtool exists
    Run the following:

    signtool.exe verify /pa /v "C:\filename.dll"

  • Method 2: Using Windows

    Right-click the signed file
    Select Properties
    Select the Digital Signatures tab. The signature will be displayed in the Signature list section.

I hope this could help you

Sources:

while installing vc_redist.x64.exe, getting error "Failed to configure per-machine MSU package."

In my case and while installing VS 2015 on Windows7 64x SP1, I experienced the same so tried to cancel and download/install the KBKB2999226 separately and for some reason the standalone update installer also get stuck searching for updates.

enter image description here

Here what I did:

  1. When the VS installer stuck at the KB2999226 update I clicked cancel.
  2. Installer took me back to confirm cancellation, waited for a while then opened the windows task manager and ended the process of wuse.exe (windows standalone update installer)
  3. On the VS installer clicked "No" to return to installation process. The process was completed without errors.

How to override a JavaScript function

You can do it like this:

alert(parseFloat("1.1531531414")); // alerts the float
parseFloat = function(input) { return 1; };
alert(parseFloat("1.1531531414")); // alerts '1'

Check out a working example here: http://jsfiddle.net/LtjzW/1/

get dictionary key by value

You could do that:

  1. By looping through all the KeyValuePair<TKey, TValue>'s in the dictionary (which will be a sizable performance hit if you have a number of entries in the dictionary)
  2. Use two dictionaries, one for value-to-key mapping and one for key-to-value mapping (which would take up twice as much space in memory).

Use Method 1 if performance is not a consideration, use Method 2 if memory is not a consideration.

Also, all keys must be unique, but the values are not required to be unique. You may have more than one key with the specified value.

Is there any reason you can't reverse the key-value relationship?

Android WebView progress bar

For a horizontal progress bar, you first need to define your progress bar and link it with your XML file like this, in the onCreate:

final TextView txtview = (TextView)findViewById(R.id.tV1);
final ProgressBar pbar = (ProgressBar) findViewById(R.id.pB1);

Then, you may use onProgressChanged Method in your WebChromeClient:

MyView.setWebChromeClient(new WebChromeClient() {
            public void onProgressChanged(WebView view, int progress) {
               if(progress < 100 && pbar.getVisibility() == ProgressBar.GONE){
                   pbar.setVisibility(ProgressBar.VISIBLE);
                   txtview.setVisibility(View.VISIBLE);
               }

               pbar.setProgress(progress);
               if(progress == 100) {
                   pbar.setVisibility(ProgressBar.GONE);
                   txtview.setVisibility(View.GONE);
               }
            }
        });

After that, in your layout you have something like this

<TextView android:text="Loading, . . ." 
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:id="@+id/tV1" android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:textColor="#000000"></TextView>

<ProgressBar android:id="@+id/pB1"
    style="?android:attr/progressBarStyleHorizontal" android:layout_width="fill_parent"
    android:layout_height="wrap_content" android:layout_centerVertical="true"
    android:padding="2dip">
</ProgressBar>

This is how I did it in my app.

Error:Failed to open zip file. Gradle's dependency cache may be corrupt

Repair Gradle Installation

This usually happens when something goes wrong in Android Studio's first launch (eg. system crash, connection loss or whatever).

To resolve this issue close Android Studio and delete the following directory's content, necessary files will be downloaded on IDE's next launch.

macOS: ~/.gradle/wrapper/dists

Linux: ~/.gradle/wrapper/dists

Windows: C:\Users\your-username\.gradle\wrapper\dists

While downloading Gradle manually works, I recommend letting Android Studio itself to do it.

Why am I getting the error "connection refused" in Python? (Sockets)

try this command in terminal:

sudo ufw enable
ufw allow 12397

Getting visitors country from their IP

echo json_decode(file_get_contents('https://iplocation.hirak.cc/?ip='.$_SERVER['REMOTE_ADDR']))->country; 
// for ip=190.2.145.41 output: Natherlands

Explination: previous api provide result like this for my ip (for exemple);

 {
    ip: "105.103.124.4",
    country_code: "DZ",
    country: "Algeria",
    attribution: "Data from https://lite.ip2location.com/"
 }

so to access to the country, we will need to decode the result as stdClass, to be accessible, because the result is text format, we add the json_decode() to the file_get_contents(), & from json_decode() returning stdClass (the same format) will access to country by ->country

How to get the last value of an ArrayList

arrays store their size in a local variable called 'length'. Given an array named "a" you could use the following to reference the last index without knowing the index value

a[a.length-1]

to assign a value of 5 to this last index you would use:

a[a.length-1]=5;

Implicit type conversion rules in C++ operators

In C++ operators (for POD types) always act on objects of the same type.
Thus if they are not the same one will be promoted to match the other.
The type of the result of the operation is the same as operands (after conversion).

If either is      long          double the other is promoted to      long          double
If either is                    double the other is promoted to                    double
If either is                    float  the other is promoted to                    float
If either is long long unsigned int    the other is promoted to long long unsigned int
If either is long long          int    the other is promoted to long long          int
If either is long      unsigned int    the other is promoted to long      unsigned int
If either is long               int    the other is promoted to long               int
If either is           unsigned int    the other is promoted to           unsigned int
If either is                    int    the other is promoted to                    int
Both operands are promoted to int

Note. The minimum size of operations is int. So short/char are promoted to int before the operation is done.

In all your expressions the int is promoted to a float before the operation is performed. The result of the operation is a float.

int + float =>  float + float = float
int * float =>  float * float = float
float * int =>  float * float = float
int / float =>  float / float = float
float / int =>  float / float = float
int / int                     = int
int ^ float =>  <compiler error>

Scatter plot and Color mapping in Python

Here is an example

import numpy as np
import matplotlib.pyplot as plt

x = np.random.rand(100)
y = np.random.rand(100)
t = np.arange(100)

plt.scatter(x, y, c=t)
plt.show()

Here you are setting the color based on the index, t, which is just an array of [1, 2, ..., 100]. enter image description here

Perhaps an easier-to-understand example is the slightly simpler

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(100)
y = x
t = x
plt.scatter(x, y, c=t)
plt.show()

enter image description here

Note that the array you pass as c doesn't need to have any particular order or type, i.e. it doesn't need to be sorted or integers as in these examples. The plotting routine will scale the colormap such that the minimum/maximum values in c correspond to the bottom/top of the colormap.

Colormaps

You can change the colormap by adding

import matplotlib.cm as cm
plt.scatter(x, y, c=t, cmap=cm.cmap_name)

Importing matplotlib.cm is optional as you can call colormaps as cmap="cmap_name" just as well. There is a reference page of colormaps showing what each looks like. Also know that you can reverse a colormap by simply calling it as cmap_name_r. So either

plt.scatter(x, y, c=t, cmap=cm.cmap_name_r)
# or
plt.scatter(x, y, c=t, cmap="cmap_name_r")

will work. Examples are "jet_r" or cm.plasma_r. Here's an example with the new 1.5 colormap viridis:

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(100)
y = x
t = x
fig, (ax1, ax2) = plt.subplots(1, 2)
ax1.scatter(x, y, c=t, cmap='viridis')
ax2.scatter(x, y, c=t, cmap='viridis_r')
plt.show()

enter image description here

Colorbars

You can add a colorbar by using

plt.scatter(x, y, c=t, cmap='viridis')
plt.colorbar()
plt.show()

enter image description here

Note that if you are using figures and subplots explicitly (e.g. fig, ax = plt.subplots() or ax = fig.add_subplot(111)), adding a colorbar can be a bit more involved. Good examples can be found here for a single subplot colorbar and here for 2 subplots 1 colorbar.

CSS to select/style first word

There isn't a plain CSS method for this. You might have to go with JavaScript + Regex to pop in a span.

Ideally, there would be a pseudo-element for first-word, but you're out of luck as that doesn't appear to work. We do have :first-letter and :first-line.

You might be able to use a combination of :after or :before to get at it without using a span.

Java JTable getting the data of the selected row

Just simple like this:

    tbl.addMouseListener(new MouseListener() {
        @Override
        public void mouseReleased(MouseEvent e) {
        }
        @Override
        public void mousePressed(MouseEvent e) {
            String selectedCellValue = (String) tbl.getValueAt(tbl.getSelectedRow() , tbl.getSelectedColumn());
            System.out.println(selectedCellValue);
        }
        @Override
        public void mouseExited(MouseEvent e) {
        }
        @Override
        public void mouseEntered(MouseEvent e) {
        }
        @Override
        public void mouseClicked(MouseEvent e) {
        }
    });

Java switch statement: Constant expression required, but it IS constant

I understand that the compiler needs the expression to be known at compile time to compile a switch, but why isn't Foo.BA_ constant?

While they are constant from the perspective of any code that executes after the fields have been initialized, they are not a compile time constant in the sense required by the JLS; see §15.28 Constant Expressions for the specification of a constant expression1. This refers to §4.12.4 Final Variables which defines a "constant variable" as follows:

We call a variable, of primitive type or type String, that is final and initialized with a compile-time constant expression (§15.28) a constant variable. Whether a variable is a constant variable or not may have implications with respect to class initialization (§12.4.1), binary compatibility (§13.1, §13.4.9) and definite assignment (§16).

In your example, the Foo.BA* variables do not have initializers, and hence do not qualify as "constant variables". The fix is simple; change the Foo.BA* variable declarations to have initializers that are compile-time constant expressions.

In other examples (where the initializers are already compile-time constant expressions), declaring the variable as final may be what is needed.

You could change your code to use an enum rather than int constants, but that brings another couple of different restrictions:

  • You must include a default case, even if you have case for every known value of the enum; see Why is default required for a switch on an enum?
  • The case labels must all be explicit enum values, not expressions that evaluate to enum values.

1 - The constant expression restrictions can be summarized as follows. Constant expressions a) can use primitive types and String only, b) allow primaries that are literals (apart from null) and constant variables only, c) allow constant expressions possibly parenthesised as subexpressions, d) allow operators except for assignment operators, ++, -- or instanceof, and e) allow type casts to primitive types or String only.

Note that this doesn't include any form of method or lambda calls, new, .class. .length or array subscripting. Furthermore, any use of array values, enum values, values of primitive wrapper types, boxing and unboxing are all excluded because of a).

MongoDB - Update objects in a document's array (nested updating)

There is no way to do this in single query. You have to search the document in first query:

If document exists:

db.bar.update( {user_id : 123456 , "items.item_name" : "my_item_two" } , 
                {$inc : {"items.$.price" : 1} } , 
                false , 
                true);

Else

db.bar.update( {user_id : 123456 } , 
                {$addToSet : {"items" : {'item_name' : "my_item_two" , 'price' : 1 }} } ,
                false , 
                true);

No need to add condition {$ne : "my_item_two" }.

Also in multithreaded enviourment you have to be careful that only one thread can execute the second (insert case, if document did not found) at a time, otherwise duplicate embed documents will be inserted.

PHP ini file_get_contents external url

The answers provided above solve the problem but don't explain the strange behaviour the OP described. This explanation should help anyone testing communication between sites in a development environment where these sites all reside on the same host (and the same virtualhost; I'm working with apache 2.4 and php7.0).

There's a subtlety with file_get_contents() I came across that is absolutely relevant here but unaddressed (probably because it's either barely documented or not documented from what I can tell or is documented in an obscure php security model whitepaper I can't find).

With allow_url_fopen set to Off in all relevant contexts (e.g. /etc/php/7.0/apache2/php.ini, /etc/php/7.0/fpm/php.ini, etc...) and allow_url_fopen set to On in the command line context (i.e. /etc/php/7.0/cli/php.ini), calls to file_get_contents() for a local resource will be allowed and no warning will be logged such as:

file_get_contents('php://input');

or

// Path outside document root that webserver user agent has permission to read. e.g. for an apache2 webserver this user agent might be www-data so a file at /etc/php/7.0/filetoaccess would be successfully read if www-data had permission to read this file
file_get_contents('<file path to file on local machine user agent can access>');

or

// Relative path in same document root
file_get_contents('data/filename.dat')

To conclude, the restriction allow_url_fopen = Off is analogous to an iptables rule in the OUTPUT chain, where the restriction is only applied when an attempt to "exit the system" or "change contexts" is made.

N.B. allow_url_fopen set to On in the command line context (i.e. /etc/php/7.0/cli/php.ini) is what I had on my system but I suspect it would have no bearing on the explanation I provided even if it were set to Off unless of course you're testing by running your scripts from the command line itself. I did not test the behaviour with allow_url_fopen set to Off in the command line context.

Delete first character of a string in Javascript

try

s.replace(/^0/,'')

_x000D_
_x000D_
console.log("0string  =>", "0string".replace(/^0/,'') );_x000D_
console.log("00string =>", "00string".replace(/^0/,'') );_x000D_
console.log("string00 =>", "string00".replace(/^0/,'') );
_x000D_
_x000D_
_x000D_

Best Regular Expression for Email Validation in C#

Email Validation Regex

^[a-z0-9][-a-z0-9._]+@([-a-z0-9]+.)+[a-z]{2,5}$

Or

^[a-z0-9][-a-z0-9._]+@([-a-z0-9]+[.])+[a-z]{2,5}$

Demo Link:

https://regex101.com/r/kN4nJ0/53

What is the purpose of Node.js module.exports and how do you use it?

A module encapsulates related code into a single unit of code. When creating a module, this can be interpreted as moving all related functions into a file.

Suppose there is a file Hello.js which include two functions

sayHelloInEnglish = function() {
  return "Hello";
};
sayHelloInSpanish = function() {
  return "Hola";
};

We write a function only when utility of the code is more than one call.

Suppose we want to increase utility of the function to a different file say World.js,in this case exporting a file comes into picture which can be obtained by module.exports.

You can just export both the function by the code given below

var anyVariable={
 sayHelloInEnglish = function() {
      return "Hello";
    };
  sayHelloInSpanish = function() {
      return "Hola";
    }; 
}
module.export=anyVariable;

Now you just need to require the file name into World.js inorder to use those functions

var world= require("./hello.js");

Postgresql - change the size of a varchar column to lower length

Try run following alter table:

ALTER TABLE public.users 
ALTER COLUMN "password" TYPE varchar(300) 
USING "password"::varchar;

Removing whitespace from strings in Java

If you prefer utility classes to regexes, there is a method trimAllWhitespace(String) in StringUtils in the Spring Framework.

What's the difference between ng-model and ng-bind

_x000D_
_x000D_
angular.module('testApp',[]).controller('testCTRL',function($scope)_x000D_
                               _x000D_
{_x000D_
  _x000D_
$scope.testingModel = "This is ModelData.If you change textbox data it will reflected here..because model is two way binding reflected in both.";_x000D_
$scope.testingBind = "This is BindData.You can't change this beacause it is binded with html..In above textBox i tried to use bind, but it is not working because it is one way binding.";            _x000D_
});
_x000D_
div input{_x000D_
width:600px;  _x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>_x000D_
_x000D_
<head>Diff b/w model and bind</head>_x000D_
<body data-ng-app="testApp">_x000D_
    <div data-ng-controller="testCTRL">_x000D_
        Model-Data : <input type="text" data-ng-model="testingModel">_x000D_
        <p>{{testingModel}}</p>_x000D_
          <input type="text" data-ng-bind="testingBind">_x000D_
          <p ng-bind="testingBind"></p>_x000D_
    </div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

How to check if iframe is loaded or it has a content?

kindly use:

$('#myIframe').on('load', function(){
    //your code (will be called once iframe is done loading)
});

Updated my answer as the standards changed.

How to create a file with a given size in Linux?

This will generate 4 MB text file with random characters in current directory and its name "4mb.txt" You can change parameters to generate different sizes and names.

base64 /dev/urandom | head -c 4000000 > 4mb.txt

jquery drop down menu closing by clicking outside

You can tell any click that bubbles all the way up the DOM to hide the dropdown, and any click that makes it to the parent of the dropdown to stop bubbling.

/* Anything that gets to the document
   will hide the dropdown */
$(document).click(function(){
  $("#dropdown").hide();
});

/* Clicks within the dropdown won't make
   it past the dropdown itself */
$("#dropdown").click(function(e){
  e.stopPropagation();
});

Demo: http://jsbin.com/umubad/2/edit

How to convert a string Date to long millseconds

Try below code

        SimpleDateFormat f = new SimpleDateFormat("your_string_format", Locale.getDefault());
        Date d = null;
        try {
            d = f.parse(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        long timeInMillis = d.getTime();

$_POST not working. "Notice: Undefined index: username..."

You should check if the POST['username'] is defined. Use this above:

$username = "";

if(isset($_POST['username'])){
    $username = $_POST['username'];
}

"SELECT password FROM users WHERE username='".$username."'"

How to convert all text to lowercase in Vim

Many ways to skin a cat... here's the way I just posted about:


:%s/[A-Z]/\L&/g

Likewise for upper case:


:%s/[a-z]/\U&/g

I prefer this way because I am using this construct (:%s/[pattern]/replace/g) all the time so it's more natural.

Xcode 10 Error: Multiple commands produce

My problem was a duplicate Product Module Name for both the Action Extension I created and the main target. The solution was changing the Product module name (Under Build Settings) for the Extension.

(XCode 11)

Run jar file in command prompt

Try this

java -jar <jar-file-name>.jar

How to upgrade OpenSSL in CentOS 6.5 / Linux / Unix from source?

My approach was:

openssl version
OpenSSL 1.0.1e 11 Feb 2013

wget https://www.openssl.org/source/openssl-1.0.2a.tar.gz
wget http://www.linuxfromscratch.org/patches/blfs/svn/openssl-1.0.2a-fix_parallel_build-1.patch
tar xzf openssl-1.0.2a.tar.gz
cd openssl-1.0.2a
patch -Np1 -i ../openssl-1.0.2a-fix_parallel_build-1.patch
./config --prefix=/usr --openssldir=/etc/ssl --libdir=lib shared zlib-dynamic
make
make install

openssl version
OpenSSL 1.0.2a 19 Mar 2015 

VBA check if object is set

The (un)safe way to do this - if you are ok with not using option explicit - is...

Not TypeName(myObj) = "Empty"

This also handles the case if the object has not been declared. This is useful if you want to just comment out a declaration to switch off some behaviour...

Dim myObj as Object
Not TypeName(myObj) = "Empty"  '/ true, the object exists - TypeName is Object

'Dim myObj as Object
Not TypeName(myObj) = "Empty"  '/ false, the object has not been declared

This works because VBA will auto-instantiate an undeclared variable as an Empty Variant type. It eliminates the need for an auxiliary Boolean to manage the behaviour.

How do I format a number to a dollar amount in PHP

Note that in PHP 7.4, money_format() function is deprecated. It can be replaced by the intl NumberFormatter functionality, just make sure you enable the php-intl extension. It's a small amount of effort and worth it as you get a lot of customizability.

$f = new NumberFormatter("en", NumberFormatter::CURRENCY);
$f->formatCurrency(12345, "USD"); // Outputs "$12,345.00"

The fast way that will still work for 7.4 is as mentioned by Darryl Hein:

'$' . number_format($money, 2);

duplicate 'row.names' are not allowed error

I had this error when opening a CSV file and one of the fields had commas embedded in it. The field had quotes around it, and I had cut and paste the read.table with quote="" in it. Once I took quote="" out, the default behavior of read.table took over and killed the problem. So I went from this:

systems <- read.table("http://getfile.pl?test.csv", header=TRUE, sep=",", quote="")

to this:

systems <- read.table("http://getfile.pl?test.csv", header=TRUE, sep=",")

Run Excel Macro from Outside Excel Using VBScript From Command Line

Ok, it's actually simple. Assuming that your macro is in a module,not in one of the sheets, you use:

  objExcel.Application.Run "test.xls!dog" 
  'notice the format of 'workbook name'!macro

For a filename with spaces, encase the filename with quotes.

If you've placed the macro under a sheet, say sheet1, just assume sheet1 owns the function, which it does.

    objExcel.Application.Run "'test 2.xls'!sheet1.dog"

Notice: You don't need the macro.testfunction notation you've been using.

How to import a class from default package

  1. Create a new package.
  2. Move your files from the default package to the new one.

How to do a redirect to another route with react-router?

Easiest solution for web!

Up to date 2020
confirmed working with:

"react-router-dom": "^5.1.2"
"react": "^16.10.2"

Use the useHistory() hook!

import React from 'react';
import { useHistory } from "react-router-dom";


export function HomeSection() {
  const history = useHistory();
  const goLogin = () => history.push('login');

  return (
    <Grid>
      <Row className="text-center">          
        <Col md={12} xs={12}>
          <div className="input-group">
            <span className="input-group-btn">
              <button onClick={goLogin} type="button" />
            </span>
          </div>
        </Col>
      </Row>
    </Grid>
  );
}

Determine whether an array contains a value

Using array .map function that executes a function for every value in an array seems cleanest to me.

Ref: Array.prototype.map()

This method can work well both for simple arrays and for arrays of objects where you need to see if a key/value exists in an array of objects.

function inArray(myArray,myValue){
    var inArray = false;
    myArray.map(function(key){
        if (key === myValue){
            inArray=true;
        }
    });
    return inArray;
};

var anArray = [2,4,6,8]
console.log(inArray(anArray, 8)); // returns true
console.log(inArray(anArray, 1)); // returns false

function inArrayOfObjects(myArray,myValue,objElement){
    var inArray = false;
    myArray.map(function(arrayObj){
        if (arrayObj[objElement] === myValue) {
            inArray=true;
        }
    });
    return inArray;
};

var objArray = [{id:4,value:'foo'},{id:5,value:'bar'}]
console.log(inArrayOfObjects(objArray, 4, 'id')); // returns true
console.log(inArrayOfObjects(objArray, 'bar', 'value')); // returns true
console.log(inArrayOfObjects(objArray, 1, 'id')); // returns false

Import CSV to SQLite

How to import csv file to sqlite3

  1. Create database

    sqlite3 NYC.db
    
  2. Set the mode & tablename

    .mode csv tripdata
    
  3. Import the csv file data to sqlite3

    .import yellow_tripdata_2017-01.csv tripdata
    
  4. Find tables

    .tables
    
  5. Find your table schema

    .schema tripdata
    
  6. Find table data

    select * from tripdata limit 10;
    
  7. Count the number of rows in the table

    select count (*) from tripdata;
    

How to remove leading and trailing whitespace in a MySQL field?

You can use the following sql, UPDATE TABLE SET Column= replace(Column , ' ','')

Unable to create/open lock file: /data/mongod.lock errno:13 Permission denied

As of today, I tried to get my way through the to create/open lock file: /data/db/mongod.lock errno:13 Permission denied Is a mongod instance already running?, terminating, and tried all the answer posted above to solve this problem, hence nothing worked out by adding

sudo chown -R mongodb:mongodb /data/db

Unless I added my current user permission to the location path by

sudo chown $USER /data/db

Hope this helps someone. Also I just installed Mongo DB on my pi. Cheers!

Visual studio code CSS indentation and formatting

After opening local bootstrap.min.css in visual studio code, it looked unindented. Tried the commad ALT+Shift+F but in vain.

Then installed

CSS Formatter extension.

Reloaded it and ALT+Shift+F indented my CSS file with charm.

Bingo !!!

@try - catch block in Objective-C

Now I've found the problem.

Removing the obj_exception_throw from my breakpoints solved this. Now it's caught by the @try block and also, NSSetUncaughtExceptionHandler will handle this if a @try block is missing.

LaTeX table positioning

At the beginning with the usepackage definitions include:

\usepackage{placeins}

And before and after add:

\FloatBarrier
\begin{table}[h]
    \begin{tabular}{llll}
      .... 
    \end{tabular}
\end{table}
\FloatBarrier

This places the table exactly where you want in the text.

How can a windows service programmatically restart itself?

The better approach may be to utilize the NT Service as a wrapper for your application. When the NT Service is started, your application can start in an "idle" mode waiting for the command to start (or be configured to start automatically).

Think of a car, when it's started it begins in an idle state, waiting for your command to go forward or reverse. This also allows for other benefits, such as better remote administration as you can choose how to expose your application.

Which comes first in a 2D array, rows or columns?

In java the rows are done first, because a 2 dimension array is considered two separate arrays. Starts with the first row 1 dimension array.

How to verify a method is called two times with mockito verify()

Using the appropriate VerificationMode:

import static org.mockito.Mockito.atLeast;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

verify(mockObject, atLeast(2)).someMethod("was called at least twice");
verify(mockObject, times(3)).someMethod("was called exactly three times");

Styling input radio with css

See this Fiddle

<input type="radio" id="radio-2-1" name="radio-2-set" class="regular-radio" /><label for="radio-2-1"></label>
<input type="radio" id="radio-2-2" name="radio-2-set" class="regular-radio" /><label for="radio-2-2"></label>
<input type="radio" id="radio-2-3" name="radio-2-set" class="regular-radio" /><label for="radio-2-3"></label>

.regular-radio {
    display: none;
}

.regular-radio + label {
    -webkit-appearance: none;
    background-color: #e1e1e1;
    border: 4px solid #e1e1e1;
    border-radius: 10px;
    width: 100%;
    display: inline-block;
    position: relative;
    width: 10px;
    height: 10px;
}

.regular-radio:checked + label {
    background: grey;
    border: 4px solid #e1e1e1;
}

How to both read and write a file in C#

var fs = File.Open("file.name", FileMode.OpenOrCreate, FileAccess.ReadWrite);
var sw = new StreamWriter(fs);
var sr = new StreamReader(fs);

...

fs.Close();
//or sw.Close();

The key thing is to open the file with the FileAccess.ReadWrite flag. You can then create whatever Stream/String/Binary Reader/Writers you need using the initial FileStream.

How to use the unsigned Integer in Java 8 and Java 9?

Per the documentation you posted, and this blog post - there's no difference when declaring the primitive between an unsigned int/long and a signed one. The "new support" is the addition of the static methods in the Integer and Long classes, e.g. Integer.divideUnsigned. If you're not using those methods, your "unsigned" long above 2^63-1 is just a plain old long with a negative value.

From a quick skim, it doesn't look like there's a way to declare integer constants in the range outside of +/- 2^31-1, or +/- 2^63-1 for longs. You would have to manually compute the negative value corresponding to your out-of-range positive value.

Node/Express file upload

If you are using Node.js Express and Typescript here is a working example, this works with javascript also, just change the let to var and the import to includes etc...

first import the following make sure you install formidable by running the following command:

npm install formidable

than import the following:

  import * as formidable from 'formidable';
  import * as fs from 'fs';

then your function like bellow:

    uploadFile(req, res) {
    let form = new formidable.IncomingForm();
    form.parse(req, function (err, fields, files) {
        let oldpath = files.file.path;
        let newpath = 'C:/test/' + files.file.name;
        fs.rename(oldpath, newpath, function (err) {
            if (err) throw err;
            res.write('File uploaded and moved!');
            res.end();
        });
    });
}

What is the best way to connect and use a sqlite database from C#

Another way of using SQLite database in NET Framework is to use Fluent-NHibernate.
[It is NET module which wraps around NHibernate (ORM module - Object Relational Mapping) and allows to configure NHibernate programmatically (without XML files) with the fluent pattern.]

Here is the brief 'Getting started' description how to do this in C# step by step:

https://github.com/jagregory/fluent-nhibernate/wiki/Getting-started

It includes a source code as an Visual Studio project.

How to execute a remote command over ssh with arguments?

I'm using the following to execute commands on the remote from my local computer:

ssh -i ~/.ssh/$GIT_PRIVKEY user@$IP "bash -s" < localpath/script.sh $arg1 $arg2

grep without showing path/file:line

From the man page:

-h, --no-filename
    Suppress the prefixing of file names on output. This is the default when there
    is only one file (or only standard input) to search.

Why does configure say no C compiler found when GCC is installed?

Maybe gcc is not in your path? Try finding gcc using which gcc and add it to your path if it's not already there.

How to show data in a table by using psql command line interface?

On windows use the name of the table in quotes: TABLE "user"; or SELECT * FROM "user";

Python pandas: fill a dataframe row by row

My approach was, but I can't guarantee that this is the fastest solution.

df = pd.DataFrame(columns=["firstname", "lastname"])
df = df.append({
     "firstname": "John",
     "lastname":  "Johny"
      }, ignore_index=True)

How do I POST urlencoded form data with $http without jQuery?

Here is the way it should be (and please no backend changes ... certainly not ... if your front stack does not support application/x-www-form-urlencoded, then throw it away ... hopefully AngularJS does !

$http({
     method: 'POST',
     url: 'api_endpoint',
     headers: {'Content-Type': 'application/x-www-form-urlencoded'},
     data: 'username='+$scope.username+'&password='+$scope.password
 }).then(function(response) {
    // on success
 }, function(response) {
    // on error
 });

Works like a charm with AngularJS 1.5

People, let give u some advice:

  • use promises .then(success, error) when dealing with $http, forget about .sucess and .error callbacks (as they are being deprecated)

  • From the angularjs site here "You can no longer use the JSON_CALLBACK string as a placeholder for specifying where the callback parameter value should go."

If your data model is more complex that just a username and a password, you can still do that (as suggested above)

$http({
     method: 'POST',
     url: 'api_endpoint',
     headers: {'Content-Type': 'application/x-www-form-urlencoded'},
     data: json_formatted_data,
     transformRequest: function(data, headers) {
          return transform_json_to_urlcoded(data); // iterate over fields and chain key=value separated with &, using encodeURIComponent javascript function
     }
}).then(function(response) {
  // on succes
}, function(response) {
  // on error
});

Document for the encodeURIComponent can be found here

dd: How to calculate optimal blocksize?

I've found my optimal blocksize to be 8 MB (equal to disk cache?) I needed to wipe (some say: wash) the empty space on a disk before creating a compressed image of it. I used:

cd /media/DiskToWash/
dd if=/dev/zero of=zero bs=8M; rm zero

I experimented with values from 4K to 100M.

After letting dd to run for a while I killed it (Ctlr+C) and read the output:

36+0 records in
36+0 records out
301989888 bytes (302 MB) copied, 15.8341 s, 19.1 MB/s

As dd displays the input/output rate (19.1MB/s in this case) it's easy to see if the value you've picked is performing better than the previous one or worse.

My scores:

bs=   I/O rate
---------------
4K    13.5 MB/s
64K   18.3 MB/s
8M    19.1 MB/s <--- winner!
10M   19.0 MB/s
20M   18.6 MB/s
100M  18.6 MB/s   

Note: To check what your disk cache/buffer size is, you can use sudo hdparm -i /dev/sda

How to convert <font size="10"> to px?

the font size to em mapping is only accurate if there is no font-size defined and changes when your container is set to different sizes.

The following works best for me but it does not account for size=7 and anything above 7 only renders as 7.

font size=1 = font-size:x-small
font size=2 = font-size:small
font size=3 = font-size:medium
font size=4 = font-size:large
font size=5 = font-size:x-large
font size=6 = font-size:xx-large

enter image description here

Convert a date format in PHP

Use date_create and date_format

Try this.

function formatDate($input, $output){
  $inputdate = date_create($input);
  $output = date_format($inputdate, $output);
  return $output;
}

C subscripted value is neither array nor pointer nor vector when assigning an array element value

C lets you use the subscript operator [] on arrays and on pointers. When you use this operator on a pointer, the resultant type is the type to which the pointer points to. For example, if you apply [] to int*, the result would be an int.

That is precisely what's going on: you are passing int*, which corresponds to a vector of integers. Using subscript on it once makes it int, so you cannot apply the second subscript to it.

It appears from your code that arr should be a 2-D array. If it is implemented as a "jagged" array (i.e. an array of pointers) then the parameter type should be int **.

Moreover, it appears that you are trying to return a local array. In order to do that legally, you need to allocate the array dynamically, and return a pointer. However, a better approach would be declaring a special struct for your 4x4 matrix, and using it to wrap your fixed-size array, like this:

// This type wraps your 4x4 matrix
typedef struct {
    int arr[4][4];
} FourByFour;
// Now rotate(m) can use FourByFour as a type
FourByFour rotate(FourByFour m) {
    FourByFour D;
    for(int i = 0; i < 4; i ++ ){
        for(int n = 0; n < 4; n++){
            D.arr[i][n] = m.arr[n][3 - i];
        }
    }
    return D;
}
// Here is a demo of your rotate(m) in action:
int main(void) {
    FourByFour S = {.arr = {
        { 1, 4, 10, 3 },
        { 0, 6, 3, 8 },
        { 7, 10 ,8, 5 },
        { 9, 5, 11, 2}
    } };
    FourByFour r = rotate(S);
    for(int i=0; i < 4; i ++ ){
        for(int n=0; n < 4; n++){
            printf("%d ", r.arr[i][n]);
        }
        printf("\n");
    }
    return 0;
}

This prints the following:

3 8 5 2 
10 3 8 11 
4 6 10 5 
1 0 7 9 

RGB to hex and hex to RGB

Shorthand version that accepts a string:

_x000D_
_x000D_
function rgbToHex(a){_x000D_
  a=a.replace(/[^\d,]/g,"").split(","); _x000D_
  return"#"+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1)_x000D_
}_x000D_
_x000D_
document.write(rgbToHex("rgb(255,255,255)"));
_x000D_
_x000D_
_x000D_

To check if it's not already hexadecimal

_x000D_
_x000D_
function rgbToHex(a){_x000D_
  if(~a.indexOf("#"))return a;_x000D_
  a=a.replace(/[^\d,]/g,"").split(","); _x000D_
  return"#"+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1)_x000D_
}_x000D_
_x000D_
document.write("rgb: "+rgbToHex("rgb(255,255,255)")+ " -- hex: "+rgbToHex("#e2e2e2"));
_x000D_
_x000D_
_x000D_

Convert java.time.LocalDate into java.util.Date type

    LocalDate date = LocalDate.now();
    DateFormat formatter = new SimpleDateFormat("dd-mm-yyyy");
    try {
        Date utilDate= formatter.parse(date.toString());
    } catch (ParseException e) {
        // handle exception
    }

How do I run a single test using Jest?

I took me a while to find this so I'd like to add it here for people like me who use yarn:

yarn test -i "src/components/folderX/folderY/.../Filename.ts" -t "name of test"

So filename after -i and testname after -t.

Modulo operation with negative numbers

It seems the problem is that / is not floor operation.

int mod(int m, float n)
{  
  return m - floor(m/n)*n;
}

Merging arrays with the same keys

I just wrote this function, it should do the trick for you, but it does left join

public function mergePerKey($array1,$array2)
    {
        $mergedArray = [];

        foreach ($array1 as $key => $value) 
        {
            if(isset($array2[$key]))
             {
               $mergedArray[$value] = null;

               continue;
             }
            $mergedArray[$value] = $array2[$key];
        }

        return $mergedArray;
    }

Do you need to dispose of objects and set them to null?

If the object implements IDisposable, then yes, you should dispose it. The object could be hanging on to native resources (file handles, OS objects) that might not be freed immediately otherwise. This can lead to resource starvation, file-locking issues, and other subtle bugs that could otherwise be avoided.

See also Implementing a Dispose Method on MSDN.

In a javascript array, how do I get the last 5 elements, excluding the first element?

If you are using lodash, its even simpler with takeRight.

_.takeRight(arr, 5);

How do I check if a string is a number (float)?

Which, not only is ugly and slow

I'd dispute both.

A regex or other string parsing method would be uglier and slower.

I'm not sure that anything much could be faster than the above. It calls the function and returns. Try/Catch doesn't introduce much overhead because the most common exception is caught without an extensive search of stack frames.

The issue is that any numeric conversion function has two kinds of results

  • A number, if the number is valid
  • A status code (e.g., via errno) or exception to show that no valid number could be parsed.

C (as an example) hacks around this a number of ways. Python lays it out clearly and explicitly.

I think your code for doing this is perfect.

How do you divide each element in a list by an int?

The idiomatic way would be to use list comprehension:

myList = [10,20,30,40,50,60,70,80,90]
myInt = 10
newList = [x / myInt for x in myList]

or, if you need to maintain the reference to the original list:

myList[:] = [x / myInt for x in myList]

TypeError: 'dict_keys' object does not support indexing

You're passing the result of somedict.keys() to the function. In Python 3, dict.keys doesn't return a list, but a set-like object that represents a view of the dictionary's keys and (being set-like) doesn't support indexing.

To fix the problem, use list(somedict.keys()) to collect the keys, and work with that.

ToggleButton in C# WinForms

You can just use a CheckBox and set its appearance to Button:

CheckBox checkBox = new System.Windows.Forms.CheckBox(); 
checkBox.Appearance = System.Windows.Forms.Appearance.Button; 

Converting String To Float in C#

You can use parsing with double instead of float to get more precision value.

Is there a limit to the length of a GET request?

Not in the RFC, no, but there are practical limits.

The HTTP protocol does not place any a priori limit on the length of a URI. Servers MUST be able to handle the URI of any resource they serve, and SHOULD be able to handle URIs of unbounded length if they provide GET-based forms that could generate such URIs. A server SHOULD return 414 (Request-URI Too Long) status if a URI is longer than the server can handle (see section 10.4.15).

Note: Servers should be cautious about depending on URI lengths above 255 bytes, because some older client or proxy implementations may not properly support these lengths.

How to find Oracle Service Name

Connect to the database with the "system" user, and execute the following command:

show parameter service_name 

Android XXHDPI resources

The newer android phones in the market like HTC one, Xperia Z etc have resolutions in the >480dpi range, putting them in the new xxhdpi class as well. The new assets might be useful for them too.

Pythonically add header to a csv file

This worked for me.

header = ['row1', 'row2', 'row3']
some_list = [1, 2, 3]
with open('test.csv', 'wt', newline ='') as file:
    writer = csv.writer(file, delimiter=',')
    writer.writerow(i for i in header)
    for j in some_list:
        writer.writerow(j)

What is a simple C or C++ TCP server and client example?

If the code should be simple, then you probably asking for C example based on traditional BSD sockets. Solutions like boost::asio are imho quite complicated when it comes to short and simple "hello world" example.

To compile examples you mentioned you must make simple fixes, because you are compiling under C++ compiler. I'm referring to following files:
http://www.linuxhowtos.org/data/6/server.c
http://www.linuxhowtos.org/data/6/client.c
from: http://www.linuxhowtos.org/C_C++/socket.htm

  1. Add following includes to both files:

    #include <cstdlib>
    #include <cstring>
    #include <unistd.h>
    
  2. In client.c, change the line:

    if (connect(sockfd,&serv_addr,sizeof(serv_addr)) < 0)
    { ... }
    

    to:

    if (connect(sockfd,(const sockaddr*)&serv_addr,sizeof(serv_addr)) < 0)
    { ... }
    

As you can see in C++ an explicit cast is needed.

ADB device list is empty

This helped me at the end:

Quick guide:

  • Download Google USB Driver

  • Connect your device with Android Debugging enabled to your PC

  • Open Device Manager of Windows from System Properties.

  • Your device should appear under Other devices listed as something like Android ADB Interface or 'Android Phone' or similar. Right-click that and click on Update Driver Software...

  • Select Browse my computer for driver software

  • Select Let me pick from a list of device drivers on my computer

  • Double-click Show all devices

  • Press the Have disk button

  • Browse and navigate to [wherever your SDK has been installed]\google-usb_driver and select android_winusb.inf

  • Select Android ADB Interface from the list of device types.

  • Press the Yes button

  • Press the Install button

  • Press the Close button

Now you've got the ADB driver set up correctly. Reconnect your device if it doesn't recognize it already.

How to customize <input type="file">?

Something like that maybe?

<form>
  <input id="fileinput" type="file" style="display:none;"/>
</form>
<button id="falseinput">El Cucaratcha, for example</button>
<span id="selected_filename">No file selected</span>

<script>
$(document).ready( function() {
  $('#falseinput').click(function(){
    $("#fileinput").click();
  });
});
$('#fileinput').change(function() {
  $('#selected_filename').text($('#fileinput')[0].files[0].name);
});

</script>

How can I suppress the newline after a print statement?

There's some information on printing without newline here.

In Python 3.x we can use ‘end=’ in the print function. This tells it to end the string with a character of our choosing rather than ending with a newline. For example:

print("My 1st String", end=","); print ("My 2nd String.")

This results in:

My 1st String, My 2nd String.

SSIS Text was truncated with status value 4

In my case, some of my rows didn't have the same number of columns as the header. Example, Header has 10 columns, and one of your rows has 8 or 9 columns. (Columns = Count number of you delimiter characters in each line)

MySQL INSERT INTO ... VALUES and SELECT

INSERT INTO table1 (col1, col2)
SELECT "a string", 5, TheNameOfTheFieldInTable2
FROM table2 where ...

Copy/Paste from Excel to a web page

For any future googlers ending up here like me, I used @tatu Ulmanen's concept and just turned it into an array of objects. This simple function takes a string of pasted excel (or Google sheet) data (preferably from a textarea) and turns it into an array of objects. It uses the first row for column/property names.

function excelToObjects(stringData){
    var objects = [];
    //split into rows
    var rows = stringData.split('\n');

    //Make columns
    columns = rows[0].split('\t');

    //Note how we start at rowNr = 1, because 0 is the column row
    for (var rowNr = 1; rowNr < rows.length; rowNr++) {
        var o = {};
        var data = rows[rowNr].split('\t');

        //Loop through all the data
        for (var cellNr = 0; cellNr < data.length; cellNr++) {
            o[columns[cellNr]] = data[cellNr];
        }

        objects.push(o);
    }

    return objects;
}

Hopefully it helps someone in the future.

The APK file does not exist on disk

In my case the problem was that debugging configuration become invalid somehow, even that the test method name, class or package has not changed.

I deleted the configurations from Run->Edit Configurations, at here:

enter image description here

Android studio will create a new one automatically.

100% width in React Native Flexbox

Use javascript to get the width and height and add them in View's style. To get full width and height, use Dimensions.get('window').width https://facebook.github.io/react-native/docs/dimensions.html

getSize() {
    return {
        width: Dimensions.get('window').width, 
        height: Dimensions.get('window').height
    }
}

and then,

<View style={[styles.overlay, this.getSize()]}>

Free XML Formatting tool

If you use Notepad++, I would suggest installing the XML Tools plugin. You can beautify any XML content (indentation and line breaks) or linarize it. Also you can (auto-)validate your file and apply XSL transformation to it.

Download the latest zip and copy the extracted DLL to the plugins directory of your Notepad++ installation. Also, download the External libs and copy them to your %SystemRoot%\system32\ directory.

Installed SSL certificate in certificate store, but it's not in IIS certificate list

when you have one certificate and 2 different web servers here how I fixed it:

  1. List item
  2. You should generate certificate at one of the servers as usually in IIS Then at that server you can also complete the certificate in IIS.
  3. Run the program DigiCertUtil and export that working certificate
  4. Go to the other web server in IIS in security certificates Import that file from step 3.
  5. Then use that certificate to create the Binding.

TypeScript - Append HTML to container element in Angular 2

You could do something like this:

htmlComponent.ts

htmlVariable: string = "<b>Some html.</b>"; //this is html in TypeScript code that you need to display

htmlComponent.html

<div [innerHtml]="htmlVariable"></div> //this is how you display html code from TypeScript in your html

Setting a minimum/maximum character count for any character using a regular expression

Like this: .

The . means any character except newline (which sometimes is but often isn't included, check your regex flavour).

You can rewrite your expression as ^.{1,35}$, which should match any line of length 1-35.

Installing PHP Zip Extension

1 Step - Install a required extension

sudo apt-get install libz-dev -y

2 Step - Install the PHP extension

pecl install zlib zip

3 Step - Restart your Apache

sudo /etc/init.d/apache2 restart

Enable PHP ZIP Extension

If does not work you can check if the zip.ini is called in your phpinfo, to check if the zip.so was included.

PHP code to convert a MySQL query to CSV

An update to @jrgns (with some slight syntax differences) solution.

$result = mysql_query('SELECT * FROM `some_table`'); 
if (!$result) die('Couldn\'t fetch records'); 
$num_fields = mysql_num_fields($result); 
$headers = array(); 
for ($i = 0; $i < $num_fields; $i++) 
{     
       $headers[] = mysql_field_name($result , $i); 
} 
$fp = fopen('php://output', 'w'); 
if ($fp && $result) 
{     
       header('Content-Type: text/csv');
       header('Content-Disposition: attachment; filename="export.csv"');
       header('Pragma: no-cache');    
       header('Expires: 0');
       fputcsv($fp, $headers); 
       while ($row = mysql_fetch_row($result)) 
       {
          fputcsv($fp, array_values($row)); 
       }
die; 
} 

Arithmetic operation resulted in an overflow. (Adding integers)

The maximum size for an int is 2147483647. You could use an Int64/Long which is far larger.

Using git to get just the latest revision

Alternate solution to doing shallow clone (git clone --depth=1 <URL>) would be, if remote side supports it, to use --remote option of git archive:

$ git archive --format=tar --remote=<repository URL> HEAD | tar xf -

Or, if remote repository in question is browse-able using some web interface like gitweb or GitHub, then there is a chance that it has 'snapshot' feature, and you can download latest version (without versioning information) from web interface.

How to comment in Vim's config files: ".vimrc"?

You can add comments in Vim's configuration file by either:

" brief descriptiion of command

or:

"" commended command

Taken from here

Issue with parsing the content from json file with Jackson & message- JsonMappingException -Cannot deserialize as out of START_ARRAY token

I sorted this problem as verifying the json from JSONLint.com and then, correcting it. And this is code for the same.

String jsonStr = "[{\r\n" + "\"name\":\"New York\",\r\n" + "\"number\": \"732921\",\r\n"+ "\"center\": {\r\n" + "\"latitude\": 38.895111,\r\n"  + " \"longitude\": -77.036667\r\n" + "}\r\n" + "},\r\n" + " {\r\n"+ "\"name\": \"San Francisco\",\r\n" +\"number\":\"298732\",\r\n"+ "\"center\": {\r\n" + "    \"latitude\": 37.783333,\r\n"+ "\"longitude\": -122.416667\r\n" + "}\r\n" + "}\r\n" + "]";

ObjectMapper mapper = new ObjectMapper();
MyPojo[] jsonObj = mapper.readValue(jsonStr, MyPojo[].class);

for (MyPojo itr : jsonObj) {
    System.out.println("Val of name is: " + itr.getName());
    System.out.println("Val of number is: " + itr.getNumber());
    System.out.println("Val of latitude is: " + 
        itr.getCenter().getLatitude());
    System.out.println("Val of longitude is: " + 
        itr.getCenter().getLongitude() + "\n");
}

Note: MyPojo[].class is the class having getter and setter of json properties.

Result:

Val of name is: New York
Val of number is: 732921
Val of latitude is: 38.895111
Val of longitude is: -77.036667
Val of name is: San Francisco
Val of number is: 298732
Val of latitude is: 37.783333
Val of longitude is: -122.416667

Image vs Bitmap class

This is a clarification because I have seen things done in code which are honestly confusing - I think the following example might assist others.

As others have said before - Bitmap inherits from the Abstract Image class

Abstract effectively means you cannot create a New() instance of it.

    Image imgBad1 = new Image();        // Bad - won't compile
    Image imgBad2 = new Image(200,200); // Bad - won't compile

But you can do the following:

    Image imgGood;  // Not instantiated object!
    // Now you can do this
    imgGood = new Bitmap(200, 200);

You can now use imgGood as you would the same bitmap object if you had done the following:

    Bitmap bmpGood = new Bitmap(200,200);

The nice thing here is you can draw the imgGood object using a Graphics object

    Graphics gr = default(Graphics);
    gr = Graphics.FromImage(new Bitmap(1000, 1000));
    Rectangle rect = new Rectangle(50, 50, imgGood.Width, imgGood.Height); // where to draw
    gr.DrawImage(imgGood, rect);

Here imgGood can be any Image object - Bitmap, Metafile, or anything else that inherits from Image!

Get $_POST from multiple checkboxes

you have to name your checkboxes accordingly:

<input type="checkbox" name="check_list[]" value="…" />

you can then access all checked checkboxes with

// loop over checked checkboxes
foreach($_POST['check_list'] as $checkbox) {
   // do something
}

ps. make sure to properly escape your output (htmlspecialchars())

How can I generate a unique ID in Python?

import time
import random
import socket
import hashlib

def guid( *args ):
    """
    Generates a universally unique ID.
    Any arguments only create more randomness.
    """
    t = long( time.time() * 1000 )
    r = long( random.random()*100000000000000000L )
    try:
        a = socket.gethostbyname( socket.gethostname() )
    except:
        # if we can't get a network address, just imagine one
        a = random.random()*100000000000000000L
    data = str(t)+' '+str(r)+' '+str(a)+' '+str(args)
    data = hashlib.md5(data).hexdigest()

    return data

Where can I find the error logs of nginx, using FastCGI and Django?

I was looking for a different solution.

Error logs, by default, before any configuration is set, on my system (x86 Arch Linux), was found in:

/var/log/nginx/error.log

Ascending and Descending Number Order in java

package pack2;

import java.util.Scanner;

public class group {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Scanner data= new Scanner(System.in);
    int value[]= new int[5];
    int temp=0,i=0,j=0;
    System.out.println("Enter 5 element of array");
    for(i=0;i<5;i++)
    value[i]=data.nextInt();
     for(i=0;i<5;i++)
     {
     for(j=i;j<5;j++)
     {
      if(value[i]>value[j])
      {
       temp=value[i];
       value[i]=value[j];
       value[j]=temp;
      }
     }

     }
      System.out.println("Increasing Order:");
      for(i=0;i<5;i++)
           System.out.println(""+value[i]); 
    }

Getting Current time to display in Label. VB.net

There are several problems here:

  • Your assignment is the wrong way round; you're trying to assign a value to DateTime.Now instead of Start
  • DateTime.Now is a value of type DateTime, not Integer, so the assignment wouldn't work anyway
  • There's no need to have the Start variable anyway; it's doing no good
  • total.Text is a property of type String - not DateTime or Integer

(Some of these would only show up at execution time unless you have Option Strict on, which you really should.)

You should use:

total.Text = DateTime.Now.ToString()

... possibly specifying a culture and/or format specifier if you want the result in a particular format.

how to clear localstorage,sessionStorage and cookies in javascript? and then retrieve?

There is no way to retrieve localStorage, sessionStorage or cookie values via javascript in the browser after they've been deleted via javascript.

If what you're really asking is if there is some other way (from outside the browser) to recover that data, that's a different question and the answer will entirely depend upon the specific browser and how it implements the storage of each of those types of data.

For example, Firefox stores cookies as individual files. When a cookie is deleted, its file is deleted. That means that the cookie can no longer be accessed via the browser. But, we know that from outside the browser, using system tools, the contents of deleted files can sometimes be retrieved.

If you wanted to look into this further, you'd have to discover how each browser stores each data type on each platform of interest and then explore if that type of storage has any recovery strategy.

Is there a way to have printf() properly print out an array (of floats, say)?

C is not object oriented programming (OOP) language. So you can not use properties in OOP. Eg. There is no .length property in C. So you need to use loops for your task.

C# Java HashMap equivalent

Dictionary is probably the closest. System.Collections.Generic.Dictionary implements the System.Collections.Generic.IDictionary interface (which is similar to Java's Map interface).

Some notable differences that you should be aware of:

  • Adding/Getting items
    • Java's HashMap has the put and get methods for setting/getting items
      • myMap.put(key, value)
      • MyObject value = myMap.get(key)
    • C#'s Dictionary uses [] indexing for setting/getting items
      • myDictionary[key] = value
      • MyObject value = myDictionary[key]
  • null keys
    • Java's HashMap allows null keys
    • .NET's Dictionary throws an ArgumentNullException if you try to add a null key
  • Adding a duplicate key
    • Java's HashMap will replace the existing value with the new one.
    • .NET's Dictionary will replace the existing value with the new one if you use [] indexing. If you use the Add method, it will instead throw an ArgumentException.
  • Attempting to get a non-existent key
    • Java's HashMap will return null.
    • .NET's Dictionary will throw a KeyNotFoundException. You can use the TryGetValue method instead of the [] indexing to avoid this:
      MyObject value = null; if (!myDictionary.TryGetValue(key, out value)) { /* key doesn't exist */ }

Dictionary's has a ContainsKey method that can help deal with the previous two problems.

Complex nesting of partials and templates

You may use ng-include to avoid using nested ng-views.

http://docs.angularjs.org/api/ng/directive/ngInclude
http://plnkr.co/edit/ngdoc:example-example39@snapshot?p=preview

My index page I use ng-view. Then on my sub pages which I need to have nested frames. I use ng-include. The demo shows a dropdown. I replaced mine with a link ng-click. In the function I would put $scope.template = $scope.templates[0]; or $scope.template = $scope.templates[1];

$scope.clickToSomePage= function(){
  $scope.template = $scope.templates[0];
};

What is the simplest method of inter-process communication between 2 C# processes?

I would suggest using the Windows Communication Foundation:

http://en.wikipedia.org/wiki/Windows_Communication_Foundation

You can pass objects back and forth, use a variety of different protocols. I would suggest using the binary tcp protocol.

How to print out all the elements of a List in Java?

    list.stream().map(x -> x.getName()).forEach(System.out::println);

Get google map link with latitude/longitude

  <iframe src="https://maps.google.com/maps?q='+YOUR_LAT+','+YOUR_LON+'&hl=en&z=14&amp;output=embed" width="100%" height="400" frameborder="0" style="border:0" allowfullscreen></iframe>

put your replace lattitude,longitude values on YOUR_LAT,YOUR_LON respectively. hl parameter for setting language on map, z for zoomlevel;

Discard all and get clean copy of latest revision?

If you're looking for a method that's easy, then you might want to try this.

I for myself can hardly remember commandlines for all of my tools, so I tend to do it using the UI:


1. First, select "commit"

Commit

2. Then, display ignored files. If you have uncommitted changes, hide them.

Show ignored files

3. Now, select all of them and click "Delete Unversioned".

Delete them

Done. It's a procedure that is far easier to remember than commandline stuff.

node.js + mysql connection pooling

You should avoid using pool.getConnection() if you can. If you call pool.getConnection(), you must call connection.release() when you are done using the connection. Otherwise, your application will get stuck waiting forever for connections to be returned to the pool once you hit the connection limit.

For simple queries, you can use pool.query(). This shorthand will automatically call connection.release() for you—even in error conditions.

function doSomething(cb) {
  pool.query('SELECT 2*2 "value"', (ex, rows) => {
    if (ex) {
      cb(ex);
    } else {
      cb(null, rows[0].value);
    }
  });
}

However, in some cases you must use pool.getConnection(). These cases include:

  • Making multiple queries within a transaction.
  • Sharing data objects such as temporary tables between subsequent queries.

If you must use pool.getConnection(), ensure you call connection.release() using a pattern similar to below:

function doSomething(cb) {
  pool.getConnection((ex, connection) => {
    if (ex) {
      cb(ex);
    } else {
      // Ensure that any call to cb releases the connection
      // by wrapping it.
      cb = (cb => {
        return function () {
          connection.release();
          cb.apply(this, arguments);
        };
      })(cb);
      connection.beginTransaction(ex => {
        if (ex) {
          cb(ex);
        } else {
          connection.query('INSERT INTO table1 ("value") VALUES (\'my value\');', ex => {
            if (ex) {
              cb(ex);
            } else {
              connection.query('INSERT INTO table2 ("value") VALUES (\'my other value\')', ex => {
                if (ex) {
                  cb(ex);
                } else {
                  connection.commit(ex => {
                    cb(ex);
                  });
                }
              });
            }
          });
        }
      });
    }
  });
}

I personally prefer to use Promises and the useAsync() pattern. This pattern combined with async/await makes it a lot harder to accidentally forget to release() the connection because it turns your lexical scoping into an automatic call to .release():

async function usePooledConnectionAsync(actionAsync) {
  const connection = await new Promise((resolve, reject) => {
    pool.getConnection((ex, connection) => {
      if (ex) {
        reject(ex);
      } else {
        resolve(connection);
      }
    });
  });
  try {
    return await actionAsync(connection);
  } finally {
    connection.release();
  }
}

async function doSomethingElse() {
  // Usage example:
  const result = await usePooledConnectionAsync(async connection => {
    const rows = await new Promise((resolve, reject) => {
      connection.query('SELECT 2*4 "value"', (ex, rows) => {
        if (ex) {
          reject(ex);
        } else {
          resolve(rows);
        }
      });
    });
    return rows[0].value;
  });
  console.log(`result=${result}`);
}

JavaScriptSerializer - JSON serialization of enum as string

I wasn't able to change the source model like in the top answer (of @ob.), and I didn't want to register it globally like @Iggy. So I combined https://stackoverflow.com/a/2870420/237091 and @Iggy's https://stackoverflow.com/a/18152942/237091 to allow setting up the string enum converter on during the SerializeObject command itself:

Newtonsoft.Json.JsonConvert.SerializeObject(
    objectToSerialize, 
    Newtonsoft.Json.Formatting.None, 
    new Newtonsoft.Json.JsonSerializerSettings()
    {
        Converters = new List<Newtonsoft.Json.JsonConverter> {
            new Newtonsoft.Json.Converters.StringEnumConverter()
        }
    })

HTML5 Dynamically create Canvas

Alternative

Use element .innerHTML= which is quite fast in modern browsers

_x000D_
_x000D_
document.body.innerHTML = "<canvas width=500 height=150 id='CursorLayer'>";


// TEST

var ctx = CursorLayer.getContext("2d");
ctx.fillStyle = "red";
ctx.fillRect(100, 100, 50, 50);
_x000D_
canvas { border: 1px solid black }
_x000D_
_x000D_
_x000D_

When to use Task.Delay, when to use Thread.Sleep?

The biggest difference between Task.Delay and Thread.Sleep is that Task.Delay is intended to run asynchronously. It does not make sense to use Task.Delay in synchronous code. It is a VERY bad idea to use Thread.Sleep in asynchronous code.

Normally you will call Task.Delay() with the await keyword:

await Task.Delay(5000);

or, if you want to run some code before the delay:

var sw = new Stopwatch();
sw.Start();
Task delay = Task.Delay(5000);
Console.WriteLine("async: Running for {0} seconds", sw.Elapsed.TotalSeconds);
await delay;

Guess what this will print? Running for 0.0070048 seconds. If we move the await delay above the Console.WriteLine instead, it will print Running for 5.0020168 seconds.

Let's look at the difference with Thread.Sleep:

class Program
{
    static void Main(string[] args)
    {
        Task delay = asyncTask();
        syncCode();
        delay.Wait();
        Console.ReadLine();
    }

    static async Task asyncTask()
    {
        var sw = new Stopwatch();
        sw.Start();
        Console.WriteLine("async: Starting");
        Task delay = Task.Delay(5000);
        Console.WriteLine("async: Running for {0} seconds", sw.Elapsed.TotalSeconds);
        await delay;
        Console.WriteLine("async: Running for {0} seconds", sw.Elapsed.TotalSeconds);
        Console.WriteLine("async: Done");
    }

    static void syncCode()
    {
        var sw = new Stopwatch();
        sw.Start();
        Console.WriteLine("sync: Starting");
        Thread.Sleep(5000);
        Console.WriteLine("sync: Running for {0} seconds", sw.Elapsed.TotalSeconds);
        Console.WriteLine("sync: Done");
    }
}

Try to predict what this will print...

async: Starting
async: Running for 0.0070048 seconds
sync: Starting
async: Running for 5.0119008 seconds
async: Done
sync: Running for 5.0020168 seconds
sync: Done

Also, it is interesting to notice that Thread.Sleep is far more accurate, ms accuracy is not really a problem, while Task.Delay can take 15-30ms minimal. The overhead on both functions is minimal compared to the ms accuracy they have (use Stopwatch Class if you need something more accurate). Thread.Sleep still ties up your Thread, Task.Delay release it to do other work while you wait.

fopen deprecated warning

This is just Microsoft being cheeky. "Deprecated" implies a language feature that may not be provided in future versions of the standard language / standard libraries, as decreed by the standards committee. It does not, or should not mean, "we, unilaterally, don't think you should use it", no matter how well-founded that advice is.

Can you put two conditions in an xslt test attribute?

Not quite, the AND has to be lower-case.

<xsl:when test="4 &lt; 5 and 1 &lt; 2">
<!-- do something -->
</xsl:when>

"401 Unauthorized" on a directory

  • Open IIS
  • select site where you are facing the problem

  • Select Below

enter image description here

- Right click on Anonymous Authentication and click on edit and follow below

enter image description here

How to wait for a process to terminate to execute another process in batch file

This is an updated version of aphoria's Answer.

I Replaced PSLIST and PSEXEC with TASKKILL and TASKLIST`. As they seem to work better, I couldn't get PSLIST to run in Windows 7.

Also replaced Sleep with TIMEOUT.

This Was everything i needed to get the script running well, and all the additions was provided by the great guys who posted the comments.

Also if there is a delay before the .exe starts it might be worth inserting a Timeout before the :loop.

@ECHO OFF

TASKKILL NOTEPAD

START "" "C:\Program Files\Windows NT\Accessories\wordpad.exe"

:LOOP
tasklist | find /i "WORDPAD" >nul 2>&1
IF ERRORLEVEL 1 (
  GOTO CONTINUE
) ELSE (
  ECHO Wordpad is still running
  Timeout /T 5 /Nobreak
  GOTO LOOP
)

:CONTINUE
NOTEPAD

SQL server 2008 backup error - Operating system error 5(failed to retrieve text for this error. Reason: 15105)

I've got the same error. I have been trying to fixing this by setting higher permission to account running SQL Client service, however it didnt help. The problem was that I run MS Sql Management studio just within my account. So, next time... assure that you are running it as Run as Administrator, if using Win7 with UAC enabled.

Use a normal link to submit a form

You are using images to submit.. so you can simply use an type="image" input "button":

<input type="image" src="yourimage.png" name="yourinputname" value="yourinputvalue" />

Inverse dictionary lookup in Python

# oneline solution using zip
>> x = {'a':100, 'b':999}
>> y = dict(zip(x.values(), x.keys()))  
>> y
{100: 'a', 999: 'b'}

The preferred way of creating a new element with jQuery

I would recommend the first option, where you actually build elements using jQuery. the second approach simply sets the innerHTML property of the element to a string, which happens to be HTML, and is more error prone and less flexible.

Android Studio Error: Error:CreateProcess error=216, This version of %1 is not compatible with the version of Windows you're running

REASON

This happens because for now they only ship 64bit JRE with Android Studio for Windows which produces glitches in 32 bit systems.

SOLUTION

  • do not use the embedded JDK: Go to File -> Project Structure dialog, uncheck "Use embedded JDK" and select the 32-bit JRE you've installed separately in your system
  • decrease the memory footprint for Gradle in gradle.properties(Project Properties), for eg set it to -Xmx768m.

For more details: https://code.google.com/p/android/issues/detail?id=219524

How to delete large data of table in SQL without log?

If you are willing (and able) to implement partitioning, that is an effective technique for removing large quantities of data with little run-time overhead. Not cost-effective for a once-off exercise, though.

Best way to return a value from a python script

If you want your script to return values, just do return [1,2,3] from a function wrapping your code but then you'd have to import your script from another script to even have any use for that information:

Return values (from a wrapping-function)

(again, this would have to be run by a separate Python script and be imported in order to even do any good):

import ...
def main():
    # calculate stuff
    return [1,2,3]

Exit codes as indicators

(This is generally just good for when you want to indicate to a governor what went wrong or simply the number of bugs/rows counted or w/e. Normally 0 is a good exit and >=1 is a bad exit but you could inter-prate them in any way you want to get data out of it)

import sys
# calculate and stuff
sys.exit(100)

And exit with a specific exit code depending on what you want that to tell your governor. I used exit codes when running script by a scheduling and monitoring environment to indicate what has happened.

(os._exit(100) also works, and is a bit more forceful)

Stdout as your relay

If not you'd have to use stdout to communicate with the outside world (like you've described). But that's generally a bad idea unless it's a parser executing your script and can catch whatever it is you're reporting to.

import sys
# calculate stuff
sys.stdout.write('Bugs: 5|Other: 10\n')
sys.stdout.flush()
sys.exit(0)

Are you running your script in a controlled scheduling environment then exit codes are the best way to go.

Files as conveyors

There's also the option to simply write information to a file, and store the result there.

# calculate
with open('finish.txt', 'wb') as fh:
    fh.write(str(5)+'\n')

And pick up the value/result from there. You could even do it in a CSV format for others to read simplistically.

Sockets as conveyors

If none of the above work, you can also use network sockets locally *(unix sockets is a great way on nix systems). These are a bit more intricate and deserve their own post/answer. But editing to add it here as it's a good option to communicate between processes. Especially if they should run multiple tasks and return values.

Pandas convert string to int

You need add parameter errors='coerce' to function to_numeric:

ID = pd.to_numeric(ID, errors='coerce')

If ID is column:

df.ID = pd.to_numeric(df.ID, errors='coerce')

but non numeric are converted to NaN, so all values are float.

For int need convert NaN to some value e.g. 0 and then cast to int:

df.ID = pd.to_numeric(df.ID, errors='coerce').fillna(0).astype(np.int64)

Sample:

df = pd.DataFrame({'ID':['4806105017087','4806105017087','CN414149']})
print (df)
              ID
0  4806105017087
1  4806105017087
2       CN414149

print (pd.to_numeric(df.ID, errors='coerce'))
0    4.806105e+12
1    4.806105e+12
2             NaN
Name: ID, dtype: float64

df.ID = pd.to_numeric(df.ID, errors='coerce').fillna(0).astype(np.int64)
print (df)
              ID
0  4806105017087
1  4806105017087
2              0

EDIT: If use pandas 0.25+ then is possible use integer_na:

df.ID = pd.to_numeric(df.ID, errors='coerce').astype('Int64')
print (df)
              ID
0  4806105017087
1  4806105017087
2            NaN

Making text bold using attributed string in swift

Accepting as valid the response of Prajeet Shrestha in this thread, I would like to extend his solution using the Label if it is known and the traits of the font.

Swift 4

extension NSMutableAttributedString {

    @discardableResult func normal(_ text: String) -> NSMutableAttributedString {
        let normal = NSAttributedString(string: text)
        append(normal)

        return self
    }

    @discardableResult func bold(_ text: String, withLabel label: UILabel) -> NSMutableAttributedString {

        //generate the bold font
        var font: UIFont = UIFont(name: label.font.fontName , size: label.font.pointSize)!
        font = UIFont(descriptor: font.fontDescriptor.withSymbolicTraits(.traitBold) ?? font.fontDescriptor, size: font.pointSize)

        //generate attributes
        let attrs: [NSAttributedStringKey: Any] = [NSAttributedStringKey.font: font]
        let boldString = NSMutableAttributedString(string:text, attributes: attrs)

        //append the attributed text
        append(boldString)

        return self
    }
}

Google Chrome forcing download of "f.txt" file

Seems related to https://groups.google.com/forum/#!msg/google-caja-discuss/ite6K5c8mqs/Ayqw72XJ9G8J.

The so-called "Rosetta Flash" vulnerability is that allowing arbitrary yet identifier-like text at the beginning of a JSONP response is sufficient for it to be interpreted as a Flash file executing in that origin. See for more information: http://miki.it/blog/2014/7/8/abusing-jsonp-with-rosetta-flash/

JSONP responses from the proxy servlet now: * are prefixed with "/**/", which still allows them to execute as JSONP but removes requester control over the first bytes of the response. * have the response header Content-Disposition: attachment.

Asynchronous vs synchronous execution, what does it really mean?

A different english definition of Synchronize is Here

Coordinate; combine.

I think that is a better definition than of "Happening at the same time". That one is also a definition, but I don't think it is the one that fits the way it is used in Computer Science.

So an asynchronous task is not co-coordinated with other tasks, whereas a synchronous task IS co-coordinated with other tasks, so one finishes before another starts.

How that is achieved is a different question.

How to use MD5 in javascript to transmit a password

In response to jt. You are correct, the HTML with just the password is susceptible to the Man in the middle attack. However, you can seed it with a GUID from the server ...

$.post(
  'includes/login.php', 
  { user: username, pass: $.md5(password + GUID) },
   onLogin, 
  'json' );

This would defeat the Man-In-The middle ... in that the server would generate a new GUID for each attempt.

Java ArrayList how to add elements at the beginning

What you are describing, is an appropriate situation to use Queue.

Since you want to add new element, and remove the old one. You can add at the end, and remove from the beginning. That will not make much of a difference.

Queue has methods add(e) and remove() which adds at the end the new element, and removes from the beginning the old element, respectively.

Queue<Integer> queue = new LinkedList<Integer>();
queue.add(5);
queue.add(6);
queue.remove();  // Remove 5

So, every time you add an element to the queue you can back it up with a remove method call.


UPDATE: -

And if you want to fix the size of the Queue, then you can take a look at: - ApacheCommons#CircularFifoBuffer

From the documentation: -

CircularFifoBuffer is a first in first out buffer with a fixed size that replaces its oldest element if full.

Buffer queue = new CircularFifoBuffer(2); // Max size

queue.add(5);
queue.add(6);
queue.add(7);  // Automatically removes the first element `5`

As you can see, when the maximum size is reached, then adding new element automatically removes the first element inserted.

How to add to an existing hash in Ruby

hash {}
hash[:a] = 'a'
hash[:b] = 'b'
hash = {:a => 'a' , :b = > b}

You might get your key and value from user input, so you can use Ruby .to_sym can convert a string to a symbol, and .to_i will convert a string to an integer.
For example:

movies ={}
movie = gets.chomp
rating = gets.chomp
movies[movie.to_sym] = rating.to_int
# movie will convert to a symbol as a key in our hash, and 
# rating will be an integer as a value.

Remove the first character of a string

Your problem seems unclear. You say you want to remove "a character from a certain position" then go on to say you want to remove a particular character.

If you only need to remove the first character you would do:

s = ":dfa:sif:e"
fixed = s[1:]

If you want to remove a character at a particular position, you would do:

s = ":dfa:sif:e"
fixed = s[0:pos]+s[pos+1:]

If you need to remove a particular character, say ':', the first time it is encountered in a string then you would do:

s = ":dfa:sif:e"
fixed = ''.join(s.split(':', 1))

Local package.json exists, but node_modules missing

Just had the same error message, but when I was running a package.json with:

"scripts": {
    "build": "tsc -p ./src",
}

tsc is the command to run the TypeScript compiler.

I never had any issues with this project because I had TypeScript installed as a global module. As this project didn't include TypeScript as a dev dependency (and expected it to be installed as global), I had the error when testing in another machine (without TypeScript) and running npm install didn't fix the problem. So I had to include TypeScript as a dev dependency (npm install typescript --save-dev) to solve the problem.

%Like% Query in spring JpaRepository

The spring data JPA query needs the "%" chars as well as a space char following like in your query, as in

@Query("Select c from Registration c where c.place like %:place%").

Cf. http://docs.spring.io/spring-data/jpa/docs/current/reference/html.

You may want to get rid of the @Queryannotation alltogether, as it seems to resemble the standard query (automatically implemented by the spring data proxies); i.e. using the single line

List<Registration> findByPlaceContaining(String place);

is sufficient.

Nested JSON objects - do I have to use arrays for everything?

Every object has to be named inside the parent object:

{ "data": {
    "stuff": {
        "onetype": [
            { "id": 1, "name": "" },
            { "id": 2, "name": "" }
        ],
        "othertype": [
            { "id": 2, "xyz": [-2, 0, 2], "n": "Crab Nebula", "t": 0, "c": 0, "d": 5 }
        ]
    },
    "otherstuff": {
        "thing":
            [[1, 42], [2, 2]]
    }
}
}

So you cant declare an object like this:

var obj = {property1, property2};

It has to be

var obj = {property1: 'value', property2: 'value'};

Check table exist or not before create it in Oracle

Any solution which relies on testing before creation can run into a 'race' condition where another process creates the table between you testing that it does not exists and creating it. - Minor point I know.

Ineligible Devices section appeared in Xcode 6.x.x

Simply deploying to another device and then switching back to the former 'ineligible' device worked here. (saved the hassle of restarting anything)

Difference between float and decimal data type

Hard & Fast Rule

If all you need to do is add, subtract or multiply the numbers you are storing, DECIMAL is best.

If you need to divide or do any other form of arithmetic or algebra on the data you're almost certainly going to be happier with float. Floating point libraries, and on Intel processors, the floating point processor itself, have TONs of operations to correct, fix-up, detect and handle the blizzard of exceptions that occur when doing typical math functions - especially transcendental functions.

As for accuracy, I once wrote a budget system that computed the % contribution of each of 3,000+ accounts, for 3,600 budget units, by month to that unit's consolidation node, then based on that matrix of percentages (3,000 + x 12 x 3,600) I multiplied the amounts budgeted by the highest organizational nodes down to the next 3 levels of the organizational nodes, and then computed all (3,000 + 12) values for all 3,200 detail units from that. Millions and millions and millions of double precision floating point calculations, any one of which would throw off the roll-up of all of those projections in a bottoms-up consolidation back to the highest level in the organization.

The total floating point error after all of those calculations was ZERO. That was in 1986, and floating point libraries today are much, much better than they were back then. Intel does all of it's intermediate calculations of doubles in 80 bit precision, which all but eliminates rounding error. When someone tells you "it's floating point error" it's almost certainty NOT true.

Returning a C string from a function

Your function prototype states your function will return a char. Thus, you can't return a string in your function.

Set initial focus in an Android application

@Someone Somewhere, I tried all of the above to no avail. The fix I found is from http://www.helloandroid.com/tutorials/remove-autofocus-edittext-android . Basically, you need to create an invisible layout just above the problematic Button:

<LinearLayout android:focusable="true"
              android:focusableInTouchMode="true" 
              android:layout_width="0px"
              android:layout_height="0px" >
    <requestFocus />
</LinearLayout>

Eclipse says: “Workspace in use or cannot be created, chose a different one.” How do I unlock a workspace?

I had this error after I restarted the system (after a long time. Normally I just make it sleep). Found out that once I mounted the drives (by clicking and opening it) where project folder is located, and relaunching eclipse, solved the issue for me.

PS: I'm an ubuntu user.

Python IndentationError: unexpected indent

find all tabs and replaced by 4 spaces in notepad ++ .It worked.

Copying PostgreSQL database to another server

I struggled quite a lot and eventually the method that allowed me to make it work with Rails 4 was:

on your old server

sudo su - postgres
pg_dump -c --inserts old_db_name > dump.sql

I had to use the postgres linux user to create the dump. also i had to use -c to force the creation of the database on the new server. --inserts tells it to use the INSERT() syntax which otherwise would not work for me :(

then, on the new server, simpy:

sudo su - postgres
psql new_database_name < dump.sql

to transfer the dump.sql file between server I simply used the "cat" to print the content and than "nano" to recreate it copypasting the content.

Also, the ROLE i was using on the two database was different so i had to find-replace all the owner name in the dump.

Converting string to integer

The function you need is CInt.

ie CInt(PrinterLabel)

See Type Conversion Functions (Visual Basic) on MSDN

Edit: Be aware that CInt and its relatives behave differently in VB.net and VBScript. For example, in VB.net, CInt casts to a 32-bit integer, but in VBScript, CInt casts to a 16-bit integer. Be on the lookout for potential overflows!

Failed to load AppCompat ActionBar with unknown error in android studio

found it on this site, it works on me. Modify /res/values/styles.xml from:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
</style>

to:

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
</style>

Copy multiple files with Ansible

Or you can use with_items:

- copy:
    src: "{{ item }}"
    dest: /etc/fooapp/
    owner: root
    mode: 600
  with_items:
    - dest_dir

How to programmatically set the ForeColor of a label to its default?

Easy

if (lblExample.ForeColor != System.Drawing.Color.Red)
{
    lblExample.ForeColor = System.Drawing.Color.Red;
}
else
{
    lblExample.ForeColor = new System.Drawing.Color();
}

Retrieve only the queried element in an object array in MongoDB collection

Another interesing way is to use $redact, which is one of the new aggregation features of MongoDB 2.6. If you are using 2.6, you don't need an $unwind which might cause you performance problems if you have large arrays.

db.test.aggregate([
    { $match: { 
         shapes: { $elemMatch: {color: "red"} } 
    }},
    { $redact : {
         $cond: {
             if: { $or : [{ $eq: ["$color","red"] }, { $not : "$color" }]},
             then: "$$DESCEND",
             else: "$$PRUNE"
         }
    }}]);

$redact "restricts the contents of the documents based on information stored in the documents themselves". So it will run only inside of the document. It basically scans your document top to the bottom, and checks if it matches with your if condition which is in $cond, if there is match it will either keep the content($$DESCEND) or remove($$PRUNE).

In the example above, first $match returns the whole shapes array, and $redact strips it down to the expected result.

Note that {$not:"$color"} is necessary, because it will scan the top document as well, and if $redact does not find a color field on the top level this will return false that might strip the whole document which we don't want.

How can I show figures separately in matplotlib?

As @arpanmangal, the solutions above do not work for me (matplotlib 3.0.3, python 3.5.2).

It seems that using .show() in a figure, e.g., figure.show(), is not recommended, because this method does not manage a GUI event loop and therefore the figure is just shown briefly. (See figure.show() documentation). However, I do not find any another way to show only a figure.

In my solution I get to prevent the figure for instantly closing by using click events. We do not have to close the figure — closing the figure deletes it.

I present two options: - waitforbuttonpress(timeout=-1) will close the figure window when clicking on the figure, so we cannot use some window functions like zooming. - ginput(n=-1,show_clicks=False) will wait until we close the window, but it releases an error :-.

Example:

import matplotlib.pyplot as plt

fig1, ax1 = plt.subplots(1) # Creates figure fig1 and add an axes, ax1
fig2, ax2 = plt.subplots(1) # Another figure fig2 and add an axes, ax2

ax1.plot(range(20),c='red') #Add a red straight line to the axes of fig1.
ax2.plot(range(100),c='blue') #Add a blue straight line to the axes of fig2.

#Option1: This command will hold the window of fig2 open until you click on the figure
fig2.waitforbuttonpress(timeout=-1) #Alternatively, use fig1

#Option2: This command will hold the window open until you close the window, but
#it releases an error.
#fig2.ginput(n=-1,show_clicks=False) #Alternatively, use fig1

#We show only fig2
fig2.show() #Alternatively, use fig1

How to import a jar in Eclipse

In eclipse I included a compressed jar file i.e. zip file. Eclipse allowed me to add this zip file as an external jar but when I tried to access the classes in the jar they weren't showing up.

After a lot of trial and error I found that using a zip format doesn't work. When I added a jar file then it worked for me.

Insert results of a stored procedure into a temporary table

  1. I'm creating a table with the following schema and data.

  2. Create a stored procedure.

  3. Now I know what the result of my procedure is, so I am performing the following query.

     CREATE TABLE [dbo].[tblTestingTree](
         [Id] [int] IDENTITY(1,1) NOT NULL,
         [ParentId] [int] NULL,
         [IsLeft] [bit] NULL,
         [IsRight] [bit] NULL,
     CONSTRAINT [PK_tblTestingTree] PRIMARY KEY CLUSTERED
     (
         [Id] ASC
     ) WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
     ) ON [PRIMARY]
     GO
     SET IDENTITY_INSERT [dbo].[tblTestingTree] ON
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (1, NULL, NULL, NULL)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (2, 1, 1, NULL)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (3, 1, NULL, 1)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (4, 2, 1, NULL)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (5, 2, NULL, 1)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (6, 3, 1, NULL)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (7, 3, NULL, 1)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (8, 4, 1, NULL)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (9, 4, NULL, 1)
     INSERT [dbo].[tblTestingTree] ([Id], [ParentId], [IsLeft], [IsRight]) VALUES (10, 5, 1, NULL)
    
     SET IDENTITY_INSERT [dbo].[tblTestingTree] OFF
     VALUES (10, 5, 1, NULL)
     SET IDENTITY_INSERT [dbo].[tblTestingTree] On
    
    
     create procedure GetDate
     as
     begin
         select Id,ParentId from tblTestingTree
     end
    
     create table tbltemp
     (
         id int,
         ParentId int
     )
     insert into tbltemp
     exec GetDate
    
     select * from tbltemp;
    

Should I use the Reply-To header when sending emails as a service to others?

You may want to consider placing the customer's name in the From header and your address in the Sender header:

From: Company A <[email protected]>
Sender: [email protected]

Most mailers will render this as "From [email protected] on behalf of Company A", which is accurate. And then a Reply-To of Company A's address won't seem out of sorts.

From RFC 5322:

The "From:" field specifies the author(s) of the message, that is, the mailbox(es) of the person(s) or system(s) responsible for the writing of the message. The "Sender:" field specifies the mailbox of the agent responsible for the actual transmission of the message. For example, if a secretary were to send a message for another person, the mailbox of the secretary would appear in the "Sender:" field and the mailbox of the actual author would appear in the "From:" field.

How to check if running in Cygwin, Mac or Linux?

Use uname -s (--kernel-name) because uname -o (--operating-system) is not supported on some Operating Systems such as Mac OS and Solaris. You may also use just uname without any argument since the default argument is -s (--kernel-name).

The below snippet does not require (i.e. does not require #!/bin/bash)

#!/bin/sh

case "$(uname -s)" in

   Darwin)
     echo 'Mac OS X'
     ;;

   Linux)
     echo 'Linux'
     ;;

   CYGWIN*|MINGW32*|MSYS*|MINGW*)
     echo 'MS Windows'
     ;;

   # Add here more strings to compare
   # See correspondence table at the bottom of this answer

   *)
     echo 'Other OS' 
     ;;
esac

The below Makefile is inspired from Git project (config.mak.uname).

ifdef MSVC     # Avoid the MingW/Cygwin sections
    uname_S := Windows
else                          # If uname not available => 'not' 
    uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
endif

# Avoid nesting "if .. else if .. else .. endif endif"
# because maintenance of matching if/else/endif is a pain

ifeq ($(uname_S),Windows)
    CC := cl 
endif
ifeq ($(uname_S),OSF1)
    CFLAGS += -D_OSF_SOURCE
endif
ifeq ($(uname_S),Linux)
    CFLAGS += -DNDEBUG
endif
ifeq ($(uname_S),GNU/kFreeBSD)
    CFLAGS += -D_BSD_ALLOC
endif
ifeq ($(uname_S),UnixWare)
    CFLAGS += -Wextra
endif
...

See also this complete answer about uname -s and Makefile.

The correspondence table in the bottom of this answer is from Wikipedia article about uname. Please contribute to keep it up-to-date (edit the answer or post a comment). You may also update the Wikipedia article and post a comment to notify me about your contribution ;-)

Operating System uname -s
Mac OS X Darwin
Cygwin 32-bit (Win-XP) CYGWIN_NT-5.1
Cygwin 32-bit (Win-7 32-bit)CYGWIN_NT-6.1
Cygwin 32-bit (Win-7 64-bit)CYGWIN_NT-6.1-WOW64
Cygwin 64-bit (Win-7 64-bit)CYGWIN_NT-6.1
MinGW (Windows 7 32-bit) MINGW32_NT-6.1
MinGW (Windows 10 64-bit) MINGW64_NT-10.0
Interix (Services for UNIX) Interix
MSYS MSYS_NT-6.1
MSYS2 MSYS_NT-10.0-17763
Windows Subsystem for Linux Linux
Android Linux
coreutils Linux
CentOS Linux
Fedora Linux
Gentoo Linux
Red Hat Linux Linux
Linux Mint Linux
openSUSE Linux
Ubuntu Linux
Unity Linux Linux
Manjaro Linux Linux
OpenWRT r40420 Linux
Debian (Linux) Linux
Debian (GNU Hurd) GNU
Debian (kFreeBSD) GNU/kFreeBSD
FreeBSD FreeBSD
NetBSD NetBSD
OpenBSD OpenBSD
DragonFlyBSD DragonFly
Haiku Haiku
NonStop NONSTOP_KERNEL
QNX QNX
ReliantUNIX ReliantUNIX-Y
SINIX SINIX-Y
Tru64 OSF1
Ultrix ULTRIX
IRIX 32 bits IRIX
IRIX 64 bits IRIX64
MINIX Minix
Solaris SunOS
UWIN (64-bit Windows 7) UWIN-W7
SYS$UNIX:SH on OpenVMS IS/WB
z/OS USS OS/390
Cray sn5176
(SCO) OpenServer SCO_SV
(SCO) System V SCO_SV
(SCO) UnixWare UnixWare
IBM AIX AIX
IBM i with QSH OS400
HP-UX HP-UX

Is there a difference between using a dict literal and a dict constructor?

These two approaches produce identical dictionaries, except, as you've noted, where the lexical rules of Python interfere.

Dictionary literals are a little more obviously dictionaries, and you can create any kind of key, but you need to quote the key names. On the other hand, you can use variables for keys if you need to for some reason:

a = "hello"
d = {
    a: 'hi'
    }

The dict() constructor gives you more flexibility because of the variety of forms of input it takes. For example, you can provide it with an iterator of pairs, and it will treat them as key/value pairs.

I have no idea why PyCharm would offer to convert one form to the other.

Printing Batch file results to a text file

For Print Result to text file

we can follow

echo "test data" > test.txt

This will create test.txt file and written "test data"

If you want to append then

echo "test data" >> test.txt

How to update fields in a model without creating a new record in django?

In my scenario, I want to update the status of status based on his id

student_obj = StudentStatus.objects.get(student_id=101)
student_obj.status= 'Enrolled'
student_obj.save()

Or If you want the last id from Student_Info table you can use the following.

student_obj = StudentStatus.objects.get(student_id=StudentInfo.objects.last().id)
student_obj.status= 'Enrolled'
student_obj.save()

Trim Cells using VBA in Excel

If you have a non-printing character at the front of the string try this


Option Explicit
Sub DoTrim()
    Dim cell As Range
    Dim str As String
    Dim nAscii As Integer
    For Each cell In Selection.Cells
        If cell.HasFormula = False Then
            str = Trim(CStr(cell))
            If Len(str) > 0 Then
                nAscii = Asc(Left(str, 1))
                If nAscii < 33 Or nAscii = 160 Then
                    If Len(str) > 1 Then
                        str = Right(str, Len(str) - 1)
                    Else
                        strl = ""
                    End If
                End If
            End If
            cell=str
        End If
    Next
End Sub

How to concatenate strings in windows batch file for loop?

A very simple example:

SET a=Hello
SET b=World
SET c=%a% %b%!
echo %c%

The result should be:

Hello World!

RuntimeWarning: invalid value encountered in divide

I think your code is trying to "divide by zero" or "divide by NaN". If you are aware of that and don't want it to bother you, then you can try:

import numpy as np
np.seterr(divide='ignore', invalid='ignore')

For more details see:

How to get the selected item of a combo box to a string variable in c#

You can use as below:

string selected = cmbbox.Text;
MessageBox.Show(selected);

Where do I put my php files to have Xampp parse them?

Look into the httpd.conf and/or httpd-vhosts.conf files and search for the DocumentRoot entry. If you configure multiple virtual hosts, there may be more than one of those, separated in <VirtualHost> tags.

Git - Ignore files during merge

Here git-update-index - Register file contents in the working tree to the index.

git update-index --assume-unchanged <PATH_OF_THE_FILE>

Example:-

git update-index --assume-unchanged somelocation/pom.xml

Passing enum or object through an intent (the best solution)

If you just want to send an enum you can do something like:

First declare an enum containing some value(which can be passed through intent):

 public enum MyEnum {
    ENUM_ZERO(0),
    ENUM_ONE(1),
    ENUM_TWO(2),
    ENUM_THREE(3);
    private int intValue;

    MyEnum(int intValue) {
        this.intValue = intValue;
    }

    public int getIntValue() {
        return intValue;
    }

    public static MyEnum getEnumByValue(int intValue) {
        switch (intValue) {
            case 0:
                return ENUM_ZERO;
            case 1:
                return ENUM_ONE;
            case 2:
                return ENUM_TWO;
            case 3:
                return ENUM_THREE;
            default:
                return null;
        }
    }
}

Then:

  intent.putExtra("EnumValue", MyEnum.ENUM_THREE.getIntValue());

And when you want to get it:

  NotificationController.MyEnum myEnum = NotificationController.MyEnum.getEnumByValue(intent.getIntExtra("EnumValue",-1);

Piece of cake!

Differences between unique_ptr and shared_ptr

When wrapping a pointer in a unique_ptr you cannot have multiple copies of unique_ptr. The shared_ptr holds a reference counter which count the number of copies of the stored pointer. Each time a shared_ptr is copied, this counter is incremented. Each time a shared_ptr is destructed, this counter is decremented. When this counter reaches 0, then the stored object is destroyed.

Differences between Ant and Maven

Just to list some more differences:

  • Ant doesn't have formal conventions. You have to tell Ant exactly where to find the source, where to put the outputs, etc.
  • Ant is procedural. You have to tell Ant exactly what to do; tell it to compile, copy, then compress, etc.
  • Ant doesn't have a lifecycle.
  • Maven uses conventions. It knows where your source code is automatically, as long as you follow these conventions. You don't need to tell Maven where it is.
  • Maven is declarative; All you have to do is create a pom.xml file and put your source in the default directory. Maven will take care of the rest.
  • Maven has a lifecycle. You simply call mvn install and a series of sequence steps are executed.
  • Maven has intelligence about common project tasks. To run tests, simple execute mvn test, as long as the files are in the default location. In Ant, you would first have to JUnit JAR file is, then create a classpath that includes the JUnit JAR, then tell Ant where it should look for test source code, write a goal that compiles the test source and then finally execute the unit tests with JUnit.

Update:

This came from Maven: The Definitive Guide. Sorry, I totally forgot to cite it.

Fatal error: Call to undefined function mb_strlen()

In case Google search for this error

Call to undefined function mb_ereg_match()

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

Ubuntu 18.04.1, PHP 7.2.10

sudo apt-get install php7.2-mbstring

How to read a file byte by byte in Python and how to print a bytelist as a binary?

Late to the party, but this may help anyone looking for a quick solution:

you can use bin(ord('b')).replace('b', '')bin() it gives you the binary representation with a 'b' after the last bit, you have to remove it. Also ord() gives you the ASCII number to the char or 8-bit/1 Byte coded character.

Cheers

Extracting the last n characters from a string in R

someone before uses a similar solution to mine, but I find it easier to think as below:

> text<-"some text in a string" # we want to have only the last word "string" with 6 letter
> n<-5 #as the last character will be counted with nchar(), here we discount 1
> substr(x=text,start=nchar(text)-n,stop=nchar(text))

This will bring the last characters as desired.

Finding all positions of substring in a larger string in C#

It could be done in efficient time complexity using KMP algorithm in O(N + M) where N is the length of text and M is the length of the pattern.

This is the implementation and usage:

static class StringExtensions
{
    public static IEnumerable<int> AllIndicesOf(this string text, string pattern)
    {
        if (string.IsNullOrEmpty(pattern))
        {
            throw new ArgumentNullException(nameof(pattern));
        }
        return Kmp(text, pattern);
    }

    private static IEnumerable<int> Kmp(string text, string pattern)
    {
        int M = pattern.Length;
        int N = text.Length;

        int[] lps = LongestPrefixSuffix(pattern);
        int i = 0, j = 0; 

        while (i < N)
        {
            if (pattern[j] == text[i])
            {
                j++;
                i++;
            }
            if (j == M)
            {
                yield return i - j;
                j = lps[j - 1];
            }

            else if (i < N && pattern[j] != text[i])
            {
                if (j != 0)
                {
                    j = lps[j - 1];
                }
                else
                {
                    i++;
                }
            }
        }
    }

    private static int[] LongestPrefixSuffix(string pattern)
    {
        int[] lps = new int[pattern.Length];
        int length = 0;
        int i = 1;

        while (i < pattern.Length)
        {
            if (pattern[i] == pattern[length])
            {
                length++;
                lps[i] = length;
                i++;
            }
            else
            {
                if (length != 0)
                {
                    length = lps[length - 1];
                }
                else
                {
                    lps[i] = length;
                    i++;
                }
            }
        }
        return lps;
    }

and this is an example of how to use it:

static void Main(string[] args)
    {
        string text = "this is a test";
        string pattern = "is";
        foreach (var index in text.AllIndicesOf(pattern))
        {
            Console.WriteLine(index); // 2 5
        }
    }

How can I keep Bootstrap popovers alive while being hovered?

I agree that the best way is to use the one given by: David Chase, Cu Ly, and others that the simplest way to do this is to use the container: $(this) property as follows:

$(selectorString).each(function () {
  var $this = $(this);
  $this.popover({
    html: true,
    placement: "top",
    container: $this,
    trigger: "hover",
    title: "Popover",
    content: "Hey, you hovered on element"
  });
});

I want to point out here that the popover in this case will inherit all properties of the current element. So, for example, if you do this for a .btn element(bootstrap), you won't be able to select text inside the popover. Just wanted to record that since I spent quite some time banging my head on this.

Syntax error on print with Python 3

Because in Python 3, print statement has been replaced with a print() function, with keyword arguments to replace most of the special syntax of the old print statement. So you have to write it as

print("Hello World")

But if you write this in a program and someone using Python 2.x tries to run it, they will get an error. To avoid this, it is a good practice to import print function:

from __future__ import print_function

Now your code works on both 2.x & 3.x.

Check out below examples also to get familiar with print() function.

Old: print "The answer is", 2*2
New: print("The answer is", 2*2)

Old: print x,           # Trailing comma suppresses newline
New: print(x, end=" ")  # Appends a space instead of a newline

Old: print              # Prints a newline
New: print()            # You must call the function!

Old: print >>sys.stderr, "fatal error"
New: print("fatal error", file=sys.stderr)

Old: print (x, y)       # prints repr((x, y))
New: print((x, y))      # Not the same as print(x, y)!

Source: What’s New In Python 3.0?

Deserialize from string instead TextReader

1-liner, takes a XML string text and YourType as the expected object type. not very different from other answers, just compressed to 1 line:

var result =  (YourType)new XmlSerializer(typeof(YourType)).Deserialize(new StringReader(text));

Can I dynamically add HTML within a div tag from C# on load event?

You can add a div with runat="server" to the page:

<div runat="server" id="myDiv">
</div>

and then set its InnerHtml property from the code-behind:

myDiv.InnerHtml = "your html here";

If you want to modify the DIV's contents on the client side, then you can use javascript code similar to this:

<script type="text/javascript">
    Sys.Application.add_load(MyLoad);
    function MyLoad(sender) {
        $get('<%= div.ClientID %>').innerHTML += " - text added on client";
    }
</script>

Reading an image file in C/C++

If you decide to go for a minimal approach, without libpng/libjpeg dependencies, I suggest using stb_image and stb_image_write, found here.

It's as simple as it gets, you just need to place the header files stb_image.h and stb_image_write.h in your folder.

Here's the code that you need to read images:

#include <stdint.h>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

int main() {
    int width, height, bpp;

    uint8_t* rgb_image = stbi_load("image.png", &width, &height, &bpp, 3);

    stbi_image_free(rgb_image);

    return 0;
}

And here's the code to write an image:

#include <stdint.h>

#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

#define CHANNEL_NUM 3

int main() {
    int width = 800; 
    int height = 800;

    uint8_t* rgb_image;
    rgb_image = malloc(width*height*CHANNEL_NUM);

    // Write your code to populate rgb_image here

    stbi_write_png("image.png", width, height, CHANNEL_NUM, rgb_image, width*CHANNEL_NUM);

    return 0;
}

You can compile without flags or dependencies:

g++ main.cpp

Other lightweight alternatives include:

Create Git branch with current changes

Like stated in this question: Git: Create a branch from unstagged/uncommited changes on master: stash is not necessary.

Just use:

git checkout -b topic/newbranch

Any uncommitted work will be taken along to the new branch.

If you try to push you will get the following message

fatal: The current branch feature/NEWBRANCH has no upstream branch. To push the current branch and set the remote as upstream, use

git push --set-upstream origin feature/feature/NEWBRANCH

Just do as suggested to create the branch remotely:

git push --set-upstream origin feature/feature/NEWBRANCH

C# Return Different Types?

You could just return an Object as all types are descended from Object.

public Object GetAnything()
{
     Hello hello = new Hello();
     Computer computer = new Computer();
     Radio radio = new Radio();

     return radio; or return computer; or return hello //should be possible?!      
}

You could then cast to its relevant type:

Hello hello = (Hello)GetAnything();

If you didn't know what the type was going to be then you could use the is keyword.

Object obj = GetAnything();
if (obj is Hello) {
    // Do something
}

This being said I would be reluctant to write code like that. It would be much better to have an interface which is implemented by each of your classes.

public ISpeak GetAnything()
{
     Hello hello = new Hello();
     Computer computer = new Computer();
     Radio radio = new Radio();

     return radio; or return computer; or return hello //should be possible?!      
}

interface ISpeak 
{
   void Speak();
}

and have each of your classes implement the interface:

public class Hello : ISpeak
{
    void Speak() {
        Console.WriteLine("Hello");
    }
}

You could then do something like:

GetAnything().Speak();

Why does the jquery change event not trigger when I set the value of a select using val()?

If you've just added the select option to a form and you wish to trigger the change event, I've found a setTimeout is required otherwise jQuery doesn't pick up the newly added select box:

window.setTimeout(function() { jQuery('.languagedisplay').change();}, 1);

installing requests module in python 2.7 windows

There are four options here:

  1. Get virtualenv set up. Each virtual environment you create will automatically have pip.

  2. Get pip set up globally.

  3. Learn how to install Python packages manually—in most cases it's as simple as download, unzip, python setup.py install, but not always.

  4. Use Christoph Gohlke's binary installers.

Defining a `required` field in Bootstrap

Use 'needs-validation' apart from form-group, it will work.

How to make node.js require absolute? (instead of relative)

If your app's entry point js file (i.e. the one you actually run "node" on) is in your project root directory, you can do this really easily with the rootpath npm module. Simply install it via

npm install --save rootpath

...then at the very top of the entry point js file, add:

require('rootpath')();

From that point forward all require calls are now relative to project root - e.g. require('../../../config/debugging/log'); becomes require('config/debugging/log'); (where the config folder is in the project root).

Run PostgreSQL queries from the command line

psql -U username -d mydatabase -c 'SELECT * FROM mytable'

If you're new to postgresql and unfamiliar with using the command line tool psql then there is some confusing behaviour you should be aware of when you've entered an interactive session.

For example, initiate an interactive session:

psql -U username mydatabase 
mydatabase=#

At this point you can enter a query directly but you must remember to terminate the query with a semicolon ;

For example:

mydatabase=# SELECT * FROM mytable;

If you forget the semicolon then when you hit enter you will get nothing on your return line because psql will be assuming that you have not finished entering your query. This can lead to all kinds of confusion. For example, if you re-enter the same query you will have most likely create a syntax error.

As an experiment, try typing any garble you want at the psql prompt then hit enter. psql will silently provide you with a new line. If you enter a semicolon on that new line and then hit enter, then you will receive the ERROR:

mydatabase=# asdfs 
mydatabase=# ;  
ERROR:  syntax error at or near "asdfs"
LINE 1: asdfs
    ^

The rule of thumb is: If you received no response from psql but you were expecting at least SOMETHING, then you forgot the semicolon ;

How to return JSON data from spring Controller using @ResponseBody

Considering @Arpit answer, for me it worked only when I add two jackson dependencies:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.4.3</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.4.3</version>
</dependency>

and configured, of cause, web.xml <mvc:annotation-driven/>.

Original answer that helped me is here: https://stackoverflow.com/a/33896080/3014866

How to Define Callbacks in Android?

In many cases, you have an interface and pass along an object that implements it. Dialogs for example have the OnClickListener.

Just as a random example:

// The callback interface
interface MyCallback {
    void callbackCall();
}

// The class that takes the callback
class Worker {
   MyCallback callback;

   void onEvent() {
      callback.callbackCall();
   }
}

// Option 1:

class Callback implements MyCallback {
   void callbackCall() {
      // callback code goes here
   }
}

worker.callback = new Callback();

// Option 2:

worker.callback = new MyCallback() {

   void callbackCall() {
      // callback code goes here
   }
};

I probably messed up the syntax in option 2. It's early.

How to remove a variable from a PHP session array

To remove a specific variable from the session use:

session_unregister('variableName');

(see documentation) or

unset($_SESSION['variableName']);

NOTE: session_unregister() has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.

Java Garbage Collection Log messages

Most of it is explained in the GC Tuning Guide (which you would do well to read anyway).

The command line option -verbose:gc causes information about the heap and garbage collection to be printed at each collection. For example, here is output from a large server application:

[GC 325407K->83000K(776768K), 0.2300771 secs]
[GC 325816K->83372K(776768K), 0.2454258 secs]
[Full GC 267628K->83769K(776768K), 1.8479984 secs]

Here we see two minor collections followed by one major collection. The numbers before and after the arrow (e.g., 325407K->83000K from the first line) indicate the combined size of live objects before and after garbage collection, respectively. After minor collections the size includes some objects that are garbage (no longer alive) but that cannot be reclaimed. These objects are either contained in the tenured generation, or referenced from the tenured or permanent generations.

The next number in parentheses (e.g., (776768K) again from the first line) is the committed size of the heap: the amount of space usable for java objects without requesting more memory from the operating system. Note that this number does not include one of the survivor spaces, since only one can be used at any given time, and also does not include the permanent generation, which holds metadata used by the virtual machine.

The last item on the line (e.g., 0.2300771 secs) indicates the time taken to perform the collection; in this case approximately a quarter of a second.

The format for the major collection in the third line is similar.

The format of the output produced by -verbose:gc is subject to change in future releases.

I'm not certain why there's a PSYoungGen in yours; did you change the garbage collector?

How can I print out just the index of a pandas dataframe?

You can access the index attribute of a df using .index:

In [277]:

df = pd.DataFrame({'a':np.arange(10), 'b':np.random.randn(10)})
df
Out[277]:
   a         b
0  0  0.293422
1  1 -1.631018
2  2  0.065344
3  3 -0.417926
4  4  1.925325
5  5  0.167545
6  6 -0.988941
7  7 -0.277446
8  8  1.426912
9  9 -0.114189
In [278]:

df.index
Out[278]:
Int64Index([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], dtype='int64')

What does mvn install in maven exactly do

It's important to point out that install and install:install are different things, install is a phase, in which maven do more than just install current project modules artifacs to local repository, it check remote repository first. On the other hand, install:install is a goal, it just build your current project and install all it's artifacts to local repository (e.g. into the .m2 directory).

NLS_NUMERIC_CHARACTERS setting for decimal

To know SESSION decimal separator, you can use following SQL command:

ALTER SESSION SET NLS_NUMERIC_CHARACTERS = ', ';

select SUBSTR(value,1,1) as "SEPARATOR"
      ,'using NLS-PARAMETER' as "Explanation"
  from nls_session_parameters
  where parameter = 'NLS_NUMERIC_CHARACTERS'

UNION ALL

select SUBSTR(0.5,1,1) as "SEPARATOR" 
      ,'using NUMBER IMPLICIT CASTING' as "Explanation"
  from DUAL;

The first SELECT command find NLS Parameter defined in NLS_SESSION_PARAMETERS table. The decimal separator is the first character of the returned value.

The second SELECT command convert IMPLICITELY the 0.5 rational number into a String using (by default) NLS_NUMERIC_CHARACTERS defined at session level.

The both command return same value.

I have already tested the same SQL command in PL/SQL script and this is always the same value COMMA or POINT that is displayed. Decimal Separator displayed in PL/SQL script is equal to what is displayed in SQL.

To test what I say, I have used following SQL commands:

ALTER SESSION SET NLS_NUMERIC_CHARACTERS = ', ';

select 'DECIMAL-SEPARATOR on CLIENT: (' || TO_CHAR(.5,) || ')' from dual;

DECLARE
    S VARCHAR2(10) := '?';
BEGIN

    select .5 INTO S from dual;

    DBMS_OUTPUT.PUT_LINE('DECIMAL-SEPARATOR in PL/SQL: (' || S || ')');
END;
/

The shorter command to know decimal separator is:

SELECT .5 FROM DUAL;

That return 0,5 if decimal separator is a COMMA and 0.5 if decimal separator is a POINT.

Mythical man month 10 lines per developer day - how close on large projects?

Steve McConnell gives an interesting statistic in his book "Software Estimation" (p62 Table 5.2) He distinguish between project types (Avionic, Business, Telco, etc) and project size 10 kLOC, 100 kLOC, 250 kLOC. The numbers are given for each combination in LOC/StaffMonth. E.G. Avionic: 200, 50, 40 Intranet Systems (Internal): 4000, 800, 600 Embedded Systems: 300, 70, 60

Which means: eg. for Avionic 250-kLOC project there are 40 (LOC/Month) / 22 (Days/Month) == <2LOC/day!

Checkout subdirectories in Git?

There is an inspiration here. Just utilize shell regex or git regex.

git checkout commit_id */*.bat  # *.bat in 1-depth subdir exclude current dir, shell regex  
git checkout commit_id '*.bat'  # *.bat in all subdir include current dir, git regex

Use quotation to escape shell regex interpretation and pass wildcards to git.

The first one is not recursive, only files in 1-depth subdir. But the second one is recursive.

As for your situation, the following may be enough.

git checkout master */*/wp-content/*/*
git checkout master '*/wp-content/*'

Just hack the lines as required.

Change a column type from Date to DateTime during ROR migration

First in your terminal:

rails g migration change_date_format_in_my_table

Then in your migration file:

For Rails >= 3.2:

class ChangeDateFormatInMyTable < ActiveRecord::Migration
  def up
    change_column :my_table, :my_column, :datetime
  end

  def down
    change_column :my_table, :my_column, :date
  end
end

How can multiple rows be concatenated into one in Oracle without creating a stored procedure?

There are many way to do the string aggregation, but the easiest is a user defined function. Try this for a way that does not require a function. As a note, there is no simple way without the function.

This is the shortest route without a custom function: (it uses the ROW_NUMBER() and SYS_CONNECT_BY_PATH functions )

SELECT questionid,
       LTRIM(MAX(SYS_CONNECT_BY_PATH(elementid,','))
       KEEP (DENSE_RANK LAST ORDER BY curr),',') AS elements
FROM   (SELECT questionid,
               elementid,
               ROW_NUMBER() OVER (PARTITION BY questionid ORDER BY elementid) AS curr,
               ROW_NUMBER() OVER (PARTITION BY questionid ORDER BY elementid) -1 AS prev
        FROM   emp)
GROUP BY questionid
CONNECT BY prev = PRIOR curr AND questionid = PRIOR questionid
START WITH curr = 1;

add to array if it isn't there already

Since there are a ton of ways to accomplish the desired results and so many people provided !in_array() as an answer, and the OP already mentions the use of array_unique, I would like to provide a couple alternatives.

Using array_diff (php >= 4.0.1 || 5) you can filter out only the new array values that don't exist. Alternatively you can also compare the keys and values with array_diff_assoc. http://php.net/manual/en/function.array-diff.php

$currentValues = array(1, 2);
$newValues = array(1, 3, 1, 4, 2);
var_dump(array_diff($newValues, $currentValues));

Result:

Array
(
    [1] => 3
    [3] => 4
)

http://ideone.com/SWO3D1

Another method is using array_flip to assign the values as keys and compare them using isset, which will perform much faster than in_array with large datasets. Again this filters out just the new values that do not already exist in the current values.

$currentValues = [1, 2];
$newValues = [1, 3, 1, 4, 2];
$a = array();
$checkValues = array_flip($currentValues);
foreach ($newValues as $v) {
    if (!isset($checkValues[$v])) {
        $a[] = $v;
    }
}

Result:

Array
(
    [0] => 3
    [1] => 4
)

http://ideone.com/cyRyzN

With either method you can then use array_merge to append the unique new values to your current values.

  1. http://ideone.com/JCakmR
  2. http://ideone.com/bwTz2u

Result:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
)

How do I use PHP namespaces with autoload?

Using has a gotcha, while it is by far the fastest method, it also expects all of your filenames to be lowercase.

spl_autoload_extensions(".php");
spl_autoload_register();

For example:

A file containing the class SomeSuperClass would need to be named somesuperclass.php, this is a gotcha when using a case sensitive filesystem like Linux, if your file is named SomeSuperClass.php but not a problem under Windows.

Using __autoload in your code may still work with current versions of PHP but expect this feature to become deprecated and finally removed in the future.

So what options are left:

This version will work with PHP 5.3 and above and allows for filenames SomeSuperClass.php and somesuperclass.php. If your using 5.3.2 and above, this autoloader will work even faster.

<?php

if ( function_exists ( 'stream_resolve_include_path' ) == false ) {
    function stream_resolve_include_path ( $filename ) {
        $paths = explode ( PATH_SEPARATOR, get_include_path () );
        foreach ( $paths as $path ) {
            $path = realpath ( $path . PATH_SEPARATOR . $filename );
            if ( $path ) {
                return $path;
            }
        }
        return false;
    }
}

spl_autoload_register ( function ( $className, $fileExtensions = null ) {
    $className = str_replace ( '_', '/', $className );
    $className = str_replace ( '\\', '/', $className );
    $file = stream_resolve_include_path ( $className . '.php' );
    if ( $file === false ) {
        $file = stream_resolve_include_path ( strtolower ( $className . '.php' ) );
    }
    if ( $file !== false ) {
        include $file;
        return true;
    }
    return false;
});

Is it possible to 'prefill' a google form using data from a google spreadsheet?

You can create a pre-filled form URL from within the Form Editor, as described in the documentation for Drive Forms. You'll end up with a URL like this, for example:

https://docs.google.com/forms/d/--form-id--/viewform?entry.726721210=Mike+Jones&entry.787184751=1975-05-09&entry.1381372492&entry.960923899

buildUrls()

In this example, question 1, "Name", has an ID of 726721210, while question 2, "Birthday" is 787184751. Questions 3 and 4 are blank.

You could generate the pre-filled URL by adapting the one provided through the UI to be a template, like this:

function buildUrls() {
  var template = "https://docs.google.com/forms/d/--form-id--/viewform?entry.726721210=##Name##&entry.787184751=##Birthday##&entry.1381372492&entry.960923899";
  var ss = SpreadsheetApp.getActive().getSheetByName("Sheet1");  // Email, Name, Birthday
  var data = ss.getDataRange().getValues();

  // Skip headers, then build URLs for each row in Sheet1.
  for (var i = 1; i < data.length; i++ ) {
    var url = template.replace('##Name##',escape(data[i][1]))
                      .replace('##Birthday##',data[i][2].yyyymmdd());  // see yyyymmdd below
    Logger.log(url);  // You could do something more useful here.
  }
};

This is effective enough - you could email the pre-filled URL to each person, and they'd have some questions already filled in.

betterBuildUrls()

Instead of creating our template using brute force, we can piece it together programmatically. This will have the advantage that we can re-use the code without needing to remember to change the template.

Each question in a form is an item. For this example, let's assume the form has only 4 questions, as you've described them. Item [0] is "Name", [1] is "Birthday", and so on.

We can create a form response, which we won't submit - instead, we'll partially complete the form, only to get the pre-filled form URL. Since the Forms API understands the data types of each item, we can avoid manipulating the string format of dates and other types, which simplifies our code somewhat.

(EDIT: There's a more general version of this in How to prefill Google form checkboxes?)

/**
 * Use Form API to generate pre-filled form URLs
 */
function betterBuildUrls() {
  var ss = SpreadsheetApp.getActive();
  var sheet = ss.getSheetByName("Sheet1");
  var data = ss.getDataRange().getValues();  // Data for pre-fill

  var formUrl = ss.getFormUrl();             // Use form attached to sheet
  var form = FormApp.openByUrl(formUrl);
  var items = form.getItems();

  // Skip headers, then build URLs for each row in Sheet1.
  for (var i = 1; i < data.length; i++ ) {
    // Create a form response object, and prefill it
    var formResponse = form.createResponse();

    // Prefill Name
    var formItem = items[0].asTextItem();
    var response = formItem.createResponse(data[i][1]);
    formResponse.withItemResponse(response);

    // Prefill Birthday
    formItem = items[1].asDateItem();
    response = formItem.createResponse(data[i][2]);
    formResponse.withItemResponse(response);

    // Get prefilled form URL
    var url = formResponse.toPrefilledUrl();
    Logger.log(url);  // You could do something more useful here.
  }
};

yymmdd Function

Any date item in the pre-filled form URL is expected to be in this format: yyyy-mm-dd. This helper function extends the Date object with a new method to handle the conversion.

When reading dates from a spreadsheet, you'll end up with a javascript Date object, as long as the format of the data is recognizable as a date. (Your example is not recognizable, so instead of May 9th 1975 you could use 5/9/1975.)

// From http://blog.justin.kelly.org.au/simple-javascript-function-to-format-the-date-as-yyyy-mm-dd/
Date.prototype.yyyymmdd = function() {
  var yyyy = this.getFullYear().toString();                                    
  var mm = (this.getMonth()+1).toString(); // getMonth() is zero-based         
  var dd  = this.getDate().toString();             

  return yyyy + '-' + (mm[1]?mm:"0"+mm[0]) + '-' + (dd[1]?dd:"0"+dd[0]);
};

SQLAlchemy insert or update example

I try lots of ways and finally try this:

def db_persist(func):
    def persist(*args, **kwargs):
        func(*args, **kwargs)
        try:
            session.commit()
            logger.info("success calling db func: " + func.__name__)
            return True
        except SQLAlchemyError as e:
            logger.error(e.args)
            session.rollback()
            return False

    return persist

and :

@db_persist
def insert_or_update(table_object):
    return session.merge(table_object)

Fatal error: Class 'SoapClient' not found

On Centos 7.8 and PHP 7.3

yum install php-soap
service httpd restart