Programs & Examples On #Apt get

GENERAL APT-GET SUPPORT IS OFF-TOPIC. Support questions may be asked on https://superuser.com. apt-get is a command-line tool used to work with Advanced Packaging Tool (APT) of Debian-based Linux distros and for performing actions such as installing or upgrading a package.

How to install Maven 3 on Ubuntu 18.04/17.04/16.10/16.04 LTS/15.10/15.04/14.10/14.04 LTS/13.10/13.04 by using apt-get?

It's best to use miske's answer.

Properly installing natecarlson's repository

If you really want to use natecarlson's repository, the instructions just below can do any of the following:

  1. set it up from scratch
  2. repair it if apt-get update gives a 404 error after add-apt-repository
  3. repair it if apt-get update gives a NO_PUBKEY error after manually adding it to /etc/apt/sources.list

Open a terminal and run the following:

sudo -i

Enter your password if necessary, then paste the following into the terminal:

export GOOD_RELEASE='precise'
export BAD_RELEASE="`lsb_release -cs`"
cd /etc/apt
sed -i '/natecarlson\/maven3/d' sources.list
cd sources.list.d
rm -f natecarlson-maven3-*.list*
apt-add-repository -y ppa:natecarlson/maven3
mv natecarlson-maven3-${BAD_RELEASE}.list natecarlson-maven3-${GOOD_RELEASE}.list
sed -i "s/${BAD_RELEASE}/${GOOD_RELEASE}/" natecarlson-maven3-${GOOD_RELEASE}.list
apt-get update
exit
echo Done!

Removing natecarlson's repository

If you installed natecarlson's repository (either using add-apt-repository or manually added to /etc/apt/sources.list) and you don't want it anymore, open a terminal and run the following:

sudo -i

Enter your password if necessary, then paste the following into the terminal:

cd /etc/apt
sed -i '/natecarlson\/maven3/d' sources.list
cd sources.list.d
rm -f natecarlson-maven3-*.list*
apt-get update
exit
echo Done!

install apt-get on linux Red Hat server

If you insist on using yum, try yum install apt. As read on this site: Link

How to check the version before installing a package using apt-get?

apt-cache policy <package-name>

$ apt-cache policy redis-server
redis-server:
  Installed: (none)
  Candidate: 2:2.8.4-2
  Version table:
     2:2.8.4-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

apt-get install -s <package-name>

$ apt-get install -s redis-server
NOTE: This is only a simulation!
      apt-get needs root privileges for real execution.
      Keep also in mind that locking is deactivated,
      so don't depend on the relevance to the real current situation!
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  libjemalloc1 redis-tools
The following NEW packages will be installed:
  libjemalloc1 redis-server redis-tools
0 upgraded, 3 newly installed, 0 to remove and 3 not upgraded.
Inst libjemalloc1 (3.5.1-2 Ubuntu:14.04/trusty [amd64])
Inst redis-tools (2:2.8.4-2 Ubuntu:14.04/trusty [amd64])
Inst redis-server (2:2.8.4-2 Ubuntu:14.04/trusty [amd64])
Conf libjemalloc1 (3.5.1-2 Ubuntu:14.04/trusty [amd64])
Conf redis-tools (2:2.8.4-2 Ubuntu:14.04/trusty [amd64])
Conf redis-server (2:2.8.4-2 Ubuntu:14.04/trusty [amd64])

apt-cache show <package-name>

$ apt-cache show redis-server
Package: redis-server
Priority: optional
Section: universe/misc
Installed-Size: 744
Maintainer: Ubuntu Developers <[email protected]>
Original-Maintainer: Chris Lamb <[email protected]>
Architecture: amd64
Source: redis
Version: 2:2.8.4-2
Depends: libc6 (>= 2.14), libjemalloc1 (>= 2.1.1), redis-tools (= 2:2.8.4-2), adduser
Filename: pool/universe/r/redis/redis-server_2.8.4-2_amd64.deb
Size: 267446
MD5sum: 066f3ce93331b876b691df69d11b7e36
SHA1: f7ffbf228cc10aa6ff23ecc16f8c744928d7782e
SHA256: 2d273574f134dc0d8d10d41b5eab54114dfcf8b716bad4e6d04ad8452fe1627d
Description-en: Persistent key-value database with network interface
 Redis is a key-value database in a similar vein to memcache but the dataset
 is non-volatile. Redis additionally provides native support for atomically
 manipulating and querying data structures such as lists and sets.
 .
 The dataset is stored entirely in memory and periodically flushed to disk.
Description-md5: 9160ed1405585ab844f8750a9305d33f
Homepage: http://redis.io/
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubunt

dpkg -l <package-name>

$ dpkg -l nginx
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                                     Version                   Architecture              Description
+++-========================================-=========================-=========================-=====================================================================================
ii  nginx                                    1.6.2-1~trusty            amd64                     high performance web server

Ubuntu apt-get unable to fetch packages

I got this issue when the Virtualbox had the wrong networking. I've updated to NAT and was able to get on internet and download packages from us.archive.ubuntu.com

How to install Android SDK on Ubuntu?

Android SDK Manager

Get it from the Snap Store

sudo snap install androidsdk

Usage

You can use the sdkmanager to perform the following tasks.

List installed and available packages

androidsdk --list [options]

Install packages

androidsdk packages [options]

The packages argument is an SDK-style path as shown with the --list command, wrapped in quotes (for example, "build-tools;29.0.0" or "platforms;android-28"). You can pass multiple package paths, separated with a space, but they must each be wrapped in their own set of quotes.

For example, here's how to install the latest platform tools (which includes adb and fastboot) and the SDK tools for API level 28:

androidsdk "platform-tools" "platforms;android-28"

Alternatively, you can pass a text file that specifies all packages:

androidsdk --package_file=package_file [options]

The package_file argument is the location of a text file in which each line is an SDK-style path of a package to install (without quotes).

To uninstall, simply add the --uninstall flag:

androidsdk --uninstall packages [options]
androidsdk --uninstall --package_file=package_file [options]

Update all installed packages

androidsdk --update [options]

Note

androidsdk it is snap wraper of sdkmanager all options of sdkmanager work with androidsdk

Location of installed android sdk files : /home/user/AndroidSDK

See all sdkmanager options in google documentation

How do I download a package from apt-get without installing it?

Don't forget the option "-o", which lets you download anywhere you want, although you have to create "archives", "lock" and "partial" first (the command prints what's needed).

apt-get install -d -o=dir::cache=/tmp whateveryouwant

Package opencv was not found in the pkg-config search path

with opencv 4.0;

  • add -DOPENCV_GENERATE_PKGCONFIG=ON to build arguments
  • pkg-config --cflags --libs opencv4 instead of opencv

How to thoroughly purge and reinstall postgresql on ubuntu?

I had a similar situation: I needed to purge postgresql 9.1 on a debian wheezy ( I had previously migrated from 8.4 and I was getting errors ).

What I did:

First, I deleted config and database

$ sudo pg_dropcluster --stop 9.1 main

Then removed postgresql

$ sudo apt-get remove --purge postgresql postgresql-9.1 

and then reinstalled

$ sudo apt-get install postgresql postgresql-9.1

In my case I noticed /etc/postgresql/9.1 was empty, and running service postgresql start returned nothing

So, after more googling I got to this command:

$ sudo pg_createcluster 9.1 main

With that I could start the server, but now I was getting log-related errors. After more searching, I ended up changing permissions to the /var/log/postgresql directory

$ sudo chown root.postgres /var/log/postgresql
$ sudo chmod g+wx /var/log/postgresql

That fixed the issue, Hope this helps

E: Unable to locate package npm

Download the the repository key with:

curl -s https://deb.nodesource.com/gpgkey/nodesource.gpg.key | apt-key add -

Then setup the repository:

sudo sh -c "echo deb https://deb.nodesource.com/node_8.x cosmic main \
                 > /etc/apt/sources.list.d/nodesource.list"
sudo apt-get update
sudo apt-get install nodejs

Docker Repository Does Not Have a Release File on Running apt-get update on Ubuntu

As suggested in official docker document also. Try running this:

  • sudo vi /etc/apt/sources.list

Then remove/comment any (deb [arch=amd64] https://download.docker.com/linux/ubuntu/ xenial stable) such entry at the last lines of the file.

Then in terminal run this command:

  • sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu/ bionic stable"

  • sudo apt-get update

It worked in my case.

Check if an apt-get package is installed and then install it if it's not on Linux

I use the following way:

which mySQL 2>&1|tee 1> /dev/null
  if [[ "$?" == 0 ]]; then
                echo -e "\e[42m MySQL already installed. Moving on...\e[0m"
        else
        sudo apt-get install -y mysql-server
                if [[ "$?" == 0 ]]; then
                        echo -e "\e[42mMy SQL installed\e[0m"
                else
                        echo -e "\e[42Installation failed\e[0m"
                fi
        fi

How to download all dependencies and packages to directory

The aptitude --download-only ... approach only works if you have a debian distro with internet connection in your hands.

If you don't, I think it is better to run the following script on the disconnected debian machine:

apt-get --print-uris --yes install <my_package_name> | grep ^\' | cut -d\' -f2 >downloads.list

move the downloads.list file into a connected linux (or non linux) machine, and run:

wget --input-file myurilist

this downloads all your files into the current directory.After that you can copy them on an USB key and install in your disconnected debian machine.

credits: http://www.tuxradar.com/answers/517

PS I basically copied the blog post because it was not very readable, and in case the post will disappear.

Installing Java 7 (Oracle) in Debian via apt-get

Managed to get answer after do some google..

echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
apt-get update
# Java 7
apt-get install oracle-java7-installer
# For Java 8 command is:
apt-get install oracle-java8-installer

How can I decode HTML characters in C#?

If there is no Server context (i.e your running offline), you can use HttpUtility.HtmlDecode.

File content into unix variable with newlines

The envdir utility provides an easy way to do this. envdir uses files to represent environment variables, with file names mapping to env var names, and file contents mapping to env var values. If the file contents contain newlines, so will the env var.

See https://pypi.python.org/pypi/envdir

Change HTML email body font type and size in VBA

I did a little research and was able to write this code:

strbody = "<BODY style=font-size:11pt;font-family:Calibri>Good Morning;<p>We have completed our main aliasing process for today.  All assigned firms are complete.  Please feel free to respond with any questions.<p>Thank you.</BODY>"

apparently by setting the "font-size=11pt" instead of setting the font size <font size=5>, It allows you to select a specific font size like you normally would in a text editor, as opposed to selecting a value from 1-7 like my code was originally.

This link from simpLE MAn gave me some good info.

Google Play Services Library update and missing symbol @integer/google_play_services_version

I faced the same issue, and apparently Eclipse somehow left the version.xml file in /res/values from the original google-play-services_lib project while making a copy. I pulled the file from original project and pasted it in my copy of the project and the problem is fixed.

Sum across multiple columns with dplyr

I would use regular expression matching to sum over variables with certain pattern names. For example:

df <- df %>% mutate(sum1 = rowSums(.[grep("x[3-5]", names(.))], na.rm = TRUE),
                    sum_all = rowSums(.[grep("x", names(.))], na.rm = TRUE))

This way you can create more than one variable as a sum of certain group of variables of your data frame.

onclick on a image to navigate to another page using Javascript

maybe this is what u want?

<a href="#" id="bottle" onclick="document.location=this.id+'.html';return false;" >
    <img src="../images/bottle.jpg" alt="bottle" class="thumbnails" />
</a>

edit: keep in mind that anyone who does not have javascript enabled will not be able to navaigate to the image page....

How to maintain a Unique List in Java?

I do not know how efficient this is, However worked for me in a simple context.

List<int> uniqueNumbers = new ArrayList<>();

   public void AddNumberToList(int num)
    {
        if(!uniqueNumbers .contains(num)) {
            uniqueNumbers .add(num);
        }
    }

Set value of hidden field in a form using jQuery's ".val()" doesn't work

If you are searching for haml then this is the answer for hidden field to set value to a hidden field like

%input#forum_id.hidden

In your jquery just convert the value to string and then append it using attr property in jquery. hope this also works in other languages also.

$('#forum_id').attr('val',forum_id.toString());

How to get the client IP address in PHP

function get_client_ip()
{
    foreach (array(
                'HTTP_CLIENT_IP',
                'HTTP_X_FORWARDED_FOR',
                'HTTP_X_FORWARDED',
                'HTTP_X_CLUSTER_CLIENT_IP',
                'HTTP_FORWARDED_FOR',
                'HTTP_FORWARDED',
                'REMOTE_ADDR') as $key) {
        if (array_key_exists($key, $_SERVER)) {
            foreach (explode(',', $_SERVER[$key]) as $ip) {
                $ip = trim($ip);
                if ((bool) filter_var($ip, FILTER_VALIDATE_IP,
                                FILTER_FLAG_IPV4 |
                                FILTER_FLAG_NO_PRIV_RANGE |
                                FILTER_FLAG_NO_RES_RANGE)) {
                    return $ip;
                }
            }
        }
    }
    return null;
}

Or the compressed version:

function get_ip() {
    foreach (array('HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_X_CLUSTER_CLIENT_IP', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED', 'REMOTE_ADDR') as $key) {
        if (array_key_exists($key, $_SERVER) === true) {
            foreach (array_map('trim', explode(',', $_SERVER[$key])) as $ip) {
                if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) !== false) {
                    return $ip;
                }
            }
        }
    }
}

Get child Node of another Node, given node name

//xn=list of parent nodes......                
foreach (XmlNode xn in xnList)
{                                           
    foreach (XmlNode child in xn.ChildNodes) 
    {
        if (child.Name.Equals("name")) 
        {
            name = child.InnerText; 
        }
        if (child.Name.Equals("age"))
        {
            age = child.InnerText; 
        }
    }
}

How to handle static content in Spring MVC?

I know there are a few configurations to use the static contents, but my solution is that I just create a bulk web-application folder within your tomcat. This "bulk webapp" is only serving all the static-contents without serving apps. This is pain-free and easy solution for serving static contents to your actual spring webapp.

For example, I'm using two webapp folders on my tomcat.

  1. springapp: it is running only spring web application without static-contents like imgs, js, or css. (dedicated for spring apps.)
  2. resources: it is serving only the static contents without JSP, servlet, or any sort of java web application. (dedicated for static-contents)

If I want to use javascript, I simply add the URI for my javascript file.

EX> /resources/path/to/js/myjavascript.js

For static images, I'm using the same method.

EX> /resources/path/to/img/myimg.jpg

Last, I put "security-constraint" on my tomcat to block the access to actual directory. I put "nobody" user-roll to the constraint so that the page generates "403 forbidden error" when people tried to access the static-contents path.

So far it works very well for me. I also noticed that many popular websites like Amazon, Twitter, and Facebook they are using different URI for serving static-contents. To find out this, just right click on any static content and check their URI.

How can I force Python's file.write() to use the same newline format in Windows as in Linux ("\r\n" vs. "\n")?

You can still use the textmode and force the linefeed-newline with the keyword argument newline

f = open("./foo",'w',newline='\n')

Tested with Python 3.4.2.

Edit: This does not work in Python 2.7.

Need to navigate to a folder in command prompt

I prefer to use

pushd d:\windows\movie

because it requires no switches yet the working directory will change to the correct drive and path in one step.

Added plus:

  • also works with UNC paths if an unused drive letter is available for automatic drive mapping,
  • easy to go back to the previous working directory: just enter popd.

Jquery button click() function is not working

After making the id unique across the document ,You have to use event delegation

$("#container").on("click", "buttonid", function () {
  alert("Hi");
});

Why am I getting error for apple-touch-icon-precomposed.png

I guess apple devices make those requests if the device owner adds the site to it. This is the equivalent of the favicon. To resolve, add 2 100×100 png files, save it as apple-touch-icon-precomposed.png and apple-touch-icon.png and upload it to the root directory of the server. After that, the error should be gone.

I noticed lots of requests for apple-touch-icon-precomposed.png and apple-touch-icon.png in the logs that tried to load the images from the root directory of the site. I first thought it was a misconfiguration of the mobile theme and plugin, but found out later that Apple devices make those requests if the device owner adds the site to it.

Source: Why Webmasters Should Analyze Their 404 Error Log (Mar 2012; by Martin Brinkmann)

Room persistance library. Delete all

To make use of the Room without abuse of the @Query annotation first use @Query to select all rows and put them in a list, for example:

@Query("SELECT * FROM your_class_table")

List`<`your_class`>` load_all_your_class();

Put his list into the delete annotation, for example:

@Delete

void deleteAllOfYourTable(List`<`your_class`>` your_class_list);

<button> background image

You absolutely need a button tag element? because you can use instead an input type="button" element.

Then just link this CSS:

_x000D_
_x000D_
  input[type="button"]{
  width:150px;
  height:150px;
  /*just this*/ background-image: url(https://images.freeimages.com/images/large-previews/48d/marguerite-1372118.jpg);
  background-position: center;
  background-repeat: no-repeat;
  background-size: 150px 150px;
}
_x000D_
<input type="button"/>
_x000D_
_x000D_
_x000D_

understanding private setters

Yes, you are using encapsulation by using properties, but there are more nuances to encapsulation than just taking control over how properties are read and written. Denying a property to be set from outside the class can be useful both for robustness and performance.

An immutable class is a class that doesn't change once it's created, so private setters (or no setters at all) is needed to protect the properties.

Private setters came into more frequent use with the property shorthand that was instroduced in C# 3. In C# 2 the setter was often just omitted, and the private data accessed directly when set.

This property:

public int Size { get; private set; }

is the same as:

private int _size;
public int Size {
  get { return _size; }
  private set { _size = value; }
}

except, the name of the backing variable is internally created by the compiler, so you can't access it directly.

With the shorthand property the private setter is needed to create a read-only property, as you can't access the backing variable directly.

PHP remove special character from string

mysqli_set_charset($con,"utf8");
$title = ' LEVEL – EXTENDED'; 
$newtitle = preg_replace('/[^(\x20-\x7F)]*/','', $title);     
echo $newtitle;

Result :  LEVEL EXTENDED

Many Strange Character be removed by applying below the mysql connection code. but in some circumstances of removing this type strange character like †you can use preg_replace above format.

How do I compare two string variables in an 'if' statement in Bash?

For a version with pure Bash and without test, but really ugly, try:

if ( exit "${s1/*$s2*/0}" )2>/dev/null
then
   echo match
fi

Explanation: In ( )an extra subshell is opened. It exits with 0 if there was a match, and it tries to exit with $s1 if there was no match which raises an error (ugly). This error is directed to /dev/null.

Ajax post request in laravel 5 return error 500 (Internal Server Error)

Using post jquery instead helped me to solve this problem

$.post('url', data, function(response) {
    console.log(response);
});

How to capitalize the first letter of word in a string using Java?

Also, There is org.springframework.util.StringUtils in Spring Framework:

StringUtils.capitalize(str);

ContractFilter mismatch at the EndpointDispatcher exception

Oddly enough we worked around this error by using the same casing the Path and OperationContract name used. Apparently it was case-sensitive. If anyone knows why, please comment. Thank you!

Close dialog on click (anywhere)

In some cases, Jason's answer is overkill. And $('.ui-widget-overlay').click(function(){ $("#dialog").dialog("close"); }); doesn't always work with dynamic content.

The solution that I find works in all cases is:

$('body').on('click','.ui-widget-overlay',function(){ $('#dialog').dialog('close'); });

How to use PowerShell select-string to find more than one pattern in a file?

To search for multiple matches in each file, we can sequence several Select-String calls:

Get-ChildItem C:\Logs |
  where { $_ | Select-String -Pattern 'VendorEnquiry' } |
  where { $_ | Select-String -Pattern 'Failed' } |
  ...

At each step, files that do not contain the current pattern will be filtered out, ensuring that the final list of files contains all of the search terms.

Rather than writing out each Select-String call manually, we can simplify this with a filter to match multiple patterns:

filter MultiSelect-String( [string[]]$Patterns ) {
  # Check the current item against all patterns.
  foreach( $Pattern in $Patterns ) {
    # If one of the patterns does not match, skip the item.
    $matched = @($_ | Select-String -Pattern $Pattern)
    if( -not $matched ) {
      return
    }
  }

  # If all patterns matched, pass the item through.
  $_
}

Get-ChildItem C:\Logs | MultiSelect-String 'VendorEnquiry','Failed',...


Now, to satisfy the "Logtime about 11:30 am" part of the example would require finding the log time corresponding to each failure entry. How to do this is highly dependent on the actual structure of the files, but testing for "about" is relatively simple:

function AboutTime( [DateTime]$time, [DateTime]$target, [TimeSpan]$epsilon ) {
  $time -le ($target + $epsilon) -and $time -ge ($target - $epsilon)
}

PS> $epsilon = [TimeSpan]::FromMinutes(5)
PS> $target = [DateTime]'11:30am'
PS> AboutTime '11:00am' $target $epsilon
False
PS> AboutTime '11:28am' $target $epsilon
True
PS> AboutTime '11:35am' $target $epsilon
True

What do raw.githubusercontent.com URLs represent?

The raw.githubusercontent.com domain is used to serve unprocessed versions of files stored in GitHub repositories. If you browse to a file on GitHub and then click the Raw link, that's where you'll go.

The URL in your question references the install file in the master branch of the Homebrew/install repository. The rest of that command just retrieves the file and runs ruby on its contents.

Reading a registry key in C#

If you want it casted to a specific type you can use this method. Most non primitive types won't by default support direct casting so you will have to handle those accordingly.

  public T GetValue<T>(string registryKeyPath, string value, T defaultValue = default(T))
  {
    T retVal = default(T);

      retVal = (T)Registry.GetValue(registryKeyPath, value, defaultValue);

      return retVal;
  }

How can I find the OWNER of an object in Oracle?

To find the name of the current user within an Oracle session, use the USER function.

Note that the owner of the constraint, the owner of the table containing the foreign key, and the owner of the referenced table may all be different. It sounds like it’s the table owner you’re interested in, in which case this should be close to what you want:

select Constraint_Name
from All_Constraints
where Table_Name = 'WHICHEVER_TABLE'
  and Constraint_Type = 'R' and Owner = User;

How do I set ANDROID_SDK_HOME environment variable?

open your adt and open preferences, then modify directory with your sdk dir, it may help you follow the pic link indication

enter image description here

Query for array elements inside JSON type

Create a table with column as type json

CREATE TABLE friends ( id serial primary key, data jsonb);

Now let's insert json data

INSERT INTO friends(data) VALUES ('{"name": "Arya", "work": ["Improvements", "Office"], "available": true}');
INSERT INTO friends(data) VALUES ('{"name": "Tim Cook", "work": ["Cook", "ceo", "Play"], "uses": ["baseball", "laptop"], "available": false}');

Now let's make some queries to fetch data

select data->'name' from friends;
select data->'name' as name, data->'work' as work from friends;

You might have noticed that the results comes with inverted comma( " ) and brackets ([ ])

    name    |            work            
------------+----------------------------
 "Arya"     | ["Improvements", "Office"]
 "Tim Cook" | ["Cook", "ceo", "Play"]
(2 rows)

Now to retrieve only the values just use ->>

select data->>'name' as name, data->'work'->>0 as work from friends;
select data->>'name' as name, data->'work'->>0 as work from friends where data->>'name'='Arya';

jquery change div text

I think this will do:

$('#'+div_id+' .widget-head > span').text("new dialog title");

Define static method in source-file with declaration in header-file in C++

Remove static keyword in method definition. Keep it just in your class definition.

static keyword placed in .cpp file means that a certain function has a static linkage, ie. it is accessible only from other functions in the same file.

What is the best comment in source code you have ever encountered?

at the end of a rather long and convoluted set of while loops and if blocks, the developer in question inserted this final comment:

else
{
    // wobbly wilson said this would *never* happen!!
}

a laconic mixture of wit and sarcasm :)

Get everything after and before certain character in SQL Server

if Input= pg102a-wlc01s.png.intel.com and Output should be pg102a-wlc01s

we can use below query :

select Substring(pc.name,0,charindex('.',pc.name,0)),pc.name from tbl_name pc

Import CSV file with mixed data types

For the case when you know how many columns of data there will be in your CSV file, one simple call to textscan like Amro suggests will be your best solution.

However, if you don't know a priori how many columns are in your file, you can use a more general approach like I did in the following function. I first used the function fgetl to read each line of the file into a cell array. Then I used the function textscan to parse each line into separate strings using a predefined field delimiter and treating the integer fields as strings for now (they can be converted to numeric values later). Here is the resulting code, placed in a function read_mixed_csv:

function lineArray = read_mixed_csv(fileName, delimiter)

  fid = fopen(fileName, 'r');         % Open the file
  lineArray = cell(100, 1);           % Preallocate a cell array (ideally slightly
                                      %   larger than is needed)
  lineIndex = 1;                      % Index of cell to place the next line in
  nextLine = fgetl(fid);              % Read the first line from the file
  while ~isequal(nextLine, -1)        % Loop while not at the end of the file
    lineArray{lineIndex} = nextLine;  % Add the line to the cell array
    lineIndex = lineIndex+1;          % Increment the line index
    nextLine = fgetl(fid);            % Read the next line from the file
  end
  fclose(fid);                        % Close the file

  lineArray = lineArray(1:lineIndex-1);              % Remove empty cells, if needed
  for iLine = 1:lineIndex-1                          % Loop over lines
    lineData = textscan(lineArray{iLine}, '%s', ...  % Read strings
                        'Delimiter', delimiter);
    lineData = lineData{1};                          % Remove cell encapsulation
    if strcmp(lineArray{iLine}(end), delimiter)      % Account for when the line
      lineData{end+1} = '';                          %   ends with a delimiter
    end
    lineArray(iLine, 1:numel(lineData)) = lineData;  % Overwrite line data
  end

end

Running this function on the sample file content from the question gives this result:

>> data = read_mixed_csv('myfile.csv', ';')

data = 

  Columns 1 through 7

    '04'    'abc'    'def'    'ghj'    'klm'    ''            ''        
    ''      ''       ''       ''       ''       'Test'        'text'    
    ''      ''       ''       ''       ''       'asdfhsdf'    'dsafdsag'

  Columns 8 through 10

    ''          ''    ''
    '0xFF'      ''    ''
    '0x0F0F'    ''    ''

The result is a 3-by-10 cell array with one field per cell where missing fields are represented by the empty string ''. Now you can access each cell or a combination of cells to format them as you like. For example, if you wanted to change the fields in the first column from strings to integer values, you could use the function str2double as follows:

>> data(:, 1) = cellfun(@(s) {str2double(s)}, data(:, 1))

data = 

  Columns 1 through 7

    [  4]    'abc'    'def'    'ghj'    'klm'    ''            ''        
    [NaN]    ''       ''       ''       ''       'Test'        'text'    
    [NaN]    ''       ''       ''       ''       'asdfhsdf'    'dsafdsag'

  Columns 8 through 10

    ''          ''    ''
    '0xFF'      ''    ''
    '0x0F0F'    ''    ''

Note that the empty fields results in NaN values.

Most efficient way to find smallest of 3 numbers Java?

For those who find this topic much later:

If you have just three values to compare there is no significant difference. But if you have to find min of, say, thirty or sixty values, "min" could be easier for anyone to read in the code next year:

int smallest;

smallest = min(a1, a2);
smallest = min(smallest, a3);
smallest = min(smallest, a4);
...
smallest = min(smallest, a37);

But if you think of speed, maybe better way would be to put values into list, and then find min of that:

List<Integer> mySet = Arrays.asList(a1, a2, a3, ..., a37);

int smallest = Collections.min(mySet);

Would you agree?

jQuery each loop in table row

Just a recommendation:

I'd recommend using the DOM table implementation, it's very straight forward and easy to use, you really don't need jQuery for this task.

var table = document.getElementById('tblOne');

var rowLength = table.rows.length;

for(var i=0; i<rowLength; i+=1){
  var row = table.rows[i];

  //your code goes here, looping over every row.
  //cells are accessed as easy

  var cellLength = row.cells.length;
  for(var y=0; y<cellLength; y+=1){
    var cell = row.cells[y];

    //do something with every cell here
  }
}

calling server side event from html button control

You may use event handler serverclick as below

//cmdAction is the id of HTML button as below

<body>
    <form id="form1" runat="server">
        <button type="submit" id="cmdAction" text="Button1" runat="server">
            Button1
        </button>
    </form>
</body>

//cs code

public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
                cmdAction.ServerClick += new EventHandler(submit_click);  
        }

        protected void submit_click(object sender, EventArgs e)
        {
            Response.Write("HTML Server Button Control");
        }
    }

calling another method from the main method in java

You can only call instance method like do() (which is an illegal method name, incidentally) against an instance of the class:

public static void main(String[] args){
  new Foo().doSomething();
}

public void doSomething(){}

Alternatively, make doSomething() static as well, if that works for your design.

Plot two histograms on single chart with matplotlib

Here you have a working example:

import random
import numpy
from matplotlib import pyplot

x = [random.gauss(3,1) for _ in range(400)]
y = [random.gauss(4,2) for _ in range(400)]

bins = numpy.linspace(-10, 10, 100)

pyplot.hist(x, bins, alpha=0.5, label='x')
pyplot.hist(y, bins, alpha=0.5, label='y')
pyplot.legend(loc='upper right')
pyplot.show()

enter image description here

CSS force new line

Use <br /> OR <br> -

<li>Post by<br /><a>Author</a></li>

OR

<li>Post by<br><a>Author</a></li>

or

make the a element display:block;

<li>Post by <a style="display:block;">Author</a></li>

Try

Android Studio Could not initialize class org.codehaus.groovy.runtime.InvokerHelper

(Solution) I tried my first flutter app in android studio , i was getting same error " Could not initialize class org.codehaus.groovy.runtime.InvokerHelper"

open build.gradle and update dependencies

    classpath 'com.android.tools.build:gradle:4.0.1'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

or just hover over com.android.tools.build:grandle:(your-version)

Is there a way to word-wrap long words in a div?

Reading the original comment, rutherford is looking for a cross-browser way to wrap unbroken text (inferred by his use of word-wrap for IE, designed to break unbroken strings).

/* Source: http://snipplr.com/view/10979/css-cross-browser-word-wrap */
.wordwrap { 
   white-space: pre-wrap;      /* CSS3 */   
   white-space: -moz-pre-wrap; /* Firefox */    
   white-space: -pre-wrap;     /* Opera <7 */   
   white-space: -o-pre-wrap;   /* Opera 7 */    
   word-wrap: break-word;      /* IE */
}

I've used this class for a bit now, and works like a charm. (note: I've only tested in FireFox and IE)

Styling an input type="file" button

If anyone still cares on how to do this without JavaScript, let me complete Josh answer:

How to display the text of the filename:

The easiest way is to set both elements to a position:relative, give the label a higher z-index and give the input file negative margin until the label text is where you want it to be. Do not use display:none on the input!

Example:

input[type="file"] {
  position:relative;
  z-index:1;
  margin-left:-90px;
}

.custom-file-upload {
  border: 1px solid #ccc;
  display: inline-block;
  padding: 6px 12px;
  cursor: pointer;
  position:relative;
  z-index:2;
  background:white;

}

How to develop Android app completely using python?

Android, Python !

When I saw these two keywords together in your question, Kivy is the one which came to my mind first.

Kivy logo

Before coming to native Android development in Java using Android Studio, I had tried Kivy. It just awesome. Here are a few advantage I could find out.


Simple to use

With a python basics, you won't have trouble learning it.


Good community

It's well documented and has a great, active community.


Cross platform.

You can develop thing for Android, iOS, Windows, Linux and even Raspberry Pi with this single framework. Open source.


It is a free software

At least few of it's (Cross platform) competitors want you to pay a fee if you want a commercial license.


Accelerated graphics support

Kivy's graphics engine build over OpenGL ES 2 makes it suitable for softwares which require fast graphics rendering such as games.



Now coming into the next part of question, you can't use Android Studio IDE for Kivy. Here is a detailed guide for setting up the development environment.

React Hook "useState" is called in function "app" which is neither a React function component or a custom React Hook function

Do not use arrow function to create functional components.

Do as one of the examples below:

function MyComponent(props) {
  const [states, setStates] = React.useState({ value: '' });

  return (
    <input
      type="text"
      value={states.value}
      onChange={(event) => setStates({ value: event.target.value })}
    />
  );
}

Or

//IMPORTANT: Repeat the function name

const MyComponent = function MyComponent(props) { 
  const [states, setStates] = React.useState({ value: '' });

  return (
    <input
      type="text"
      value={states.value}
      onChange={(event) => setStates({ value: event.target.value })}
    />
  );
};

If you have problems with "ref" (probably in loops), the solution is to use forwardRef():

// IMPORTANT: Repeat the function name
// Add the "ref" argument to the function, in case you need to use it.

const MyComponent = React.forwardRef( function MyComponent(props, ref) {
  const [states, setStates] = React.useState({ value: '' });

  return (
    <input
      type="text"
      value={states.value}
      onChange={(event) => setStates({ value: event.target.value })}
    />
  );
});

Invalid column name sql error

first create database name "School" than create table "students" with following columns 1. id 2. name 3. address

now open visual studio and create connection:

namespace school
{
    public partial class Form1 : Form
    {
        SqlConnection scon;


        public Form1()
        {

            InitializeComponent();

            scon = new SqlConnection("Data Source = ABC-PC; trusted_connection = yes; Database = school; connection timeout = 30");
        }

//create command

SqlCommand scom = new SqlCommand("insert into students (id,name,address) values(@id,@name,@address)", scon);

//pass parameters

scom.Parameters.Add("id", SqlDbType.Int);
scom.Parameters["id"].Value = textBox1.Text;

           scom.Parameters.Add("name", SqlDbType.VarChar);
            scom.Parameters["name"].Value = this.textBox2.Text;

            scom.Parameters.Add("address", SqlDbType.VarChar);
            scom.Parameters["address"].Value = this.textBox6.Text;


            scon.Open();
            scom.ExecuteNonQuery();
            scon.Close();
            reset();

        }

also check solution here: http://solutions.musanitech.com/?p=6

Removing address bar from browser (to view on Android)

Here's the NON-jQuery solution that instantly removes the address bar without scrolling. Also, it works when you rotate the browser's orientation.

function hideAddressBar(){
  if(document.documentElement.scrollHeight<window.outerHeight/window.devicePixelRatio)
    document.documentElement.style.height=(window.outerHeight/window.devicePixelRatio)+'px';
  setTimeout(window.scrollTo(1,1),0);
}
window.addEventListener("load",function(){hideAddressBar();});
window.addEventListener("orientationchange",function(){hideAddressBar();});

It should work with the iPhone also, but I couldn't test this.

Get all files and directories in specific path fast

In .NET 4.0 there's the Directory.EnumerateFiles method which returns an IEnumerable<string> and is not loading all the files in memory. It's only once you start iterating over the returned collection that files will be returned and exceptions could be handled.

Setting Margin Properties in code

Margin is returning a struct, which means that you are editing a copy. You will need something like:

var margin = MyControl.Margin;
margin.Left = 10;
MyControl.Margin = margin;

Initialize array of strings

Its fine to just do char **strings;, char **strings = NULL, or char **strings = {NULL}

but to initialize it you'd have to use malloc:

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main(){
    // allocate space for 5 pointers to strings
    char **strings = (char**)malloc(5*sizeof(char*));
    int i = 0;
    //allocate space for each string
    // here allocate 50 bytes, which is more than enough for the strings
    for(i = 0; i < 5; i++){
        printf("%d\n", i);
        strings[i] = (char*)malloc(50*sizeof(char));
    }
    //assign them all something
    sprintf(strings[0], "bird goes tweet");
    sprintf(strings[1], "mouse goes squeak");
    sprintf(strings[2], "cow goes moo");
    sprintf(strings[3], "frog goes croak");
    sprintf(strings[4], "what does the fox say?");
    // Print it out
    for(i = 0; i < 5; i++){
        printf("Line #%d(length: %lu): %s\n", i, strlen(strings[i]),strings[i]);
    } 
    //Free each string
    for(i = 0; i < 5; i++){
        free(strings[i]);
    }
    //finally release the first string
    free(strings);
    return 0;
}

What are App Domains in Facebook Apps?

I think it is the domain that you run your app.

For example, your canvas URL is facebook.yourdomain.com, you should give App domain as .yourdomain.com

Comparing the contents of two files in Sublime Text

UPDATE JAN 2018 - especially for Sublime/Mac

(This is very similar to Marty F's reply, but addresses some issues from previous responses, combines several different suggestions and discusses the critical distinction that gave me problems at first.)

I'm using Sublime Text 3 (build 3143) on Mac and have been trying for about 30 minutes to find this File Compare feature. I had used it before on Sublime/Mac without any problems, but this time, it was trickier. But, I finally figured it out.

  1. The file format does not need to be UTF-8. I have successfully compared files that are UTF-8, ISO-8559-1, and Windows-1252.

  2. There is no File > Open Folders on Sublime/Mac. Many instructions above start with "Select File > Open Folders," but that doesn't exist on Sublime/Mac.

  3. File compare works on a Project basis. If you want to compare two files, they must be saved to disk and part of the current project.

  4. Ways to open a project

  • If Sublime/Mac is not running or if it's running but no windows are open, drag a folder onto the Sublime app.
  • If Sublime/Mac is running, select "File > Open", navigate to the desired folder, don't select a file or folder and click "Open".
  1. Add a folder to a project. If the files you want to compare are not part of the same hierarchy, first open the folder containing one of the files. Then, select "Project > Add Folder to Project", navigate to the folder you want and click "Open". You will now see two root-level folders in your sidebar.

  2. The Sidebar must be visible. You can either "View > Side Bar > Show Side Bar" or use the shortcut, Command-K, Command-B.

  3. Files must be closed (ie, saved) to compare. Single-clicking a file in the Side Bar does not open the file, but it does display it. You can tell if a file is open if it's listed in the "Open Files" section at the top of the Side Bar. Double-clicking a file or making a modification to a file will automatically change a file's status to "Open". In this case, be sure to close it before trying to compare.

  4. Select files from the folder hierarchy. Standard Mac shorcut here, (single) click the first file, then Command-click the second file. When you select the first file, you'll see its contents, but it's not open. Then, when you Command-click the second file, you'll see its contents, but again, neither are open. You'll notice only one tab in the editing panel.

  5. Control-click is not the same as right-click. This was the one that got me. I use my trackpad and often resort to Control-click as a right-click or secondary-click. This does not work for me. However, since I configured my trackpad in System Preferences to use the bottom-right corner of my trackpad as a right-click, that worked, displaying the contextual menu, with "Delete", "Reveal in Finder", and.... "Diff Files..."

Voilà!

is there a tool to create SVG paths from an SVG file?

Open the svg using Inkscape.

Inkscape is a svg editor it is a bit like Illustrator but as it is built specifically for svg it handles it way better. It is a free software and it's available @ https://inkscape.org/en/

  • ctrl A (select all)
  • shift ctrl C (=Path/Object to paths)
  • ctrl s (save (choose as plain svg))

done

all rect/circle have been converted to path

CodeIgniter Select Query

This is your code

$q = $this -> db
       -> select('id')
       -> where('email', $email)
       -> limit(1)
       -> get('users');

Try this

$id = $q->result()[0]->id;

or this one, it's simpler

$id = $q->row()->id;

Auto-redirect to another HTML page

If you want to redirect your webpage to another HTML FILE, just use as followed:

<meta http-equiv="refresh" content"2;otherpage.html">

2 being the seconds you want the client to wait before redirecting. Use "url=" only when it's an URL, to redirect to an HTML file just write the name after the ';'

AngularJS - How to use $routeParams in generating the templateUrl?

Router:-

...
.when('/enquiry/:page', {
    template: '<div ng-include src="templateUrl" onload="onLoad()"></div>',
    controller: 'enquiryCtrl'
})
...

Controller:-

...
// template onload event
$scope.onLoad = function() {
    console.log('onLoad()');
    f_tcalInit();  // or other onload stuff
}

// initialize
$scope.templateUrl = 'ci_index.php/adminctrl/enquiry/'+$routeParams.page;
...

I believe it is a weakness in angularjs that $routeParams is NOT visible inside the router. A tiny enhancement would make a world of difference during implementation.

Compiling a C++ program with gcc

By default, gcc selects the language based on the file extension, but you can force gcc to select a different language backend with the -x option thus:

gcc -x c++

More options are detailed in the gcc man page under "Options controlling the kind of output". See e.g. http://linux.die.net/man/1/gcc (search on the page for the text -x language).

This facility is very useful in cases where gcc can't guess the language using a file extension, for example if you're generating code and feeding it to gcc via stdin.

Changing :hover to touch/click for mobile devices

document.addEventListener("touchstart", function() {}, true);

This snippet will enable hover effects for touchscreens

How to create a new img tag with JQuery, with the src and id from a JavaScript object?

You save some bytes by avoiding the .attr altogether by passing the properties to the jQuery constructor:

var img = $('<img />',
             { id: 'Myid',
               src: 'MySrc.gif', 
               width: 300
             })
              .appendTo($('#YourDiv'));

How to get the changes on a branch in Git

git log --cherry-mark --oneline from_branch...to_branch

(3dots) but sometimes it shows '+' instead of '='

How to Split Image Into Multiple Pieces in Python

I find it easier to skimage.util.view_as_windows or `skimage.util.view_as_blocks which also allows you to configure the step

http://scikit-image.org/docs/dev/api/skimage.util.html?highlight=view_as_windows#skimage.util.view_as_windows

The OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)"

In the SQL Server, try these steps:

  1. Open one database.
  2. Click in the option Server Object.
  3. Click in Linked Servers.
  4. Click in Providers.
  5. Right click on Microsoft.ACE.OLEDB.12.0 and click Properties.
  6. Uncheck all the options and close.

Get index of selected option with jQuery

try this

 alert(document.getElementById("dropDownMenuKategorie").selectedIndex);

How to connect SQLite with Java?

You need to have a SQLite JDBC driver in your classpath.

Taro L. Saito (xerial) forked the Zentus project and now maintains it under the name sqlite-jdbc. It bundles the native drivers for major platforms so you don't need to configure them separately.

Trying to pull files from my Github repository: "refusing to merge unrelated histories"

If there is not substantial history on one end (aka if it is just a single readme commit on the github end), I often find it easier to manually copy the readme to my local repo and do a git push -f to make my version the new root commit.

I find it is slightly less complicated, doesn't require remembering an obscure flag, and keeps the history a bit cleaner.

How to sort strings in JavaScript

<!doctype html>
<html>
<body>
<p id = "myString">zyxtspqnmdba</p>
<p id = "orderedString"></p>
<script>
var myString = document.getElementById("myString").innerHTML;
orderString(myString);
function orderString(str) {
    var i = 0;
    var myArray = str.split("");
    while (i < str.length){
        var j = i + 1;
        while (j < str.length) {
            if (myArray[j] < myArray[i]){
                var temp = myArray[i];
                myArray[i] = myArray[j];
                myArray[j] = temp;
            }
            j++;
        }
        i++;
    }
    var newString = myArray.join("");
    document.getElementById("orderedString").innerHTML = newString;
}
</script>
</body>
</html>

Alter column, add default constraint

You're specifying the table name twice. The ALTER TABLE part names the table. Try: Alter table TableName alter column [Date] default getutcdate()

Handling urllib2's timeout? - Python

There are very few cases where you want to use except:. Doing this captures any exception, which can be hard to debug, and it captures exceptions including SystemExit and KeyboardInterupt, which can make your program annoying to use..

At the very simplest, you would catch urllib2.URLError:

try:
    urllib2.urlopen("http://example.com", timeout = 1)
except urllib2.URLError, e:
    raise MyException("There was an error: %r" % e)

The following should capture the specific error raised when the connection times out:

import urllib2
import socket

class MyException(Exception):
    pass

try:
    urllib2.urlopen("http://example.com", timeout = 1)
except urllib2.URLError, e:
    # For Python 2.6
    if isinstance(e.reason, socket.timeout):
        raise MyException("There was an error: %r" % e)
    else:
        # reraise the original error
        raise
except socket.timeout, e:
    # For Python 2.7
    raise MyException("There was an error: %r" % e)

Generating combinations in c++

A simple way using std::next_permutation:

#include <iostream>
#include <algorithm>
#include <vector>

int main() {
    int n, r;
    std::cin >> n;
    std::cin >> r;

    std::vector<bool> v(n);
    std::fill(v.end() - r, v.end(), true);

    do {
        for (int i = 0; i < n; ++i) {
            if (v[i]) {
                std::cout << (i + 1) << " ";
            }
        }
        std::cout << "\n";
    } while (std::next_permutation(v.begin(), v.end()));
    return 0;
}

or a slight variation that outputs the results in an easier to follow order:

#include <iostream>
#include <algorithm>
#include <vector>

int main() {
   int n, r;
   std::cin >> n;
   std::cin >> r;

   std::vector<bool> v(n);
   std::fill(v.begin(), v.begin() + r, true);

   do {
       for (int i = 0; i < n; ++i) {
           if (v[i]) {
               std::cout << (i + 1) << " ";
           }
       }
       std::cout << "\n";
   } while (std::prev_permutation(v.begin(), v.end()));
   return 0;
}

A bit of explanation:

It works by creating a "selection array" (v), where we place r selectors, then we create all permutations of these selectors, and print the corresponding set member if it is selected in in the current permutation of v.


You can implement it if you note that for each level r you select a number from 1 to n.

In C++, we need to 'manually' keep the state between calls that produces results (a combination): so, we build a class that on construction initialize the state, and has a member that on each call returns the combination while there are solutions: for instance

#include <iostream>
#include <iterator>
#include <vector>
#include <cstdlib>

using namespace std;

struct combinations
{
    typedef vector<int> combination_t;

    // initialize status
   combinations(int N, int R) :
       completed(N < 1 || R > N),
       generated(0),
       N(N), R(R)
   {
       for (int c = 1; c <= R; ++c)
           curr.push_back(c);
   }

   // true while there are more solutions
   bool completed;

   // count how many generated
   int generated;

   // get current and compute next combination
   combination_t next()
   {
       combination_t ret = curr;

       // find what to increment
       completed = true;
       for (int i = R - 1; i >= 0; --i)
           if (curr[i] < N - R + i + 1)
           {
               int j = curr[i] + 1;
               while (i <= R-1)
                   curr[i++] = j++;
               completed = false;
               ++generated;
               break;
           }

       return ret;
   }

private:

   int N, R;
   combination_t curr;
};

int main(int argc, char **argv)
{
    int N = argc >= 2 ? atoi(argv[1]) : 5;
    int R = argc >= 3 ? atoi(argv[2]) : 2;
    combinations cs(N, R);
    while (!cs.completed)
    {
        combinations::combination_t c = cs.next();
        copy(c.begin(), c.end(), ostream_iterator<int>(cout, ","));
        cout << endl;
    }
    return cs.generated;
}

test output:

1,2,
1,3,
1,4,
1,5,
2,3,
2,4,
2,5,
3,4,
3,5,
4,5,

Converting a factor to numeric without losing information R (as.numeric() doesn't seem to work)

First, factor consists of indices and levels. This fact is very very important when you are struggling with factor.

For example,

> z <- factor(letters[c(3, 2, 3, 4)])

# human-friendly display, but internal structure is invisible
> z
[1] c b c d
Levels: b c d

# internal structure of factor
> unclass(z)
[1] 2 1 2 3
attr(,"levels")
[1] "b" "c" "d"

here, z has 4 elements.
The index is 2, 1, 2, 3 in that order.
The level is associated with each index: 1 -> b, 2 -> c, 3 -> d.

Then, as.numeric converts simply the index part of factor into numeric.
as.character handles the index and levels, and generates character vector expressed by its level.

?as.numeric says that Factors are handled by the default method.

error: This is probably not a problem with npm. There is likely additional logging output above

Delete node_module directory and run below in command line

rm -rf node_modules
rm package-lock.json yarn.lock
npm cache clear --force
npm install

If still not working, try below

npm install webpack --save

Notepad++ Multi editing

Notepad++ also handles multiple cursors now.

Go into Settings => Preferences => Editing and check "Enable" in "Multi editing settings" Then, just use Ctrl+click to use multiple cursors.

Feature demo on official website here : https://npp-user-manual.org/docs/editing/

White space at top of page

Add a css reset to the top of your website style sheet, different browsers render some default margin and padding and perhaps external style sheets do something you are not aware of too, a css reset will just initialize a fresh palette so to speak:

html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, font, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, caption {
    margin: 0;
    padding: 0;
    border: 0;
    outline: 0;
    font-size: 100%;
    vertical-align: baseline;
    background: transparent;
}

UPDATE: Use the Universal Selector Instead: @Frank mentioned that you can use the Universal Selector: * instead of listing all the elements, and this selector looks like it is cross browser compatible in all major browsers:

* {
        margin: 0;
        padding: 0;
        border: 0;
        outline: 0;
        font-size: 100%;
        vertical-align: baseline;
        background: transparent;
    }

How to delete a file from SD card?

Recursively delete all children of the file ...

public static void DeleteRecursive(File fileOrDirectory) {
    if (fileOrDirectory.isDirectory()) {
        for (File child : fileOrDirectory.listFiles()) {
            DeleteRecursive(child);
        }
    }

    fileOrDirectory.delete();
}

remove objects from array by object property

with filter & indexOf

withLodash = _.filter(arrayOfObjects, (obj) => (listToDelete.indexOf(obj.id) === -1));
withoutLodash = arrayOfObjects.filter(obj => listToDelete.indexOf(obj.id) === -1);

with filter & includes

withLodash = _.filter(arrayOfObjects, (obj) => (!listToDelete.includes(obj.id)))
withoutLodash = arrayOfObjects.filter(obj => !listToDelete.includes(obj.id));

set background color: Android

This question is a old one but it can help for others too.

Try this :

    li.setBackgroundColor(getResources().getColor(R.color.blue));

    or

    li.setBackgroundColor(getResources().getColor(android.R.color.red));

    or

    li.setBackgroundColor(Color.rgb(226, 11, 11));


    or
    li.setBackgroundColor(Color.RED)

How do Python functions handle the types of the parameters that you pass in?

I didn't see this mentioned in other answers, so I'll add this to the pot.

As others have said, Python doesn't enforce type on function or method parameters. It is assumed that you know what you're doing, and that if you really need to know the type of something that was passed in, you will check it and decide what to do for yourself.

One of the main tools for doing this is the isinstance() function.

For example, if I write a method that expects to get raw binary text data, rather than the normal utf-8 encoded strings, I could check the type of the parameters on the way in and either adapt to what I find, or raise an exception to refuse.

def process(data):
    if not isinstance(data, bytes) and not isinstance(data, bytearray):
        raise TypeError('Invalid type: data must be a byte string or bytearray, not %r' % type(data))
    # Do more stuff

Python also provides all kinds of tools to dig into objects. If you're brave, you can even use importlib to create your own objects of arbitrary classes, on the fly. I did this to recreate objects from JSON data. Such a thing would be a nightmare in a static language like C++.

Split string with PowerShell and do something with each token

-split outputs an array, and you can save it to a variable like this:

$a = -split 'Once  upon    a     time'
$a[0]

Once

Another cute thing, you can have arrays on both sides of an assignment statement:

$a,$b,$c = -split 'Once  upon    a'
$c

a

Function inside a function.?

Not sure what the author of that code wanted to achieve. Definining a function inside another function does NOT mean that the inner function is only visible inside the outer function. After calling x() the first time, the y() function will be in global scope as well.

How to stop mysqld

For MAMP

  1. Stop servers (but you may notice MySQL stays on)
  2. Remove or rename /Applications/MAMP/tmp/mysql/ which holds the mysql.pid and mysql.sock.lock files
  3. When you go back to Mamp, you'll see MySQL is now off. You can "Start Servers" again.

Java, looping through result set

Result Set are actually contains multiple rows of data, and use a cursor to point out current position. So in your case, rs4.getString(1) only get you the data in first column of first row. In order to change to next row, you need to call next()

a quick example

while (rs.next()) {
    String sid = rs.getString(1);
    String lid = rs.getString(2);
    // Do whatever you want to do with these 2 values
}

there are many useful method in ResultSet, you should take a look :)

Reading column names alone in a csv file

import pandas as pd
data = pd.read_csv("data.csv")
cols = data.columns

How to match letters only using java regex, matches method?

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.*;

/* Write an application that prompts the user for a String that contains at least
 * five letters and at least five digits. Continuously re-prompt the user until a
 * valid String is entered. Display a message indicating whether the user was
 * successful or did not enter enough digits, letters, or both.
 */
public class FiveLettersAndDigits {

  private static String readIn() { // read input from stdin
    StringBuilder sb = new StringBuilder();
    int c = 0;
    try { // do not use try-with-resources. We don't want to close the stdin stream
      BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
      while ((c = reader.read()) != 0) { // read all characters until null
        // We don't want new lines, although we must consume them.
        if (c != 13 && c != 10) {
          sb.append((char) c);
        } else {
          break; // break on new line (or else the loop won't terminate)
        }
      }
      // reader.readLine(); // get the trailing new line
    } catch (IOException ex) {
      System.err.println("Failed to read user input!");
      ex.printStackTrace(System.err);
    }

    return sb.toString().trim();
  }

  /**
   * Check the given input against a pattern
   *
   * @return the number of matches
   */
  private static int getitemCount(String input, String pattern) {
    int count = 0;

    try {
      Pattern p = Pattern.compile(pattern);
      Matcher m = p.matcher(input);
      while (m.find()) { // count the number of times the pattern matches
        count++;
      }
    } catch (PatternSyntaxException ex) {
      System.err.println("Failed to test input String \"" + input + "\" for matches to pattern \"" + pattern + "\"!");
      ex.printStackTrace(System.err);
    }

    return count;
  }

  private static String reprompt() {
    System.out.print("Entered input is invalid! Please enter five letters and five digits in any order: ");

    String in = readIn();

    return in;
  }

  public static void main(String[] args) {
    int letters = 0, digits = 0;
    String in = null;
    System.out.print("Please enter five letters and five digits in any order: ");
    in = readIn();
    while (letters < 5 || digits < 5) { // will keep occuring until the user enters sufficient input
      if (null != in && in.length() > 9) { // must be at least 10 chars long in order to contain both
        // count the letters and numbers. If there are enough, this loop won't happen again.
        letters = getitemCount(in, "[A-Za-z]");
        digits = getitemCount(in, "[0-9]");

        if (letters < 5 || digits < 5) {
          in = reprompt(); // reset in case we need to go around again.
        }
      } else {
        in = reprompt();
      }
    }
  }

}

No MediaTypeFormatter is available to read an object of type 'String' from content with media type 'text/plain'

I know this is an older question, but I felt the answer from t3chb0t led me to the best path and felt like sharing. You don't even need to go so far as implementing all the formatter's methods. I did the following for the content-type "application/vnd.api+json" being returned by an API I was using:

public class VndApiJsonMediaTypeFormatter : JsonMediaTypeFormatter
{
    public VndApiJsonMediaTypeFormatter()
    {
        SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/vnd.api+json"));
    }
}

Which can be used simply like the following:

HttpClient httpClient = new HttpClient("http://api.someaddress.com/");
HttpResponseMessage response = await httpClient.GetAsync("person");

List<System.Net.Http.Formatting.MediaTypeFormatter> formatters = new List<System.Net.Http.Formatting.MediaTypeFormatter>();
formatters.Add(new System.Net.Http.Formatting.JsonMediaTypeFormatter());
formatters.Add(new VndApiJsonMediaTypeFormatter());

var responseObject = await response.Content.ReadAsAsync<Person>(formatters);

Super simple and works exactly as I expected.

Notice: Undefined offset: 0 in

getAllVotes() isn't returning an array with the indexes 0 or 1. Make sure it's returning the data you want by calling var_dump() on the result.

How to get a list of installed Jenkins plugins with name and version pair

If Jenkins run in a the Jenkins Docker container you can use this command line in Bash:

java -jar /var/jenkins_home/war/WEB-INF/jenkins-cli.jar -s http://localhost:8080/ list-plugins --username admin --password `/bin/cat /var/jenkins_home/secrets/initialAdminPassword`

Put text at bottom of div

Wrap the text in a span or similar and use the following CSS:

.your-div {
    position: relative;
}

.your-div span {
    position: absolute;
    bottom: 0;
    right: 0;
}

What is the best way to programmatically detect porn images?

This is actually reasonably easy. You can programatically detect skin tones - and porn images tend to have a lot of skin. This will create false positives but if this is a problem you can pass images so detected through actual moderation. This not only greatly reduces the the work for moderators but also gives you lots of free porn. It's win-win.

#!python    
import os, glob
from PIL import Image

def get_skin_ratio(im):
    im = im.crop((int(im.size[0]*0.2), int(im.size[1]*0.2), im.size[0]-int(im.size[0]*0.2), im.size[1]-int(im.size[1]*0.2)))
    skin = sum([count for count, rgb in im.getcolors(im.size[0]*im.size[1]) if rgb[0]>60 and rgb[1]<(rgb[0]*0.85) and rgb[2]<(rgb[0]*0.7) and rgb[1]>(rgb[0]*0.4) and rgb[2]>(rgb[0]*0.2)])
    return float(skin)/float(im.size[0]*im.size[1])

for image_dir in ('porn','clean'):
    for image_file in glob.glob(os.path.join(image_dir,"*.jpg")):
        skin_percent = get_skin_ratio(Image.open(image_file)) * 100
        if skin_percent>30:
            print "PORN {0} has {1:.0f}% skin".format(image_file, skin_percent)
        else:
            print "CLEAN {0} has {1:.0f}% skin".format(image_file, skin_percent)

This code measures skin tones in the center of the image. I've tested on 20 relatively tame "porn" images and 20 completely innocent images. It flags 100% of the "porn" and 4 out of the 20 of the clean images. That's a pretty high false positive rate but the script aims to be fairly cautious and could be further tuned. It works on light, dark and Asian skin tones.

It's main weaknesses with false positives are brown objects like sand and wood and of course it doesn't know the difference between "naughty" and "nice" flesh (like face shots).

Weakness with false negatives would be images without much exposed flesh (like leather bondage), painted or tattooed skin, B&W images, etc.

source code and sample images

What’s the difference between “{}” and “[]” while declaring a JavaScript array?

When you declare

var a=[];

you are declaring a empty array.

But when you are declaring

var a={};

you are declaring a Object .

Although Array is also Object in Javascript but it is numeric key paired values. Which have all the functionality of object but Added some few method of Array like Push,Splice,Length and so on.

So if you want Some values where you need to use numeric keys use Array. else use object. you can Create object like:

var a={name:"abc",age:"14"}; 

And can access values like

console.log(a.name);

Is it possible to install Xcode 10.2 on High Sierra (10.13.6)?

Cracked it. Just @Damnum steps and then follow the path to run xcode. Bad way but running like a charm.

Double click to /Applications/Xcode102.app/Contents/MacOS/Xcode

Change route params without reloading in Angular 2

For anyone like me finding this question the following might be useful.

I had a similar problem and initially tried using location.go and location.replaceState as suggested in other answers here. However I ran into problems when I had to navigate to another page on the app because the navigation was relative to the current route and the current route wasn't being updated by location.go or location.replaceState (the router doesn't know anything about what these do to the URL)

In essence I needed a solution that DIDN'T reload the page/component when the route parameter changed but DID update the route state internally.

I ended up using query parameters. You can find more about it here: https://angular-2-training-book.rangle.io/handout/routing/query_params.html

So if you need to do something like save an order and get an order ID you can update your page URL like shown below. Updating a centre location and related data on a map would be similar

// let's say we're saving an order. Initally the URL is just blah/orders
save(orderId) {
    // [Here we would call back-end to save the order in the database]

    this.router.navigate(['orders'], { queryParams: { id: orderId } });
    // now the URL is blah/orders?id:1234. We don't reload the orders
    // page or component so get desired behaviour of not seeing any 
    // flickers or resetting the page.
}

and you keep track of it within the ngOnInit method like:

ngOnInit() {
    this.orderId = this.route
        .queryParamMap
        .map(params => params.get('id') || null);
    // orderID is up-to-date with what is saved in database now, or if
    // nothing is saved and hence no id query paramter the orderId variable
    // is simply null.
    // [You can load the order here from its ID if this suits your design]
}

If you need to go direct to the order page with a new (unsaved) order you can do:

this.router.navigate(['orders']);

Or if you need to go direct to the order page for an existing (saved) order you can do:

this.router.navigate(['orders'], { queryParams: { id: '1234' } });

Connect Android Studio with SVN

Android Studio is based on IntelliJ, and it comes with support for SVN (along with git and mercurial) bundled in. Check http://www.jetbrains.com/idea/features/version_control.html for more info.

Can I do Android Programming in C++, C?

You can take a look also at C++ Builder XE6, and XE7 supports android in c++ code, and with Firemonkey library.

http://www.embarcadero.com/products/cbuilder

Pretty easy way to start, and native code. But the binaries have a big size.

Creating a zero-filled pandas data frame

Similar to @Shravan, but without the use of numpy:

  height = 10
  width = 20
  df_0 = pd.DataFrame(0, index=range(height), columns=range(width))

Then you can do whatever you want with it:

post_instantiation_fcn = lambda x: str(x)
df_ready_for_whatever = df_0.applymap(post_instantiation_fcn)

GIT_DISCOVERY_ACROSS_FILESYSTEM not set

For complete the accepted answer, Had the same issue. First specified the remote

git remote add origin https://github.com/XXXX/YYY.git

git fetch 

Then get the code

git pull origin master

Proper MIME type for .woff2 fonts

In IIS you can declare the mime type for WOFF2 font files by adding the following to your project's web.config:

<system.webServer>
  <staticContent>
    <remove fileExtension=".woff2" />
    <mimeMap fileExtension=".woff2" mimeType="font/woff2" />
  </staticContent>
</system.webServer>

Update: The mime type may be changing according to the latest W3C Editor's Draft WOFF2 spec. See Appendix A: Internet Media Type Registration section 6.5. WOFF 2.0 which states the latest proposed format is font/woff2

Mockito: Inject real objects into private @Autowired fields

In Spring there is a dedicated utility called ReflectionTestUtils for this purpose. Take the specific instance and inject into the the field.


@Spy
..
@Mock
..

@InjectMock
Foo foo;

@BeforeEach
void _before(){
   ReflectionTestUtils.setField(foo,"bar", new BarImpl());// `bar` is private field
}

No tests found for given includes Error, when running Parameterized Unit test in Android Studio

For me it worked when I've added @EnableJUnit4MigrationSupport class annotation.

(Of course together with already mentioned gradle libs and settings)

Jquery: how to trigger click event on pressing enter key

Jquery: Fire Button click event Using enter Button Press try this::

tabindex="0" onkeypress="return EnterEvent(event)"

 <!--Enter Event Script-->
    <script type="text/javascript">
        function EnterEvent(e) {
            if (e.keyCode == 13) {
                __doPostBack('<%=btnSave.UniqueID%>', "");
            }
        }
    </script>
    <!--Enter Event Script-->

How to draw text using only OpenGL methods?

Load an image with characters as texture and draw the part of that texture depending on what character you want. You can create that texture using a paint program, hardcode it or use a window component to draw to an image and retrieve that image for an exact copy of system fonts.

No need to use Glut or any other extension, just basic OpenGL operability. It gets the job done, not to mention that its been done like this for decades by professional programmers in very succesfull games and other applications.

Is there a way to automatically generate getters and setters in Eclipse?

Ways to Generate Getters & Setters -

1) Press Alt+Shift+S, then R
2) Right click -> Source -> Generate Getters & Setters
3) Go to Source menu -> Generate Getters & Setters
4) Go to Windows menu -> Preferences -> General -> Keys (Write Generate Getters & Setters on text field)
5) Click on error bulb of the field -> create getters & setters ...
6) Press Ctrl+3 and write getters & setters on text field then select option Generate Getters & Setters

if Mac OS press Alt+cmd+S then select Getters & Setters

Auto highlight text in a textbox control

In ASP.NET:

textbox.Attributes.Add("onfocus","this.select();");

How to resolve Value cannot be null. Parameter name: source in linq?

When you call a Linq statement like this:

// x = new List<string>();
var count = x.Count(s => s.StartsWith("x"));

You are actually using an extension method in the System.Linq namespace, so what the compiler translates this into is:

var count = Enumerable.Count(x, s => s.StartsWith("x"));

So the error you are getting above is because the first parameter, source (which would be x in the sample above) is null.

How to set back button text in Swift

If you are using xib file for view controller then do this in your view controller class.

class AboutUsViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    edgesForExtendedLayout = []
    setUpNavBar()
}

func setUpNavBar(){
    //For title in navigation bar
    self.navigationController?.view.backgroundColor = UIColor.white
    self.navigationController?.view.tintColor = UIColor.orange
    self.navigationItem.title = "About Us"

    //For back button in navigation bar
    let backButton = UIBarButtonItem()
    backButton.title = "Back"
    self.navigationController?.navigationBar.topItem?.backBarButtonItem = backButton
}

}

The result will be:

enter image description here

How does one make random number between range for arc4random_uniform()?

Since Swift 4.2:

Int {    
    public static func random(in range: ClosedRange<Int>) -> Int
    public static func random(in range: Range<Int>) -> Int
}

Used like:

Int.random(in: 2...10)

XSS prevention in JSP/Servlet web application

My personal opinion is that you should avoid using JSP/ASP/PHP/etc pages. Instead output to an API similar to SAX (only designed for calling rather than handling). That way there is a single layer that has to create well formed output.

How large should my recv buffer be when calling recv in the socket library

For streaming protocols such as TCP, you can pretty much set your buffer to any size. That said, common values that are powers of 2 such as 4096 or 8192 are recommended.

If there is more data then what your buffer, it will simply be saved in the kernel for your next call to recv.

Yes, you can keep growing your buffer. You can do a recv into the middle of the buffer starting at offset idx, you would do:

recv(socket, recv_buffer + idx, recv_buffer_size - idx, 0);

Eclipse Build Path Nesting Errors

The accepted solution didn't work for me but I did some digging on the project settings.

The following solution fixed it for me at least IF you are using a Dynamic Web Project:

  1. Right click on the project then properties. (or alt-enter on the project)
  2. Under Deployment Assembly remove "src".

You should be able to add the src/main/java. It also automatically adds it to Deployment Assembly.

Caveat: If you added a src/test/java note that it also adds it to Deployment Assembly. Generally, you don't need this. You may remove it.

PHP convert date format dd/mm/yyyy => yyyy-mm-dd

I can see great answers, so there's no need to repeat here, so I'd like to offer some advice:

I would recommend using a Unix Timestamp integer instead of a human-readable date format to handle time internally, then use PHP's date() function to convert the timestamp value into a human-readable date format for user display. Here's a crude example of how it should be done:

// Get unix timestamp in seconds
$current_time = date();

// Or if you need millisecond precision

// Get unix timestamp in milliseconds
$current_time = microtime(true);

Then use $current_time as needed in your app (store, add or subtract, etc), then when you need to display the date value it to your users, you can use date() to specify your desired date format:

// Display a human-readable date format
echo date('d-m-Y', $current_time);

This way you'll avoid much headache dealing with date formats, conversions and timezones, as your dates will be in a standardized format (Unix Timestamp) that is compact, timezone-independent (always in UTC) and widely supported in programming languages and databases.

What is REST? Slightly confused

REST is a software design pattern typically used for web applications. In layman's terms this means that it is a commonly used idea used in many different projects. It stands for REpresentational State Transfer. The basic idea of REST is treating objects on the server-side (as in rows in a database table) as resources than can be created or destroyed.

The most basic way of thinking about REST is as a way of formatting the URLs of your web applications. For example, if your resource was called "posts", then:

/posts Would be how a user would access ALL the posts, for displaying.

/posts/:id Would be how a user would access and view an individual post, retrieved based on their unique id.

/posts/new Would be how you would display a form for creating a new post.

Sending a POST request to /users would be how you would actually create a new post on the database level.

Sending a PUT request to /users/:id would be how you would update the attributes of a given post, again identified by a unique id.

Sending a DELETE request to /users/:id would be how you would delete a given post, again identified by a unique id.

As I understand it, the REST pattern was mainly popularized (for web apps) by the Ruby on Rails framework, which puts a big emphasis on RESTful routes. I could be wrong about that though.

I may not be the most qualified to talk about it, but this is how I've learned it (specifically for Rails development).

When someone refers to a "REST api," generally what they mean is an api that uses RESTful urls for retrieving data.

Background blur with CSS

You can use a pseudo-element to position as the background of the content with the same image as the background, but blurred with the new CSS3 filter.

You can see it in action here: http://codepen.io/jiserra/pen/JzKpx

I made that for customizing a select, but I added the blur background effect.

Disable double-tap "zoom" option in browser on touch devices

If there is anyone like me who is experiencing this issue using Vue.js, simply adding .prevent will do the trick: @click.prevent="someAction"

correct way to define class variables in Python

I think this sample explains the difference between the styles:

james@bodacious-wired:~$cat test.py 
#!/usr/bin/env python

class MyClass:
    element1 = "Hello"

    def __init__(self):
        self.element2 = "World"

obj = MyClass()

print dir(MyClass)
print "--"
print dir(obj)
print "--"
print obj.element1 
print obj.element2
print MyClass.element1 + " " + MyClass.element2
james@bodacious-wired:~$./test.py 
['__doc__', '__init__', '__module__', 'element1']
--
['__doc__', '__init__', '__module__', 'element1', 'element2']
--
Hello World
Hello
Traceback (most recent call last):
  File "./test.py", line 17, in <module>
    print MyClass.element2
AttributeError: class MyClass has no attribute 'element2'

element1 is bound to the class, element2 is bound to an instance of the class.

Using variable in SQL LIKE statement

Joel is it that @SearchLetter hasn't been declared yet? Also the length of @SearchLetter2 isn't long enough for 't%'. Try a varchar of a longer length.

Proper way of checking if row exists in table in PL/SQL block

select nvl(max(1), 0) from mytable;

This statement yields 0 if there are no rows, 1 if you have at least one row in that table. It's way faster than doing a select count(*). The optimizer "sees" that only a single row needs to be fetched to answer the question.

Here's a (verbose) little example:

declare
  YES constant      signtype := 1;
  NO  constant      signtype := 0;
  v_table_has_rows  signtype;
begin

  select nvl(max(YES), NO)
    into v_table_has_rows
    from mytable -- where ...
  ;

  if v_table_has_rows = YES then
    DBMS_OUTPUT.PUT_LINE ('mytable has at least one row');
  end if;

end;

How do I get the color from a hexadecimal color code using .NET?

in asp.net:

color_black = (Color)new ColorConverter().ConvertFromString("#FF76B3");

Generating Random Passwords

I created this class that uses RNGCryptoServiceProvider and it is flexible. Example:

var generator = new PasswordGenerator(minimumLengthPassword: 8,
                                      maximumLengthPassword: 15,
                                      minimumUpperCaseChars: 2,
                                      minimumNumericChars: 3,
                                      minimumSpecialChars: 2);
string password = generator.Generate();

How to install xgboost in Anaconda Python (Windows platform)?

The following worked for me

conda install libxgboost

Automatically plot different colored lines

Late to the party. I was looking into this myself and just found about this axes option called ColorOrder you can specify the colour order for the session or just for the figure and then just plot an array and let MATLAB automatically cycle through the colours specified.

see Changing the Default ColorOrder

example

set(0,'DefaultAxesColorOrder',jet(5))
A=rand(10,5);
plot(A);

How to add an extra column to a NumPy array

np.r_[ ... ] and np.c_[ ... ] are useful alternatives to vstack and hstack, with square brackets [] instead of round ().
A couple of examples:

: import numpy as np
: N = 3
: A = np.eye(N)

: np.c_[ A, np.ones(N) ]              # add a column
array([[ 1.,  0.,  0.,  1.],
       [ 0.,  1.,  0.,  1.],
       [ 0.,  0.,  1.,  1.]])

: np.c_[ np.ones(N), A, np.ones(N) ]  # or two
array([[ 1.,  1.,  0.,  0.,  1.],
       [ 1.,  0.,  1.,  0.,  1.],
       [ 1.,  0.,  0.,  1.,  1.]])

: np.r_[ A, [A[1]] ]              # add a row
array([[ 1.,  0.,  0.],
       [ 0.,  1.,  0.],
       [ 0.,  0.,  1.],
       [ 0.,  1.,  0.]])
: # not np.r_[ A, A[1] ]

: np.r_[ A[0], 1, 2, 3, A[1] ]    # mix vecs and scalars
  array([ 1.,  0.,  0.,  1.,  2.,  3.,  0.,  1.,  0.])

: np.r_[ A[0], [1, 2, 3], A[1] ]  # lists
  array([ 1.,  0.,  0.,  1.,  2.,  3.,  0.,  1.,  0.])

: np.r_[ A[0], (1, 2, 3), A[1] ]  # tuples
  array([ 1.,  0.,  0.,  1.,  2.,  3.,  0.,  1.,  0.])

: np.r_[ A[0], 1:4, A[1] ]        # same, 1:4 == arange(1,4) == 1,2,3
  array([ 1.,  0.,  0.,  1.,  2.,  3.,  0.,  1.,  0.])

(The reason for square brackets [] instead of round () is that Python expands e.g. 1:4 in square -- the wonders of overloading.)

Java split string to array

Try this

String[] array = values.split("\\|",-1); 

How to find out when a particular table was created in Oracle?

You copy and paste the following code. It will display all the tables with Name and Created Date

SELECT object_name,created FROM user_objects
WHERE object_name LIKE  '%table_name%'
AND object_type = 'TABLE'; 

Note: Replace '%table_name%' with the table name you are looking for.

List columns with indexes in PostgreSQL

Just do: \d table_name

But I'm not sure what do you mean that the information about columns is not there.

For example:

# \d pg_class
       Table "pg_catalog.pg_class"
     Column      |   Type    | Modifiers
-----------------+-----------+-----------
 relname         | name      | not null
 relnamespace    | oid       | not null
 reltype         | oid       | not null
 reloftype       | oid       | not null
 relowner        | oid       | not null
 relam           | oid       | not null
 relfilenode     | oid       | not null
 reltablespace   | oid       | not null
 relpages        | integer   | not null
 reltuples       | real      | not null
 reltoastrelid   | oid       | not null
 reltoastidxid   | oid       | not null
 relhasindex     | boolean   | not null
 relisshared     | boolean   | not null
 relistemp       | boolean   | not null
 relkind         | "char"    | not null
 relnatts        | smallint  | not null
 relchecks       | smallint  | not null
 relhasoids      | boolean   | not null
 relhaspkey      | boolean   | not null
 relhasexclusion | boolean   | not null
 relhasrules     | boolean   | not null
 relhastriggers  | boolean   | not null
 relhassubclass  | boolean   | not null
 relfrozenxid    | xid       | not null
 relacl          | aclitem[] |
 reloptions      | text[]    |
Indexes:
    "pg_class_oid_index" UNIQUE, btree (oid)
    "pg_class_relname_nsp_index" UNIQUE, btree (relname, relnamespace)

It clearly shows which columns given index is on this table.

MS Access: how to compact current database in VBA

If you don't wish to use compact on close (eg, because the front-end mdb is a robot program that runs continually), and you don't want to create a separate mdb just for compacting, consider using a cmd file.

I let my robot.mdb check its own size:

FileLen(CurrentDb.Name))

If its size exceeds 1 GB, it creates a cmd file like this ...

Dim f As Integer
Dim Folder As String
Dim Access As String
    'select Access in the correct PF directory (my robot.mdb runs in 32-bit MSAccess, on 32-bit and 64-bit machines)
    If Dir("C:\Program Files (x86)\Microsoft Office\Office\MSACCESS.EXE") > "" Then
        Access = """C:\Program Files (x86)\Microsoft Office\Office\MSACCESS.EXE"""
    Else
        Access = """C:\Program Files\Microsoft Office\Office\MSACCESS.EXE"""
    End If
    Folder = ExtractFileDir(CurrentDb.Name)
    f = FreeFile
    Open Folder & "comrep.cmd" For Output As f
    'wait until robot.mdb closes (ldb file is gone), then compact robot.mdb
    Print #f, ":checkldb1"
    Print #f, "if exist " & Folder & "robot.ldb goto checkldb1"
    Print #f, Access & " " & Folder & "robot.mdb /compact"
    'wait until the robot mdb closes, then start it
    Print #f, ":checkldb2"
    Print #f, "if exist " & Folder & "robot.ldb goto checkldb2"
    Print #f, Access & " " & Folder & "robot.mdb"
    Close f

... launches the cmd file ...

Shell ExtractFileDir(CurrentDb.Name) & "comrep.cmd"

... and shuts down ...

DoCmd.Quit

Next, the cmd file compacts and restarts robot.mdb.

Hide keyboard in react-native

This just got updated and documented! No more hidden tricks.

import { Keyboard } from 'react-native'

// Hide that keyboard!
Keyboard.dismiss()

Github link

Laravel 5 call a model function in a blade view

I solve the problem. So simple. Syntax error.

  • App\Product
  • App\Service

enter image description here

But I also want to know how to pass a function with parameters to view....

How to catch exception correctly from http.request()?

Perhaps you can try adding this in your imports:

import 'rxjs/add/operator/catch';

You can also do:

return this.http.request(request)
  .map(res => res.json())
  .subscribe(
    data => console.log(data),
    err => console.log(err),
    () => console.log('yay')
  );

Per comments:

EXCEPTION: TypeError: Observable_1.Observable.throw is not a function

Similarly, for that, you can use:

import 'rxjs/add/observable/throw';

Why are unnamed namespaces used and what are their benefits?

Unnamed namespace limits access of class,variable,function and objects to the file in which it is defined. Unnamed namespace functionality is similar to static keyword in C/C++.
static keyword limits access of global variable and function to the file in which they are defined.
There is difference between unnamed namespace and static keyword because of which unnamed namespace has advantage over static. static keyword can be used with variable, function and objects but not with user defined class.
For example:

static int x;  // Correct 

But,

static class xyz {/*Body of class*/} //Wrong
static structure {/*Body of structure*/} //Wrong

But same can be possible with unnamed namespace. For example,

 namespace {
           class xyz {/*Body of class*/}
           static structure {/*Body of structure*/}
  } //Correct

Eclipse shows errors but I can't find them

Right Click on Project -> Build Path -> Configure Build Path. Check if Maven Dependencies is there in list, if not then update maven project by Right Click on Project -> Maven -> Update Project

How to implement class constants?

For me none of earlier answer works. I did need to convert my static class to enum. Like this:

export enum MyConstants {
  MyFirstConstant = 'MyFirstConstant',
  MySecondConstant = 'MySecondConstant'
}

Then in my component I add new property as suggested in other answers

export class MyComponent {
public MY_CONTANTS = MyConstans;
constructor() { }
}

Then in my component's template I use it this way

<div [myDirective]="MY_CONTANTS.MyFirstConstant"> </div>

EDIT: Sorry. My problem was different than OP's. I still leave this here if someelse have same problem than I.

git pull displays "fatal: Couldn't find remote ref refs/heads/xxxx" and hangs up

I had a similar issue when I tried to get a pull with a single quote ' in it's name.

I had to escape the pull request name:

git pull https://github.com/foo/bar namewithsingle"'"quote

Please enter a commit message to explain why this merge is necessary, especially if it merges an updated upstream into a topic branch

I found the error because i was new to git you must check whether you have entered the correct syntax

i made a mistake and wrote git commit

and got the same error

use git commit -m 'some comment'

and you wont be seeing the page with

Setting width of spreadsheet cell using PHPExcel

setAutoSize method must come before setWidth:

$objPHPExcel->getActiveSheet()->getColumnDimensionByColumn('C')->setAutoSize(false);
$objPHPExcel->getActiveSheet()->getColumnDimensionByColumn('C')->setWidth('10');

Scanner is never closed

I am assuming you are using java 7, thus you get a compiler warning, when you don't close the resource you should close your scanner usually in a finally block.

Scanner scanner = null;
try {
    scanner = new Scanner(System.in);
    //rest of the code
}
finally {
    if(scanner!=null)
        scanner.close();
}

Or even better: use the new Try with resource statement:

try(Scanner scanner = new Scanner(System.in)){
    //rest of your code
}

Stop embedded youtube iframe?

_x000D_
_x000D_
$('#aboutVideo .close').on('click',function(){_x000D_
   var reSrc = $('.aboutPlayer').attr("src");_x000D_
   $('.aboutPlayer').attr("src",reSrc)_x000D_
  })
_x000D_
#aboutVideo{_x000D_
 width: 100%;_x000D_
 height: 100%;_x000D_
}_x000D_
#aboutVideo .modal-dialog, #aboutVideo .modal-dialog .modal-content, #aboutVideo .modal-dialog .modal-content .modal-body{_x000D_
 width: 100%;_x000D_
 height: 100%;_x000D_
 margin: 0 !important;_x000D_
 padding: 0 !important;_x000D_
}_x000D_
#aboutVideo .modal-header{_x000D_
 padding: 0px; _x000D_
 border-bottom: 0px solid #e5e5e5; _x000D_
 position: absolute;_x000D_
 right: 4%;_x000D_
 top: 4%;_x000D_
}_x000D_
#aboutVideo .modal-header .close{_x000D_
 opacity: 1;_x000D_
 position: absolute;_x000D_
 z-index: 99;_x000D_
 color: #fff;_x000D_
}_x000D_
#aboutVideo .modal-header button.close{_x000D_
      border-radius: 50%;_x000D_
    width: 7vw;_x000D_
    height: 7vw;_x000D_
    position: absolute;_x000D_
    right: 4%;_x000D_
    top: 7%;_x000D_
    background: aliceblue;_x000D_
}_x000D_
#aboutVideo .modal-header button.close:hover{_x000D_
 background-color: rgba(255, 255, 255, 0.28);_x000D_
}_x000D_
#aboutVideo .modal-header button.close img{_x000D_
 width: 20px;_x000D_
 margin-top: -0.2vw;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<!-- Latest compiled and minified CSS -->_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
_x000D_
<!-- Optional theme -->_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">_x000D_
_x000D_
<!-- Latest compiled and minified JavaScript -->_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>_x000D_
<li class="see-video fa" type="button" data-toggle="modal" data-target="#aboutVideo">_x000D_
   <label>SEE VIDEO</label>_x000D_
  </li>_x000D_
<div class="modal fade" id="aboutVideo" tabindex="-1" role="dialog" aria-labelledby="aboutVideoLabel">_x000D_
  <div class="modal-dialog" role="document">_x000D_
   <div class="modal-content">_x000D_
    <div class="modal-header">_x000D_
     <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true"><img src="http://www.freeiconspng.com/uploads/white-close-button-png-16.png"></span></button>_x000D_
    </div>_x000D_
    <div class="modal-body">_x000D_
    <iframe class="aboutPlayer" width="100%" height="100%" src="https://www.youtube.com/embed/fju9ii8YsGs?autoplay=0&showinfo=0&controls=2&rel=0" frameborder="0" allowfullscreen poster="https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiOvaagmqfWAhUHMY8KHUuJCnkQjRwIBw&url=http%3A%2F%2Fnodeframework.com%2F&psig=AFQjCNEaHveDtZ81veNPSvQDx4IqaE_Tzw&ust=1505565378467268"></iframe>_x000D_
    </div>_x000D_
   </div>_x000D_
  </div>_x000D_
 </div>
_x000D_
_x000D_
_x000D_

How to find the highest value of a column in a data frame in R?

Similar to colMeans, colSums, etc, you could write a column maximum function, colMax, and a column sort function, colSort.

colMax <- function(data) sapply(data, max, na.rm = TRUE)
colSort <- function(data, ...) sapply(data, sort, ...)

I use ... in the second function in hopes of sparking your intrigue.

Get your data:

dat <- read.table(h=T, text = "Ozone Solar.R Wind Temp Month Day
1     41     190  7.4   67     5   1
2     36     118  8.0   72     5   2
3     12     149 12.6   74     5   3
4     18     313 11.5   62     5   4
5     NA      NA 14.3   56     5   5
6     28      NA 14.9   66     5   6
7     23     299  8.6   65     5   7
8     19      99 13.8   59     5   8
9      8      19 20.1   61     5   9")

Use colMax function on sample data:

colMax(dat)
#  Ozone Solar.R    Wind    Temp   Month     Day 
#   41.0   313.0    20.1    74.0     5.0     9.0

To do the sorting on a single column,

sort(dat$Solar.R, decreasing = TRUE)
# [1] 313 299 190 149 118  99  19

and over all columns use our colSort function,

colSort(dat, decreasing = TRUE) ## compare with '...' above

C# Dictionary get item by index

If you need to extract an element key based on index, this function can be used:

public string getCard(int random)
{
    return Karta._dict.ElementAt(random).Key;
}

If you need to extract the Key where the element value is equal to the integer generated randomly, you can used the following function:

public string getCard(int random)
{
    return Karta._dict.FirstOrDefault(x => x.Value == random).Key;
}

Side Note: The first element of the dictionary is The Key and the second is the Value

Android: Proper Way to use onBackPressed() with Toast

I would implement a dialog asking the user if they wanted to exit and then call super.onBackPressed() if they did.

@Override
public void onBackPressed() {
    new AlertDialog.Builder(this)
        .setTitle("Really Exit?")
        .setMessage("Are you sure you want to exit?")
        .setNegativeButton(android.R.string.no, null)
        .setPositiveButton(android.R.string.yes, new OnClickListener() {

            public void onClick(DialogInterface arg0, int arg1) {
                WelcomeActivity.super.onBackPressed();
            }
        }).create().show();
}

In the above example, you'll need to replace WelcomeActivity with the name of your activity.

ERROR Android emulator gets killed

I had same issue, the problem was there is no enough space in my disk drive.. you can see details about you specific situation in layer 'Event Log' this layer regularly is in the bottom on Android studio, it was my output Log:

"02:45 PM Emulator: emulator: ERROR: Not enough space to create userdata partition. Available: 3310.363281 MB at /home/user/.android/avd/my_Nexus_5X_API_27.avd, need 7372.800000 MB."

I had just 7 GB free, so just delete some GB's in my D.D. and it's working fine.

Remove blue border from css custom-styled button in Chrome

try this code for all element which have blue border problem

*{
outline: none;
}

or

*{
outline-style: none;
}

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

Note that :

typeof $(this) is JQuery object.

and

typeof $(this)[0] is HTMLElement object

then : if you want to apply .val() on HTMLElement , you can add this extension .

HTMLElement.prototype.val=function(v){
   if(typeof v!=='undefined'){this.value=v;return this;}
   else{return this.value}
}

Then :

document.getElementById('myDiv').val() ==== $('#myDiv').val()

And

 document.getElementById('myDiv').val('newVal') ==== $('#myDiv').val('newVal')

????? INVERSE :

Conversely? if you want to add value property to jQuery object , follow those steps :

  1. Download the full source code (not minified) i.e: example http://code.jquery.com/jquery-1.11.1.js .

  2. Insert Line after L96 , add this code value:"" to init this new prop enter image description here

  3. Search on jQuery.fn.init , it will be almost Line 2747

enter image description here

  1. Now , assign a value to value prop : (Before return statment add this.value=jQuery(selector).val()) enter image description here

Enjoy now : $('#myDiv').value

How to plot two columns of a pandas data frame using points?

Pandas uses matplotlib as a library for basic plots. The easiest way in your case will using the following:

import pandas as pd
import numpy as np

#creating sample data 
sample_data={'col_name_1':np.random.rand(20),
      'col_name_2': np.random.rand(20)}
df= pd.DataFrame(sample_data)
df.plot(x='col_name_1', y='col_name_2', style='o')

enter image description here

However, I would recommend to use seaborn as an alternative solution if you want have more customized plots while not going into the basic level of matplotlib. In this case you the solution will be following:

import pandas as pd
import seaborn as sns
import numpy as np

#creating sample data 
sample_data={'col_name_1':np.random.rand(20),
      'col_name_2': np.random.rand(20)}
df= pd.DataFrame(sample_data)
sns.scatterplot(x="col_name_1", y="col_name_2", data=df)

enter image description here

forward declaration of a struct in C?

A struct (without a typedef) often needs to (or should) be with the keyword struct when used.

struct A;                      // forward declaration
void function( struct A *a );  // using the 'incomplete' type only as pointer

If you typedef your struct you can leave out the struct keyword.

typedef struct A A;          // forward declaration *and* typedef
void function( A *a );

Note that it is legal to reuse the struct name

Try changing the forward declaration to this in your code:

typedef struct context context;

It might be more readable to do add a suffix to indicate struct name and type name:

typedef struct context_s context_t;

Java, How to add values to Array List used as value in HashMap

First you retreieve the value (given a key) and then you add a new element to it

    ArrayList<String> grades = examList.get(courseId);
    grades.add(aGrade);

Unable to add window -- token android.os.BinderProxy is not valid; is your activity running?

I solved it by putting this:

@Override
protected void onDestroy() {
    accessTokenTracker.stopTracking();
    super.onDestroy();
}

XAMPP Port 80 in use by "Unable to open process" with PID 4

Your port 80 is being used by the system.

  1. In Windows “World Wide Publishing" Service is using this port and it's process is system which PID is 4 maximum time and stopping this service(“World Wide Publishing") will free the port 80 and you can connect Apache using this port. To stop the service go to the “Task manager –> Services tab”, right click the “World Wide Publishing Service” and stop.
  2. If you don't find there then Then go to "Run > services.msc" and again find there and right click the “World Wide Publishing Service” and stop.
  3. If you didn't find “World Wide Publishing Service” there then go to "Run>>resmon.exe>> Network Tab>>Listening Ports" and see which process is using port 80

enter image description here

And from "Overview>>CPU" just Right click on that process and click "End Process Tree". If that process is system that might be a critical issue.

Google maps Marker Label with multiple characters

For anyone trying to

...in 2019, it's worth noting some of the code referenced here no longer exists (officially). Google discontinued support for the "MarkerWithLabel" project a long time ago. It was originally hosted on Google code here, now it's unofficially hosted on Github here.

But there is another project Google maintained until 2016, called "MapLabel"s. That approach is different (and arguably better). You create a separate map label object with the same origin as the marker instead of adding a mapLabel option to the marker itself. You can make a marker with label with multiple characters using js-marker-label.

Reverse order of foreach list items

Assuming you just need to reverse an indexed array (not associative or multidimensional) a simple for loop would suffice:

$fruits = ['bananas', 'apples', 'pears'];
for($i = count($fruits)-1; $i >= 0; $i--) {
    echo $fruits[$i] . '<br>';
} 

How do you access the value of an SQL count () query in a Java program

I have done it this way (example):

String query="SELECT count(t1.id) from t1, t2 where t1.id=t2.id and t2.email='"[email protected]"'";
int count=0;
try {
    ResultSet rs = DatabaseService.statementDataBase().executeQuery(query);
    while(rs.next())
        count=rs.getInt(1);
} catch (SQLException e) {
    e.printStackTrace();
} finally {
    //...
}

Where does MySQL store database files on Windows and what are the names of the files?

For Windows 7: c:\users\all users\MySql\MySql Server x.x\Data\

Where x.x is the version number of the sql server installed in your machine.

Fidel

Python how to plot graph sine wave

import numpy as np
import matplotlib.pyplot as plt

F = 5.e2          # No. of cycles per second, F = 500 Hz
T = 2.e-3         # Time period, T = 2 ms
Fs = 50.e3        # No. of samples per second, Fs = 50 kHz
Ts = 1./Fs        # Sampling interval, Ts = 20 us
N = int(T/Ts)     # No. of samples for 2 ms, N = 100

t = np.linspace(0, T, N)
signal = np.sin(2*np.pi*F*t)

plt.plot(t, signal)
plt.xlabel('Time (s)')
plt.ylabel('Voltage (V)')
plt.show()

stale element reference: element is not attached to the page document

According to @Abhishek Singh's you need to understand the problem:

What is the line which gives exception ?? The reason for this is because the element to which you have referred is removed from the DOM structure

and you can not refer to it anymore (imagine what element's ID has changed).

Follow the code:

class TogglingPage {
  @FindBy(...)
  private WebElement btnTurnOff;

  @FindBy(...)
  private WebElement btnTurnOn;

  TogglingPage turnOff() {
    this.btnTurnOff.isDisplayed();  
    this.btnTurnOff.click();          // when clicked, button should swap into btnTurnOn
    this.btnTurnOn.isDisplayed();
    this.btnTurnOn.click();           // when clicked, button should swap into btnTurnOff
    this.btnTurnOff.isDisplayed();    // throws an exception
    return new TogglingPage();
  }
}

Now, let us wonder why?

  1. btnTurnOff was found by a driver - ok
  2. btnTurnOff was replaced by btnTurnOn - ok
  3. btnTurnOn was found by a driver. - ok
  4. btnTurnOn was replaced by btnTurnOff - ok
  5. we call this.btnTurnOff.isDisplayed(); on the element which does not exist anymore in Selenium sense - you can see it, it works perfectly, but it is a different instance of the same button.

Possible fix:

  TogglingPage turnOff() {
    this.btnTurnOff.isDisplayed();  
    this.btnTurnOff.click();

    TogglingPage newPage = new TogglingPage();
    newPage.btnTurnOn.isDisplayed();
    newPage.btnTurnOn.click();

    TogglingPage newerPage = new TogglingPage();
    newerPage.btnTurnOff.isDisplayed();    // ok
    return newerPage;
  }

Select first occurring element after another element

Just hit on this when trying to solve this type of thing my self.

I did a selector that deals with the element after being something other than a p.

.here .is.the #selector h4 + * {...}

Hope this helps anyone who finds it :)

Load a bitmap image into Windows Forms using open file dialog

It's simple. Just add:

PictureBox1.BackgroundImageLayout = ImageLayout.Zoom;

Convert string to boolean in C#

You must use some of the C # conversion systems:

string to boolean: True to true

string str = "True";
bool mybool = System.Convert.ToBoolean(str);

boolean to string: true to True

bool mybool = true;
string str = System.Convert.ToString(mybool);

//or

string str = mybool.ToString();

bool.Parse expects one parameter which in this case is str, even .

Convert.ToBoolean expects one parameter.

bool.TryParse expects two parameters, one entry (str) and one out (result).

If TryParse is true, then the conversion was correct, otherwise an error occurred

string str = "True";
bool MyBool = bool.Parse(str);

//Or

string str = "True";
if(bool.TryParse(str, out bool result))
{
   //Correct conversion
}
else
{
     //Incorrect, an error has occurred
}

Checking images for similarity with OpenCV

If for matching identical images ( same size/orientation )

// Compare two images by getting the L2 error (square-root of sum of squared error).
double getSimilarity( const Mat A, const Mat B ) {
if ( A.rows > 0 && A.rows == B.rows && A.cols > 0 && A.cols == B.cols ) {
    // Calculate the L2 relative error between images.
    double errorL2 = norm( A, B, CV_L2 );
    // Convert to a reasonable scale, since L2 error is summed across all pixels of the image.
    double similarity = errorL2 / (double)( A.rows * A.cols );
    return similarity;
}
else {
    //Images have a different size
    return 100000000.0;  // Return a bad value
}

Source

android: stretch image in imageview to fit screen

The accepted answer is perfect, however if you want to do it from xml, you can use android:scaleType="fitXY"

Check if enum exists in Java

One of my favorite lib: Apache Commons.

The EnumUtils can do that easily.

Following an example to validate an Enum with that library:

public enum MyEnum {
    DIV("div"), DEPT("dept"), CLASS("class");

    private final String val;

    MyEnum(String val) {
    this.val = val;
    }

    public String getVal() {
    return val;
    }
}


MyEnum strTypeEnum = null;

// test if String str is compatible with the enum 
// e.g. if you pass str = "div", it will return false. If you pass "DIV", it will return true.
if( EnumUtils.isValidEnum(MyEnum.class, str) ){
    strTypeEnum = MyEnum.valueOf(str);
}

How to read a CSV file into a .NET Datatable

public class Csv
{
    public static DataTable DataSetGet(string filename, string separatorChar, out List<string> errors)
    {
        errors = new List<string>();
        var table = new DataTable("StringLocalization");
        using (var sr = new StreamReader(filename, Encoding.Default))
        {
            string line;
            var i = 0;
            while (sr.Peek() >= 0)
            {
                try
                {
                    line = sr.ReadLine();
                    if (string.IsNullOrEmpty(line)) continue;
                    var values = line.Split(new[] {separatorChar}, StringSplitOptions.None);
                    var row = table.NewRow();
                    for (var colNum = 0; colNum < values.Length; colNum++)
                    {
                        var value = values[colNum];
                        if (i == 0)
                        {
                            table.Columns.Add(value, typeof (String));
                        }
                        else
                        {
                            row[table.Columns[colNum]] = value;
                        }
                    }
                    if (i != 0) table.Rows.Add(row);
                }
                catch(Exception ex)
                {
                    errors.Add(ex.Message);
                }
                i++;
            }
        }
        return table;
    }
}

Executing multiple commands from a Windows cmd script

I don't know the direct answer to your question, but if you do a lot of these scripts, it might be worth learning a more powerful language like perl. Free implementations exist for Windows (e.g. activestate, cygwin). I've found it worth the initial effort for my own tasks.

Edit:

As suggested by @Ferruccio, if you can't install extra software, consider vbscript and/or javascript. They're built into the Windows scripting host.

How do I connect to this localhost from another computer on the same network?

That's definitely possible. We'll take a general case with Apache here.

Let's say you're a big Symfony2 fan and you would like to access your symfony website at http://symfony.local/ from 4 different computers (the main one hosting your website, as well as a Mac, a Windows and a Linux distro connected (wireless or not) to the main computer.

General Sketch:

enter image description here


1 Set up a virtual host:

You first need to set up a virtual host in your apache httpd-vhosts.conf file. On XAMP, you can find this file here: C:\xampp\apache\conf\extra\httpd-vhosts.conf. On MAMP, you can find this file here: Applications/MAMP/conf/apache/extra/httpd-vhosts.conf. This step prepares the Web server on your computer for handling symfony.local requests. You need to provide the name of the Virtual Host as well as the root/main folder of your website. To do this, add the following line at the end of that file. You need to change the DocumentRoot to wherever your main folder is. Here I have taken /Applications/MAMP/htdocs/Symfony/ as the root of my website.

<VirtualHost *:80>
    DocumentRoot "/Applications/MAMP/htdocs/Symfony/"
    ServerName symfony.local
</VirtualHost>

2 Configure your hosts file:

For the client (your browser in that case) to understand what symfony.local really means, you need to edit the hosts file on your computer. Everytime you type an URL in your browser, your computer tries to understand what it means! symfony.local doesn't mean anything for a computer. So it will try to resolve the name symfony.local to an IP address. It will do this by first looking into the hosts file on your computer to see if he can match an IP address to what you typed in the address bar. If it can't, then it will ask DNS servers. The trick here is to append the following to your hosts file.

  • On MAC, this file is in /private/etc/hosts;
  • On LINUX, this file is in /etc/hosts;
  • On WINDOWS, this file is in \Windows\system32\private\etc\hosts;
  • On WINDOWS 7, this file is in \Windows\system32\drivers\etc\hosts;
  • On WINDOWS 10, this file is in \Windows\system32\drivers\etc\hosts;

Hosts file

##
# Host Database
# localhost is used to configure the loopback interface
##
#...
127.0.0.1           symfony.local

From now on, everytime you type symfony.local on this computer, your computer will use the loopback interface to connect to symfony.local. It will understand that you want to work on localhost (127.0.0.1).

3 Access symfony.local from an other computer:

We finally arrive to your main question which is:

How can I now access my website through an other computer?

Well this is now easy! We just need to tell the other computers how they could find symfony.local! How do we do this?

3a Get the IP address of the computer hosting the website:

We first need to know the IP address on the computer that hosts the website (the one we've been working on since the very beginning). In the terminal, on MAC and LINUX type ifconfig |grep inet, on WINDOWS type ipconfig. Let's assume the IP address of this computer is 192.168.1.5.

3b Edit the hosts file on the computer you are trying to access the website from.:

Again, on MAC, this file is in /private/etc/hosts; on LINUX, in /etc/hosts; and on WINDOWS, in \Windows\system32\private\etc\hosts (if you're using WINDOWS 7, this file is in \Windows\system32\drivers\etc\hosts).. The trick is now to use the IP address of the computer we are trying to access/talk to:

##
# Host Database
# localhost is used to configure the loopback interface
##
#...
192.168.1.5         symfony.local

4 Finally enjoy the results in your browser

You can now go into your browser and type http://symfony.local to beautifully see your website on different computers! Note that you can apply the same strategy if you are a OSX user to test your website on Internet Explorer via Virtual Box (if you don't want to use a Windows computer). This is beautifully explained in Crafting Your Windows / IE Test Environment on OSX.


You can also access your localhost from mobile devices

You might wonder how to access your localhost website from a mobile device. In some cases, you won't be able to modify the hosts file (iPhone, iPad...) on your device (jailbreaking excluded).

Well, the solution then is to install a proxy server on the machine hosting the website and connect to that proxy from your iphone. It's actually very well explained in the following posts and is not that long to set up:

On a Mac, I would recommend: Testing a Mac OS X web site using a local hostname on a mobile device: Using SquidMan as a proxy. It's a 100% free solution. Some people can also use Charles as a proxy server but it's 50$.

On Linux, you can adapt the Mac OS way above by using Squid as a proxy server.

On Windows, you can do that using Fiddler. The solution is described in the following post: Monitoring iPhone traffic with Fiddler


Edit 23/11/2017: Hey I don't want to modify my Hosts file

@Dre. Any possible way to access the website from another computer by not editing the host file manually? let's say I have 100 computers wanted to access the website

This is an interesting question, and as it is related to the OP question, let me help.

You would have to do a change on your network so that every machine knows where your website is hosted. Most everyday routers don't do that so you would have to run your own DNS Server on your network.

Let's pretend you have a router (192.168.1.1). This router has a DHCP server and allocates IP addresses to 100 machines on the network.

Now, let's say you have, same as above, on the same network, a machine at 192.168.1.5 which has your website. We will call that machine pompei.

$ echo $HOSTNAME
pompei

Same as before, that machine pompei at 192.168.1.5 runs an HTTP Server which serves your website symfony.local.

For every machine to know that symfony.local is hosted on pompei we will now need a custom DNS Server on the network which knows where symfony.local is hosted. Devices on the network will then be able to resolve domain names served by pompei internally.

3 simple steps.

Step 1: DNS Server

Set-up a DNS Server on your network. Let's have it on pompei for convenience and use something like dnsmasq.

Dnsmasq provides Domain Name System (DNS) forwarder, ....

We want pompei to run DNSmasq to handle DNS requests Hey, pompei, where is symfony.local and respond Hey, sure think, it is on 192.168.1.5 but don't take my word for it.

Go ahead install dnsmasq, dnsmasq configuration file is typically in /etc/dnsmasq.conf depending on your environment.

I personally use no-resolv and google servers server=8.8.8.8 server=8.8.8.4.

*Note:* ALWAYS restart DNSmasq if modifying /etc/hosts file as no changes will take effect otherwise.

Step 2: Firewall

To work, pompei needs to allow incoming and outgoing 'domain' packets, which are going from and to port 53. Of course! These are DNS packets and if pompei does not allow them, there is no way for your DNS server to be reached at all. Go ahead and open that port 53. On linux, you would classically use iptables for this.

Sharing what I came up with but you will very likely have to dive into your firewall and understand everything well.

#
# Allow outbound DNS port 53
#
 iptables -A INPUT -p tcp --dport 53 -j ACCEPT
 iptables -A INPUT -p udp --dport 53 -j ACCEPT

 iptables -A OUTPUT -p tcp --dport 53 -j ACCEPT
 iptables -A OUTPUT -p udp --dport 53 -j ACCEPT

 iptables -A INPUT -p udp --sport 53 -j ACCEPT
 iptables -A INPUT -p tcp --sport 53 -j ACCEPT

 iptables -A OUTPUT -p tcp --sport 53 -j ACCEPT
 iptables -A OUTPUT -p udp --sport 53 -j ACCEPT

Step 3: Router

Tell your router that your dns server is on 192.168.1.5 now. Most of the time, you can just login into your router and change this manually very easily.

That's it, When you are on a machine and ask for symfony.local, it will ask your DNS Server where symfony.local is hosted, and as soon as it has received its answer from the DNS server, will then send the proper HTTP request to pompei on 192.168.1.5.

I let you play with this and enjoy the ride. These 2 steps are the main guidelines, so you will have to debug and spend a few hours if this is the first time you do it. Let's say this is a bit more advanced networking, there are primary DNS Server, secondary DNS Servers, etc.. Good luck!

laravel 5 : Class 'input' not found

This clean code snippet works fine for me:

use Illuminate\Http\Request;
Route::post('/register',function(Request $request){

   $user = new \App\User;
   $user->username = $request->input('username');
   $user->email  = $request->input('email');
   $user->password = Hash::make($request->input('username'));
   $user->designation = $request->input('designation');
   $user->save();
});

How to replace existing value of ArrayList element in Java

You must use

list.remove(indexYouWantToReplace);

first.

Your elements will become like this. [zero, one, three]

then add this

list.add(indexYouWantedToReplace, newElement)

Your elements will become like this. [zero, one, new, three]

Rotation of 3D vector?

It can also be solved using quaternion theory:

def angle_axis_quat(theta, axis):
    """
    Given an angle and an axis, it returns a quaternion.
    """
    axis = np.array(axis) / np.linalg.norm(axis)
    return np.append([np.cos(theta/2)],np.sin(theta/2) * axis)

def mult_quat(q1, q2):
    """
    Quaternion multiplication.
    """
    q3 = np.copy(q1)
    q3[0] = q1[0]*q2[0] - q1[1]*q2[1] - q1[2]*q2[2] - q1[3]*q2[3]
    q3[1] = q1[0]*q2[1] + q1[1]*q2[0] + q1[2]*q2[3] - q1[3]*q2[2]
    q3[2] = q1[0]*q2[2] - q1[1]*q2[3] + q1[2]*q2[0] + q1[3]*q2[1]
    q3[3] = q1[0]*q2[3] + q1[1]*q2[2] - q1[2]*q2[1] + q1[3]*q2[0]
    return q3

def rotate_quat(quat, vect):
    """
    Rotate a vector with the rotation defined by a quaternion.
    """
    # Transfrom vect into an quaternion 
    vect = np.append([0],vect)
    # Normalize it
    norm_vect = np.linalg.norm(vect)
    vect = vect/norm_vect
    # Computes the conjugate of quat
    quat_ = np.append(quat[0],-quat[1:])
    # The result is given by: quat * vect * quat_
    res = mult_quat(quat, mult_quat(vect,quat_)) * norm_vect
    return res[1:]

v = [3, 5, 0]
axis = [4, 4, 1]
theta = 1.2 

print(rotate_quat(angle_axis_quat(theta, axis), v))
# [2.74911638 4.77180932 1.91629719]

How to find memory leak in a C++ code/project?

You can use some techniques in your code to detect memory leak. The most common and most easy way to detect is, define a macro say, DEBUG_NEW and use it, along with predefined macros like __FILE__ and __LINE__ to locate the memory leak in your code. These predefined macros tell you the file and line number of memory leaks.

DEBUG_NEW is just a MACRO which is usually defined as:

#define DEBUG_NEW new(__FILE__, __LINE__)
#define new DEBUG_NEW

So that wherever you use new, it also can keep track of the file and line number which could be used to locate memory leak in your program.

And __FILE__, __LINE__ are predefined macros which evaluate to the filename and line number respectively where you use them!

Read the following article which explains the technique of using DEBUG_NEW with other interesting macros, very beautifully:

A Cross-Platform Memory Leak Detector


From Wikpedia,

Debug_new refers to a technique in C++ to overload and/or redefine operator new and operator delete in order to intercept the memory allocation and deallocation calls, and thus debug a program for memory usage. It often involves defining a macro named DEBUG_NEW, and makes new become something like new(_FILE_, _LINE_) to record the file/line information on allocation. Microsoft Visual C++ uses this technique in its Microsoft Foundation Classes. There are some ways to extend this method to avoid using macro redefinition while still able to display the file/line information on some platforms. There are many inherent limitations to this method. It applies only to C++, and cannot catch memory leaks by C functions like malloc. However, it can be very simple to use and also very fast, when compared to some more complete memory debugger solutions.

Fatal error: Call to undefined function curl_init()

For Ubuntu

Install Curl extension for PHP & restart apache server.

sudo apt-get install php5-curl
sudo service apache2 restart

For Windows

Problem arises because of not including the lib_curl.dll to PHP. also load following extension if not working,so those extension in php.ini or remove comment if already exist in php.ini file then remove comment.

extension=php_bz2.dll
extension=php_curl.dll
extension=php_dba.dll

Now restart apache server. If you get an error "Unable to Load php_curl.dll", copy SSLEAY32.PHP, libEAY32.dll (OpenSSL) Libraries to the System32 folder.

Apply CSS Style to child elements

The > selector matches direct children only, not descendants.

You want

div.test th, td, caption {}

or more likely

div.test th, div.test td, div.test caption {}

Edit:

The first one says

  div.test th, /* any <th> underneath a <div class="test"> */
  td,          /* or any <td> anywhere at all */
  caption      /* or any <caption> */

Whereas the second says

  div.test th,     /* any <th> underneath a <div class="test"> */
  div.test td,     /* or any <td> underneath a <div class="test"> */
  div.test caption /* or any <caption> underneath a <div class="test">  */

In your original the div.test > th says any <th> which is a **direct** child of <div class="test">, which means it will match <div class="test"><th>this</th></div> but won't match <div class="test"><table><th>this</th></table></div>

How to select first parent DIV using jQuery?

Use .closest() to traverse up the DOM tree up to the specified selector.

var classes = $(this).parent().closest('div').attr('class').split(' '); // this gets the parent classes.

How we can bold only the name in table td tag not the value

I might be misunderstanding your question, so apologies if I am.

If you're looking for the words "Quid", "Application Number", etc. to be bold, just wrap them in <strong> tags:

<strong>Quid</strong>: ...

Hope that helps!

How do I test if a recordSet is empty? isNull?

If temp_rst1.BOF and temp_rst1.EOF then the recordset is empty. This will always be true for an empty recordset, linked or local.

How do I set the rounded corner radius of a color drawable using xml?

Try below code

<shape xmlns:android="http://schemas.android.com/apk/res/android">
<corners
    android:bottomLeftRadius="30dp"
    android:bottomRightRadius="30dp"
    android:topLeftRadius="30dp"
    android:topRightRadius="30dp" />
<solid android:color="#1271BB" />

<stroke
    android:width="5dp"
    android:color="#1271BB" />

<padding
    android:bottom="1dp"
    android:left="1dp"
    android:right="1dp"
    android:top="1dp" /></shape>

How to convert the ^M linebreak to 'normal' linebreak in a file opened in vim?

In vim, use command:

:%s/\r\n/\r/g

Where you want to search and replace:

\r\n

into

\r

and the

/g

is for global

Note that this is the same as the answer by @ContextSwitch but with the gobal flag

How to show/hide if variable is null

In this case, myvar should be a boolean value. If this variable is true, it will show the div, if it's false.. It will hide.

Check this out.

Stopword removal with NLTK

There is an in-built stopword list in NLTK made up of 2,400 stopwords for 11 languages (Porter et al), see http://nltk.org/book/ch02.html

>>> from nltk import word_tokenize
>>> from nltk.corpus import stopwords
>>> stop = set(stopwords.words('english'))
>>> sentence = "this is a foo bar sentence"
>>> print([i for i in sentence.lower().split() if i not in stop])
['foo', 'bar', 'sentence']
>>> [i for i in word_tokenize(sentence.lower()) if i not in stop] 
['foo', 'bar', 'sentence']

I recommend looking at using tf-idf to remove stopwords, see Effects of Stemming on the term frequency?

Excel formula to remove space between words in a cell

Suppose the data is in the B column, write in the C column the formula:

=SUBSTITUTE(B1," ","")

Copy&Paste the formula in the whole C column.

edit: using commas or semicolons as parameters separator depends on your regional settings (I have to use the semicolons). This is weird I think. Thanks to @tocallaghan and @pablete for pointing this out.

WARNING: sanitizing unsafe style value url

You have to wrap the entire url statement in the bypassSecurityTrustStyle:

<div class="header" *ngIf="image" [style.background-image]="image"></div>

And have

this.image = this.sanitization.bypassSecurityTrustStyle(`url(${element.image})`);

Otherwise it is not seen as a valid style property

Only variables should be passed by reference

$file_extension = end(explode('.', $file_name)); //ERROR ON THIS LINE

change this line as,

$file_extension = end((explode('.', $file_name))); //no errors

Technique is simple please put one more brackets for explode,

(explode()), then only it can perform independently..

How to pick element inside iframe using document.getElementById

You need to make sure the frame is fully loaded the best way to do it is to use onload:

<iframe id="nesgt" src="" onload="custom()"></iframe>

function custom(){
    document.getElementById("nesgt").contentWindow.document;
    }

this function will run automatically when the iframe is fully loaded.

it could be done with setTimeout but we can't get the exact time of the frame load.

hope this helps someone.

Node.js/Windows error: ENOENT, stat 'C:\Users\RT\AppData\Roaming\npm'

This can also be fixed by installing a node package manually.

npm install npm -g

The process of doing that will setup all the required directories.

Where is Python language used?

Many websites uses Django or Zope/Plone web framework, these are written in Python.

Python is used a lot for writing system administration software, usually when bash scripts (shell script) isn't up to the job, but going C/C++ is an overkill. This is also the spectrum where perl, awk, etc stands. Gentoo's emerge/portage is one example. Mercurial/HG is a distributed version control system (DVCS) written in python.

Many desktop applications are also written in Python. The original Bittorrent was written in python.

Python is also used as the scripting languages for GIMP, Inkscape, Blender, OpenOffice, etc. Python allows advanced users to write plugins and access advanced functionalities that cannot typically be used through a GUI.

Comparing two dataframes and getting the differences

There is a simpler solution that is faster and better, and if the numbers are different can even give you quantities differences:

df1_i = df1.set_index(['Date','Fruit','Color'])
df2_i = df2.set_index(['Date','Fruit','Color'])
df_diff = df1_i.join(df2_i,how='outer',rsuffix='_').fillna(0)
df_diff = (df_diff['Num'] - df_diff['Num_'])

Here df_diff is a synopsis of the differences. You can even use it to find the differences in quantities. In your example:

enter image description here

Explanation: Similarly to comparing two lists, to do it efficiently we should first order them then compare them (converting the list to sets/hashing would also be fast; both are an incredible improvement to the simple O(N^2) double comparison loop

Note: the following code produces the tables:

df1=pd.DataFrame({
    'Date':['2013-11-24','2013-11-24','2013-11-24','2013-11-24'],
    'Fruit':['Banana','Orange','Apple','Celery'],
    'Num':[22.1,8.6,7.6,10.2],
    'Color':['Yellow','Orange','Green','Green'],
})
df2=pd.DataFrame({
    'Date':['2013-11-24','2013-11-24','2013-11-24','2013-11-24','2013-11-25','2013-11-25'],
    'Fruit':['Banana','Orange','Apple','Celery','Apple','Orange'],
    'Num':[22.1,8.6,7.6,10.2,22.1,8.6],
    'Color':['Yellow','Orange','Green','Green','Red','Orange'],
})

What are the options for (keyup) in Angular2?

The keyCode is deprecated you can use key property in the KeyboardEvent

<textarea (keydown)=onKeydownEvent($event)></textarea>

Typescript:

onKeydownEvent($event: KeyboardEvent){

    // you can use the following for checkig enter key pressed or not
    if ($event.key === 'Enter') {
      console.log($event.key); // Enter
    }


    if ($event.key === 'Enter' && event.shiftKey) {
           //This is 'Shift+Enter' 
    }
}

How to convert string date to Timestamp in java?

You can even try this.

   String date="09/08/1980";    // take a string  date
    Timestamp ts=null;  //declare timestamp
    Date d=new Date(date); // Intialize date with the string date
    if(d!=null){  // simple null check
        ts=new java.sql.Timestamp(d.getTime()); // convert gettime from date and assign it to your timestamp.
    }

Increment a database field by 1

Updating an entry:

A simple increment should do the trick.

UPDATE mytable 
  SET logins = logins + 1 
  WHERE id = 12

Insert new row, or Update if already present:

If you would like to update a previously existing row, or insert it if it doesn't already exist, you can use the REPLACE syntax or the INSERT...ON DUPLICATE KEY UPDATE option (As Rob Van Dam demonstrated in his answer).

Inserting a new entry:

Or perhaps you're looking for something like INSERT...MAX(logins)+1? Essentially you'd run a query much like the following - perhaps a bit more complex depending on your specific needs:

INSERT into mytable (logins) 
  SELECT max(logins) + 1 
  FROM mytable

How to find if an array contains a specific string in JavaScript/jQuery?

You really don't need jQuery for this.

var myarr = ["I", "like", "turtles"];
var arraycontainsturtles = (myarr.indexOf("turtles") > -1);

Hint: indexOf returns a number, representing the position where the specified searchvalue occurs for the first time, or -1 if it never occurs

or

function arrayContains(needle, arrhaystack)
{
    return (arrhaystack.indexOf(needle) > -1);
}

It's worth noting that array.indexOf(..) is not supported in IE < 9, but jQuery's indexOf(...) function will work even for those older versions.

EC2 instance has no public DNS

Just launch another instance (and also delete the one in question if it has no use) and make sure this time you check "Autoatically assign a public IP address to your instance". If not then as slayedbylucifer suggested; assign an Elastic IP (EIP) to the instance and then log in using that IP. Be careful though, if you are running the free AWS tier, an EIP will cost you money-- that's a whole 'nother topic..

How to dynamically add and remove form fields in Angular 2

addAccordian(type, data) { console.log(type, data);

let form = this.form;

if (!form.controls[type]) {
  let ownerAccordian = new FormArray([]);
  const group = new FormGroup({});
  ownerAccordian.push(
    this.applicationService.createControlWithGroup(data, group)
  );
  form.controls[type] = ownerAccordian;
} else {
  const group = new FormGroup({});
  (<FormArray>form.get(type)).push(
    this.applicationService.createControlWithGroup(data, group)
  );
}
console.log(this.form);

}

SQL Server error on update command - "A severe error occurred on the current command"

In my case, I was using System.Threading.CancellationTokenSource to cancel a SqlCommand but not handling the exception with catch (SqlException) { }

How can I get the intersection, union, and subset of arrays in Ruby?

If Multiset extends from the Array class

x = [1, 1, 2, 4, 7]
y = [1, 2, 2, 2]
z = [1, 1, 3, 7]

UNION

x.union(y)           # => [1, 2, 4, 7]      (ONLY IN RUBY 2.6)
x.union(y, z)        # => [1, 2, 4, 7, 3]   (ONLY IN RUBY 2.6)
x | y                # => [1, 2, 4, 7]

DIFFERENCE

x.difference(y)      # => [4, 7] (ONLY IN RUBY 2.6)
x.difference(y, z)   # => [4] (ONLY IN RUBY 2.6)
x - y                # => [4, 7]

INTERSECTION

x & y                # => [1, 2]

For more info about the new methods in Ruby 2.6, you can check this blog post about its new features

how to avoid a new line with p tag?

Flexbox works.

_x000D_
_x000D_
.box{_x000D_
  display: flex;_x000D_
  flex-flow: row nowrap;_x000D_
  justify-content: center;_x000D_
  align-content: center;_x000D_
  align-items:center;_x000D_
  border:1px solid #e3f2fd;_x000D_
}_x000D_
.item{_x000D_
  flex: 1 1 auto;_x000D_
  border:1px solid #ffebee;_x000D_
}
_x000D_
<div class="box">_x000D_
  <p class="item">A</p>_x000D_
  <p class="item">B</p>_x000D_
  <p class="item">C</p>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Getting Http Status code number (200, 301, 404, etc.) from HttpWebRequest and HttpWebResponse

Just coerce the StatusCode to int.

var statusNumber;
try {
   response = (HttpWebResponse)request.GetResponse();
   // This will have statii from 200 to 30x
   statusNumber = (int)response.StatusCode;
}
catch (WebException we) {
    // Statii 400 to 50x will be here
    statusNumber = (int)we.Response.StatusCode;
}

How to access child's state in React?

If you already have onChange handler for the individual FieldEditors I don't see why you couldn't just move the state up to the FormEditor component and just pass down a callback from there to the FieldEditors that will update the parent state. That seems like a more React-y way to do it, to me.

Something along the line of this perhaps:

const FieldEditor = ({ value, onChange, id }) => {
  const handleChange = event => {
    const text = event.target.value;
    onChange(id, text);
  };

  return (
    <div className="field-editor">
      <input onChange={handleChange} value={value} />
    </div>
  );
};

const FormEditor = props => {
  const [values, setValues] = useState({});
  const handleFieldChange = (fieldId, value) => {
    setValues({ ...values, [fieldId]: value });
  };

  const fields = props.fields.map(field => (
    <FieldEditor
      key={field}
      id={field}
      onChange={handleFieldChange}
      value={values[field]}
    />
  ));

  return (
    <div>
      {fields}
      <pre>{JSON.stringify(values, null, 2)}</pre>
    </div>
  );
};

// To add abillity to dynamically add/remove fields keep the list in state
const App = () => {
  const fields = ["field1", "field2", "anotherField"];

  return <FormEditor fields={fields} />;
};

Original - pre-hooks version:

_x000D_
_x000D_
class FieldEditor extends React.Component {_x000D_
  constructor(props) {_x000D_
    super(props);_x000D_
    this.handleChange = this.handleChange.bind(this);_x000D_
  }_x000D_
_x000D_
  handleChange(event) {_x000D_
    const text = event.target.value;_x000D_
    this.props.onChange(this.props.id, text);_x000D_
  }_x000D_
_x000D_
  render() {_x000D_
    return (_x000D_
      <div className="field-editor">_x000D_
        <input onChange={this.handleChange} value={this.props.value} />_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
}_x000D_
_x000D_
class FormEditor extends React.Component {_x000D_
  constructor(props) {_x000D_
    super(props);_x000D_
    this.state = {};_x000D_
_x000D_
    this.handleFieldChange = this.handleFieldChange.bind(this);_x000D_
  }_x000D_
_x000D_
  handleFieldChange(fieldId, value) {_x000D_
    this.setState({ [fieldId]: value });_x000D_
  }_x000D_
_x000D_
  render() {_x000D_
    const fields = this.props.fields.map(field => (_x000D_
      <FieldEditor_x000D_
        key={field}_x000D_
        id={field}_x000D_
        onChange={this.handleFieldChange}_x000D_
        value={this.state[field]}_x000D_
      />_x000D_
    ));_x000D_
_x000D_
    return (_x000D_
      <div>_x000D_
        {fields}_x000D_
        <div>{JSON.stringify(this.state)}</div>_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
}_x000D_
_x000D_
// Convert to class component and add ability to dynamically add/remove fields by having it in state_x000D_
const App = () => {_x000D_
  const fields = ["field1", "field2", "anotherField"];_x000D_
_x000D_
  return <FormEditor fields={fields} />;_x000D_
};_x000D_
_x000D_
ReactDOM.render(<App />, document.body);
_x000D_
_x000D_
_x000D_

How to reload apache configuration for a site without restarting apache?

Updated for Apache 2.4, for non-systemd (e.g., CentOS 6.x, Amazon Linux AMI) and for systemd (e.g., CentOS 7.x):

There are two ways of having the apache process reload the configuration, depending on what you want done with its current threads, either advise to exit when idle, or killing them directly.

Note that Apache recommends using apachectl -k as the command, and for systemd, the command is replaced by httpd -k

apachectl -k graceful or httpd -k graceful

Apache will advise its threads to exit when idle, and then apache reloads the configuration (it doesn't exit itself), this means statistics are not reset.

apachectl -k restart or httpd -k restart

This is similar to stop, in that the process kills off its threads, but then the process reloads the configuration file, rather than killing itself.

Source: https://httpd.apache.org/docs/2.4/stopping.html

How to negate specific word in regex?

If it's truly a word, bar that you don't want to match, then:

^(?!.*\bbar\b).*$

The above will match any string that does not contain bar that is on a word boundary, that is to say, separated from non-word characters. However, the period/dot (.) used in the above pattern will not match newline characters unless the correct regex flag is used:

^(?s)(?!.*\bbar\b).*$

Alternatively:

^(?!.*\bbar\b)[\s\S]*$

Instead of using any special flag, we are looking for any character that is either white space or non-white space. That should cover every character.

But what if we would like to match words that might contain bar, but just not the specific word bar?

(?!\bbar\b)\b\[A-Za-z-]*bar[a-z-]*\b
  1. (?!\bbar\b) Assert that the next input is not bar on a word boundary.
  2. \b\[A-Za-z-]*bar[a-z-]*\b Matches any word on a word boundary that contains bar.

See Regex Demo

Batch File; List files in directory, only filenames?

create a batch-file with the following code:

dir %1 /b /a-d > list.txt

Then drag & drop a directory on it and the files inside the directory will be listed in list.txt

Plotting histograms from grouped data in a pandas DataFrame

Your function is failing because the groupby dataframe you end up with has a hierarchical index and two columns (Letter and N) so when you do .hist() it's trying to make a histogram of both columns hence the str error.

This is the default behavior of pandas plotting functions (one plot per column) so if you reshape your data frame so that each letter is a column you will get exactly what you want.

df.reset_index().pivot('index','Letter','N').hist()

The reset_index() is just to shove the current index into a column called index. Then pivot will take your data frame, collect all of the values N for each Letter and make them a column. The resulting data frame as 400 rows (fills missing values with NaN) and three columns (A, B, C). hist() will then produce one histogram per column and you get format the plots as needed.