From [`man 1 bash`][1], section **Pipelines**:

&gt; [time [-p]] [ ! ] command [ [|⎪|&amp;] command2 ... ]
&gt;
&gt; If |&amp; is used, `command`&#39;s standard error, in addition to its standard output, is connected to `command2`&#39;s standard input through the pipe

So it is just like the pipe operator `|`, but piping both [standard output][2] and [standard error][3].

  [1]: https://linux.die.net/man/1/bash
  [2]: https://en.wikipedia.org/wiki/Standard_streams#Standard_output_.28stdout.29
  [3]: https://en.wikipedia.org/wiki/Standard_streams#Standard_error_(stderr)

This operator pipes both standard output and standard error from the left hand side to the right hand side.

The [Bash reference manual][1] has a comprehensive index of all operators where you can look up these operators.

  [1]: http://www.gnu.org/software/bash/manual/bashref.html


If ‘|&amp;’ is used, command1’s standard error, in addition to its standard output, is connected to command2’s standard input through the pipe; it is shorthand for 2&gt;&amp;1 |. This implicit redirection of the standard error to the standard output is performed after any redirections specified by the command.

I&#39;ve been upgrading my custom directives to the new [component architecture](https://docs.angularjs.org/guide/component#component-based-application-architecture). I&#39;ve read that components do not support watchers. Is this correct? If so how do you detect changes on an object? For a basic example I have custom component `myBox` which has a child component game with a binding on the game . If  there is a change game within the game component how do I show an alert message within the myBox? I understand there is rxJS method is it possible to do this purely in angular? My [JSFiddle][1]

**JavaScript**

    var app = angular.module(&#39;myApp&#39;, []);
    app.controller(&#39;mainCtrl&#39;, function($scope) {
        
       $scope.name = &quot;Tony Danza&quot;;
      
    });
    
    app.component(&quot;myBox&quot;,  {
          bindings: {},
          controller: function($element) {
            var myBox = this;
            myBox.game = &#39;World Of warcraft&#39;;
            //IF myBox.game changes, show alert message &#39;NAME CHANGE&#39;
          },
          controllerAs: &#39;myBox&#39;,
          templateUrl: &quot;/template&quot;,
          transclude: true
    })
    app.component(&quot;game&quot;,  {
          bindings: {game:&#39;=&#39;},
          controller: function($element) {
            var game = this;
            
           
          },
          controllerAs: &#39;game&#39;,
          templateUrl: &quot;/template2&quot;
    })
    
**HTML**

    &lt;div ng-app=&quot;myApp&quot; ng-controller=&quot;mainCtrl&quot;&gt;
      &lt;script type=&quot;text/ng-template&quot; id=&quot;/template&quot;&gt;
        &lt;div style=&#39;width:40%;border:2px solid black;background-color:yellow&#39;&gt;
          Your Favourite game is: {{myBox.game}}
          &lt;game game=&#39;myBox.game&#39;&gt;&lt;/game&gt;
        &lt;/div&gt;
      &lt;/script&gt;
      
     &lt;script type=&quot;text/ng-template&quot; id=&quot;/template2&quot;&gt;
        &lt;div&gt;
        &lt;/br&gt;
        	Change Game
          &lt;textarea ng-model=&#39;game.game&#39;&gt;&lt;/textarea&gt;
        &lt;/div&gt;
      &lt;/script&gt;
      
      Hi {{name}}
      &lt;my-box&gt;
        
      &lt;/my-box&gt;
      
    &lt;/div&gt;&lt;!--end app--&gt;


  [1]: https://jsfiddle.net/bkarv/swv22g3s/

AngularJS 1.5+ Components do not support Watchers, what is the work around?

I updated from VSCode 0.10.6 to 0.10.8, and tried using Typescript for the first time.  Unfortunately I when I tell VSCode to build, I get the error:

&gt;tsc is not a recognized as an internal or external command...

Here are the relevant details:

 * I created a fresh &quot;HelloWorld&quot; project [according to VS Code instructions][1].  This included:
   * I ran `npm init` for a new package.json
   * I ran `npm i --save-dev typescript` because I want a local install, rather than a global install.
   * I created a launch.json to define a node.js project.
   * I created the tasks.json file, with prescribed settings for tsc.
 * I have made a settings.json file, [as shown here][2].  It did not help.
 * I do have Visual Studio 2015 Community installed, but I have not installed a Typescript extension of any kind.  When I type &quot;where tsc&quot; at a developer command prompt, it replies &quot;could not find&quot;. I assume this is a good thing.

I have restarted VSCode (several times).  What am I missing?  What more must be done?

## Update
I tried the solution offered by @zlumer.  It succeeded in making the typescript compiler run, but then it caused thousands of errors to appear.  To fix that, I also had to adjust my tsconfig.json to exclude the node_modules folder:

    &quot;exclude&quot;: [
        &quot;node_modules&quot;
    ]


  [1]: https://code.visualstudio.com/Docs/languages/typescript
  [2]: https://stackoverflow.com/questions/34430205/after-recent-update-vs-code-transpiling-stopped-working-tsc-is-not-recognized-a

tsc is not recognized as internal or external command

For example

    echo &quot;aaa&quot; |&amp; cat

What does `|&amp;` mean here?

Is there a website recommended to look up those? Since most search engines can&#39;t support searching special characters.



What does &quot;|&amp;&quot; mean in Bash?

For example
<pre><code class="hljs language-bash">echo "aaa" |&#x26; cat
</code></pre>
What does <code>|&#x26;</code> mean here?
Is there a website recommended to look up those? Since most search engines can't support searching special characters.

How do I execute a bash command from Ipython/Jupyter notebook passing the value of a python variable as an argument like in this example:

    py_var=&quot;foo&quot;
    !grep py_var bar.txt

(obviously I want to grep for `foo` and not the literal string `py_var`)


Passing IPython variables as arguments to bash commands

I&#39;m on a Mac running El Capitan. I have node v5.6.0 and npm v3.6.0. 
When I try to run nodemon, I get: 

    -bash: nodemon: command not found

I thought this may mean that I didn&#39;t have nodemon installed, so when I tried to install it using...

    sudo npm install -g nodemon

...I get this:

    npm ERR! Darwin 15.2.0
    npm ERR! argv &quot;/usr/local/bin/node&quot; &quot;/usr/local/bin/npm&quot; &quot;install&quot; &quot;-g&quot;     &quot;nodemon&quot;
    npm ERR! node v5.6.0
    npm ERR! npm  v3.6.0
    npm ERR! path /usr/local/bin/nodemon
    npm ERR! code EEXIST

    npm ERR! Refusing to delete /usr/local/bin/nodemon: ../lib/node_modules/nodemon/nodemon.js symlink target is not controlled by         npm /usr/local
    npm ERR! File exists: /usr/local/bin/nodemon
    npm ERR! Move it away, and try again.

    npm ERR! Please include the following file with any support request:
    npm ERR!     /Users/brianeoneill/npm-debug.log

If it makes a difference, I&#39;m trying to run nodemon on a project that uses Express v4.13.1

Thanks for any help you can offer!

nodemon not working: -bash: nodemon: command not found

I have a simple script : 

    #!/bin/bash
    set -e
    trap &quot;echo BOO!&quot; ERR 
    
    function func(){
        ls /root/
    }
    
    func

I would like to trap ERR if my script fails (as it will here b/c I do not have the permissions to look into /root). However, when using `set -e` it is not trapped. Without `set -e` ERR is trapped.  

According to the bash man page, for `set -e` : 

&gt;  ... A trap on ERR, if set, is executed before the  shell  exits. ...

Why isn&#39;t my trap executed?  From the man page it seems like it should.

How to trap ERR when using &#39;set -e&#39; in Bash

I am trying to match a string with a regex in a shell script.
This string is a parameter of the script ( $1 ) and it is a date (MM/DD/YYYY)
The regex I&#39;m trying to use is : 

    ^\d{2}[\/\-]\d{2}[\/\-]\d{4}$

It seems to work, I tried it on several regex tests websites.

My shell code is : 

    REGEX_DATE=&quot;^\d{2}[\/\-]\d{2}[\/\-]\d{4}$&quot;
    &#160;
    echo &quot;$1&quot; | grep -q $REGEX_DATE
    echo $?

The &quot;echo $?&quot; returns 1 no matter is the string I&#39;m putting in parameter.

Do you guys have an idea ?

Thanks !

How do I use a regex in a shell script?

I want to write a script that loops through the output (array possibly?) of a shell command, `ps`.

Here is the command and the output:

    $ ps -ewo pid,cmd,etime | grep python | grep -v grep | grep -v sh
     3089 python /var/www/atm_securit       37:02
    17116 python /var/www/atm_securit       00:01
    17119 python /var/www/atm_securit       00:01
    17122 python /var/www/atm_securit       00:01
    17125 python /var/www/atm_securit       00:00


Convert it into bash script (snippet):

    for tbl in $(ps -ewo pid,cmd,etime | grep python | grep -v grep | grep -v sh)
    do
       echo $tbl
    done

But the output becomes:

    3089
    python
    /var/www/atm_securit
    38:06
    17438
    python
    /var/www/atm_securit
    00:02
    17448
    python
    /var/www/atm_securit
    00:01

How do I loop through every row like in the shell output, but in a bash script?

Content Type	Original Author	Original Content on Stackoverflow
Question	Nan Hua	View Question on Stackoverflow
Solution 1 - Bash	Oleg Andriyanov	View Answer on Stackoverflow
Solution 2 - Bash	lunaryorn	View Answer on Stackoverflow
Solution 3 - Bash	honzajde	View Answer on Stackoverflow

What does "|&" mean in Bash?

Bash Problem Overview

Bash Solutions

Solution 1 - Bash

Solution 2 - Bash

Solution 3 - Bash

tsc is not recognized as internal or external command

AngularJS 1.5+ Components do not support Watchers, what is the work around?

Attributions