Using pure [tag:bash] :

    $ cat file.txt
    US/Central - 10:26 PM (CST)
    $ while read a b time x; do [[ $b == - ]] &amp;&amp; echo $time; done &lt; file.txt


another solution with bash regex :


    $ [[ &quot;US/Central - 10:26 PM (CST)&quot; =~ -[[:space:]]*([0-9]{2}:[0-9]{2}) ]] &amp;&amp;
        echo ${BASH_REMATCH[1]}


another solution using `grep` and look-around advanced regex :

    $ echo &quot;US/Central - 10:26 PM (CST)&quot; | grep -oP &quot;\-\s+\K\d{2}:\d{2}&quot;

another solution using sed :

    $ echo &quot;US/Central - 10:26 PM (CST)&quot; |
        sed &#39;s/.*\- *$[0-9]\{2\}:[0-9]\{2\}$.*/\1/&#39;

another solution using perl :

    $ echo &quot;US/Central - 10:26 PM (CST)&quot; |
        perl -lne &#39;print $&amp; if /\-\s+\K\d{2}:\d{2}/&#39;

and last one using awk :

    $ echo &quot;US/Central - 10:26 PM (CST)&quot; |
        awk &#39;{for (i=0; i&lt;=NF; i++){if ($i == &quot;-&quot;){print $(i+1);exit}}}&#39;

        echo &quot;US/Central - 10:26 PM (CST)&quot; | sed -n &quot;s/^.*-\s*$\S*$.*$/\1/p&quot;

    -n      suppress printing
    s       substitute
    ^.*     anything at the beginning
    -       up until the dash
    \s*     any space characters (any whitespace character)
    $      start capture group
    \S*     any non-space characters
    $      end capture group
    .*$     anything at the end
    \1      substitute 1st capture group for everything on line
    p       print it

Quick &#39;n dirty, regex-free, low-robustness chop-chop technique

    string=&quot;US/Central - 10:26 PM (CST)&quot;
    etime=&quot;${string% [AP]M*}&quot;
    etime=&quot;${etime#* - }&quot;
    

If your string is

    foo=&quot;US/Central - 10:26 PM (CST)&quot;

then

    echo &quot;${foo}&quot; | cut -d &#39; &#39; -f3

will do the job.


foo=&quot;US/Central - 10:26 PM (CST)&quot;

echo ${foo} | date +%H:%M 



How do I enable Entity Framework 5 (version 5.0.0) migrations for multiple DB contexts in the same project, where each context corresponds to its own database? When I run `Enable-Migrations` in the PM console (Visual Studio 2012), there&#39;s an error because of there being multiple contexts:

    PM&gt; Enable-Migrations
    More than one context type was found in the assembly &#39;DatabaseService&#39;.
    To enable migrations for DatabaseService.Models.Product1DbContext, use Enable-Migrations -ContextTypeName DatabaseService.Models.Product1DbContext.
    To enable migrations for DatabaseService.Models.Product2DbContext, use Enable-Migrations -ContextTypeName DatabaseService.Models.Product2DbContext.

If I run `Enable-Migrations -ContextTypeName DatabaseService.Models.Product1DbContext` I&#39;m not allowed to run `Enable-Migrations -ContextTypeName DatabaseService.Models.Product2DbContext` because a migration already exists: `Migrations have already been enabled in project &#39;DatabaseService&#39;. To overwrite the existing migrations configuration, use the -Force parameter.`

How do I enable EF migrations for multiple contexts to separate databases?

How do I simply switch columns with rows in SQL?
Is there any simple command to transpose?

ie turn this result:

    	    Paul  |	John  |	Tim  |  Eric
    Red	    1	    5	    1	    3
    Green	8	    4	    3	    5
    Blue	2	    2	    9	    1

into this:


    	    Red  | Green | Blue
    Paul	1	    8	    2
    John	5	    4	    2
    Tim	    1	    3	    9
    Eric	3	    5	    1

`PIVOT` seems too complex for this scenario.




Simple way to transpose columns and rows in SQL?

I&#39;m trying to extract the time from a string using bash, and I&#39;m having a hard time figuring it out.

My string is like this:

    US/Central - 10:26 PM (CST)

And I want to extract the `10:26` part.

Anybody knows of a way of doing this only with bash - without using sed, awk, etc?

Like, in PHP I would use - not the best way, but it works - something like:

    preg_match( &quot;&quot;(\d{2}\:\d{2}) PM $CST$&quot;&quot;, &quot;US/Central - 10:26 PM (CST)&quot;, $matches );

Thanks for any help, even if the answer uses sed or awk

Extract substring using regexp in plain bash

I'm trying to extract the time from a string using bash, and I'm having a hard time figuring it out.
My string is like this:
<pre><code class="hljs">US/Central - 10:26 PM (CST)
</code></pre>
And I want to extract the <code>10:26</code> part.
Anybody knows of a way of doing this only with bash - without using sed, awk, etc?
Like, in PHP I would use - not the best way, but it works - something like:
<pre><code class="hljs language-bash">preg_match( ""(\d{2}\:\d{2}) PM $CST$"", "US/Central - 10:26 PM (CST)", $matches );
</code></pre>
Thanks for any help, even if the answer uses sed or awk

I searched a lot and can&#39;t find the solution for this RegExp (I have to say I&#39;m not very experienced in Reg. Expressions). 

    Regex = ^[1-9]?[0-9]{1}$|^100$

I would like to test a number **between 1 and 100, excluding 0** 




Regex number between 1 and 100

I have the following input elements:

    &lt;input id=&quot;AAA_RandomString_BBB&quot; type=&quot;text&quot; /&gt;
    &lt;input id=&quot;AAA_RandomString_BBB_Start&quot; type=&quot;text&quot; /&gt;
    &lt;input id=&quot;AAA_RandomString_BBB_End&quot; type=&quot;text&quot; /&gt;

AAA &amp; BBB are constants and I will always know what they are.  However RandomString will always be random.

I want to get the value of AAA_RandomString_BBB.  I do not want the values from the input elements with ID ending in either _Start or _End.

I tried the folowing:

    $(&#39;[id^=&quot;AAA_&quot;]&#39;)

But the above selects all of the input elements that have an ID starting with &quot;AAA_&quot;

I need some way to select using a regex type syntax like:

    $(&#39;[id^=&quot;AAA_(.+?)_BBB&quot;]&#39;)

Is this possible? If not, can anyone suggest a method of selecting 

How can I select an element by ID with jQuery using regex?

The `\K` escape sequence resets the beginning of the match to the current position in
the token list (this only affects what is reported as the full match).
 
What environments/languages/versions support `\K` (keep) in its regular expression engines and what libraries are needed (if any) to use this feature within patterns?

Support of \K in regex

What would be the most efficient way to check whether a string contains a &quot;.&quot; or not?

I know you can do this in many different ways like with [regular expressions][1] or loop through the string to see if it contains a dot (&quot;.&quot;).

  [1]: http://en.wikipedia.org/wiki/Regular_expression


PHP string &quot;contains&quot;

I have  a list of alphanumeric characters that looks like: 

    x &lt;-c(&#39;ACO2&#39;, &#39;BCKDHB456&#39;, &#39;CD444&#39;)

I would like the following output: 

    x &lt;-c(&#39;ACO&#39;, &#39;BCKDHB&#39;, &#39;CD&#39;)

Any suggestions?


    # dput(tmp2)

    structure(c(432L, 326L, 217L, 371L, 179L, 182L, 188L, 268L, 255L,..., 
    ), class = &quot;factor&quot;)



Remove numbers from alphanumeric characters

I want to remove some *n* lines from the end of a file. Can this be done using sed?

For example, to remove lines from 2 to 4, I can use

    $ sed &#39;2,4d&#39; file

But I don&#39;t know the line numbers.  I can delete the last line using 

    $sed $d file

but I want to know the way to remove *n* lines from the end. Please let me know how to do that using sed or some other method.

How to use sed to remove the last n lines of a file

I&#39;m trying to create a simple Bash script to check if the website is down and for some reason the &quot;and&quot; operator doesn&#39;t work:

    #!/usr/bin/env bash

    WEBSITE=domain.com
    SUBJECT=&quot;$WEBSITE DOWN!&quot;
    EMAILID=&quot;an@email.com&quot;
    STATUS=$(curl -sI $WEBSITE | awk &#39;/HTTP\/1.1/ { print $2 }&#39;)
    STRING=$(curl -s $WEBSITE | grep -o &quot;string_to_search&quot;)
    VALUE=&quot;string_to_search&quot;

    if [ $STATUS -ne 200 ] &amp;&amp; [[ &quot;$STRING&quot; != &quot;$VALUE&quot; ]]; then
        echo &quot;Website: $WEBSITE is down, status code: &#39;$STATUS&#39; - $(date)&quot; | mail -s &quot;$SUBJECT&quot; $EMAILID
    fi

The &quot;-a&quot; operator also doesn&#39;t work:

    if [ $STATUS -ne 200 ] -a [[ &quot;$STRING&quot; != &quot;$VALUE&quot; ]]

Could you also please advise when to use:

- single and double square brackets
- parenthesis

?


An &quot;and&quot; operator for an &quot;if&quot; statement in Bash

I have a variable `$data` and variable `$file` in a bash script:

    data=$(echo &quot;$(printf &#39;%s\n&#39; &quot;${array[@]/%/$&#39;\n\n&#39;}&quot;)&quot;)
    file=$(&lt;scriptfile_results)

Those variables will contain text. How to compare those two? One option is to use *diff*(1) utility like this:

    diff -u &lt;(echo &quot;$data&quot;) &lt;(echo &quot;$file&quot;)

Is this an correct and elegant way to compare content of two variables? In addition how is the `&lt;( )` technique called? As I understand, for each `&lt;( )` a temporary file(named pipe) is created..

compare content of two variables in bash

I have directory structure like this

    data
    |___
       |
       abc
        |____incoming
       def
        |____incoming
        |____processed
       123
        |___incoming
       456
        |___incoming
        |___processed

There is an incoming sub-folder in all of the folders inside Data directory. I want to get all files from all the folders and sub-folders except the def/incoming and 456/incoming dirs.
I tried out with following command
 
     find /home/feeds/data -type d $ -name &#39;def/incoming&#39; -o -name &#39;456/incoming&#39; -o -name arkona $ -prune -o -name &#39;*.*&#39; -print

but it is not working as expected.

Ravi
   

Exclude a sub-directory using find

I would like to know the following;

1. Why the given non-working example doesn&#39;t work.
2. If there are any other cleaner methods than those given in working example.

*Non-working example*

    &gt; ids=(1 2 3 4);echo ${ids[*]// /|}
    1 2 3 4
    &gt; ids=(1 2 3 4);echo ${${ids[*]}// /|}
    -bash: ${${ids[*]}// /|}: bad substitution
    &gt; ids=(1 2 3 4);echo ${&quot;${ids[*]}&quot;// /|}
    -bash: ${&quot;${ids[*]}&quot;// /|}: bad substitution

*Working example*

    &gt; ids=(1 2 3 4);id=&quot;${ids[@]}&quot;;echo ${id// /|}
    1|2|3|4
    &gt; ids=(1 2 3 4); lst=$( IFS=&#39;|&#39;; echo &quot;${ids[*]}&quot; ); echo $lst
    1|2|3|4

In context, the delimited string to be used in a [sed][1] command for further parsing.


  [1]: https://www.gnu.org/software/sed/manual/sed.html

Content Type	Original Author	Original Content on Stackoverflow
Question	andrux	View Question on Stackoverflow
Solution 1 - Regex	Gilles Quenot	View Answer on Stackoverflow
Solution 2 - Regex	jgshawkey	View Answer on Stackoverflow
Solution 3 - Regex	doubleDown	View Answer on Stackoverflow
Solution 4 - Regex	LeChatDeNansen	View Answer on Stackoverflow
Solution 5 - Regex	Jimbro	View Answer on Stackoverflow

Extract substring using regexp in plain bash

Regex Problem Overview

Regex Solutions

Solution 1 - Regex

Solution 2 - Regex

Solution 3 - Regex

Solution 4 - Regex

Solution 5 - Regex

Simple way to transpose columns and rows in SQL?

How do I enable EF migrations for multiple contexts to separate databases?

Attributions