Use the &amp;&amp; (and) and || (or) operators:

    if [[ expression ]] &amp;&amp; [[ expression ]] || [[ expression ]] ; then

They can also be used within a single [[ ]]:

    if [[ expression &amp;&amp; expression || expression ]] ; then

And, finally, you can group them to ensure order of evaluation:

    if [[ expression &amp;&amp; ( expression || expression ) ]] ; then




If I run the following Perl program:

    perl -e &#39;use utf8; print &quot;鸡\n&quot;;&#39;

I get this warning:

    Wide character in print at -e line 1.

If I run this Perl program:

    perl -e &#39;print &quot;鸡\n&quot;;&#39;

I do not get a warning.

I thought `use utf8` was required to use UTF-8 characters in a Perl script.  Why does this not work and how can I fix it? I&#39;m using Perl 5.16.2. I have the same issue if this is in a file instead of being a one liner on the command line.



Use of &#39;use utf8;&#39; gives me &#39;Wide character in print&#39;

Can a div tag have two classes?

I am using twitter bootstrap, and there are two predefined classes that I would like to use.

One is an `active` class that I would like to use on a `dropdown-toggle` within a nav bar.

What is the best way of approaching this in the html, with out overriding the css.

Can a div have multiple classes (Twitter Bootstrap)

I want to have some groups of conditions in a Bash *if* statement. Specifically, I&#39;m looking for something like the following:

    if &lt;myCondition1 and myCondition2&gt; or &lt;myCondition3 and myCondition4&gt; then...

How may I group the conditions together in the way I describe for use with one *if* statement in Bash?





Groups of compound conditions in Bash test

I want to have some groups of conditions in a Bash if statement. Specifically, I'm looking for something like the following:
<pre><code class="hljs language-php-template">if &#x3C;myCondition1 and myCondition2> or &#x3C;myCondition3 and myCondition4> then...
</code></pre>
How may I group the conditions together in the way I describe for use with one if statement in Bash?

How to retrieve the first 10 characters of a variable with Bash?

    FOO=&quot;qwertzuiopasdfghjklyxcvbnm&quot;

I need to get `qwertzuiop`.

How to retrieve the first n characters of a variable in Bash?

I want to rename all files and directories that contain the word &quot;special&quot; to &quot;regular&quot;. It should maintain case sensitivity so &quot;Special&quot; won&#39;t become &quot;regular&quot;.

How can i do this in bash recursively? 

Rename files and directories recursively under ubuntu /bash

I know some very basic commands in Linux and am trying to write some scripts. I have written a function which evaluates the sum of last 2-digits in a 5-digit number. The function should concatenate this resultant sum in between the last 2-digits and return it. The reason I want to return this value is because I will be using this value in the other function. 

Ex: if I have 12345, then my function will calculate 4+5 and return 495.

    #!/bin/bash
    
    set -x
    echo &quot;enter: &quot;
            read input
    
    function password_formula
    {
            length=${#input}
            last_two=${input:length-2:length}
            first=`echo $last_two| sed -e &#39;s/$.$/\1 /g&#39;|awk &#39;{print $2}&#39;`
            second=`echo $last_two| sed -e &#39;s/$.$/\1 /g&#39;|awk &#39;{print $1}&#39;`
            let sum=$first+$second
            sum_len=${#sum}
            echo $second
            echo $sum
    
            if [ $sum -gt 9 ]
            then
                   sum=${sum:1}
            fi
    
            value=$second$sum$first
            return $value
    }
    result=$(password_formula)
    echo $result

I am trying to echo and see the result but I am getting the output as shown below. 

    -bash-3.2$ ./file2.sh 
    +++ password_formula
    +++ echo &#39;enter: &#39;
    +++ read input
    12385
    +++ length=8
    +++ last_two=85
    ++++ echo 85
    ++++ sed -e &#39;s/$.$/\1 /g&#39;
    ++++ awk &#39;{print $2}&#39;
    +++ first=5
    ++++ echo 85
    ++++ sed -e &#39;s/$.$/\1 /g&#39;
    ++++ awk &#39;{print $1}&#39;
    +++ second=8
    +++ let sum=5+8
    +++ sum_len=2
    +++ echo 5
    +++ echo 8
    +++ echo 13
    +++ &#39;[&#39; 13 -gt 9 &#39;]&#39;
    +++ sum=3
    +++ value=835
    +++ return 835
    ++ result=&#39;enter: 
    5
    8
    13&#39;
    ++ echo enter: 5 8 13
    enter: 5 8 13


I also tried to print the result as:

    password_formula
    RESULT=$?
    echo $RESULT

But that is giving some unknown value: 

    ++ RESULT=67
    ++ echo 67
    67


How can I properly store the correct value and print (to double check) on the screen? 

Thanks in advance.






In bash, how to store a return value in a variable?

I have a backup script on my server which does cron jobs of backups, and sends me a summary of  files backed up, including the size of the new backup file. As part of the script, I&#39;d like to divide the final size of the file by (1024^3) to get the file size in GB, from the file size in bytes. 

Since bash does not have floating point calculation, I am trying to use pipes to bc to get the result, however I&#39;m getting stumped on basic examples.

I tried to get the value of Pi to a scale, however,

even though the following works:

	~ #bc -l
	bc 1.06.95
	Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc.
	This is free software with ABSOLUTELY NO WARRANTY.
	For details type `warranty&#39;.
	4/3
	1.33333333333333333333
	22/7
	3.14285714285714285714
	q
	0
	quit

A non interactive version does not work:

	#echo $(( 22/7 )) | bc
	3
This works:

	#echo &#39;22/7&#39; | bc -l
	3.14285714285714285714

But I need to use variables. So it doesnt help that the following does not work:

	#a=22 ; b=7
	#echo $(( a/b )) | bc -l
	3

I&#39;m obviously missing something in the syntax for using variables in Bash, and could use with some &#39;pointers&#39; on what I&#39;ve misunderstood.

As DigitalRoss said, I can use the following:

	#echo $a / $b | bc -l
	3.14285714285714285714

However I cant use complex expressions like:

	#echo $a / (( $b-34 )) | bc -l
	-bash: syntax error near unexpected token `(&#39;
	#echo $a / (( b-34 )) | bc -l
	-bash: syntax error near unexpected token `(&#39;
	#echo $a / (( b-34 )) | bc -l
	-bash: syntax error near unexpected token `(&#39;

Can someone give me a working correct syntax for getting floating point results with complicated arithmetic expresssions?

Floating point results in Bash integer division

I have something in `bash` like

    myArray=(&#39;red&#39; &#39;orange&#39; &#39;green&#39;)

And I would like to do something like

    echo ${myArray[&#39;green&#39;]}

Which in this case would output `2`. Is this achievable?

Get the index of a value in a Bash array

I&#39;m trying to make a function that will compare multiple variables to an integer and output a string of three letters. I was wondering if there was a way to translate this into Python. So say:

    x = 0
    y = 1
    z = 3
    mylist = []

    if x or y or z == 0 :
    	mylist.append(&quot;c&quot;)
    if x or y or z == 1 :
        mylist.append(&quot;d&quot;)
    if x or y or z == 2 :
        mylist.append(&quot;e&quot;)
    if x or y or z == 3 : 
        mylist.append(&quot;f&quot;)

which would return a list of:

    [&quot;c&quot;, &quot;d&quot;, &quot;f&quot;]

Is something like this possible?
    
    

How to test multiple variables for equality against a single value?

We all know python&#39;s

    [f(x) for x in y if g(x)]

syntax.

However the 
[AST][1] representation of list comprehension has room for more than one &#39;if&#39; expression:

    comprehension = (expr target, expr iter, expr* ifs)

Can somebody give me an example of python code that would produce an AST with more than one &#39;if&#39; expression?

  [1]: http://docs.python.org/2/library/ast.html#abstract-grammar

python list comprehension with multiple &#39;if&#39;s

**Without** iterating over the entire array, how can I check if `x` in array using Go? Does the language have a construct?

Like Python: `if &quot;x&quot; in array: ...`

Does Go have &quot;if x in&quot; construct similar to Python?

I want to compare 2 iterables and print the items which appear in both iterables.

    &gt;&gt;&gt; a = (&#39;q&#39;, &#39;r&#39;)
    &gt;&gt;&gt; b = (&#39;q&#39;)
   

    # Iterate over a. If y not in b, print y.
    # I want to see [&#39;r&#39;] printed.
    &gt;&gt;&gt; print([ y if y not in b for y in a])
                                  ^
But it gives me a invalid syntax error where the `^` has been placed.
What is wrong about this lamba function?






List comprehension with if statement

Hi I have simply select and works great:


    select &#39;CARAT Issue Open&#39; issue_comment, i.issue_id, i.issue_status, i.issue_title, i.ISSUE_summary ,i.issue_description, i.severity,
    gcrs.Area_name, gcrs.sector_name,
 
    substr(gcrs.stream_name,1,case when instr(gcrs.stream_name,&#39; (&#39;)=0 then 100 else instr(gcrs.stream_name,&#39; (&#39;)-1 end) ISSUE_DIVISION,
 
    case when gcrs.STREAM_NAME like &#39;NON-GT%&#39; THEN &#39;NON-GT&#39; ELSE gcrs.STREAM_NAME END as ISSUE_DIVISION_2
 
 
    from table(f_carat_issues_as_of(&#39;31/MAR/2013&#39;)) i
    inner join v_gcrs_with_stream gcrs on i.segment_id = gcrs.segment_id
 
    where UPPER(ISSUE_STATUS) like &#39;%OPEN%&#39;

Now I want to call two columns:
ISSUE_DIVISION and ISSUE_DIVISION_2

if they are equal in new columns should be value 1 if are not equal should be 0,

how can I do it ? 

---

my full code:

    select &#39;CARAT Issue Open&#39; issue_comment, i.issue_id, i.issue_status, i.issue_title, i.ISSUE_summary ,i.issue_description, i.severity,
    gcrs.Area_name, gcrs.sector_name,

    substr(gcrs.stream_name,1,case when instr(gcrs.stream_name,&#39; (&#39;)=0 then 100 else instr(gcrs.stream_name,&#39; (&#39;)-1 end) ISSUE_DIVISION,

    case when gcrs.STREAM_NAME like &#39;NON-GT%&#39; THEN &#39;NON-GT&#39; ELSE gcrs.STREAM_NAME END as ISSUE_DIVISION_2


    from table(f_carat_issues_as_of(&#39;31/MAR/2013&#39;)) i
    inner join v_gcrs_with_stream gcrs on i.segment_id = gcrs.segment_id

    where UPPER(ISSUE_STATUS) like &#39;%OPEN%&#39; and 

    CASE WHEN ISSUE_DIVISION = ISSUE_DIVISION_2 THEN 
         CASE WHEN  ISSUE_DIVISION is null then &quot;Null Value found&quot;
         Else 1 End
    ELSE 0 END As Issue_Division_Result

but I get error on line:
    ELSE 0 END As Issue_Division_Result

ORA-00920: invalid relational operator :(
     
       

Content Type	Original Author	Original Content on Stackoverflow
Question	d3pd	View Question on Stackoverflow
Solution 1 - Bash	William	View Answer on Stackoverflow

Groups of compound conditions in Bash test

Bash Problem Overview

Bash Solutions

Solution 1 - Bash

Can a div have multiple classes (Twitter Bootstrap)

Use of 'use utf8;' gives me 'Wide character in print'

Attributions