lundi 21 janvier 2013

The expr command

The expr command is used to evaluate an expression and output the corresponding value. It could be used for example to use the terminal as a calculator:

    $ expr 80 - 25
    55
    $ expr 80 / 25
    3
 
Note that there is a space between the different arguments, otherwise the expression might not be evaluated properly.
It can be used as well for string operations and boolean operations

    $ expr length "abc"
    3
    $ expr 1 "&" 0
    0

2 commentaires:

  1. For Bash shell, there is no need to use expr

    you can simply use :

    $(( 80 / 25 ))
    or
    $[ 80 / 25 ]

    example:
    $ var=$[ 80 / 25 ]
    $ echo $var
    3

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    1. Thank you for the info. This doesn't work with korn shell though.

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