Linux bash Multiple variable assignment

Question

Does exist in linux bash something similar to the following code in PHP   list  var1   var2   var3    function that returns a three element array       i e  you assign in one sentence a corresponding value to 3 different variables   Let s say I have the bash function myBashFuntion that writes to stdout the string  qwert asdfg zxcvb   Is it possible to do something like    var1 var2 var3       myBashFuntion param1 param2      The part at the left of the equal sign is not valid syntax of course  I m just trying to explain what I m asking for   What does work  though  is the following   array      myBashFuntion param1 param2    echo   array 0     array 1     array 2     But an indexed array is not as descriptive as plain variable names  However  I could just do   var1     array 0     var2     array 1     var3     array 2     But those are 3 more statements that I d prefer to avoid   I m just looking for a shortcut syntax  Is it possible

User · Answer

Sometimes you have to do something funky. Let's say you want to read from a command (the date example by SDGuero for example) but you want to avoid multiple forks.

read month day year << DATE_COMMAND
 $(date "+%m %d %Y")
DATE_COMMAND
echo $month $day $year

You could also pipe into the read command, but then you'd have to use the variables within a subshell:

day=n/a; month=n/a; year=n/a
date "+%d %m %Y" | { read day month year ; echo $day $month $year; }
echo $day $month $year

results in...

13 08 2013
n/a n/a n/a

User · Answer

Chapter 5 of the Bash Cookbook by O Reilly  discusses  at some length  the reasons for the requirement in a variable assignment that there be no spaces around the     sign  MYVAR  something    The explanation has something to do with distinguishing between the name of a command and a variable  where     may be a valid argument    This all seems a little like justifying after the event  but in any case there is no mention of a method of assigning to a list of variables

User · Answer

I think this might help     In order to break down user inputted dates  mm dd yyyy  in my scripts  I store the day  month  and year into an array  and then put the values into separate variables as follows     DATE ARRAY   echo  2   sed -e  s      g    MONTH   echo   DATE ARRAY 0     DAY   echo   DATE ARRAY 1     YEAR   echo   DATE ARRAY 2

User · Answer

I wanted to assign the values to an array  So  extending Michael Krelin s approach  I did   read a  1  3    lt  lt  lt    echo 2 4 6   echo    a 1     a 2     a 3      which yields   2 4 6    as expected

User · Answer

First thing that comes into my mind   read -r a b c  lt  lt  lt   echo 1 2 3    echo   a  b  c    output is  unsurprisingly  1 2 3

[linux] Linux bash: Multiple variable assignment

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