[BASH] Assign output to variable(s)

useretail · 12-05-2014, 02:51 PM

Let's say I have a script that outputs a string with multiple values divided by '?':

Quote:

# ./test
aaa?bbb?ccc

Is it possible to assign aaa, bbb, ccc to three variables in one query (one line command)?
Can you do it using only bash?
Can you do it without sed/perl/awk?

Like this:

Quote:

# ./test | somecommand
# echo $var1
aaa
# echo $var2
bbb
# echo $var3
ccc

smallpond · 12-05-2014, 03:05 PM

Not that I know of, since some bash substitutions can't be nested. It's easy enough to do in two lines:

Code:

Q=$(./test)
read var1 var2 var3 <<<${Q//\?/ }

useretail · 12-05-2014, 03:14 PM

Thanks, smallpond. Why there are three redirections?

jpollard · 12-05-2014, 04:55 PM

From the bash manpage:

Code:

 Here Strings
       A variant of here documents, the format is:

              <<<word

       The word is expanded and supplied to the command on its standard input.

In the example provided, the data is passed through bash string expression evaluation to then be "read" and assigned to the given variables.

grail · 12-06-2014, 06:08 AM

Or you could use IFS;

Code:

IFS=? read var1 var2 var3 <<<$(./test)