I want to assign the ouput of the following command to a variable in shell:
${arr2[0]} | rev | cut -c 9- | rev
For example:
mod=${arr2[0]} | rev | cut -c 9- | rev
echo $mod
The above method is not working: the output is blank.
I also tried:
mod=( "${arr2[0]}" | rev | cut -c 9- | rev )
But I get the error:
34: syntax error near unexpected token `|'
line 34: ` mod=( "${arr2[0]}" | rev | cut -c 9- | rev ) '
To add an explanation to your correct answer:
You had to combine your variable assignment with a command substitution (var=$(...)) to capture the (stdout) output of your command in a variable.
By contrast, your original command used just var=(...) - no $ before the ( - which is used to create arrays[1], with each token inside ( ... ) becoming its own array element - which was clearly not your intent.
As for why your original command broke:
The tokens inside (...) are subject to the usual shell expansions and therefore the usual quoting requirements.
Thus, in order to use $ and the so-called shell metacharacters (| & ; ( ) < > space tab) as literals in your array elements, you must quote them, e.g., by prepending \.
All these characters - except $, space, and tab - cause a syntax error when left unquoted, which is what happened in your case (you had unquoted | chars.)
[1] In bash, and also in ksh and zsh. The POSIX shell spec. doesn't support arrays at all, so this syntax will always break in POSIX-features-only shells.
mod=$(echo "${arr2[0]}" | rev | cut -c 9- | rev )
echo "****:"$mod
or
mod=`echo "${arr2[0]}" | rev | cut -c 9- | rev`
echo "****:"$mod
$arr2? How do you assign it? How exactly is it not working (error message, expected vs. actual output)?