On Tue, Dec 24, 2024 at 10:37:29 -0500, Roberto C. Sánchez wrote: > I think that '==' is the wrong tool. That is testing for string > equality, whilst you are looking for a partial match. This is what I was > able to get working after hacking on it for a minute or two: > > #! /bin/bash -u > set -x > BAD=0; > while read L; > do if [[ $L =~ \[(U_|_U|__)\] ]]; then BAD=1; break; fi; > done < /proc/mdstat; > echo $BAD
Yeah, that works too. But == or = also works here, if you use an extended glob. (And extended glob matching inside the [[ command is on by default in all recent bash versions.) = or == is a glob (or extglob) match first and foremost. It degenerates to a plain string match if all the characters on the right hand side are quoted. hobbit:~$ stat=$'blah blah\ncheese [2/1] [U_]\nblah blah' hobbit:~$ if [[ $stat = *\[@(U_|_U|__)\]* ]]; then echo "bad"; fi bad hobbit:~$ stat=$'blah blah\ncheese [2/1] [UU]\nblah blah' hobbit:~$ if [[ $stat = *\[@(U_|_U|__)\]* ]]; then echo "bad"; fi hobbit:~$
