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tbh, i only tested the second option, but i have used constructs similar to the first. you might want to put the echo | grep in brackets, curly iirc.
make it a habit to (almost) always put variables in double quotes: "$test".
in your particular example, the curly brackets around test improve exactly nothing.
I think that your sample is already a good answer:
Code:
if echo "$test" | grep -iq "abc"
then
:
else
echo "Not Found"
fi
Using the else branch is a negation of
Code:
if echo "$test" | grep -iq "abc"
then
echo "Found"
fi
The
Code:
if ! command
then
is ugly and not portable IMHO.
I would have liked a keyword unless in the meaning of if not (like perl has); strangly the shell has only the keyword until in the meaning of while not.
The =~ is an ERE (like egrep).
All RE are fuzzy so you never need .* at the beginning or end!
And the [[ ]] does word splitting BEFORE variable substitution, and NO globbing, so $var does not need quotes. (In contast to the [ ].)
Code:
if [[ ! $test =~ (abc)|(ABC) ]]; then echo "Not found"; fi
Last but not least, the traditional (and portable) check is with a case-esac
Code:
case $test in
*abc*|*ABC*)
;;
*)
echo "Not found"
;;
esac
You see the empty action on the positive catch, and the * (=catch-all) works like an else branch.
BTW this glob match is somewhat different from an RE!
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