I got it now, confused I was. Grep is not the culprit.
FWIW, grep -s -i -E (\t|\s)fastboot($|\t|\s)' should be just fine. printf ' i915.fastboot=1' | grep -s -i -E '(\t|\s)fastboot($|\t|\s)' echo $? 1 $ printf ' fastboot' | grep -s -i -E (\t|\s)fastboot($|\t|\s)' fastboot $ printf ' fastboot ' | grep -s -i -E (\t|\s)fastboot($|\t|\s)' fastboot -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
