Using OR Operator
Sample file,
cat fruits.txt yellow bananas green apples red oranges red apples
Using OR operator in grep search. Note you need a somewhat current version of grep (you are out of luck with Solaris use egrep for Solaris),
grep 'apples\|oranges' fruits.txt green apples red oranges red apples
Grep for items that do not match,
grep -v 'read' fruits.txt yellow bananas green apples
Have grep tell you if it found a match in the file,
grep "diddle" -q fruits.txt && echo "FOUND" || echo "NOPE" NOPE grep "apples" -q fruits.txt && echo "FOUND" || echo "NOPE" FOUND
Look up if time permits how to do this using quotes to handle spaces or special characters....
Hmm, maybe all I need to do is escape any special characters and spaces probably work as is.