grep Command

grep -n "pattern" filename
man find | grep -e "-exec" (Extended Regex Find)
grep -r "pattern" ./<folder-name> # Recursively Search all files in Directory

Flags
-w: Matching whole words only
-i: Case Insensitive Search
-n: Line Number
-C num: View n lines before and after the match
-e: Regex Find
-E: Extended Regex Find
-P: Perl Compatible Regex Find
-r: Recursive Search
-l: Filenames that contain match
-c: Filenames that contain match with count