Name grep
comes from “globally search for a regular expression and print matching lines“
For search “my text” in current directory (“./”) use next command line:
# grep -irnsw ./ -e 'my text'
Where each option is for:
-i – ignore case
-n – display line number where match was found
-r – recursive, loop through all files under each directory
-s – suppress error messages (like when unable to open file)
-w – matching whole words only
For searching only in certain type of files, you can use --inlude
selection:
# grep -rn ./ --include \*.log -e 'find my text'
@source: https://en.wikibooks.org/wiki/Grep