bash: Find text in files in subdirectories recursively

grep -rnw '/path/to/somewhere/' -e 'pattern'

• -r or -R is recursive,
• -n is line number, and
• -w stands for match the whole word.
• -l (lower-case L) can be added to just give the file name of matching files.

Along with these, --exclude, --include, --exclude-dir flags could be used for efficient searching.

Original Stack Overflow answer: https://stackoverflow.com/a/16957078/1059672