[Linux] How to find all files containing specific text on Linux?

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.

P.S. example: to find "if ["

grep -rnw '/path/to/somewhere/' -e 'if \['