egrep

Find patterns in files using extended regular expression (supports ?, +, {}, () and |). More information: https://manned.org/egrep.

egrep "search_pattern" path/to/file

egrep "search_pattern" path/to/file1 path/to/file2 ...

cat path/to/file | egrep search_pattern

egrep --with-filename --line-number "search_pattern" path/to/file

egrep --recursive --binary-files=without-match "search_pattern" path/to/directory

egrep --invert-match "search_pattern" path/to/file