egrep

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

• Search for a pattern within a file:
  egrep "{{search_pattern}}" {{path/to/file}}
• Search for a pattern within multiple files:
  egrep "{{search_pattern}}" {{path/to/file1}} {{path/to/file2}} {{path/to/file3}}
• Search stdin for a pattern:
  cat {{path/to/file}} | egrep {{search_pattern}}
• Print file name and line number for each match:
  egrep --with-filename --line-number "{{search_pattern}}" {{path/to/file}}
• Search for a pattern in all files recursively in a directory, ignoring binary files:
  egrep --recursive --binary-files={{without-match}} "{{search_pattern}}" {{path/to/directory}}
• Search for lines that do not match a pattern:
  egrep --invert-match "{{search_pattern}}" {{path/to/file}}