tldr/pages/common/grep.md

grep

Find patterns in files using regular expressions. More information: https://www.gnu.org/software/grep/manual/grep.html.

• Search for a pattern within a file:

grep "{{search_pattern}}" {{path/to/file}}

• Search for an exact string (disables regular expressions):

grep {{[-F|--fixed-strings]}} "{{exact_string}}" {{path/to/file}}

• Search for a pattern in all files recursively in a directory, showing line numbers of matches, ignoring binary files:

grep {{[-rnI|--recursive --line-number --binary-files=without-match]}} "{{search_pattern}}" {{path/to/directory}}

• Use extended regular expressions (supports ?, +, {}, (), and |), in case-insensitive mode:

grep {{[-Ei|--extended-regexp --ignore-case]}} "{{search_pattern}}" {{path/to/file}}

• Print 3 lines of [C]ontext around, [B]efore or [A]fter each match:

grep --{{context|before-context|after-context}} 3 "{{search_pattern}}" {{path/to/file}}

• Print file name and line number for each match with color output:

grep {{[-Hn|--with-filename --line-number]}} --color=always "{{search_pattern}}" {{path/to/file}}

• Search for lines matching a pattern, printing only the matched text:

grep {{[-o|--only-matching]}} "{{search_pattern}}" {{path/to/file}}

• Search stdin for lines that do not match a pattern:

cat {{path/to/file}} | grep {{[-v|--invert-match]}} "{{search_pattern}}"