tldr/pages/common/grep.md

grep

Matches patterns in input text. Supports simple patterns and regular expressions.

• Search for a pattern within a file:

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

• Search for an exact string:

grep -F {{exact_string}} {{path/to/file}}

• Search for a pattern [R]ecursively in the current directory, showing matching line [n]umbers, [I]gnoring non-text files:

grep -RIn {{search_pattern}} .

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

grep -Ei {{search_pattern}} {{path/to/file}}

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

grep -{{C|B|A}} 3 {{search_pattern}} {{path/to/file}}

• Print file name with the corresponding line number for each match:

grep -Hn {{search_pattern}} {{path/to/file}}

• Use the standard input instead of a file:

cat {{path/to/file}} | grep {{search_pattern}}

• Invert match for excluding specific strings:

grep -v {{search_pattern}}