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 {{-r|--recursive}} {{-n|--line-number}} --binary-files {{without-match}} "{{search_pattern}}" {{path/to/directory}}`

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

`grep {{-E|--extended-regexp}} {{-i|--ignore-case}} "{{search_pattern}}" {{path/to/file}}`

- Print 3 lines of context around, before, or after 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 {{-H|--with-filename}} {{-n|--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}}"`