grep

Search text with patterns — flags, regex modes, and context lines.

grep pattern fileBasic search

grep -r pattern dir/Recursive search

grep pattern *.txtMultiple files

cat file | grep patternPipe input

-iCase-insensitive

-vInvert (non-matching lines)

-wWhole word match

-xWhole line match

-e patternExplicit pattern

-f filePatterns from file

-EExtended regex (like egrep)

-FFixed strings, no regex

-PPerl-compatible regex

-GBasic regex (default)

-cCount matching lines

-lFilenames only

-nShow line numbers

-oPrint only the match

-qQuiet (exit code only)

-m NUMStop after NUM matches

--colorHighlight matches

-A NUMNUM lines after match

-B NUMNUM lines before match

-C NUMNUM lines around match

More Tools cheatsheets

Git

Everyday version control — branches, commits, undo, and rebase.

Bash

Shell scripting, redirection, and command-line survival.

Regex

Pattern matching — anchors, classes, quantifiers, groups.