How do I run a normal mode command on every line matching a pattern?

Explanation

Combining :global with :normal lets you run any normal-mode keystrokes on every line that matches a pattern. This is one of Vim's most powerful editing techniques, turning a single Ex command into a targeted batch operation across your entire file.

How it works

• :g/pattern/ — select all lines where pattern matches
• normal {cmd} — execute {cmd} as if you typed it in normal mode on each selected line
• The cursor visits each matching line in order, running the keystrokes from the beginning of that line
• <CR>, <Esc>, and other special keys can be entered with their literal notation

Example

Given a Python file with several function definitions, to add a blank line before each def:

:g/^def /normal O

This executes O (open a new line above) on every line starting with def .

To append a semicolon to every non-empty line:

:g/./normal A;

g/./ matches any non-blank line, and A; appends a semicolon.

Tips

• Use \ to enter a literal newline inside the :normal argument when needed
• Combine with a range to limit scope: :'<,'>g/TODO/normal dw operates only on the visual selection
• For multi-step sequences, record a macro first and then call it: :g/pattern/normal @q
• The inverse :v/pattern/normal {cmd} runs the command on lines that do not match
• Undo with a single u — all edits from one :g invocation are one undo block