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

Explanation

The :g/pattern/normal {commands} command executes normal mode keystrokes on every line in the file that matches the given pattern. It combines the power of the global command (:g) with the :normal Ex command, letting you apply any normal mode editing sequence to a filtered set of lines.

How it works

• :g/pattern/ finds every line matching the regular expression
• normal tells Vim to execute the following text as if it were typed in normal mode
• dd (or any other sequence) is the normal mode command to run on each matching line

Vim processes each matching line one at a time, positioning the cursor at the beginning of the line before executing the normal mode commands.

Examples

Delete all lines containing "console.log":

:g/console\.log/normal dd

Comment out all lines containing "TODO" (prepend // ):

:g/TODO/normal I// 

Indent all lines containing "return":

:g/return/normal >>

Append a semicolon to every line containing a function call:

:g/()/normal A;

Tips

• Use :g/pattern/normal @a to run a recorded macro on every matching line
• Use :v/pattern/normal dd to run the command on lines that do not match the pattern
• The :normal command does not process special keys like <Esc> written literally — use :normal! (with a bang) to ignore user mappings, or use :execute with escape sequences for special keys:

:g/pattern/execute "normal I// \<Esc>A;"

• The cursor is placed at column 1 of each matching line before the normal command runs
• You can limit the range: :10,50g/pattern/normal dd only affects lines 10 through 50
• This technique is often faster and more readable than writing a complex substitution with regex