How do I restrict the :global command to operate on only a portion of the file?

Explanation

The :global command accepts an optional line range prefix that restricts which lines it even considers matching. Without a range it applies to the entire file, but with a range like :1,50g/pattern/d it only searches and acts within lines 1–50. This is essential when working with structured files where you need scoped operations on a defined section.

How it works

• [range] — Any valid Ex range: absolute lines (:10,50), marks (:'a,'b), relative offsets (:.,.+20), or pattern boundaries (:/start/,/end/).
• g/pattern/ — The global command's match pattern, applied only within the specified range.
• command — Any Ex command to execute on each matched line.

Without a range, :g defaults to 1,$ (the entire file). Specifying a range narrows that scope.

Example

Delete all blank lines, but only within the first 40 lines:

:1,40g/^$/d

Add a trailing semicolon to every return statement, but only inside a function demarcated by marks a and b:

:'a,'bg/\breturn\b/s/$/;/

Tips

• Visual selection works as a range: :'<,'>g/TODO/d deletes TODO lines only within the selection.
• The inverse command :v (:g!) accepts a range the same way: :1,20v/./d deletes empty lines only in lines 1–20.
• Pattern-bounded ranges work well for section scoping: :/^## Section/,/^## /g/^-/d deletes bullet lines within a specific markdown section.