How do I perform a substitute only within a visual block column?

Explanation

Using \%V in a substitute pattern restricts matching to within the visual block area only, rather than the full lines.

How it works

• Make a block selection with <C-v>
• Type : (auto-fills '<,'>)
• Use \%V in the pattern to restrict to the block
• Only text within the block column is affected

Example

With a CSV file:

Alice,30,NYC
Bob,25,LA
Carol,35,SF

Select only the age column, then :'<,'>s/\%V\d\+/0/g replaces just the ages with 0.

Tips

• Without \%V, the entire line is subject to substitution
• \%V is the key atom for block-restricted operations
• Works with any regex pattern
• Very powerful for editing tabular data or fixed-width formats