How do I override case sensitivity for a single search pattern without changing my settings?

Explanation

Vim lets you embed \c or \C directly inside a search pattern to control case sensitivity for that search only, regardless of your 'ignorecase' and 'smartcase' settings.

How it works

• \c anywhere in the pattern makes the entire match case-insensitive
• \C anywhere in the pattern makes the entire match case-sensitive
• The modifier can appear at any position in the pattern — beginning, middle, or end
• These override both 'ignorecase' and 'smartcase' for the duration of that pattern

Example

With 'ignorecase' off, searching for:

/\cError

matches error, Error, ERROR, and any other capitalisation.

With 'ignorecase' on, searching for:

/\CERROR

matches only the exact string ERROR, ignoring your case setting.

The modifier also works in substitutions and :global:

:%s/\cfoo/bar/g
:g/\CTODO/d

Tips

• \c is invaluable when 'smartcase' is enabled and your pattern has no uppercase letters — you can force truly case-insensitive matching by adding \c
• Combine with \v (very magic) for powerful patterns: /\v\cfoo(bar|baz)
• The position of \c/\C in the pattern does not matter; putting it first is a common convention for readability