Sams Teach Yourself Perl in 21 Days, Second Edition

Using Patterns for Search and Replace

One of the niftiest uses of regular expressions involves not just searching for a pattern or extracting matches into lists or variables or whatever, but also replacing that pattern with some other string. This is equivalent to a search and replace in your favorite word processor or editor—only with all the power and flexibility that regular expressions give you.

To search for a pattern and then replace it with some other pattern, use this syntax:

s/pattern/replacement/

For this syntax the pattern is some form of regular expression; replacement is the string that will replace the match. A missing replacement will delete the match from the string. For example:

 s/\s+/ / # replace one or more whitespace characters ...