The Substitution Operator
Syntax
Perl supports another powerful operator, which performs substitutions in a string. The syntax of the Perl substitution operator is:
| s/PATTERN/REPLACEMENT/egimosx |
The substitution operator searches a string for PATTERN, and, if found, replaces the match (not the pattern, of course) with the REPLACEMENT text, and returns the number of substitutions made (this can be more than one if you use the /g modifier).