You are viewing the version of this documentation from Perl 5.41.2. This is a development version of Perl.
$PREMATCH
$`

The string preceding whatever was matched by the last successful pattern match. (See "Scoping Rules of Regex Variables").

See "Performance issues" above for the serious performance implications of using this variable (even once) in your code.

This variable is read-only, and its value is dynamically scoped.

Mnemonic: ` often precedes a quoted string.