[autoexec]

It doesn't need an import at all. It's just a normal part of the language's syntax and can be used just about anywhere:

    $foo =~ /regex/
    $result = $foo =~ /regex/
    if ($foo =~ /regex/) {whatever;}
    while (/regex/) {whatever;}

The captures ($1, $2, etc.) are global and usable wherever you need them.

In this particular case the default is that $ matches the end of a string without a newline but you can include it anytime you need to:

   $foo =~ /regex$/ # end of string without newline
   $foo =~ /regex$/m # end of string with newline