# Captures all but the leading and trailing parens.
($file_name) = $string =~ /^\((.*)\)$/;

##</code><code>##

# Captures the filename from the middle of the string.
# You might have incorrect results if parens are used in more than one place.
($file_name) = $string =~ /\((.*)\)/;

##</code><code>##

# Removes the leading paren and the trailing paren in place.
$string =~ s/^\(//;
$string =~ s/\)$//;