Question

sub my_sub {
    my $str = shift;
    $str =~ s/some/regex/;
    return $str;
}

Five lines seems too long for such a simple subroutine. Can it be simplified, e.g. by not using an intermediary variable?

Answer 1

Without intermediary variable and one line shorter:

sub my_sub {
    $_[0] =~ s/some/regex/;
    return $_[0];
}

Edit: As @pavel noted, this will modify the original variable.

Since Perl 5.13.2, there is the non-destructive modifier /r (for reference, see perlop), which will not modify the variable the regex operates on – this also allows to ditch another line:

sub my_sub {
    return $_[0] =~ s/some/regex/r;
}