$data =~ s/^\s*//;
$data =~ s/\s*$//;

##</code><code>##

use Benchmark;

sub dotstar {
    my $data = $testdata;
    $data =~ s/^\s*(.*?)\s*$/$1/;
    return $data;
}

sub first_n_last {
    my $data = $testdata;
    $data =~ s/^\s*//;
    $data =~ s/\s*$//;
    return $data;
}

sub first_n_last_must_match {
    my $data = $testdata;
    $data =~ s/^\s+//;
    $data =~ s/\s+$//;
    return $data;
}

$testdata = ' ' x 200 . "abcd" x 20 . " " x 200;
timethese( 100000, 
    {
        dotstar        => '&dotstar',
        first_n_last_1 => '&first_n_last',
        first_n_last_2 => '&first_n_last_must_match'
    }
)

##</code><code>##

Benchmark: timing 100000 iterations of dotstar, first_n_last_1, first_n_last_2...
   dotstar:  7 wallclock secs ( 6.91 usr +  0.02 sys =  6.93 CPU) @ 14430.01/s (n=100000)
first_n_last_1:  4 wallclock secs ( 4.21 usr +  0.00 sys =  4.21 CPU) @ 23775.56/s (n=100000)
first_n_last_2:  2 wallclock secs ( 1.30 usr +  0.00 sys =  1.30 CPU) @ 76804.92/s (n=100000)