http://qs1969.pair.com?node_id=294344


in reply to remove both leading and trailing spaces

Yes, you can do s/^\s+|\s+$//g but it is definaly not optimized. It is generally preferred to use the two regexes, since it is roughly 3 times faster:
use Benchmark; my $val = " Smart Way "; timethese(1000000, { regex1 => sub { my $tmp = $val; $tmp =~ s/^\s+|\s+$//g; }, regex2 => sub { my $tmp = $val; $tmp =~ s/^\s+//; $tmp =~ s/\s+$//; } });
Results:
Benchmark: timing 1000000 iterations of regex1, regex2... regex1: 9 wallclock secs ( 6.43 usr + 0.02 sys = 6.45 CPU) @ 155038.76/s (n=1000000) regex2: 2 wallclock secs ( 2.65 usr + 0.00 sys = 2.65 CPU) @ 377358.49/s (n=1000000)