Regexs are soooo last decade!
use String::Util

use String::Util qw(trim)
my $s = trim('  here are lots of nasty spaces        ');
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UPDATE: seems i accidently caused a small argument with my tounge in cheek comments. However, IMHO this is a nice little module, with the trim() function being one of many nice little snipits provided that i use often, worth checking out!. Also, just becuase it hasnt been updated in a year does not make it a obsolete, its more likely that there are no bugs to be fixed, as all the subs are quite small & simple.