The question mark after a quantifier turns off greeding matching. In your regex it doesn't make much sense though. You're trying to match exactly 5 times, so greedy and non-greedy are the same thing.
/a{1,5}/; # match 1-5 'a's prefer the longest.
/a{1,5}?/; # match 1-5 'a's prefer the shortest.
Here is an example:
#!/usr/bin/perl -wT
use strict;
$_ = 'aaaab';
# greedily match upto 5 'a's followed by a word char
print "Greedy: ";
print /(a{1,5})\w/, "\n";
# non-greedily match upto 5 'a's followed by a word char
print "NonGreedy: ";
print /(a{1,5}?)\w/, "\n";
__END__
Greedy: aaaa
NonGreedy: a
-Blake
