sort (described in sort):
@list = sort { $a <=> $b } @list;
The default sort function is cmp, string comparison, which would sort into . <=>, used above, is the numerical comparison operator.
If you have a complicated function needed to pull out the part you want, then don't do it inside the sort function. Pull it out first, because the sort function can be called many times for the same element. Here's an example of how to pull out the first word after the first number on each item, and then sort those words case-insensitively.
@idx = ();
for (@data) {
($item) = /\d+\s*(\S+)/;
push @idx, uc($item);
}
@sorted = @data[ sort { $idx[$a] cmp $idx[$b] } 0 .. $#idx ];
Which could also be written this way, using a trick that's come to be known as the Schwartzian Transform:
@sorted = map { $_->[0] }
sort { $a->[1] cmp $b->[1] }
map { [ $_, uc((/\d+\s*(\S+) )[0] ] } @data;
If you need to sort on several fields, the following paradigm is useful.
@sorted = sort { field1($a) <=> field1($b) ||
field2($a) cmp field2($b) ||
field3($a) cmp field3($b)
} @data;
This can be conveniently combined with precalculation of keys as given above.
See CPAN/doc/FMTEYEWTK/sort.html for more about this approach.
See also the question below on sorting hashes.