Here, here.. ;)
Seriously though, I have found the internal grep to suit my needs very nicely when parsing files. I haven't really done much in terms of post processing of other commands. I was honestly amazed at the difference in speed between say
open(IN, "/some/file") || die "Cant open /some/file: $!\n";
while (<IN>) {
next unless (m/^$some_match/);
chomp($capture = $_);
}
close(IN);
as opposed to
open(IN, "/some/file") || die "Cant open /some/file: $!\n";
chomp( ($capture) = grep(/^$some_match/, <IN>) );
close(IN);
Especially as the size of the file being processed increases. Im not sure of the why of it, as I haven't gone poking around Perl's internals, but it certainly increased my regular useage of grep.
MMMMM... Chocolaty Perl Goodness.....