in reply to regexp performance on large logfiles

Some improvements. Notes:

{ my %patmap = ( '*' => '.*', '?' => '.', '[' => '[', ']' => ']', ); my ($norm) = map qr/[^$_]/, join '', keys %patmap; sub glob2pat { my $globstr = @_ ? $_[0] : $_; $globstr =~ s{($norm+|.)} { $patmap{$1} || "\Q$1" }sge; return "^$globstr$"; } } my %ignore = map { $_ => qr/$_/ }, map glob2pat, @list_regexps; my %ignored; LINE: while(<FILE>) { chomp; my( @cols ) = split(" ", $_); ... for my $re_name ( keys %ignore ) { my $re = $ignore{$re_name}; if ( $cols[0] =~ $re ) { $ignored{$re_name}++; next LINE; } } ... }

If you can live without %ignored,

use Regexp::Assemble qw( ) { my %patmap = ( '*' => '.*', '?' => '.', '[' => '[', ']' => ']', ); my ($norm) = map qr/[^$_]/, join '', keys %patmap; sub glob2pat { my $globstr = @_ ? $_[0] : $_; $globstr =~ s{($norm+|.)} { $patmap{$1} || "\Q$1" }sge; return "^$globstr$"; } } my $ignore_re = do { my $ra = Regexp::Assemble->new(); $ra->add(glob2pat($_)) for @list_regexps; $ra->re() }; while(<FILE>) { chomp; my( @cols ) = split(" ", $_); ... next if $cols[0] =~ $ignore_re; ... }