>perl -wMstrict -le
"my $s = '1a2b3c';
;;
print qq{no /o};
for my $i (qw(3 2 1)) {
print qq{matched '$1'} if $s =~ m{ ($i.) }xms;
}
;;
print qq{with /o};
for my $i (qw(3 2 1)) {
print qq{matched '$1'} if $s =~ m{ ($i.) }xmso;
}
"
no /o
matched '3c'
matched '2b'
matched '1a'
with /o
matched '3c'
matched '3c'
matched '3c'
####
$pattern = 'Seuss';
while (<>) {
print if /$pattern/;
}
##
##
#!/usr/bin/perl
# Improved simple_grep
$regexp = shift;
while (<>) {
print if /$regexp/o; # a good deal faster
}