$ cat /tmp/x
my $regex = '(2[0-4]|1?[0-9])?[0-9]|25[0-5]';
while (<>) {
chomp;
if ($_ =~ /^$regex$/) {
print "$_ matched\n";
} else {
print "$_ did not match\n";
}
}
$ perl /tmp/x
100
100 matched
200
200 matched
300
300 matched
^C
####
my $regex = '(2[0-4]|1?[0-9])?[0-9]|a';
##
##
my $regex = '(2[0-4]|1?[0-9])?[0-9]|25[0-5]';
##
##
my $regex = qr/(2[0-4]|1?[0-9])?[0-9]|25[0-5]/;