Shell Programming and Scripting

#!/usr/bin/perl
#
#
#
$ticket=1212;

my $rx_ticket = qr/^\d{4}$/;

if ($ticket !~ /$rx_ticket/) {
        print "It matches\n";
}
else {
        print "No match\n";
}


print "Finished\n\n";
print "$ticket\n";

$ ./ticket.pl
No match
Finished

1212

$ 
$ perl -le '$ticket = 1212;
            $rx_ticket = qr/^\d{4}$/;
            # ==================================================
            # !~ returns true if scalar does not match pattern
            # =~ returns true if scalar matches pattern
            # ==================================================
            if ($ticket =~ /$rx_ticket/){
                print "It matches\n";
            } else {
                print "No match\n";
            }
            print "Finished\n";
            print "$ticket\n";
           '
It matches

Finished

1212

$ 
$ 
$ perl -le '$ticket = "12ABC12";
            $rx_ticket = qr/^\d{4}$/;
            # ==================================================
            # !~ returns true if scalar does not match pattern
            # =~ returns true if scalar matches pattern
            # ==================================================
            if ($ticket !~ /$rx_ticket/){
                print "It does not match\n";
            } else {
                print "It matches\n";
            }
            print "Finished\n";
            print "$ticket\n";
           '
It does not match

Finished

12ABC12

$ 
$