#!/usr/bin/perl
use strict;

##</code><code>##

Print “enter a 4 digit number:\n”;

##</code><code>##

print "enter a 4 digit number:\n";

##</code><code>##

Test: {
my $number = <STDIN>;
chomp $number;

##</code><code>##

If $number !=~ /[0-9][0-9][0-9][0-9]/{

##</code><code>##

if $number !~ /^[0-9][0-9][0-9][0-9]$/ {

##</code><code>##

    Print “try again – 4 digits\n”;

##</code><code>##

    print "try again – 4 digits\n";

##</code><code>##

    Redo TEST;

##</code><code>##

    redo Test;

##</code><code>##

    }
}

##</code><code>##

#!/usr/bin/perl
use strict;
print "enter a 4 digit number:\n";
Test: {
my $number = <STDIN>;
chomp $number;
if ($number !~ /^[0-9][0-9][0-9][0-9]$/) {
    print "try again – 4 digits\n";
    redo Test;
    }
}