The problem with your piece of code is that the regex you tried to build include "/" and the delimiters are also "/". This is going to work:

chomp($value = <STDIN>); 
if ($value =~ m#(0[1-9]|[12][0-9]|3[01])[-/.](0[1-9]|1[012])[- /.](\d\
+d\d\d)#) { 
    print "date"; 
} else { 
    print $value; print "not a date"; 
}
[download]

Here I used alternative delimiters by using m## syntax. You may read more about it at section "Regexp Quote-Like Operators" in perlop.

And while we're at the issue of validating dates, your code may work for dates like "01/02/2007" and recognize "32/04/2007" as bad, but it will accept things like "29/02/2007" and the like. If you want correctness and minimum effort, you can use some CPAN module to check it out for you. For instance, using DateTime::Format::Strptime, you may write code like this:

se DateTime::Format::Strptime;

my $dt_format = DateTime::Format::Strptime->new(pattern => "%d-%m-%Y")
+; 

sub val_date {
    my $dt = shift;
    $dt =~ s|[./]|-|g; # '.' and '/' become '-' for simplicity
    return $dt_format->parse_datetime($dt);
}

my $s = '01-02-2007';
my $dt = val_date($s);
if ($dt) {
    print "valid date\n";
} else {
    print "not a date\n";
}
[download]

As an extra bonus, the return of val_date gives you a DateTime object which is much better to handle than just a string.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.