One way to do this is to use the substitution operator s/// (see perlfunc and perlop) and use the e modifier to executed a small 'program' in the second part of the operator. By using arrays to store your months and day endings, you greatly simplify the logic of the code. 

#!perl
use strict;

my @months = qw( -- January February March April May June July August 
+September October November December);
my @dayends = qw( -- st nd rd th th th th th th th th th th th th th t
+h th th th st nd rd th th th th th th th st);

while(my $date = <DATA>) {
    chomp $date;
    $date =~ s!(\d{1,2})(\/|\-)(\d{1,2})(\/|\-)(\d{2,4})! $1 . $dayend
+s[$1] . ' ' . $months[$3] . ' ' . $5 !eg;
    print $date, $/;
}

__DATA__
3/3/2002
5/11/2002
31-07-2002
1-4-02
21-2-02
31-12-2002

[download]

Gives output 

c:\test>209700
3rd March 2002
5th November 2002
31st July 2002
1st April 02
21st February 02
31st December 2002

c:\test>

[download]

Maybe you can adapt this to your purposes.

Nah! Your thinking of Simon Templar, originally played by Roger Moore and later by Ian Ogilvy

In reply to Re: pattern matching through a whole document by BrowserUk
in thread pattern matching through a whole document by r_mehmed

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