Question

Using a single regex line (this goes in a config file for an application) I need to capture the localpart of an email address.

If it consists of only numbers, pass it along unmodified.
If it has any non-numeric character on it, truncate to 11 chars max.

I made this simple program to test but if the localpart is over 11 characters there is no match (the whole email address is printed).

#!/usr/bin/env perl

my @emails = ('[e-mail]', '[e-mail]', '[e-mail]', '[e-mail]', '[e-mail]', '[e-mail]', '[e-mail]');

for my $email (@emails){

    # will put $1$2 on the substituion spot
    $email =~ s/^(\d+)@.+|^([a-zA-Z0-9._%+-]{1,11})@.+/  /;

    print '===> ' . $email  . " \n\n ";

}

Where am I going wrong?

Answer 1

You need to include a regex atom such as \S*? in case the number of characters exceeds 11…

    $email =~ s/^(\d+)@.+|^([a-zA-Z0-9._%+-]{1,11})\S*?@.+/$1$2/;

Using this produces correct output:

[mpenning@Bucksnort ~]$ perl sample.pl
===> the-chuck.t

 ===> 358451399991

 ===> ph33t

 ===> the-average

 ===> alongnameit

 ===> alongnameit

 ===> a1234567890

 [mpenning@Bucksnort ~]$