Hello Monks,

I have the following code to find duplicate UIDs:

use strict;
use warnings;
use User::pwent;    # overrides normal getpwent()
use Test::More 'no_plan';

# Duplicate UIDs
my @dups = duplicate_uids();
is( @dups, 0, "duplicate uids (@dups)" );

sub duplicate_uids {
    my @uids;
    while ( my $pwent = getpwent() ) {
        push @uids, $pwent->uid;
    }
    endpwent();
    my %seen = ();
    my @dups = grep { $seen{$_}++ } @uids;
    if (@dups) {
        return @dups;
    } else {
        return 0;
    }
}
[download]

I'm getting this output ...

not ok 10 - duplicate uids (0 65534)
#   Failed test 'duplicate uids (0 65534)'
#   at sys-test.pl line 57.
#          got: '2'
#     expected: '0'
[download]

... and the reason is that root (0) and nobody (65534) accounts exist both in /etc/passwd and LDAP.

Is there a way to distinguish between various user account backends (e.g. /etc/passwd, LDAP) from within a Perl program using getpwent?