#!/usr/bin/perl

$add_user=$ssh->add_account(login=>"bob",uid=123);
$ssh->print_error and die if (!$add_user);
print "$add_user\n";

sub add_account {
    .....
    if (condition) { return "success: user added"; }
    elsif (condition { 
        $ssh->{error} = "failed: uid not unique"; 
    }
    else { 
        $ssh->{error} = "failed: unknown error";
    }
    return;
}