NAME

Unix::Login - Customizable Unix login prompt and validation

SYNOPSIS

   #
   # You can use the function-oriented syntax
   #
   use Unix::Login qw(login);
  
   # This will return the same thing as getpwnam() on success
   my(@pw) = login(login => "Username: ", cdhome => 1);


   #
   # Or, use the more flexible object-oriented syntax
   #
   use Unix::Login;

   my $ul = Unix::Login->new(banner => "-- Welcome to Newix --\n");
   my $username = $ul->login;   # will die if login fails

DESCRIPTION

This is a simple yet flexible module that provides a Unix-esque login prompt w/ password validation. This can be used in custom applications that need to validate the username/password of the person using the app.

The above examples are pretty much all you'll ever need (and all this module provides). Here are some specifics on the two functions provided:

new(option => value, option => value)

This creates a new Unix::Login object. You only need to use this if you're using the object-oriented calling form. The parameters accepted and their default values are:

   attempts      Max login attempts [3]
   failmesg      Print this on failure ["Login incorrect\n"]
   failsleep     And sleep for this many seconds [3]
   failexit      If can't login after (3) attempts, exit fatally [1]

   banner        Banner printed once up top ["Please Login\n"]
   bannerfile    If set, printed after banner (i.e. /etc/issue) []
   login         Prompt asking for username ["login: "]
   password      Prompt asking for password ["Password: "]

   passreq       Require a password for all users? [1]
   nohomemesg    Printed if no homedir ["No home directory! Setting HOME=/\n"]

   setenv        If true, setup HOME and other %ENV variables [1]
   clearenv      If true, first undef %ENV before setenv [0]
   path          If setenv, set PATH to this for non-root [/usr/bin:]
   supath        If setenv, set PATH to this for root [/usr/sbin:/usr/bin]
   maildir       If setenv, set MAIL to this dir/username [/var/mail]

   pwent         Return a User::pwent struct in scalar context? [0]
   cdhome        Chdir to the person's homedir on success? [0]
   execshell     Execute the person's shell as login session? [0]

If the "pwent" option is set, then User::pwent is used to provide an object in a scalar context. See the man page for User::pwent.

If the "execshell" option is set, then if login() is successful the user's shell is forked and the current process is terminated, just like a real Unix login session.

With these options, you could create a very Unix-like login with the following:

   use Unix::Login;

   my $ul = Unix::Login->new(bannerfile => '/etc/issue',
                             banner     => `uname -rs`,
                             setenv     => 1,
                             clearenv   => 1,
                             cdhome     => 1,
                             execshell  => 1);

   my(@pwent) = $ul->login || exit 1;

This will validate our login, clear our environment and reset it, then exec the shell as a login shell just like a real life Unix login.

login(option => value, option => value)

This prompts for the username and password and tries to validate the login. On success, it returns the same thing that getpwuid() does: the username in a scalar context, or the passwd struct as a list in a list context. It returns undef on failure.

Just like new(), you can pass it an optional set of parameters. These will specify options for that login prompt only. As such, you can create a fully-customized login screen from the function-oriented calling form:

   use Unix::Login qw(login);

   my(@pwent) = login(login => "User: ", password => "Pass: ")
        || die "Sorry, try remembering your password next time.\n";

This would create a simple dialog which would return the passwd struct if the user could be logged in. So, unless you really like OO modularity, or intend on calling login() multiple times (in which case setting options via new() would give you an advantage), use this form.

VERSION

$Id: Login.pm,v 1.5 2001/06/01 21:37:01 nwiger Exp $

SEE ALSO

User::pwent(3), login(1), perlfunc(1)

AUTHOR

Copyright (c) 2000-2001 Nathan Wiger <nate@nateware.com>. All Rights Reserved.

This module is free software; you may copy this under the terms of the GNU General Public License, or the Artistic License, copies of which should have accompanied your Perl kit.