#!/usr/bin/perl -w

# user_disuse.pl - by dual
#
# Determine and email user disuse
#
# Less draconian then wiping the
# user and all of their files
#################################


use strict;
use Date::Calc qw (Delta_Days);


# So, yeah, I've only got one user
my $user = 'USER';
my $mon_to_num;


# Get script run time
(my $yr_now, my $mon_now, my $day_now) = (localtime)[5, 4, 3];
$yr_now  = $yr_now + 1900;
$mon_now = $mon_now + 1;

my @now = ($yr_now, $mon_now, $day_now);


# Get last login time for user
my $yr_then = `date '+%G'`;

my @array = `last | grep $user`;

# Test if user is even in last
if (! @array) { mail(); exit; }

my @reverse = reverse @array;
my $pop = pop @reverse;
my @split = split (/\s+/, $pop);

my $mon_then = $split[4];
my $day_then = $split[5];

if    ($mon_then =~ /Jan/) { $mon_to_num = 1; }
elsif ($mon_then =~ /Feb/) { $mon_to_num = 2; }
elsif ($mon_then =~ /Mar/) { $mon_to_num = 3; }
elsif ($mon_then =~ /Apr/) { $mon_to_num = 4; }
elsif ($mon_then =~ /May/) { $mon_to_num = 5; }
elsif ($mon_then =~ /Jun/) { $mon_to_num = 6; }
elsif ($mon_then =~ /Jul/) { $mon_to_num = 7; }
elsif ($mon_then =~ /Aug/) { $mon_to_num = 8; }
elsif ($mon_then =~ /Sep/) { $mon_to_num = 9; }
elsif ($mon_then =~ /Oct/) { $mon_to_num = 10; }
elsif ($mon_then =~ /Nov/) { $mon_to_num = 11; }
else  { $mon_to_num = 12; }

my @then = ($yr_then, $mon_to_num, $day_then);


# Compare dates and mail results or exit
my $diff = Delta_Days (@then, @now);
if ($diff >= 20) { mail(); }


# Begin mail function
sub mail {
	open MAIL, "|/bin/mail -s \"Check on user: $user\" EMAIL\@HOST"
		or die "Can't pipe: $!";
	print MAIL "User $user isn't in last or hasn't logged in in 20 days.";
	print MAIL "\n";
	close MAIL;
}