#!/usr/local/bin/perl
#
# oldsessions [-u user]
#
# find login sessions idle longer than $OLD days
# print a list of kill commands that can be sent to the shell
# -u flag allows for specifying a user, otherwise all users are checked


# The simple ways are shorter but less flexible
# #!/bin/sh
#   t1=/tmp/t1_$$
#   t2=/tmp/t2_$$
#   finger | sort > $t1
#   who -u | sort > $t2
#   join  -1 4 -2 2 -o 2.7 2.1 1.5 2.2 $t1 $t2

# How old is old? One user (tbob) says he leaves terms running for up to
# 7 days. For Fred (fjones) and Vicki (vlb), anything over a day idle is moldy
# due to autologouts.

# minimum days for an idle session to be considered "old"

my $OLD = 1;
my %old = (
  tbob => 7,
);

my @a;
my $pty;
my %name, %days, %pid;
my $user;

while (@ARGV and $ARGV[0] =~ /^-/) {
    $_ = shift;
    if (/^-u(.*)/) {
       $user = $1;
       $user = shift unless($user);
    }
}

# fjones   Fred Jones     pts/1         3d Tue 06:59  208.193.8.188
# fjones   Fred Jones     pts/10       42d Fri 08:37  64.94.242.12
# fjones   Fred Jones     pts/19        3d Mon 13:40  208.193.8.188

$pid = open(FINGER, "finger | sort |") or die "couldn't fork finger";
while (<FINGER>) {
    @a = split;
    next if ($user and ($a[0] ne $user));
    my $idle = $a[4];

    if ($idle =~ /(\d+)d/) {
        my $d = $1;
        my $n = $a[0];
        $pty = $a[3];
        if ( (defined ($old{$n}) and $d > $old{$n})
          or (!defined ($old{$n}) and $d > $OLD) )
          {
            $name{$pty} = $n;
            $days{$pty} = $d;
        }
    }
}
close(FINGER);

# fjones     pts/1        Jul  3 06:59  old   26897     (208.193.8.188)
# fjones     pts/10       May 25 08:37  old   11211     (64.94.242.12)
# fjones     pts/19       Jul  2 13:40  old   20000     (208.193.8.188)

$pid2 = open(WHO, "who -u | sort |") or die "couldn't fork who";
while (<WHO>) {
    @a = split;
    $pty = $a[1];
    if (defined($name{$pty})) {
        $pid{$pty} = $a[6];
    }
}
close(WHO);

# join  -1 4 -2 2 -o 2.7 2.1 1.5 2.2 $t1 $t2

print "#Kill -9 PID\tName\tPTY\tIdle Time\n" if (%name);

for my $key (keys (%name)) {
    print "kill -9 $pid{$key}\t# $name{$key}\t$key\t$days{$key} d\n"
}