Subversion Repositories sysadmin_scripts

#! /usr/bin/env perl

use strict;

use warnings;

use File::Slurp; # apt install -y libfile-slurp-perl

# It is difficult to tell who is on line with a UI based Linux system

# as all the cli functions assume the other are logged in via cli.

#

# This script determines all "real users" (UUID > 1000, but not 'nobody')

# and then does a ps aux to see if any of them are online.

# Copyright 2024 Daily Data, Inc.

# 

# Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following 

# conditions are met:

#

#   Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

#   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer 

#   in the documentation and/or other materials provided with the distribution.

#   Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived

#   from this software without specific prior written permission.

# 

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT

# NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL

# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE

# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# define the version number

# see https://metacpan.org/pod/release/JPEACOCK/version-0.97/lib/version.pod

use version;

our $VERSION = version->declare("0.0.1");

my @users;

my @passwords = read_file( '/etc/passwd' );

while ( my $line = pop @passwords ) {

   next if $line =~ m/^#/;

   my @columns = split( ':', $line );

   push @users, $columns[0] if $columns[2] >= 1000 && $columns[2] < 65534;

}

#print join( "\n", @users );

my $users = join( '\|', @users );

print qx/ps aux | cut -d' ' -f1 | sort | uniq | grep '$users'/;

1;