adkinss

#!/usr/bin/perl -w

## This script listens for a UDP message on a port containing the text "hello".
## The listener will respond back to the client with its own "hello" string.
## Clients can send messages to this listener using netcat.  The following works:
##   echo hello | nc -4u -w1 <listener_hostname> <listener_port>
## Substitute the hostname and port for where this listener is running from.
## Keep in mind that ports less than 1024 will require the listener to run as root.
##
## The listener does not yet take any command line options.

adkinss

#!/bin/sh

# This script displays all the packages installed on a RedHat/CentOS system
# with additional information about installation time sorted by most recently
# installed packages first.  This is useful when looking at what packages
# were recently updated.
#
#   $ ./rpm_query.sh | head
#   1449154458 Thu 03 Dec 2015 02:54:18 PM UTC filesystem-3.2-20.el7.x86_64
#   1449154458 Thu 03 Dec 2015 02:54:18 PM UTC libgcc-4.8.5-4.el7.x86_64

adkinss

#/bin/bash

# This script demonstrates how to create a queue of items to work
# from and then process X number of jobs in parallel, increasing
# speed and efficiency.  Adjust MAX_JOBS according to how many
# items from the queue should be ran in parallel.  This script
# preloads the queue with stuff from the home directory just as
# a demonstration.

### Keep track of the number of children processing queue items

adkinss

#!/usr/bin/perl -w

# Without parameters, the script displays the current date in three different
# formats (epoch, julian, and gregorian).  Here is a example run:
#
#   $ ./complicated_date.pl
#   epoch:     1471012564  Fri Aug 12 10:36:04 2016
#   julian:    2457613.10837963
#   gregorian: 1471012564  Fri Aug 12 10:36:03 2016
#

adkinss

#!/usr/bin/perl -w

# Without parameters, the script displays all the CIDRs and corresponding networks.
# The script will also demonstrate convering a netmask back into a CIDR, but it
# appears that conversion is broken and needs to be looked at.
#
# With parameters, if display network netmask, broadcast, etc info about each IP
# address provided on the command line.
#
# Ultimately, this script intends to demostrate reusable functions that can be

adkinss

#!/usr/bin/perl -w

# Converts an IP address string to a single integer number

use strict;

sub ip_to_int ($)
{
    my $addr = shift @_;
    return unpack("N", pack("C4", split(/\./, $addr)));

adkinss

#!/usr/bin/perl -w

# Converts an integer number representing an IP back into an IP address string

use strict;

sub ip_to_int ($)
{
    my $addr = shift @_;
    return unpack("N", pack("C4", split(/\./, $addr)));