linux

Finding My Most Commonly Used Commands On Linux

28th November 2020 - 8 minutes read time

I'm a proponent of automation, so when I find myself running the same commands over and over I always look for a way of wrapping that in an alias or script.

I spend a lot of my day to day job in the command line and I realised today that I must have typed 'git status' for the millionth time and wondered what my most commonly used commands were. So I found a stack overflow post showing my most used commands in a nice little bash one liner.

Scanning Linux For Intrusion With RKHunter

16th July 2015 - 7 minutes read time
RKHunter (or Root Kit Hunter) is a program that can be used to scan a Linux machine to see if there is anything there that might be a sign of a security breach. It will scan all of the files on the system and look out for any suspicious files or unexpected changes to system files that might indicate a security breach. Just like anti-virus systems it has a database of root kit definitions that it will use to compare files against to see if they are infected but will also just check for changes to core system files.

Some Useful Curl Snippets

14th July 2015 - 7 minutes read time
Curl is an incredibly useful tool and has all sorts of flags and options available for every situation. I tend to use curl quite a lot for all kinds of stuff, and not just downloading large files. So I thought I would post a few of the most common things that I use the tool for. Note that most of the following URLs don't really exist, they are just for demo purposes. I have also left out the output of these commands as they vary from a few lines to many pages of output.

Find Architecture And Version Of A Linux Box

12th August 2014 - 3 minutes read time

When doing an audit of an existing Linux server a good first step is to find out what distribution is running and if the server is running a 32 or 64 bit architecture.

To find out what architecture a server is running you can run the uname command, which will print out certain system information. This must be supplied with the -a flag in order to print out as much information as possible.

uname -a

This will print out a line similar to the following on an Ubuntu system.

Print A Specific Block Of Lines From A File In Linux

20th May 2014 - 2 minutes read time

If you have a large file of data that you are trying to import, or a log file you are trying to dissect then you'll rarely want to print it directly out to the screen. Using commands like more or programs like vim can make things a little easier but you still have to run through potentially thousands of lines to find the correct block.

Adding iptables Rules With Ansible

16th February 2014 - 3 minutes read time

Many systems and applications require certain access to certain ports and protocols. When installing these systems using Ansible it is necessary to also open up the needed ports so that the systems can function correctly. As there is no iptables module in Ansible the shell command is needed to add the iptables rules.

As an example, here is a task that adds a iptables rule to allow Apache to communicate on port 80.

Automatically List Directory Contents When Changing Directory In Linux

28th January 2014 - 2 minutes read time

When navigating around a Linux box I tend to find I use the same two commands a lot. The first is 'cd' to change a directory, and the second is 'ls' in order to see what is in the new directory. Rather than do this over and over again I decided to look around for a good solution to automate this.

Adding Apache Reporting To Munin

26th July 2013 - 3 minutes read time

When you first install a Munin node it will try to install as many plugins as it can so that it can report on different things. For example, if you have a Varnish server running then Munin will detect this and enable the plugins so that it can report on the activity of Varnish. Once you have started getting data through to your Munin server then you can turn on plugins on the nodes to get more data.

Copying Files With Secure Copy

15th June 2013 - 4 minutes read time

The secure copy command (run using scp) is a Linux command that allows the transfer of files between two computers. This can be locally to a remote server, from a remote server to a local location, or even between two remote servers.

When copying to or from a remote host scp uses ssh for the data transfer. This means that authentication is required, but the files are copied in a secure fashion. When starting a scp request the command first sets up an ssh connection to the remote location, which is then used for the rest of the transfer.

Monitoring Performance With Munin

20th May 2013 - 17 minutes read time

I have been searching for a good server monitoring solution for a while so that I can keep an eye on some of the servers that I run. Tools like Smokeping, Cacti and Nagios seemed promising at the outset, but they are more concerned with bandwidth and server status, not how the server is running.