UNIX has hundreds if not thousands of commands, and it's impossible to remember every option and nuance. But, happily, you don't have to: man, UNIX's built-in, online reference system, is man's best friend. Take a look at this shortcut guide to the UNIX man pages system.

When you’re looking for some documentation and help about a specific command, man really is your best friend. Almost all the commands on your system will have a man page where you can look to find all sorts of information.

If you just want enough information to fix your problem quickly, you can read the How-To section of this post and skip the rest. I would highly recommend reading everything though, as a good understanding of the concepts and commands outlined here will serve you well in the future. We also have Video and Audio included with this post that may be a good quick reference for you.

PHP offers simple but effective solution to log all errors to a log fiie.

Here are some useful commands that you can use to find (almost) every information that you want to know about your system from the command line.

GNU/Linux is bursting with information about the system on which it runs. The system's hardware and memory, its Internet link and current processes, the latest activity of each user -- all this information and more is available. And, despite such desktop tools as the KDE Control Center or GNOME's System Monitor, the easiest place to get all the system information available is still the command line.

Use gnuplot to dynamically generate Web pages from your system using raw data to provide graphic images. This raw data typically contains MIS-related information, on system performance, storage, or database growth.

This document describes how to set up the light-weight Conky system monitor on Ubuntu 7.04. Conky is a desktop widget that is able to display most diverse information like CPU temperature, current used network-bandwith or anything you want. You can customize the whole layout including colors and fonts.

The sar command collect, report, or save UNIX / Linux system activity information. It will save selected counters in the operating system to the /var/log/sa/sadd file. From the collected data, you get lots of information about your server...