Linux/Unix/BSD

Information And Reviews On Linux, Unix And Bsd Operating Systems

Unix is a multi-user, multi-tasking operating system that was initially developed by Bell Labs in the 1970s. Various similar operating systems that are POSIX compliant (ie compatible with Unix) have since been developed (POSIX is an abbreviation for Portable Operating System Interface for UNIX). These include the following: the BSD family (OpenBSD, FreeBSD, NetBSD, Mac OS/X), Solaris, IRIX, AIX, SunOS, UnixWare, OpenServer and Linux.

Software written for POSIX compliant operating systems is generally able to be compiled for all POSIX platforms with little or no platform-specific changes. This makes the commands and utilities available for this extended family of operating systems very similar, and there are few differences between administering them.

The articles in this section are about useful command line utilities and commonly used application software on POSIX compliant operating systems. For Mac OSX specific articles see my OSX section.

Overriding the AWStats LogFile Configuration Option

I run AWStats on one of my servers and it copies files over from some of the other servers I manage every 15 minutes and processes them. However, I had a server issue yesterday with the machine that AWStats runs on, and it meant the auto process which copies the files over and runs AWStats stopped running for about 12 hours. The end result was some lost information and needing to regenerate stats for the month to date. I needed to override the AWStats LogFile configuration directive on the command line to be able to do this.

Changing the default text editor on Linux

The default command line text editor on Linux (and BSD varaiants) determines what is used when you run commands such as "crontab -e" and is often not what you want to use yourself. Typcially vi/vim is the default text editor; many people prefer emacs or other editors, and I prefer to use nano myself.

Installing Geo IP PurePerl

I process logs on my webservers using AWStats, and use the GeoIP plugin to translate IP addresses into country codes. This article looks at how to install the Geo I PurePerl plugin, which is used by AWStats, and also how to download and install the Geo IP database files which are required by this plugin. The server I installed this onto was a CentOS 5 server, but the instructions here should work equally well on other Linux distributions.

Unknown partition table error

After re-partitioning a hard drive by removing all existing partitions and creating a single primary parition which takes up the entire disk, I formatted it as ext3, mounted it at /mnt/hdh and copied all the ISO images across from the exsting ISO drive. I rebooted, pausing to swap the disk over to a different cable, and got the error message "hdb: unknown partition table".

Installing AWStats on CentOS

AWStats provides a useful overview of website statistics from your Apache log files. There is no automatic way to install AWStats on CentOS using yum, so this article looks at how to install AWStats on CentOS. The instructions below should also work on other Linux distributions that do not have an automatic way of installing AWStats.

Checking daylight savings settings on Linux

The date daylight savings starts and ends changed in New Zealand last year, but unfortunately there was only a few months between when the decision was made and when it happened and the updates to the timezone databases on various Linux distributions wasn’t done in time in many cases. This affected many servers and services which displayed the wrong time for the couple of weeks between when daylight savings actually started and when it would have in previous years.