An Introduction to Linux

To download the Linux source code, available under the GNU Public license, from the official kernel site.

Remember that would be the kernel or core of the operating system that you would be downloading, if wanting additional functionality then most of that additional functionality that you may want to have will also be available under the GNU Public license.

When installing Linux, the source code is usually stored in /usr/src/linux.

You may find it easier to work with a distribution of Linux that has already put all the required functionality onto a CD-ROM. (Debian, Red Hat, SuSE, Mandrake to mention a few.)

As long as Linux conforms to the POSIX - IEEE Portable operating system standards, it will be compliant with most UNIX type (or other type of apps See Running Programs below) applications. Enabling you to compile and run your UNIX apps on a Linux machine.

Linux conforms to quite a few of the UNIX brands taking the best of breed from products such as SVR4 and Solaris 2.x and using some of the technology such as:

  1. The ability to load and unload kernel modules.

  2. It is possible to mount a file system on Linux, from UNIX instead of the file systems already supplied in Linux (ext2, and ext3), for example the journaling file system from AIX (IBM version of UNIX) or the IRIX file system called XFS (Silicon Graphics). This is hugely powerful, to be able to bring an alien file system to use on the Linux system.

When working in UNIX I always thought that one of its powerful features was that the operating system did not "care" what type of file you were working with. It was always up to how the application or how you accessed the file, but we could load any kind of file on the system and work with it (a DOS file, a DOS database file). We would do a massive amount of shuffling information around using the powerful tools that are available in UNIX itself, and then easily port the changed file back to the originating system.

We could mount any device as a file system and work with the data as required, an excellent way of being able to support our clients.

Well when rooting around for more in-depth knowledge of Linux I found out the following, and I am sure that there is probably more: