Welcome to Linux Chap#1

Linux History GNU Project: Started at 1983 by Richard Stallman. Goal: creating a UNIX-like free operating system. His vision: software should be free from restrictions against copying or modification in order to make better and efficient computer programs. (Incidentally, the name GNU is a recursive acronym which actually stands for 'GNU is Not Unix'). By 1991 GNU created a lot of tools, but there was still no operating system.

MINIX was written from scratch by Andrew S. Tanenbaum, a US- born Dutch professor who wanted to teach his students the inner workings of a real operating system. In 1991: Linux kernel is developed by Linus Torvalds. combining Linux kernel with the not-quite-complete GNU system resulted in a complete free operating system called linux.

Though a recent arrival, Linux is very well known as a child of UNIX first posted on Internet in 1991 Linux 1.0 in 1994; 2.2 in 1999 Today used on 7-10 million computers with 1000’s of programmers working to enhance it

Linux is Open Source Software When programmers on the Internet can read, redistribute, and modify the source for a piece of software, it evolves People improve it, people adapt it, people fix bugs. And this can happen at a speed that, compared to conventional software development.

Linux is a Free Software Free software is Software Used for any purpose Study to learn how it work and adapt to meet your needs. Copy and redistribute. Distribute as a part of an improved software.

LINUX System Components Kernel Directly interacts with the hardware, provides common services to program, and gives insulation from hardware characteristics. Consists of file subsystem, process control subsystem, device drivers and system calls interfaces. Shell A program that takes commands typed in at the terminal and translates them into instruction to internal system. Eg. Bourne shell (sh), C shell (csh), Korn shell (ksh), etc

Linux Distributions Various organizations package the Linux kernel and system programs as Linux distributions Such as : SUSE, Fedora, Ubuntu, Red Hat, Debian, and Mandriva. The differences between distributions typically : is how the user installs the operating system. which graphical configuration tools are installed by default and which tools are used to keep the system up-to-date.

Common Linux features Multiuser: Multitasking: Multiple users can log in and working on the system at the same time Multiuser systems divide computer resources among multiple users, allowing for more efficient use of these resources. Multitasking: it is possible to have many programs running at the same time Graphical User Interface (X Window System) Hardware support you can configure support for almost every type of hardware that can be connected to a computer Networking connectivity: Linux offers support for a variety of local area network boards, modems, and serial devices.

Common Linux features Network servers Application support Providing networking services to the client computers on the LAN or to the entire Internet is what Linux does best. Application support a wide range of freeware and shareware software is available for Linux. Most of Linux is written in the C programming language. When written in a portable style, C programs can be moved from one platform (processor or CPU-based system) to another by simply recompiling the code.

Linux file system The Linux file system is the structure in which all the information on your computer is stored. Files are organized within a hierarchy of directories. Each directory can contain files, as well as other directories.

/ /bin /boot /dev /etc /home /mnt /tmp /usr /var /sbin Directory Content Directory The root directory / Contains common Linux user commands such as ls, sort /bin Has the bootable Linux kernel and boot loader configuration files /boot Contains references to all the CPU peripheral hardware, which are represented as files /dev Contains administrative configuration files /etc Contains directories assigned to each user with a login account /home Contains Standard mount point for external file systems, e.g. a CD-ROM or a digital camera. /mnt Temporary space for use by the system /tmp Contains programs, libraries, documentation etc. for all user-related programs. /usr Contains storage for all variable files and temporary files created by users, such as log files, the mail queue, the print spooler area, space for temporary storage of files downloaded from the Internet, or to keep an image of a CD before burning it. /var Programs for use by the system and the system administrator. /sbin

Linux file system / bin boot dev etc home mnt temp user var sbin manal nawal mona bash login.defs passwd group skel