UNIX/Linux System Programming

1. UNIX/Linux System Programming History Jordan University of Science and Technology

2. UNIX History • First UNIX implementation in 1969 by Ken Thompson at Bell Laboratories, a division of the telephone corporation, AT&T. • 1969 is the same year that LinusTorvaldswas born. • It was written in assembler for a Digital PDP-7 minicomputer. • The name UNIX came from MULTICS (Multiplexed Information and • Computing Service), the name of an earlier operating system project in which AT&T • collaborated with MIT and GE. Jordan University of Science and Technology

3. C programming language • B programming language was initially implemented by Thompson and drew many of its ideas from an earlier programming language named BCPL. • A short time later, Dennis Ritchie, one of Thompson’s colleagues at Bell Laboratories and an early collaborator on UNIX, designed and implemented the C programming language. • This was an evolutionary process. • By 1973, C had matured to a point where the UNIX kernel could be almost entirely rewritten in the new language.

4. Six edition of UNIX (1969-1979) • First Edition, November 1971: By this time, UNIX was running on the PDP-11 and already had a FORTRAN compiler and versions of many programs still used today, including ar, cat, chmod, chown, cp, dc, ed, find, ln, ls, mail, mkdir, mv, rm, sh, su, and who. • Second Edition, June 1972: By this time, UNIX was installed on ten machines within AT&T. • Third Edition, February 1973: This edition included a C compiler and the first implementation of pipes. • Fourth Edition, November 1973: This was the first version to be almost totally written in C. • Fifth Edition, June 1974: By this time, UNIX was installed on more than 50 systems. • Sixth Edition, May 1975: This was the first edition to be widely used outside AT&T.

5. BSD at Berkeley • Thompson went to the University of California at Berkeley. He worked with graduate students • One of them was Bill Joy, subsequently went on to cofound Sun Microsystems. • C shell, the vi editor, the Berkeley Fast File System, sendmail, etc. • Under the name Berkeley Software Distribution (BSD), a version of UNIX, including its source code, came to be widely distributed.

6. The GNU project

7. The GNU project • 1982 AT&T was permitted to market UNIX--- System III, System V, SVR4 • In 1984, Richard Stallman, an exceptionally talented programmer working at MIT, set to work on creating a “free” UNIX implementation. Stallman’s outlook was a moral one. • Emacs text editor, GCC (originally the GNU C compiler, GNU compiler collection, comprising compilers for C, C++, and other languages), the bash shell, and glibc (the GNU C • 1990s, the GNU project had produced a system that was virtually complete, except for one important component: a working UNIX kernel library.

8. Richard Stallman

9. The Linux Kernel • In 1991, LinusTorvalds, a student at the University of Helsinki, was inspired to write an operating system for his Intel 80386 PC. • Torvalds developed a basic kernel that allowed him to compile and run various GNU programs • October 5, 1991, Torvalds requested the help of other programmers • Other programmers joined Torvaldsin the development of Linux • Linux is used to refer to the entire UNIX-like operating systems of which the Linux kernel forms a part

10. LinusTorvalds

11. Operating System User 1 User 2

12. Linux OS

13. Gnome

14. The Terminal (Shell)

15. Linux Distributions • Debian

16. Linux Distributions

17. Linux Distributions

18. Standardization • The portabilityproblems: Many variations in UNIX and C implementations • Strong pressure for standardization • The C language was standardized in 1989 (C89), and a revised standard was produced in 1999 (C99). • The first attempt to standardize the operating system interface (API) yielded (Portable Operating System Interfac) POSIX.1

19. Flavors of UNIX Proprietary: (redistribution and modification prohibited or restricted; not free) • Solaris • IRIX • Mac OS X Open Source: (source code is available and free to modify) • FreeBSD • RedHat • Mandrake • Debian-Ubuntu • SuSE • Slackware GUIs: • Gnome • K Desktop Environment (KDE)

20. Unix Overview Directory Structure

21. Programming Tools and Utilities Available under Linux • Text Editors • Xemacs • Emacs • Pico • vi • Compilers • C compiler - gcc • C++ compiler - g++ • Java compiler & Java Virtual Machine - javac & java • Others • Debuggers • C / C++ debugger - gdb • Interpreters • Perl - perl • Tcl/Tk - tcl & wish • Miscellaneous • Web Browsers - Mozilla, Netscape, Firefox • Instant Messengers - Gaim • Email - Thunderbird

22. UNIX/Linux directories • / : Root of the tree. Where it starts. • bin, sbin, usr/bin: software for the shells and most common Unix commands. • dev: short for devices, holds the files necessary to operate peripherals such as printers and terminals. • home: contains the home directories of users (/export/home on sun computers).

23. UNIX/Linux directories • tmp: holds temporary files. • var: contains files that vary in size; (Mail irectories, printer spool files, logs, etc.) • etc: administrative files such as lists of user names and passwords. • usr: Contains application programs • lib: Contains libraries for programs • proc: a pseudo-filesystem used as an interface to kernel data structures.

24. Windows : administrator • UNIX/Linux : root

25. Project # 1 • Install Linux (Ubuntu). • You can use Virtual Machine • Vmplayer. • http://downloads.vmware.com/d/info/desktop_downloads/vmware_player/3_0 • VirtualBox. • http://www.virtualbox.org/wiki/Downloads • Download Ubuntu ISO • http://www.ubuntu.com/download/ubuntu/download

26. Project # 1 • Get familiar with Ubuntu. • A lot of recourses in WWW • How to use Shell • Run commands on the shell as you can • Create and run “Hello Word” program in C under Linux • Submit snapshots of your work (E-Learning) before next class

27. Project # 1 Send Me for any thing any time. yaser.amd@gmail.com