Orientation for fresh VDTT Students Introduction to UNIX

1. Orientation for fresh VDTT StudentsIntroduction to UNIX July 28, 2001 Anup Gangwar

2. Overview • Prerequisites and goals of this course • Differences between UNIX and Windows • Overview of unices • Basic UNIX commands and utilities • Lunch Break • File editors in UNIX • Programming and Shell Scripting • Document formatting using UNIX • References and further study • Thank You

3. Prerequisites and Goals • What you should know • Basic familiarity with computers • Working Knowledge of atleast one operating system • A will to learn • What you will know • This is not a complete UNIX tutorial • Don’t try to learn the whole UNIX in one day • How to do the most common set of tasks with UNIX • Self-Help is the best help • Pointers for further information

4. Differences: UNIX and Windows • The UNIX and Windows philosophies • Client-Server model of Computation • Multi-User and Multi-Tasking. Login? • Concept of the Kernel and User Shell • Concept of file ownership and groups • GUI on UNIX and X windows • Tips: • UNIX is the most used OS in scientific and industrial community • Instead of avoiding UNIX take it heads on • Learning UNIX now will help you save precious time later on

5. Overview of Unices-1 • The ?original? UNIX • The AT&T SVR and BSD • Others: HP-UX, Solaris, Linux, AIX, IRIX etc. • Why are there so many unices? Vendor Wars! • How do I understand all of them? POSIX! • Tips: • Learn the common set of commands for all the unices • Linux utilities will contain enhancements not found in others • Try to clear trivial doubts like command syntax yourself

6. Overview of Unices-2 • HP-UX • Processors: HP PA-RISC and Intel Itanium • Vendors: HP • Markets: High End Servers and Workstations • Solaris/SunOS • Processors: Sun Ultra Sparc • Vendors: Sun Microsystems • Markets: All ranges of Servers and Workstations

7. Overview of Unices-3 • Linux/GNU Systems • Processors: Intel 386 and up, Sun Ultra Sparc, IBM PowerPC etc. • Vendors: Free/GNU GPL • Markets: Low End Servers and Workstations • AIX (Advanced UNIX) • Processors: IBM Power PC • Vendors: IBM • Markets: All ranges of Servers and Workstations

8. Overview of Unices-4 • IRIX • Processors: MIPS • Vendors: SGI (Silicon Graphics International) • Markets: High End Graphics Servers and Workstations • Others • BeOS, FreeBSD etc. • RTOS’s: PSoS, QNX, RTEMS, ?RTLinux? etc.

9. What we have • Philips VLSI Design Lab • HP Server running HP-UX • Sun Workstation • Linux Workstations • VDTT Lab • Linux Workstations • Windows NT Workstations • New VLSI Lab • Sun Workstations • Windows NT Workstations

10. Basic UNIX Commands and Utilities-1 • Files and Directories • File Types: Windows and UNIX • File and Directory creation (Editors, mkdir, ln etc.) • Listing contents of a directory (ls) • File and Directory deletion (rmdir, rm etc.) • File and Directory permissions (chmod) • File and Directory ownership (chown, chgrp) • Organizing your work in directories (mv) • Tips: • UNIX doesn’t have a recycle bin! • Try not to make the mistake of rm -rf * command

11. Basic UNIX Commands and Utilities-2 • Managing your account • What is meant by managing your account? • Concept of setup files • Why are there so many different Shells? • Environment variables • .bashrc and .cshrc files • Customizing your environment with .bashrc and .cshrc files • Example: The TERM environment variable and stty • Tips: • Try an environment variable on command-line first • Always set the PATH variable properly

12. Basic UNIX Commands and Utilities-3 • Remote process execution • Why do we need remote process execution? • Telnet and rlogin • Remote execution of graphics programs • X-Security, granting permissions and colormap • The DISPLAY environment variable • dot-rhosts (.rhosts), xon • Moving files between computers: FTP (?anonymous? FTP login) • Tips: • Graphics performance suffers in remote graphics execution • xhost+ is the worst thing to do! • Ncftp is a better ftp client than the vanilla default UNIX ftp

13. Basic UNIX Commands and Utilities-4 • Taking printouts • Concept of network and local printers • Printer languages: Postscript and PCL • GhostView and Acroread programs • Spooling, Deleting and Checking a printer job • Duplex printing and mpage • Taking backups • Tarring, zipping, gzipping and compressing • Comparison with winzip and common filename extensions • Tips: • Do not issue the command tar -cvf <file-name> * • Acroread just might be a better program to open pdf files

14. Basic UNIX Commands and Utilities-5 • Miscellaneous stuff • Forcing a process in background (&, fg, bg) • Setting aliases • Online manual pages, man • Concept of NIS and NFS • Changing password, passwd (?yppasswd?) • Searching for patterns, grep and regular expressions • Working with files with special characters in names • The file utility • finger, who and rwho • ps and kill • Mailand mail clients, netscape, pine, emacs and mail • startx, .Xclients and .xinitrc files • Tips: • Instead of asking someone try man -k • It is a good practice to stick to one shell (csh is available on all)

15. Lunch Break

16. Editors in UNIX-1 • What all is available, Vi, Emacs, Pico, Joe?, Nedit? • Vi: The king of all editors? Tutorial? • Why learn vi? • Getting in and out? • Basic keys for editing • Moving around, deleting, joining lines • Repeating commands • Search and replace • Tips: • Vim is not Vi • Learn the keypad scroll key combinations instead of arrow keys • Vi is fast, try to make the best use of its capabilities

17. Editors in UNIX-2 • Emacs: Much more than an editor? • Why learn Emacs? History, Tutorial • Getting in and out? • Basic keys for editing • Moving around, deleting a line • Search and replace • Formatted text, postscript spooling • mail in emacs • Syntax highlighting and templates • Tips: • Emacs recognizes 20+ languages out of the box • Emacs is slow • Emacs is not available by default on all unices

18. Editors in UNIX-3 • Pico: Is there really a need? • Pico and Pine • Editor Keys • Joe?, Nedit? • Keys similar to Norton Editor • Nedit has some features similar to Emacs • Tips: • Don’t fall for Pico or Nedit • Learn Vi and Emacs if you really want to get into UNIX • In the end it is a matter of choice

19. Programming on UNIX-1 • Is programming on UNIX tough? What all is available? • Concept of IDE and differences with TurboC++ • Compilers, Linkers, Debuggers and front-ends • Managing big projects: make and comparison with TC project file • Example of a simple makefile • GUI development on UNIX • Java • Tips: • UNIX is a programmers paradise

20. Programming on UNIX-2 • Gcc, The GNU C/C++ compiler • Simplest possible way to use: gcc <file-name> • Common options • output filename: -o • compile only: -c • Warnings: -Wall • optimizations: -O{1,2,3,4} • Debug: -g • Linking: -l<library-name> • Tips: • Not every UNIX systems will have gcc • Turning on optimization makes the compilation slow • Debugging and optimizing donot go together

21. Programming on UNIX-3 • Ld, The Linker • What exactly are libraries? • Shared and static libraries • Is there a need to call Ld explicitly? • Passing options to Ld from gcc • The -l option • The -L option • The LD_LIBRARY_PATH environment variable • The LD_RUN_PATH environment variable • Tips: • Always check the Ld on the system, HP-UX doesn’t use GNU Ld • Environment variables are different with non GNU Ld

22. Programming on UNIX-4 • Gdb, The GNU C/C++ debugger • Why is a debugger needed? • gdb and ?core? File • Common commands • list • run, break, resume • backtrace and where • Tips: • Using gdb directly might be tedious • Try the various front-ends to gdb: emacs, xxgdb, mxgdb etc. • Not every system will have gdb, you just might have to use ?dbx?

23. Programming on UNIX-5 • Gmake or GNU make • What is the need for a Makefile? • Dependencies • Targets in a makefile • Patterns in makefile • Automatic variables in a makefile • Pattern substitution • Common target names: all, clean, docs • Tips: • Never forget the TAB • Make is language independent!

24. Programming on UNIX-6 • Example of a makefile CC=gcc COPTS= -g -Wall TARGET=run.x SRCS=hello.c junk.c OBJS=$(SRCS:.c=.o) all:$(OBJS) $(CC) $(COPTS) $(OBJS) -o $(TARGET) clean: rm -f $(OBJS) core %.o:%.c $(CC) $(COPTS) -c $<

25. Programming on UNIX-7 • GUI in UNIX? • Differences with TurboC++ • Vanilla X windows programming, why not? • TCL/Tk • Widget libraries • Motif • GTK • QT, etc. • Tips: • Always provide a command line interface to your programs • Using a GUI is slow

26. Programming on UNIX-8 • Java • What is really different with the windows version? • Is Jfc, Java2D, Java3D available? • IDE’s for Java over UNIX? • Tips: • Don’t try to use a %.class dependency with make • If you run Java from a server, graphics would be slow

27. Introduction to Shell Programming-1 • What is the need for shell programming? • Bourne shell (sh, ksh, zsh and bash) • c shell (csh, tcsh) • Examples of shell programming • Moving all a.{i}.txt files to a.{i+1}.txt • Cleaning up your directory at the end of a day • Tips: • Perl just might be a better option • Don’t forget ?sed? and ?awk?

28. Introduction to Shell Programming-2 • Moving files script #!/bin/sh -f FILE_LIST=`ls | grep "\.[0-9]\." ` for CURR_FILE in $FILE_LIST; do FIRST_NM=`echo $CURR_FILE | cut -d'.' -f1` NUM=`echo $CURR_FILE | cut -d'.' -f2 ` SECOND_NM=`echo $CURR_FILE | cut -d'.' -f3` NUM_PLUS=`expr $NUM + 1 ` mv -i $CURR_FILE $FIRST_NM.$NUM_PLUS.$SECOND_NM done

29. Introduction to Shell Programming-3 • Cleanup directory script #!/bin/csh -f # Assume that ps, pdf etc. directories are present set FILE_LIST=`ls` foreach CURR_FILE ( $FILE_LIST ) set TST=`echo $CURR_FILE | grep \.pdf\$ ` if( $TST != "" ) then mv $CURR_FILE pdf endif set TST=`echo $CURR_FILE | grep \.ps\$ ` if( $TST != "" ) then mv $CURR_FILE ps endif end

30. Text formatting using UNIX-1 • What is the need for text formatting? • WYSWYG or NOT? • LaTeX & Emacs PS renderer • LaTeX WYSWYG front-end Lyx • Other text formatters: ?troff? • How to make Presentations? Slides? • Tips: • PowerPoint is still the best software for making presentations • It is easy to convert PowerPoint slides to html

31. Text formatting using UNIX-2 • LaTeX • origin: LaTeX and TeX • usage • LaTeX tutorials and manuals • A not so short introduction to LaTeX • The LaTeX manual • LaTeX by Lesslie Lamport • Lyx a WYSWIG interface to LaTeX • Emacs ps-renderer and troff • Tips: • For small formatted text Emacs is still the best

32. Before wrapping up Any questions/doubts which you would like to clarify?

33. Wrapping up • Self help is the best help! • The UNIX man pages. ?Manual sections? • Using man, whatis etc. • Experiment. You can never kill the system. • Links • http://www.gnu.org, for GNU tools and manuals • http://sunsite.unc.edu, world’s largest collection of free software • http://upavan.cse.iitd.ernet.in, Philips Lab. internal page • http://poorvi.cse.iitd.ernet.in/local, Intel cluster archives • Books • The UNIX programming environment, Kernighan & Pike

34. Thank You