2. Plan
• Introduction to Unix/Linux
• Basic Utilities and Commands
• Programming in Unix/Linux
• Text formatting
3. Why another tutorial on Linux?
• To give you brief and quick introduction
• Motivations for new Linux users
• Something which is more specific to our
department and labs
• Not a detailed description of commands, you
have to relay on “man” pages
• Can be served as a quick reference material
4. Introduction to Unix/Linux as OS
• Kernel and shell
– Kernel is one who all the job and shell is one
with whome you interface. Better known as
'Command Line Interface'
• Multi-user
– Each shell is a user for linux
– You can open a shell from any other computer
also – remote login
5. Introduction to Unix/Linux as OS
• Multi-tasking
• Linux directory structure
» - Root directory
» home - Home directory
» usrbin - Most commanly used binaries
» usrlocal - Tools those are installed specifically in the
machines,
» better to have a look to see what is there in machine on
which you are sitting
• Versions of linux
– Fedora Core 2.0 – One of the stable linux
– Fedora Core 7.0 – One of the latest version
– Latest version doesn't means better!
6. Basic Commands and Utilities
• File Commands
• Home settings
• Network logins
• Backups
• Internet
• Miscellaneous
7. File Commands
• Unix directory structure revisited
– 'cd ~' change directory to your home
– 'cd ~sonali' change directory to sonali's home
– 'cd ..' change directory to upper directory
– 'cd / ' change directory to root
– Use tabs to complete the file name (write partial
file name and then use tab)
8. File Commands
• Some other general commands
– ls, list the files,
– '-a' option means 'list all', will show hidden files as well
– all filenames starting with . are hidden file
– Other options you can try is '-l', '--color'
– mkdir, making new directories
– rm, removing a file
– BEWARE!! There is no recycle bin in Unix
– 'rm -i' will ask “are you sure that you want to delete”
– 'rm -r' will do everything recursivily, '-f' force
– rmdir, remove directory
– 'cp', means copy 'mv', means rename or move
9. File Commands
• Permissions – important for sharing your files and
restricting access on your work
– 'chmod 755' => rwx rwx rwx (user group all)
– 'chmod a+r' => (u/g/a) ( +/ -) (r/w/x)
• ‘file’ utility tells type of file like text, word or pdf
• Helpful when extension is not given
• Important filters- (Best way to learn is use commands)
– 'grep word path/filename', grep find a word in a file
– pipes ' | ' : redirect output of one command to other command
– 'more' or 'less' shows files pagewise
• ‘find’ and ‘locate’ utility help to find a file by filename
– ‘find –r path –name filename’ will find the location of file in given
path. Useful command as we can use wild card pattern
10. Setting your home
• Different shells – sh, csh, bash, tcsh, ksh
– ‘csh’ more programmer friendly- default in Philips lab
• Different desktops – gnome, kde, windows-maker
– Gnome or Kde more user friendly
– Windows-maker – fast and simple
• Setting environment variables
– alias, alias any command
– setenv, sets the variable name
– PATH, is a environment variable that is searched when you type a command.
– MAN PATH
– LD_LIBRARY_PATH, library search path
– umask, default set the permissions of a new created file by you
• Your cshrc/bashrc – these files are executed when you open a new shell
– For Philips Lab users: Copy ~neeraj/.cshrc to your home.
• Disk space limitation – quota, du
– ‘quota –v username’ will tell your status of quota
– ‘du –sh filename’ tells disk usage of a file
11. Using Network
• Unix to Unix- ssh, telnet
• ‘ssh’ is a secure shall, X-settings are default
• “ssh login@machine.cse.iitd.ernet.in”
• ‘su username’ switch user command used for switching user on same machine
• Unix to Winodws- rdesktop
• Rdesktop enables you to use windows terminal sitting on your linux system
• Windows to Unix – Xmanager, putty
• Tools like Xmanager help you to easily access linux from your hostel PCs
• Using ftp and ncftp
• ‘ftp machine’ then use ‘get’ or ‘put’ to get the file from machine or put the file one
machine
• ‘ncftp –u user machine’ more interactive
• Using startx for new X terminal
• Cntrl + alt + (f1/f2/f3/f4), for new window in text mode
• For GUI desktop mode use ‘startx -- : 2’ (any number instead of 2)
• Cntrl + alt + f7 for previous locked window
• ‘wine’ and cygwin,
• wine is used for executing windows command on linux terminal and cygwin is a
software windows software to execute most common linux commands on windows
terminal
12. Backups
• Zip and Tar, gzip, gunzip
• Various extentions – Z, bz2, zip, gzip, tgz,
tar.gz
• Tar oprtions c,x,z,v,f
• ‘c’ for compress, ‘x’ for expend, ‘z’ for zip, ‘v’ for
verbose, ‘f’ force
• For compression ‘tar –czvf file.tar.gz ./dirname
• For Decompression ‘tar –xzvf file.tar.gz’
13. Internet
• Tools- netscape, mozilla, firefox
– Use tabs in mozilla
– Proxy settings
• Edit -> preference -> advance -> proxy
• OR Tools -> Options -> Connection Settings
• Server name: pushpa(10.20.5.2), port: 8080
• Use pine for mails: fast and easy for local mails
– Configuring pine,
» copy ~neeraj/.pinerc to your home and change to your login name
replacing ‘neeraj’ in .pinerc file
– In pine, all commands are given on bottom of editor
• http://poorvi.cse.iitd.ernet.in/help/userGuide.html
14. Miscellaneous
• Unix process – ps, fg, bg, kill, &
• ‘ps’ gives the list of processes
• ‘kill’ can kill a process, you have to write pid given by ps
• Writing ‘&’ in and of a command will force process to run in
background
• ‘ctrl z’ for suspending a process, ‘ctrl c’ to kill a process
• ‘bg’ running a process in background
• ‘fg’ bringing a process in foreground
• Finger, who, rwho
• ‘finger’ gives list of user on a machine
• ‘finger username’ will give some details about user – name shell etc
• ‘finger user@desh’ will tell when user has last checked his mails
• ‘who’ gives all users on a macine
• ‘rwho’ gives all users on all the machines
15. Miscellaneous
• Use man and man –k
• Help for using any command
• Change password- ‘passwd’, ‘yppasswd’, ‘kpasswd’
• ‘talk username@machine’ Try this when one of your friend is
login on another machine. This you will feel better than yahoo or msn
messenger
• Printing- lp, lpr
• ‘lpq’ for checking request queue on printer
• ‘ruptime’ gives list of all the machines and their load and
number of users on each
• Help you in selecting machine on which you should login
16. LDAP, NIS, NFS
• NIS and LDAP
– All user accounts are created and maintained on one
machine (NIS server), other machines use this info.
• By creating account on NIS server you can login anywhere
• NFS
– All HOME’s are on NFS server, all other machines
“mount” it from there.
• Wherever you login, you see same files
• Know your servers
– Intel Lab cluster servers: LDAP: bhairav, NFS: hpnas
– Philips Lab cluster server: NIS and NFS: virat
17. Important Utilities
• ooffice: OpenOffice, for word, presentation,
spreadsheets
• xfig, for drawing figures.
• Can be exported to eps, jpeg, gif or any format
• gimp - Viewing and editing images
• eog – (Eye of Gnome) for viewing images
• acroread – Acrobat reader for PDF files
• gnumeric - Spreadsheet viewer and editor in Linux
• Editors: vi, emacs, pico, gedit
18. Vi Editor
• Why vi, fast and easy
• Basic modes- edit and command,
• ‘esc’ for command mode
• ‘i, a’ for edit mode (insert or append mode)
• Other commands using colon- :q,:w,:q!,:e
• :q for quit, :w for write, :q! quit without save
• :e open another file for editing, :wq write and quit
• Searching using ‘/’
• In command mode use ‘/’ then write the word you want to search
• ‘n’ for forward search, ‘N’ for backward search
• Search and replace
• :s/ram/mohan - will search string “ram” and replace with “mohan”
• Advanced vi – vim(vi improve) and gvim(gnu vim)
19. Programming in Unix
• Unix made by programmer for programming
• Gcc compiler – for ‘c’, g++ for ‘c++’
• Various options, -O,-c,-g,-I
• ‘-O’ sets optimization level
• ‘-c’ only compile not link
• ‘-g’ for debug
• ‘-I’ for pre-processing only
• Linking with –l
• All the files are previously compiled and then linked by giving library
information
• Debugger- gdb
• Use ‘gdb a.out’ for debugging
20. Other tools for programmers
• Kdevelope, glade – gui based C/C++ programming
environment (like VC++ development environment)
• ‘ddd’ debugger.
• Makefile
• Makefile will have targets, prerequisite and commands
• Left of colon is target, right of colon is prerequisite, line next to target
line is command
• Command line should be tabbed
• ‘make’ will execute target given by ‘all’ or first target, else specify
your target in command line
• Make will resolve the dependencies recursively
» All dependencies of a target should be resolved before executing its
command
21. 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 $<
22. Text formatting
• Using Latex
– Text formatting in Linux
– Advantage of latex
• Automated formatting in standard form
• Generation of index and cross-references
• Figures and mathematical formulas
• Bibliography
– A latex template document given in my homepage:
http://www.cse.iitd.ernet.in/~neeraj/doc
23. Lab rules
• Keys issues
• If you have student keys of the lab then it must be returned next day in
morning
• Lab timings
• Lab is open for you most of the time. But due to one key you have to
coordinate in yourself to keep lab opened
• Discipline in the lab
• Don’t make noise in lab
• No eating drinking
• Labs are not for discussion in general that disturbs others
• No sharing of password, even with your project-mates
• Any mischief can lead to suspension of your account
24. Conclusion
• 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://karnali.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
