Introduction to Linux & Basic Commands
- 1. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE LINUX INTERNALS Dr. Vikram Neerugatti Associate Professor Department of CSE 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 1
- 2. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE • History • Distributions • Licensing • Linux commands – Man pages – Working with directories – Working with files – General purpose utilities Content 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 2
- 3. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ 1969 - Dennis Ritchie - and Ken Thompson developed the C language and the Unix operating system at AT&T Bell Labs. ✓ 1975 – Commercial UNIX & BSD UNIX. ✓ 1980 – Many companies has their own UNIX - Richard Stallman – GNU (1984) – root of Linux ✓ 1990- Linus Torvalds, a Swedish speaking Finnish student, buying a 386 computer and writing a brand new POSIX compliant kernel. combination of this kernel with the GNU tools. ✓ 2015 - Linux History 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 3
- 4. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ overview of current Linux distributions. ✓ distribution is a collection of (usually open source) software on top of a Linux kernel. ✓ Red Hat ✓ Ubuntu ✓ Debian ✓ Others ✓ Which to choose? Distributions 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 4
- 5. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Red Hat – Company – Develop Linux ✓ Red Hat Enterprise Linux and Fedora – Free ✓ Red Hat Enterprise Linux – with Support ✓ Fedora – without Support Distributions - Red Hat 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 5
- 6. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Ubuntu – 2004 ✓ Graphical Linux desktop ✓ In lab ✓ Support - payment Distributions - Ubuntu 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 6
- 7. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Debian – no company ✓ Organized developers that elect a Debian Project Leader every two years ✓ Three versions: stable, testing and unstable Distributions - Debian 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 7
- 8. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Red Hat Enterprise Linux ✓ CentOS ✓ Oracle Enterprise Linux ✓ Scientific Linux ✓ Ubuntu ✓ Linux Mint ✓ Edubuntu ✓ other *buntu ✓ hundreds of other Linux distributions Distributions - Others 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 8
- 9. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE Distributions - Which to choose? 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 9
- 10. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ About software licenses ✓ Proprietary software ✓ Free and Open Source Software ✓ Public domain software ✓ Given all rights ✓ Rules ✓ Freeware ✓ can use without paying a license cost ✓ Free Software or Open Source Software ✓ No cost – No Code or rights ✓ No cos – No rights Licensing 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 10
- 11. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ GNU General Public License ✓ Copy left principle ✓ No - Copy right protected parts ✓ using GPLv3 software ✓ Full freedom ✓ BSD license ✓ Berkeley Distribution License ✓ Copy the modified versions ✓ Others ✓ Ensure, before using it Licensing – Cont.. 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 11
- 12. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Man $ command ✓ Man $ configfile ✓ Man $ daemon ✓ Man –k (apropos) ✓ Whatis ✓ Whereis ✓ Man sections ✓ Man $section $file ✓ Man man ✓ Mandb Linux commands – Man/Manual Pages 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 12
- 13. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Man $ command ✓ Man whois (help) – press q to quite the manual page ✓ Man $ configfile ✓ Man syslog.conf manual for configuration files ✓ Man $ daemon ✓ Man syslogd true for background programs ✓ Man –k (apropos) ✓ Man –k syslog shows list of all files contain the string ✓ Whatis ✓ Whatis route gets description of manual pages Linux commands – Man Pages 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 13
- 14. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Whereis ✓ Whereis –m whois location of the manpage will be revealed ✓ Man sections ✓ Section numbers will be in brackets ex. (1) ✓ Man $section $file ✓ man passwd opens the first manual found ✓ man 5 passwd opens a page from section 5 ✓ Man man ✓ If you want to know more about man, then Read The Fantastic Manual (RTFM) ✓ Mandb ✓ Mandb man page exists, but you can't access it Linux commands – Man/Manual Pages 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 14
- 15. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Pwd ✓ Pwd print working directory ✓ Cd ✓ Cd touched change your current directory ✓ Absolute and relative paths ✓ Paths in the file tree ✓ Path starting with a slash (/), then the root of the file tree is assumed ✓ If you don't start your path with a slash, then the current directory is the assumed starting point. ✓ Cd home or cd /home Linux commands – Working with directories 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 15
- 16. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Path completion ✓ Tab key will help us cdet will change to cdetc ✓ Ls ✓ Ls list the contents of directory ✓ Ls – a show all files, including hidden files ✓ Ls –l gives long listing of files ✓ Ls –lh files sizes in human readable format ✓ Mkdir ✓ Mkdir vikram create own directory ✓ Rmdir ✓ Rmdir vikram remove the directory Linux commands – Working with directories 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 16
- 17. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ File ✓ File vikram.png determines the type of file ✓ Touch ✓ Touch vikram creates empty file ✓ Rm ✓ Rm vikram removes forever ✓ Rm –I it will ask? Yes /no then it will ✓ Rm –rf will removes anyfile ✓ Cp ✓ Cp file file.copy copies ✓ Cp file dir Linux commands – Working with files 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 17
- 18. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Mv ✓ Mv old new remane ✓ Mv dirold dirnew rename directories ✓ Rename ✓ abc.txt file33.txt file42.txt ✓ rename 's/.txt/.png/' *.txt ✓ abc.png file33.png file42.png ✓ abc.png file33.png file42.png ✓ rename 's/file/document/' *.png ✓ abc.png document33.png document42.png Linux commands – Working with files 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 18
- 19. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Cal ✓ Cal Shows current month calendar on the terminal with the current date highlighted. ✓ Cal –y Shows the calendar of the complete current year with the current date highlighted ✓ Cal 08 2000 ✓ Cal 2000 ✓ Date ✓ Date displays date - pacific daylight time ✓ Date –u Greenwich Mean Time)/UTC(Coordinated Universal Time ) ✓ Date –date=“2 year ago” ✓ Date –date=“5 sec ago” Linux commands – general purpose utilities 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 19
- 20. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Script ✓ script command in Linux is used to make typescript or record all the terminal activities. ✓ After executing the script command it starts recording everything printed on the screen including the inputs and outputs until exit. ✓ By default, all the terminal information is saved in the file typescript ✓ Script ✓ Who ✓ The who command is used to get information about currently logged in user on to system. ✓ who Linux commands – general purpose utilities 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 20
- 21. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Tty ✓ tty which displays information related to terminal ✓ tty is short of teletype, but popularly known as a terminal it allows you to interact with the system by passing on the data (you input) to the system, and displaying the output produced by the system. ✓ Tty --version ✓ Pwd ✓ pwd stands for Print Working Directory. It prints the path of the working directory, starting from the root Linux commands – general purpose utilities 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 21
- 22. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE ✓ Ps ✓ Linux provides us a utility called ps for viewing information related with the processes on a system which stands as abbreviation for “Process Status”. ✓ ps command is used to list the currently running processes and their PIDs along with some other information depends on different options. ✓ Ps ✓ Uname ✓ The command ‘uname‘ displays the information about the system. ✓ Uname -a Linux commands – general purpose utilities 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 22
- 23. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 23
- 24. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 24 Any Questions/Clarifications/Doubts
- 25. JAIN – DEEMED TO BE UNIVERSITY GLOBAL CAMPUS: 45th km NH - 209 Jakkasandra Post, Kanakapura Rd, Bengaluru, Karnataka 562112 Department of CSE 2/9/2023 Linux Internals by Dr. Vikram Neerugatti 25 Thank you all