Operating System Laboratory presentation .ppt
- 1. Handled By X. IGNATIUS SELVARANI, AP/IT
- 2. OPERATING SYSTEM An Operating System is a set of programs that Functions as an virtual machine by presenting an interface that is easier to program than the underlying hardware Acts as resource management through orderly and controlled allocation of the processors, memories, and I/O devices among the programs competing for it.
- 3. ORGANIZATION OF UNIX The UNIX system is functionally organized at three levels and are: 1. The kernel, which schedules tasks and manages storage; 2. The shell, which connects and interprets users' commands, calls programs from memory, and executes them; and 3. The tools and applications that offer additional functionality to the OS
- 5. HARDWARE AND SOFTWARE REQUIREMENTS Hardware requirements Processor : Pentium III / Pentium 4/M or equivalent RAM : 256 MB to 1GB Disk space : 500MB to 5GB Software requirements Operating System : Windows XP /Vista/2003/2008 Languages : C/C++
- 6. PuTTY PuTTY is a free and open-source terminal emulator. The name "PuTTY" has no official meaning. PuTTY was originally written for Microsoft Windows, but it has been ported to various other operating systems. PuTTY is the most used SSH client for the Microsoft Windows platform. The SSH protocol was developed as a secure, encrypted replacement for the RSH protocol. PuTTY is a very versatile tool for remote access to another computer. It's probably used more often by people who want secure remote shell access to a UNIX or Linux system than for any other purpose
- 7. COURSE OBJECTIVES To learn Unix commands and shell programming To implement various CPU Scheduling Algorithms To implement Process Creation and Inter Process Communication. To implement Deadlock Avoidance and Deadlock Detection Algorithms To implement Page Replacement Algorithms To implement File Organization and File Allocation Strategies
- 8. LIST OF EXPERIMENTS 1. Basics of UNIX commands 2. Write programs using the following system calls of UNIX operating system fork, exec, getpid, exit, wait, close, stat, opendir, readdir 3. Write C programs to simulate UNIX commands like cp, ls, grep, etc. 4. Shell Programming 5. Write C programs to implement the various CPU Scheduling Algorithms 6. Implementation of Semaphores 7. Implementation of Shared memory and IPC 8. Bankers Algorithm for Deadlock Avoidance 9. Implementation of Deadlock Detection Algorithm
- 9. LIST OF EXPERIMENTS (Contd..) 10. Write C program to implement Threading & Synchronization Applications 11. Implementation of the following Memory Allocation Methods for fixed partition a) First Fit b) Worst Fit c) Best Fit 12. Implementation of Paging Technique of Memory Management 13. Implementation of the following Page Replacement Algorithms a) FIFO b) LRU c) LFU 14. Implementation of the various File Organization Techniques 15. Implementation of the following File Allocation Strategies a) Sequential b) Indexed c) Linked
- 10. Basics of UNIX commands Command Function date Used to display the current system date and time. date +%D Displays date only date +%T Displays time only date +% Y Displays the year part of date date +% H Displays the hour part of time cal Calendar of the current month Cal year Displays calendar for all months of the specified year
- 11. Command Function who Login details of all users such as their IP, Terminal No, User name, who am i Used to display the login details of the user tty Used to display the terminal name uname Displays the Operating System echo "txt" Displays the given text on the screen echo $HOME Displays the user's home directory bc Basic calculator. Press Ctrl+d to quit mancmdname Manual for the given command. Press q to exit history To display the commands used by the user since log on. exit Exit from a process. If shell is the only process then logs out
- 12. Directory commands Command Function pwd Path of the present working directory mkdirdir A directory is created in the given name under the current directory mkdirdir1 dir2 A number of sub-directories can be created under one stroke cdsubdir Change Directory. If the subdir starts with / then path starts from root (absolute) otherwise from current working directory. cd To switch to the home directory. cd / To switch to the root directory. cd .. To move back to the parent directory rmdirsubdir Removes an empty sub-directory.
- 13. File commands Command Function cat >filename To create a file with some contents. To end typing press Ctrl+d. The > symbol means redirecting output to a file. (< for input) catfilename Displays the file contents. cat >>filename Used to append contents to a file cpsrc des Copy files to given location. If already exists, it will be overwritten cp -isrc des Warns the user prior to overwriting the destination file cp -r src des Copies the entire directory, all its sub-directories and files. mv old new To rename an existing file or directory. -ioption can also be used mvf1 f2 f3 dir To move a group of files to a directory. mv -v old new Display name of each file as it is moved.
- 14. File commands (Contd..) Command Function rm file Used to delete a file or group of files. -ioption can also be used rm * To delete all the files in the directory. rm -r * Deletes all files and sub-directories rm -f * To forcibly remove even write-protected files ls Lists all files and subdirectories (blue colored) in sorted manner. lsname To check whether a file or directory exists. lsname* Short-hand notation to list out filenames of a specific pattern. ls -a Lists all files including hidden files (files beginning with .) ls -xdirname To have specific listing of a directory. ls -R Recursive listing of all files in the subdirectories ls -l Long listing showing file access rights (read/write/execute-rwx for user/group/others-ugo). cmpfile1 file2 Used to compare two files. Displays nothing if files are identical. wcfile It produces a statistics of lines (l), words(w), and characters(c).
- 15. Vi Editor Unix provides a versatile editor vi, a full-screen editor. vi" stands for visual editor. A vi session begins by invoking vi with or without a filename. $vi filename vi functions in three modes namely: 1. Input mode—Where any key depressed is entered as text 2. Command mode—Where keys are used as commands to act on text (initial mode) 3. ex mode—ex mode commands that can be entered in the last line to act on text
- 17. INPUT MODE vi starts with command mode. To insert text any of the following commands should be used. Commands Function i Inserts text to the left of the cursor. I Inserts text at the beginning of line. a Appends text to right of cursor A Appends text at end of line In Input mode the editor displays INSERT in the last line. Press Enter key to start a fresh line of text in Input mode and the ~ disappears. To quit input mode press Esc key.
- 18. COMMAND MODE EDIT COMMANDS Command Function s Deletes a single character to the left and switches to Input mode. x Deletes the character in the current cursor position Uor u Reverses the last change made to the buffer. dd Cuts the entire line dw Cuts the entire word d$ Cuts a line from cursor position to the end of the line d0 Cuts from the cursor position to the start of the line yy Copies (yanks) the entire line yw Copies the entire word p Pastes the text
- 19. NAVIGATION COMMANDS Command Function b Moves back to beginning of a word w Moves forward to beginning of word k Up one line j Down one line h Left one character l Right one character Ctrl+f Scrolls a page forward Ctrl+b Scrolls a page backward
- 20. THE EX MODE The essential save and exit commands form the features of ex mode. Press : (colon) in command mode to switch to ex mode. The : is displayed in the last line. Type the command and press Enter key to execute the same. Command Function w Saves file, displays the number of lines & characters and returns toInput mode. If it is an unnamed file then vi puts a message. w file The file is saved under the given name q Quits vi session and returns to $ prompt. vi has a safety mechanism that warns if changes made to file are not saved. q! Quits vi session without saving any changes made since the last save wq Save and exit sh Escape to shell r file To insert another file into the current file. new file Splits screen into multiple windows and opens the file.