Linux & Shell Programming 2014

Transcription

1 Unit -1: Introduction to UNIX/LINUX Operating System Practical Practice Questions: Find errors (if any) otherwise write output or interpretation of following commands. (Consider default shell is bash shell.) (a) echo n Hello \n World (b) echo e Hello \n World (c) echo `date` (d) echo $$ (e) cp file1 /f (f) cp f1 f2 f3 (g) rm * (h) mkdir p A A/B (i) mkdir A/B A (j) mv file1 /f (k) mv f1 f2 f3 f4 (l) ls r (m) cd ~ Write ls command with wildcards to search following file patterns: (a) file20,file21,., file29 (b) All files whose extension is.cpp (c) All files which having length only one character exclude * (asterisk) and? (question mark) characters. (d) All files which not starting with any special symbols (e) All files in parent directory. (f) All files which start with consonant character. Short Question: In which language is Linux written? How many words will display in output of date command? Can you get information about the man command itself using the man command? What is the meaning of first column in the result of who command? What is hidden file in UNIX? What is a utility program? Write date command to display current date in following format. MM/DD/YY Is it possible to move user s home directory without knowing the path of home directory? How? How can you copy a file while preserving the attributes? 10. What is purpose of (?) question mark symbol as wildcard character? 1 Where is the password stored? 1 How mv command is used to rename file? 1 Write command for removing directory although it is not empty. 1 What happens when you give the following commands if the file named done already exists? $ cp to_do done $ mv to_do done 1 Which command is used to display absolute path of current directory? 1 How can you display the following line on the screen you are working on? Hi $2, I m number * (guess)! 1 What does the.. entry in a directory point to? What does this entry point to in the root (/) directory? Page 1

2 Long Question: How UNIX is called multi-user and multitasking operating system? What is purpose of wildcard character in UNIX? Describe all wildcards with their uses. Give examples. Mention the different categories of UNIX files and discuss each of them very brief. Explain following terms with respect to directory. Also differentiate absolute path and relative pathname. Current directory, Home directory, Parent directory, Root directory Describe the contained stored by super block and Inode block. What are the hard link and soft link? Explain with difference of both. Write short note on /etc directory. Multiple Choice Questions: Which is the incorrect statement from following? A. Shell is a command interpreter. B. Shell is the interface between user and kernel. C. System can't work without a shell. D. Shell is a program. Kernel is A. Hardware B. System Software C. Operating System D. None of above Which of the following file names cannot be displayed if ls * is run? A. Xy B.?X C..X D. Hidden In UNIX, internal command means A. The process which will execute. B. It is not creating any separate process. C. Store in separate directory than external command. D. Must have option. Which is not shell file from following? A. Zee Shell B. Fish Shell C. bash Shell D. pdksh Shell Which is not true from following for kernel? A. Kernel handles I/O operations. B. Kernel is command interpreter. C. Only one kernel is available in single UNIX operating system. D. All of above. BSD UNIX originate from A. A T & T Bell B. Microsoft C. University of California D. None of above. Which is not true statement from following? Page 2

3 A. Shell is knows as command interpreter. B. Kernel is heart of UNIX. C. UNIX has portability. D. All commands in UNIX are called application program. What information stored in 6th column of /etc/passwd file? A. Name of users B. Default shell of users C. Default directory/home directory of users D. id of Users Which of the following information is not contained in Inode structure? A. The file size. B. The name of the owner of the file. C. The date of modification of file. D. The number of symbolic links for this file. Which directory under the root contains the information on devices A. /bin B. /dev C. /adm D. /etc Which command used to create a new directory file? A. tee B. cat < C. copy cone D. mkdir If cd command is fail, which of the following reason? A. Directory doesn t having read permission. B. Directory doesn t having write permission. C. Directory doesn t having execute permission. D. User doesn t have execute permission for cd command. The x option with ls is used for A. Listing all files with their Inode number. B. Listing all files in five columns. C. Give error. D. Display only executable files. Which of the following is used to count the number of files in current directories? A. ls l wc l B. ls l wc c C. ls wc w D. ls wc c Which of the following match exact three characters file name? A. *** B. ABC C.??? D. [???] Which of the following exact match with file name contain p character? A. p** B. *p C. p?p D. *p* What will output of ls * command? A. Display * as regular character. B. Display all files/directory lists from current directory. Page 3

4 C. Display all file which name having *character. D. Give error if any files are not found in current directory. Which of the following command used to list all files including hidden files? A. ls h B. ls H C. ls a D. ls A Which of the following command used to rename file? A. ren B. mv C. rename D. file What is significant of first character in the output of ls l command? A. File Permission B. File Mode C. File Type D. File Size Which command is used to display file type? A. file B. ls C. tee D. cat If 7 terminals are currently logged on, then the command $date ; who wc l, display A. date followed by 7 B. date followed by 8 C. date followed by 1 D. an error message. True FALSE: Kernel is hardware in system. Kernel stored in file name sh. UNIX is not a portable operating system. One responsibility of UNIX shell is I/O operation controlled. In UNIX interrupt handled by kernel. Kernel is responsible to display prompt of UNIX. % symbol used for korn shell. In UNIX all file system has bootstrapping program in boot block. / symbol denoted for root file in UNIX. 10. The Super block contains the size of file in UNIX. 1 The Inode number is unique for every file in a single file system. 1 For a directory, each data block contains 16 bytes entries. 1 The b character denoted binary type file in UNIX. 1 The root directory does not have parent directory. 1 There is no size of device file. 1 In UNIX all devices are implemented as files. 1 The echo 5+4 command will display value 1 (Single quota) is used to override meaning of meta-character. 1 Only file owner can rename file. 20. To run cat command successfully file must have read permission. Page 4

5 Fill in the blanks: The option of ls command is displayed all files name with its inode number. Third column of ls l command s output is. The command is used to change directory. The command is used for terminate session of UNIX. The symbol for the parent directory is. In UNIX, character denoted as symbolic link file. The lists of all the registered users information of the system stored in file. The command is used to view file permission. Bourn shell doesn t have and facilities. 10. C shell developed at. 1 Shell doesn t need to create process for command. 1 In UNIX multitasking done by & process. Page 5