Linux Programming VIVA QUESTIONS

Linux Programming VIVA QUESTIONS

1. Define UNIX?

* To develop an o/s that could serve a large community of users & allow them to share data whenever they require.

2. Define Linux?

* It is a freely distributed implementation of Unix like kernel, the low level core of an o/s.

3. What is an Operating System?

* It is a s/w program design to act as an interface b/w user & the computer.

4. List types of o/s?

* Single user o/s, Multi user o/s, Network o/s.

5. Define features of Linux?

* Multi user capability, Multi task capability,

Communication, Security, Portable.

6. What is Kernel & Shell?

* Kernel is an o/s that provides services like file s/m , memory mgt, CPU scheduling, I/O mgt.

* Shell is an mediator or command interpreter.

7. List types of Shells?

* Bourne shell, C shell, Korn shell.

8. Define Vi editor?

* Vi is text editor.

9. List modes of vi editor?

* Command mode, Insert mode, Exit mode.

10. What is Process?

* A program in execution.

11. List types of Process Status?

* Fore ground process, Back ground process.

12. Define awk?

* It is a powerful native text & manipulation utility.

13. What is sed?

* It is a stream editor & multipurpose tool which combines the work of several filters.

14. What is Script?

* It is a textual form.

15. Define Shell Script?

*A group of commands which stored in one file called Shell script.

16. Define pipe?

* It is a buffer & stores o/p of one action as an i/p to another action.

17. List i/p & o/p redirections?

* Standard i/p, Standard o/p, Standard error.

18. Define Stream& Here document?

* It is simply a sequence of bytes.

* It is a way of passing i/p to a cmd from a shell script.

19. What are Shell MetaCharacters?

* File name Substitution, I/O Redirection,

Process Execution, Quoting Meta characters,

Positional parameters, Special characters.

20. Define Shell Variable?

*It provides ability to store & manipulate information with in the shell program.

21. List types of Variables?

* System defined variable & User defined variable.

22. List types of test command?

* Numerical test, String test, File test.

23. List types of Control structures?

* Selection/Decision, Repetition/Loop, Case-esac.

24. What is Arithmetic shell script?

* It is used for performing arithmetic operations.

25. What is Interactive shell script?

* It is used for reading operations.

26. Define Interrupt process?

* It states that shell script will terminate when ever the interrupt key is pressed.

27. What is purpose of using ‘trap’ cmd?

* It is used to stop Program execution.

28. Define Function?

*It is used to execute a group of statements as bunch.

29. Define File?

* File is a collection of information storing in a container. (Or) It is a collection of records.

30. What are the categories of files?

* Ordinary/regular, Directory, Device files.

31. List Block Types?

*Boot block, Super block, Data block, Inode block.

32. List File Types?

* Regular, Directory, Character special,

Block special, FIFO, Socket, Symbolic link files.

33. List Standard I/O & Stream error functions?

* Std I/O: fopen,fclose,fflush,fseek,fgetc,getc,getchar,

fputc,putc,putchar,fgets,gets,fread,fwrite.

* Std Error: feof,ferror,clearerr.

34. What are Formatted I/O functions?

* I/p: scanf,fscanf,sscanf.

* O/p: printf,fprintf,sprintf & printf,vfprintf,vsprintf.

35. Define System call?

* It is an interface b/w process & kernel.

36. Define Library Function?

* It invokes appropriate kernel services.

37. What is the difference b/w s/m call & library function?

* S/m calls are part of kernel but Library functions are part of linux super structure.

38. Define File Descriptor?

* It is a non –ve integer,depending on permission kernel has to create file descriptor.

39. What are Low level file access permissions?

* creat,open,read,write,close,lseek,stat,fstat,lstat,

access,umask,ioctl,dup/dup1,dup2, fcntl.

40. List File & directory management functions?

*mkdir,rmdir,chdir,geetcwd,link,unlink,symlink,

chmod,chown.

41. What is difference b/w Hard link & Soft link?

* Hard link is direct pointer to a file, but Soft link

is indirect pointer to a file.

42. List Directory handling system calls?

* Opendir, readdir, closedir, rewinddir, seekdir, telldir.

43. What is File locking & Record locking?

* File locking locks on entire file where record locking allows a processor to lock a specified portion of a file.

44. List types of locking?

* Advisory locking & Mandatory locking.

45. What is process image?

* It contains user program, user data, stack, PCB.

46. Define PCB?

* Process control block is used to control process states.

47. Define process attributes?

* Process has a series of characteristics which are called as a process attributes.

48. List process states?

* Ready, Execution, Suspend, Stopped, Zombie.

49. Define Zombie process?

* The child process terminates while before the parent dies.

50. Define Orphan process?

* The parent process wants to terminate before the child process.

51. List process management functions?

* fork,vfork,exit,wait,waitpid,exec family ,system.

52. What is vfork?

* It is a virtual fork.

53. Define Signal?

* Signal is a software interrupt.

54. Define Reliable signal?

* Signal is generated by process when event occurs that causes the signal occurs.

55. Define Unreliable signal?

* Signals that cannot be identified.

56. What is IPC?

* Inter process communication describes different ways of msg passing b/w different processes that are running on some o/s.

57. List methods of IPC?

* Pipes, FIFO’s, Msgqueues, Semaphores, Shared m/y.

58. List types of pipes?

* Unidirectional & Bidirectional pipes.

59. What is unidirectional pipe?

* Single directional flow of data.

60. What is Bidirectional pipe?

* Bi directional flow of data.

61. Define FIFO?

*FIFO/Named pipe is a permanent fixture.

62. Define Message Queue?

* It describes storing of data in a orbitary order.

63. Define Semaphore?

* Semaphore is synchronization primitive.

64. Define Shared Memory? * It provides a way around this by letting two

or more processes shared a memory segment.

65. Define Socket?

* It is a local network of a people with outside world process.

66. List Linux API’s of messages?

*msgget, msgsnd, msgrcv, msgctl.

67. List Linux API’s of semaphores?

* Semget, semop, semctl

68. List Linux API’s of shared memory?

* Shmget, shmat, shmdt, shmctl.

69. Define Thread?

* Multiple strands of execution in a single program .

70. Define light weight process?

* It can be viewed as a mapping b/w user threads & kernel threads.

71. List POSIX threads API’s?

* Creating threads, Thread semaphores, Thread mutexes, Thread attributes, cancelling a thread.

72. Define Mutex?

* Which act as an mutual exclusion device to protect sections of code.

73. List Thread attributes?

* detached state,sched policy,sched param,

inherit sched,scope,stack size.

74. List Socket s/m call for connection oriented protocol?

* socket, bind,listen,accept,connect,read,write.

75. List Socket s/m call for connection less protocol?

* socket,bind,sendto,recvfrom.