Sixth Semester B.E. Degree Examination, June/July 2013 UNIX System Programming

Sixth Semester B.E. Degree Examination, June/July 2013 UNIX System Programming Time: 3 hrs. Max. Marks:lOO Note: 1. Answer FIVEfull questions, selecting atleast TWO questions from each part. 2. Write comments for all the programs

 PART-A

1)a. What is POSIX standard? Explain the different subsets of POSIX standards.(05 Marks)

b. Write a CIC++PPSIX complaint program to check the following limits:i) Number of clock ticks ii) Maximum number of child processes iii) Maximum path length iv) Maximum characters in a filename v) Maximum number of open files per process.(10 Marks)

c. Explain the common characteristics of API and describe the error status code.  (05 Marks) 

2) a. Explain the different file types available in UNIX or POSIX systems.(10 Marks)

D. Describe tile UNIX kernel(06 Marks)    

c. Differentiate between hard links and symbolic links.  (04 Marks) 

3) a. Explain the importance of file and record locking in UNIX. Show how "fcntl" API can be used for file and record locking. (10 Marks)

b. Write a CIC++ program to emulate In command in UNIX. (05 Marks)

c. Write a CIC++ program to emulate mv command in UNIX. (05 Marks)

4) a. Explain with a neat block diagram, the memory layout of a C program. (05 Marks)

b. For the following given C program, identify the various segments when the program is executed:

# include 

int a = 5;

int b;

int data [10];

const int i = 5;

int maine () {

int X;

char * ptr = malloc(50);

return 0;

} (05 Marks)

c. Explain the setjmp( ) and longjmp( ) functions with an example CIC++ program illustrating their usage. (10 Marks)

PART-B

5) a. What do you mean by fork( ) and vfork( ) functions? Explain both functions with example programs (write-separate programs). (10 Marks)

b. What is job control? Summarize the job control features with the help of neat diagram. (10 Marks)

6) a. Explain the sigaction( ) function by giving the prototype and discuss its features.(08 Marks)

b. Briefly explain the kill( ) API and the alarm( ) API.(06 Marks)

c. What is a daemon process? Discuss its characteristics.   (06 Marks)

7) a. What is FIFO? Explain how it is used in IPC. Discuss with an example C/C++ program the client -server communication using FIFO's. (10 Marks)

b. Write short notes on the following: i) Message queues ii) Semaphores. (10 Marks)

8) a. Explain the concept of shared memory with an example C/C++ program.(10 Marks)

b. What do you mean by passingfile descriptors between processes? Explain. (10 Marks) 

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