Sample Questions Best site for GRE, LSAT, SAT, GMAT, TOEFL, CCNA, CCSA and interview sample questions  

Technical Sample Questions : C |  C++ |  Oracle |  Java | Unix |  Operating Systems |  Data Structure

Sample Technical Questions

Unix Sample Questions

Questions on Process model and IPC in uinx

  1. Brief about the initial process sequence while the system boots up.

    Answer:

    While booting, special process called the 'swapper' or 'scheduler' is created with Process-ID 0. The swapper manages memory allocation for processes and influences CPU allocation.

    The swapper inturn creates 3 children:


    the process dispatcher,
    vhand and
    dbflush
    with IDs 1,2 and 3 respectively.

    This is done by executing the file /etc/init. Process dispatcher gives birth to the shell. Unix keeps track of all the processes in an internal data structure called the Process Table (listing command is ps -el).

  2. What are various IDs associated with a process?

    Answer:

    Unix identifies each process with a unique integer called ProcessID. The process that executes the request for creation of a process is called the 'parent process' whose PID is 'Parent Process ID'. Every process is associated with a particular user called the 'owner' who has privileges over the process. The identification for the user is 'UserID'. Owner is the user who executes the process. Process also has 'Effective User ID' which determines the access privileges for accessing resources like files.
    getpid() -process id
    getppid() -parent process id
    getuid() -user id
    geteuid() -effective user id
  3. Explain fork() system call.

    Answer:

    The 'fork()' used to create a new process from an existing process. The new process is called the child process, and the existing process is called the parent. We can tell which is which by checking the return value from 'fork()'. The parent gets the child's pid returned to him, but the child gets 0 returned to him.
  4. Predict the output of the following program code
    main()
    {
     	fork();
    printf("Hello World!");
    }

    Answer:

    Hello World!Hello World!

    Explanation:

    The fork creates a child that is a duplicate of the parent process. The child begins from the fork().All the statements after the call to fork() will be executed twice.(once by the parent process and other by child). The statement before fork() is executed only by the parent process.
  5. Predict the output of the following program code
    main()
    {
    fork(); fork(); fork();
    printf("Hello World!");
    }

    Answer:

    "Hello World" will be printed 8 times.

    Explanation:

    2^n times where n is the number of calls to fork()

« Previous || Next »

Unix Sample Question Number : 1-5 | 6-11 | 12-16 | 17-23 | 24-29 | 30-36 | 37-41 | 42-48 | 49-55 | 56-61 | 62-67 | 68-73
Sample Test Questions
GRE Sample Questions
CAT Sample Questions
GMAT Sample Questions
TOEFL Sample Questions
ACT Sample Questions
SAT Sample Questions
LSAT Sample Questions
PSAT Sample Questions
MCAT Sample Questions
PMP Sample Questions
GED Sample Questions
ECDL Sample Questions
DMV Sample Questions
CCNA Sample Questions
MCSE Sample Questions
Network+ Sample Questions
A+ Sample Questions
Technical Sample Questions
WASL Sample Questions
CISA Sample Questions

Other Sample Questions
Sample Interview Questions
Sample Teacher Interview Questions
Sample Citizenship Questions
Accuplacer Sample Questions
Science Bowl sample Questions
Driving Test Sample Questions
Sample Survey Questions Sample Essay Questions
Sample Behavioral Interview Questions

Copyright © 2004-2013, Best BSQ. All Rights Reserved.