UNIX for Dummies Questions & Answers

fork() system is used to create a child a process.lets consider fork() echo krace will print krace twice .if i give it in loop it will print krace 2 power n time..in this case all child and parent process executes same process ...but i want to create a four different child process to execute four different tasks?
reply as soon as possible...

I'm not sure I understand your problem. So, you want a program that spawns multiple childs so that each child can execute a certain code, right?

Here's a sample:

Code:

int
main ()
{
    long int pids[4];
    int i;

    for (i=0; i < 4; i++)
    {  
        pids[i] = fork();
        if (pids[i] == 0)
        {  
            printf ("I'm a child, and my parent is %ld\n", getppid());
            exit (0);
        }
        else
        {  
            printf ("parent spawned child %ld\n", pids[i]);
        }
    }

}

Write a C program to create a hierarchy of processes as shown in figure.


Parent


Child1 Child 2 Child3 Child4

First child process should display the information regarding users (users login, how many users etc). Second child should display system characteristics (the CPU characteristics, other system properties, memory, OS name, OS type, etc).Third child should fork for one more child process. Fourth child should display the name, age and qualification of the user doing the program. The parent process waits for all children’s to terminate and displays the process id of all processes.

That totally looks like homework.

Child1: use getpwent()
Child2: use uname() and read /proc
Child3: fork()
Child4: printf()

@above
i dint get it exactly ...first i want to create four child processes,tell me how to do it sir??and can u tell how to write the source code exactly..