Improve company productivity with a Business Account.Sign Up

x
?
Solved

modify the program code using 'for' loop to create the 4 processes

Posted on 2004-08-15
6
Medium Priority
?
210 Views
Last Modified: 2010-04-15
the code should be changed so that the 4 child processes are created using the 'for ' loop:
PLS HELP! thanx!

[create wait process]
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

void ShowStatus( int stat )
{
  if (WIFEXITED(stat))
    fprintf(stderr, "Normal termination: Exit status %d\n", WEXITSTATUS(stat) );
  else if (WIFSIGNALED(stat))
    fprintf( stderr, "Abnoral termination: Signal number %d\n", WTERMSIG(stat) );
  else
    fprintf(stderr,  "Unknown problem detected\n" );
}

int main(int argc, int **argv)
{
  pid_t retFork;
  int status;
  int up = 200;
  int down = 0;
  int * pointer = null;

   retFork= fork();  /*Create first child process*/
   switch (retFork){
   case -1:
     perror( "fork error" );
     exit (1);
   case 0:         /* Child process */
     exit( 1 );    /* Terminate normally */
   default:        /* Parent process */
    if (wait( &status ) != retFork){  /* wait for child */
      perror( "wait error" );
    }
    ShowStatus ( status );
  }
   retFork = fork();  /*Create second child process*/
   switch (retFork){
   case -1:
     perror( "fork error" );
     exit (1);
   case 0:         /* Child process */
     abort(  );    /* Generate SIGABRT */
     exit( 2 );     /*Terminate abnormally*/
   default:        /* Parent process */
    if (wait( &status ) != retFork ){  /* wait for child */
      perror( "wait error" );
    }
    ShowStatus ( status );
  }
   retFork = fork();  /*Create third child process*/
   switch (retFork){
   case -1:
     perror( "fork error" );
     exit (1);
   case 0:         /* Child process */
     up = up / down;    /* Generate SIGFPE (i.e., division by zero)*/
     exit(2);     /*Terminate abnormally*/
   default:        /* Parent process */
    if (wait( &status ) != retFork ){  /* wait for child */
      perror( "wait error" );
    }
    ShowStatus (status);
  }
     retFork = fork();  /*Create four child process*/
   switch (retFork){
   case -1:
     perror( "fork error" );
     exit (1);
   case 0:         /* Child process */
     *pointer = 100;    /* Generate SIGFPE (i.e., division by zero)*/
     exit(2);     /*Terminate abnormally*/
   default:        /* Parent process */
    if (wait( &status ) != retFork ){  /* wait for child */
      perror( "wait error" );
    }
    ShowStatus (status);
  }
return 0;
}



0
Comment
Question by:kuganesh
  • 3
  • 2
6 Comments
 
LVL 3

Expert Comment

by:pulupul
ID: 11803653
What for loop? I don't see any. If you mean where to put the for, explain what you want to do first.
0
 

Author Comment

by:kuganesh
ID: 11803720
yes. just change all the child processes into a for structure... not case switch..
its quite basic.. just have to change the structure of the code so that it executes in a for loop..
0
 
LVL 3

Expert Comment

by:pulupul
ID: 11803753
You want all the child processes to execute at the same time, and then wait for them? or you want to never stop creating processes and waiting for them?. What should be the condition of the for loop?
0
What Kind of Coding Program is Right for You?

There are many ways to learn to code these days. From coding bootcamps like Flatiron School to online courses to totally free beginner resources. The best way to learn to code depends on many factors, but the most important one is you. See what course is best for you.

 

Author Comment

by:kuganesh
ID: 11803882
the condition for the loop should be :
for(i=0; i<4; i++)
from what i understand i should put this infront of retfork
but i dont know how... can you please code it so that the whole thing is able to use 'for' execution ... thank you
0
 
LVL 3

Expert Comment

by:pulupul
ID: 11803923
Ok, I wans't getting the point, here it goes the code:

int main(int argc, int **argv)
{
      pid_t retFork;
      int status;
      int up = 200;
      int down = 0;
      int * pointer = null;


      for (int i=0; i < 4; i++)
      {
            retFork= fork();  /*Create first child process*/
            switch (retFork)
            {
            case -1:
                  perror( "fork error" );
                  exit (1);
            case 0:         /* Child process */
                  switch(i) {
                  case 0:
                        exit( 1 );    /* Terminate normally */
                        break;
                  case 1:
                        abort(  );    /* Generate SIGABRT */
                        exit( 2 );     /*Terminate abnormally*/
                        break;
                  case 2:
                        up = up / down;    /* Generate SIGFPE (i.e., division by zero)*/
                        exit( 2 );     /*Terminate abnormally*/
                        break;
                  case 3:
                        *pointer = 100;    /* Generate SIGFPE (i.e., division by zero)*/
                        exit( 2 );     /*Terminate abnormally*/
                        break;
                  }
            default:        /* Parent process */
                  if (wait( &status ) != retFork){  /* wait for child */
                  perror( "wait error" );
            }
            ShowStatus ( status );
      }

      return 0;
}
0
 

Accepted Solution

by:
lebuihung earned 1200 total points
ID: 11867725
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

void ShowStatus( int stat )
{
  if (WIFEXITED(stat))
    fprintf(stderr, "Normal termination: Exit status %d\n", WEXITSTATUS(stat) );
  else if (WIFSIGNALED(stat))
    fprintf( stderr, "Abnoral termination: Signal number %d\n", WTERMSIG(stat) );
  else
    fprintf(stderr,  "Unknown problem detected\n" );
}

int main(int argc, int **argv)
{
  pid_t retFork;
  int status;
  int up = 200;
  int down = 0;
  int * pointer = NULL;
  int i;
 
 
  for(i=0;i<4;i++)
  {
        retFork=fork();
      
      if(retFork==0) /* if its a child process */
      {
            if(i==0) /* first child process */
            {
                  exit(1);
            }
            else if(i==1)
            {
                     abort(  );    /* Generate SIGABRT */
                   exit( 2 );     /*Terminate abnormally*/
            }
            else if(i==2)
            {
                    up = up / down;    /* Generate SIGFPE (i.e., division by zero)*/
                    exit(2);     /*Terminate abnormally*/
            }
            else if(i==3)
            {
                    *pointer = 100  ;  /* Generate SIGFPE (i.e., division by zero)*/
                    exit(2);     /*Terminate abnormally*/
            }
      }
      else if(retFork<0)
      {      
            perror( "fork error" );
            exit (1);
      }
          else
      {
            if (wait( &status ) != retFork)
            {  /* wait for child */
                        perror( "wait error" );
                }
      
            ShowStatus ( status );
      }
   }
   return 0;
 }
0

Featured Post

What Kind of Coding Program is Right for You?

There are many ways to learn to code these days. From coding bootcamps like Flatiron School to online courses to totally free beginner resources. The best way to learn to code depends on many factors, but the most important one is you. See what course is best for you.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Preface I don't like visual development tools that are supposed to write a program for me. Even if it is Xcode and I can use Interface Builder. Yes, it is a perfect tool and has helped me a lot, mainly, in the beginning, when my programs were small…
There's never been a better time to become a computer scientist. Employment growth in the field is expected to reach 22% overall by 2020, and if you want to get in on the action, it’s a good idea to think about at least minoring in computer science …
The goal of this video is to provide viewers with basic examples to understand recursion in the C programming language.
The goal of this video is to provide viewers with basic examples to understand and use conditional statements in the C programming language.

580 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question