Question

follow the steps below to create a C program

a) In the main function, fork a child process.

b) In the child process, using an infinite loop to print out something. For example, you can print out the value of an int variable and each iteration increase the value of this int variable. You may also optionally sleep for a second or two in the loop to slow down the loop.

c) In the parent process, sleep for a few second first, then send the SIGSTOP signal to the child process.

d) In the parent process, again sleep for a few second, then send the SIGCONT signal to the child process.

e) Lastly, in the parent process, you can send the SIGINT signal to the child process to terminate it.

When running your program, observe what happens at step c) and d). Is the child process stopped and continued upon the receipt of the signals

Answer 1

CODE :

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#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
void signalExample()
{
   int pid;
// child process
pid = fork();
if (pid == 0) {
   int i = 1;
      int j = 0;
       while(j <= 5)
       {  
           sleep(1);
          printf("%d\n", i*2);
          i *= 2;
       }
   }
  
// parent process
else{
   sleep(5);
printf("Sending SIGSTOP signal\n");
kill(pid, SIGSTOP);
sleep(5);
printf("Sending SIGCONT signal\n");
kill(pid, SIGCONT);
sleep(5);
printf("Sending SIGINT signal sent\n");
kill(pid, SIGINT);
}
}
int main()
{
signalExample();
return 0;
}
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Screenshot :