Creating num processes with fork and then deleting some that i will not use

Question

Okay so i am making a program and i am creating a number of child processes with fork, letting user decide their number, as such

for(int i=1;i<=number;i++){
        pid_t pid;
        if((pid=fork())<0){
            perror("fork failed");
        }else if(pid==0){ //is a child
            exit(0);
        }
    }
for(int i=1;i<=number;i++)
        wait(NULL);

If the user wants me to create 5 and i create them, but later in my program I only want to use the first 4 lets say, how do i "delete" the last process?

Answer 1

You can use kill:

#include <sys/types.h>
#include <signal.h>
kill(child_pid, SIGKILL);

---

Edit

If you want the child process to do some cleanup before exiting, use SIGTERM instead, and in the child process implement a signal handler. Parent:

kill(child_pid, SIGTERM);

Child:

void on_sig_term(int sig_num)
{
    \\ cleanup
    return;
}
signal(SIGTERM, on_sig_term);