kill child process if exec fails

Question

I am creating a program that creates many children from one parent. I do not want any more children to be created, if there was an error executing exec . The following code still continues to create children even after an exec failure.

void synch_signal (int sig)
{
  fprintf(stderr,"%s","ERROR");
  exit(0);
}


void create_children(int numberOfChildren, char **argc){
    struct sigaction usr_action;

    usr_action.sa_handler = synch_signal;
    sigaction (SIGUSR1, &usr_action, NULL);

    int pid = 0;
    char mystring[100] = { 0 };

    for (i; i <numberOfChildren; i++){


        //removed for simplicity. 

        pid = fork();

        if (pid){       
            //removed       
        }
        else {
             //removed 
             exec(...);
             //exec failed
             kill (getppid (), SIGUSR1);
        }


    }


}

thanks daniel

Answer 1

您需要在kill()之后添加return语句，否则子进程将在kill()函数完成后再次循环，并成为父进程。