#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

extern char **environ;

void do_child(void)
{
        char *argv[3];

        printf("This is child (pid=%d).\n", getpid());

        argv[0] = "/bin/ls";
        argv[1] = "/";
        argv[2] = NULL;

        execve(argv[0], argv, environ);
}

int main(void)
{
        int child, status;

        if ((child = fork()) < 0) {
                perror("fork");
                exit(1);
        }

        if (child == 0) {
                do_child();
        } else {
                if (wait(&status) < 0) {
                        perror("wait");
                        exit(1);
                }
                printf("The child (pid=%d) exited with status(%d).\n",
                       child, WEXITSTATUS(status));
        }

        return 100;
}