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

static void die(const char *s) { perror(s); exit(1); }

int main()
{
    char	buf[100];
    pid_t	pid;
    int		status;

    printf("AP> ");
    while (fgets(buf, sizeof(buf), stdin) != NULL) {

        if (buf[strlen(buf) - 1] == '\n') {
            buf[strlen(buf) - 1] = 0; // replace newline with '\0'
        }

        pid = fork();

        if (pid < 0) {
            die("fork error");

        } else if (pid == 0) { // child process

            char *argv[] = { buf, NULL };
            execv(argv[0], argv);

            // or alternatively:
            // execl(buf, buf, (char *)0);

            die("execl failed");

        } else { // parent process

            if (waitpid(pid, &status, 0) != pid) {
                die("waitpid failed");
            }
        }
        printf("AP> ");
    }
}