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

int main() {

	int fd[2];

	if(pipe(fd) == -1) {
		perror("Pipe failed");
		return 1;
	}

	int id;
	char password[256];

	if (fork() == 0) {

		dup2(fd[0],STDIN_FILENO);
		dup2(fd[0],STDIN_FILENO);
		dup2(fd[1],STDOUT_FILENO);

		execlp("./validate", "./validate", (char*)NULL);
		perror("Exec error!");
		exit(0);

	} else {

		printf("Introduza o ID do User: ");
		scanf("%d", &id);

		getchar();

		printf("Introduza a Password: ");
		fgets(password, 255, stdin);

		close(fd[0]);
		write(fd[1], &id, sizeof(int));
		write(fd[1], password, sizeof(password));

		int status;
		wait(&status);

		status = WEXITSTATUS(status);

		if (status == 3) {
			printf("No such user\n");
		} else if (status == 2) {
			printf("Invalid password\n");
		} else if (status == 1) {
			printf("Password verified\n");
		}

	}

	return 0;

}