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

#define ERRFILE "error.log"
#define OUTFILE "output.log"

int main (int argc, char ** argv)
{
	int i, fd;
	pid_t pid;
	unlink (ERRFILE);
	unlink (OUTFILE);
	for (i = 1; i<argc; ++i) {
		fflush (NULL);
		pid = fork ();
		if (pid < 0) {
			perror ("fork");
			continue;
		}
		if (pid > 0) {  /* Parent */
			int status;
			while (pid != wait (&status));
			if (!WIFEXITED (status) || WEXITSTATUS (status)) {
				fprintf (stderr, "Error at file %s\n",
					 argv[i]);
			}
			continue;
		}
		/* Child */
		fd = open (ERRFILE, O_CREAT | O_WRONLY | O_APPEND, 0666);
		if (fd < 0)
			exit (1);
		if (dup2 (fd, 2) < 0)
			exit (1);
		if (fd != 2)
			close (fd);
		fd = open (OUTFILE, O_WRONLY | O_APPEND | O_CREAT, 0666);
		if (fd < 0)
			exit (1);
		if (dup2 (fd, 1) < 0)
			exit (1);
		if (fd != 1)
			close (fd);
		if (strncmp (argv[i], "patch.", 6) == 0) {
			fd = open (argv[i], O_RDONLY);
			if (fd < 0)
				exit (1);
			if (dup2 (fd, 0) < 0)
				exit (1);
			if (fd != 0)
				close (fd);
			execlp ("patch", "patch", NULL);
		} else {
			execlp ("gcc", "gcc", "-o", "output", argv[i], NULL);
		}
		/* exec failed */
		exit (1);
	}
	return 0;
}