#include	<signal.h>
#include	<stdio.h>
#include	<unistd.h>

#define MAXLINE 10240
static void sig_pipe(int );

int main(int argc, char *argv[])
{
	int	n, counter,fd1[2], fd2[2];
	pid_t	pid;
	char	line[MAXLINE];
	FILE	*fp;
	char temp[MAXLINE];
	char tmpfile[MAXLINE];
	char tmpfile2[MAXLINE];
	
	if (argc != 3)
	{
		printf("Too few arguments:%d\n",argc);
		printf("usage SUSAN file1 file 2\n");
		exit(1);
	}

	for (counter=1; counter <3; counter++)
		{
		sprintf(tmpfile, "%s.out", argv[counter]);
		sprintf(tmpfile2, "%s.final", argv[counter]);
	
	
		sprintf(temp, "./hw3.sh < %s > %s", argv[counter], tmpfile);
	
	printf("file 1 = %s, file 2 = %s,command = %s\n", tmpfile, tmpfile2, temp);
		
		if (signal(SIGPIPE, sig_pipe) == SIG_ERR)
			printf("signal error\n");
		
		if (pipe(fd1) < 0 || pipe(fd2) < 0)
			printf("pipe error\n");
	
		if ((pid = fork()) < 0)
			printf("fork error\n");
	
		else if (pid > 0)
			{
			close (fd1[0]); 
			close (fd2[1]);
			
			/*system("./hw3.sh < 2.txt > out.txt");*/
			system(temp);
	/*execl("./","test.sh", "<","2.txt",">","out2.txt",(char *) 0);*/
			
			/*printf("file being read is %s\n",argv[counter+1]);*/
			/*fp = fopen("out.txt", "r");*/
			fp = fopen(tmpfile,"r");
			while (fgets(line, MAXLINE, fp) != NULL)
				{
				n = strlen(line);
/*printf("line from file = %s", line); */
				if (write(fd1[1], line, n) != n)
					printf("write error to pipe\n");
	/*
			if ((n = read(fd2[0], line, MAXLINE)) < 0)
					printf("read error from pipe\n");
				if (n == 0)
					{
					printf("child closed pipe\n");
					break;
					}
				line[n] = 0;
				if (fputs(line, stdout) == EOF)
					printf("fputs error\n");
	*/			}
			if (ferror(stdin))
				printf("fgets error on stdin\n");
	
		/*	exit(0); */
	
			}
		else
			{
			close(fd1[1]);
			close(fd2[0]);
			if (fd1[0] != STDIN_FILENO)
				{
				if (dup2(fd1[0], STDIN_FILENO) != STDIN_FILENO)
					printf("dup2 error to stdin\n");
				close(fd1[0]);
				}
			if (fd2[1] != STDOUT_FILENO)
				{
				if (dup2(fd2[1], STDOUT_FILENO) != STDOUT_FILENO)
					printf("dup2 error to stdout\n");
				close(fd2[1]);
				}
	/*
			if (execl("/usr/bin/cat", "cat", (char *)0) < 0)
			if (execl("./hw4","hw4",tmpfile2, (char *) 0) < 0)
	*/
			if (execl("./hw4", "hw4", (char *)0) < 0)
				printf("execl error\n");
			}
		}
	}

static void sig_pipe(int signo)
	{
	printf("SIGPIPE caught\n");
	exit(1);
	}