/*#* noncanonical.c

   Usage: see below.
*/
#include <termios.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#define errExit(msg) 	do { perror(msg); exit(EXIT_FAILURE); \
			} while (0)


int
main(int argc, char *argv[])
{
    char buf[100000];
    struct termios tp;
    ssize_t numRead;
    int sleepTime;

    if (argc < 4) {
	fprintf(stderr, "Usage: %s TIME MIN num-bytes-to-read "
		"[sleep-secs [O_NONBLOCK flag]]\n", argv[0]);
	exit(EXIT_FAILURE);
    }

    if (tcgetattr(STDIN_FILENO, &tp) == -1)
	errExit("tcgetattr");

    tp.c_lflag &= ~ICANON;
    tp.c_cc[VTIME] = atoi(argv[1]);
    tp.c_cc[VMIN] = atoi(argv[2]);

    if (tcsetattr(STDIN_FILENO, TCSANOW, &tp) == -1)
        errExit("tcsetattr");

    if (argc > 5) {
	int flags;

	flags = fcntl(STDIN_FILENO, F_GETFL);
	if (flags == -1)
	    errExit("fcntl");
	flags |= O_NONBLOCK;
	if (fcntl(STDIN_FILENO, F_SETFL, flags) == -1)
	    errExit("fcntl");
    }

    sleepTime = (argc > 4) ? atoi(argv[4]) : 5;
    printf("About to sleep for %d seconds\n", sleepTime);
    sleep(sleepTime);
    printf("Done sleeping\n");

    printf("About to read %d bytes\n", atoi(argv[3]));
    numRead = read(STDIN_FILENO, buf, atoi(argv[3]));
    if (numRead == -1)
	errExit("read");
    printf("read returned %ld\n", (long) numRead);

    exit(EXIT_SUCCESS);
} /* main */