/* Silly program used to verify a tty is in fact connected to a solidoodle.
 * Change B115200 to different baud rate define if your firmware is set
 * to operate at a different rate.
 *
 * typical usage: send-this /dev/ttyACM0 M115
 *
 * That will send an M115 gcode command which should respond by printing the
 * info about the firmware and wot-not. If it doesn't maybe the device you
 * just plugged in isn't really a solidoodle...
 */

#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include <sys/select.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>

int
main(int argc, char ** argv) {
   struct termios settings;
   int fd;
   fd_set rset;
   struct timeval tmo;
   int selstat;
   char buf[1024];
   int i;

   /* Make sure there is at least a device name and one word to send */

   if (argc < 2) {
      fprintf(stderr, "usage: send-this tty string...\n");
      exit(2);
   }

   /* Make sure we can open the device in nonblocking mode */

   fd = open(argv[1], O_RDWR|O_NONBLOCK);
   if (fd == -1) {
      i = errno;
      fprintf(stderr, "Unable to open %s : %s (%d)\n",
         argv[1], strerror(i), i);
      exit(2);
   }

   /* Set it to "raw" mode */

   memset((void *)&settings, 0, sizeof(settings));
   cfmakeraw(&settings);
   cfsetospeed(&settings, B115200);
   cfsetispeed(&settings, B115200);
   if (tcsetattr(fd, TCSANOW, &settings) == -1) {
      i = errno;
      fprintf(stderr, "Unable to set %s to raw mode : %s (%d)\n",
         argv[1], strerror(i), i);
      exit(2);
   }

   /* If there is any gibberish buffered up, discard it */

   for ( ; ; ) {
      FD_ZERO(&rset);
      FD_SET(fd, &rset);
      tmo.tv_sec = 0;
      tmo.tv_usec = 0;
      selstat = select(fd+1, &rset, NULL, NULL, &tmo);
      if (selstat <= 0) {
         break;
      }
      read(fd, buf, sizeof(buf));
   }

   /* Now send space separated words from argument list followed by newline */

   for (i = 2; i < argc; ++i) {
      write(fd, " ", 1);
      write(fd, argv[i], strlen(argv[i]));
   }
   write(fd, "\r", 1);

   /* Echo everything returned till we get no data for 1/10 of a second */

   for ( ; ; ) {
      FD_ZERO(&rset);
      FD_SET(fd, &rset);
      tmo.tv_sec = 0;
      tmo.tv_usec = 100000;
      selstat = select(fd+1, &rset, NULL, NULL, &tmo);
      if (selstat <= 0) {
         break;
      }
      i = read(fd, buf, sizeof(buf));
      write(fileno(stdout), buf, i);
   }
   return 0;
}