main.c

#include "apue.h"
#include <termios.h>
#include <sys/types.h>
#include <sys/wait.h>

#ifdef LINUX
#define OPTSTR "+d:einvr"
#else
#define OPTSTR "d:einvr"
#endif

static void set_noecho (int);	/* at the end of this file */
void do_driver (char *);	/* in the file driver.c */
void loop (int, int);		/* in the file loop.c */

int
main (int argc, char *argv[])
{
  int fdm, c, ignoreeof, interactive, noecho, verbose, returncode, status;
  pid_t pid;
  char *driver;
  char slave_name[20];
  struct termios orig_termios;
  struct winsize size;

  interactive = isatty (STDIN_FILENO);
  ignoreeof = 0;
  noecho = 0;
  verbose = 0;
  driver = NULL;
  returncode = 0;

  opterr = 0;			/* don't want getopt() writing to stderr */
  while ((c = getopt (argc, argv, OPTSTR)) != EOF)
    {
      switch (c)
	{
	case 'd':		/* driver for stdin/stdout */
	  driver = optarg;
	  break;

	case 'e':		/* noecho for slave pty's line discipline */
	  noecho = 1;
	  break;

	case 'i':		/* ignore EOF on standard input */
	  ignoreeof = 1;
	  break;

	case 'n':		/* not interactive */
	  interactive = 0;
	  break;

	case 'v':		/* verbose */
	  verbose = 1;
	  break;

	case 'r':
	  returncode = 1;
	  break;

	case '?':
	  err_quit ("unrecognized option: -%c", optopt);
	}
    }
  if (optind >= argc)
    err_quit ("usage: pty [ -d driver -einv ] program [ arg ... ]");

  if (interactive)
    {				/* fetch current termios and window size */
      if (tcgetattr (STDIN_FILENO, &orig_termios) < 0)
	err_sys ("tcgetattr error on stdin");
      if (ioctl (STDIN_FILENO, TIOCGWINSZ, (char *) &size) < 0)
	err_sys ("TIOCGWINSZ error");
      pid = pty_fork (&fdm, slave_name, sizeof (slave_name),
		      &orig_termios, &size);
    }
  else
    {
      pid = pty_fork (&fdm, slave_name, sizeof (slave_name), NULL, NULL);
    }

  if (pid < 0)
    {
      err_sys ("fork error");
    }
  else if (pid == 0)
    {				/* child */
      if (noecho)
	set_noecho (STDIN_FILENO);	/* stdin is slave pty */

      if (execvp (argv[optind], &argv[optind]) < 0)
	err_sys ("can't execute: %s", argv[optind]);
    }

  if (verbose)
    {
      fprintf (stderr, "slave name = %s\n", slave_name);
      if (driver != NULL)
	fprintf (stderr, "driver = %s\n", driver);
    }

  if (interactive && driver == NULL)
    {
      if (tty_raw (STDIN_FILENO) < 0)	/* user's tty to raw mode */
	err_sys ("tty_raw error");
      if (atexit (tty_atexit) < 0)	/* reset user's tty on exit */
	err_sys ("atexit error");
    }

  if (driver)
    do_driver (driver);		/* changes our stdin/stdout */

  loop (fdm, ignoreeof);	/* copies stdin -> ptym, ptym -> stdout */

  if (returncode)
    {
      if (waitpid (pid, &status, 0) < 0)
	err_sys ("waitpid error");
      if (WIFEXITED (status))
	exit (WEXITSTATUS (status));
      else
	exit (EXIT_FAILURE);
    }


  exit (0);
}

static void
set_noecho (int fd)		/* turn off echo (for slave pty) */
{
  struct termios stermios;

  if (tcgetattr (fd, &stermios) < 0)
    err_sys ("tcgetattr error");

  stermios.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);

  /*
   * Also turn off NL to CR/NL mapping on output.
   */
  stermios.c_oflag &= ~(ONLCR);

  if (tcsetattr (fd, TCSANOW, &stermios) < 0)
    err_sys ("tcsetattr error");
}