mtimeout.c: Fix (impossible) `printf' format-string bug.

[misc] / pause.c

/* -*-c-*-
 *
 * $Id$
 *
 * Pause for a while
 *
 * (c) 1999 Mark Wooding
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of Pause.
 *
 * Pause is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later ersion.
 *
 * Pause is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Pause; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include <errno.h>
#include <math.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <termios.h>

#include <mLib/mdwopt.h>
#include <mLib/quis.h>
#include <mLib/report.h>
#include <mLib/tv.h>

/*----- Static variables --------------------------------------------------*/

static struct termios ts_old, ts;

/*----- Main code ---------------------------------------------------------*/

/* --- @sig@ --- *
 *
 * Arguments:	@int s@ = signal number
 *
 * Returns:	Doesn't.
 *
 * Use:		Handles various fatal signals by resetting the terminal state
 *		and re-emitting the signal.
 */

static void sig(int s)
{
  tcsetattr(STDIN_FILENO, TCSAFLUSH, &ts_old);
  signal(s, SIG_DFL);
  raise(s);
}

/* --- @suspend@ --- *
 *
 * Arguments:	@int s@ = signal number
 *
 * Returns:	---
 *
 * Use:		Handles a job control signal, as recommended in APUE.  It
 *		resets the terminal state, resets the signal disposition,
 *		unblocks the signal and re-emits it (so that the shell
 *		shows the right message).  When that call returns, the
 *		signal handler is reattached, and the terminal state is set
 *		again.
 */

static void suspend(int s)
{
  sigset_t ss;

  tcsetattr(STDIN_FILENO, TCSAFLUSH, &ts_old);
  signal(s, SIG_DFL);
  sigemptyset(&ss);
  sigaddset(&ss, s);
  sigprocmask(SIG_UNBLOCK, &ss, 0);
  raise(s);
  signal(s, suspend);
  tcsetattr(STDIN_FILENO, TCSAFLUSH, &ts);
}

/* --- Traditional GNUey help options --- */

static void usage(FILE *fp)
{
  pquis(fp, "Usage: $ [time]\n");
}

static void version(FILE *fp)
{
  pquis(fp, "$ version " VERSION "\n");
}

static void help(FILE *fp)
{
  version(fp);
  fputc('\n', fp);
  usage(fp);
  pquis(fp, "\n\
Pauses until a key is pressed or an optional time-limit expires.  The\n\
time is given as a floating point number with an option suffix of `s',\n\
`m', `h' or `d' (for `seconds', `minutes', `hours' or `days'\n\
respectively).\n\
\n\
Options available:\n\
\n\
-h, --help	Show this help message.\n\
-v, --version	Show program's version number.\n\
-u, --usage	Show terse usage summary.\n\
");
}

/* --- @main@ --- *
 *
 * Arguments:	@int argc@ = number of command line arguments
 *		@char *argv[]@ = vector of command line arguments
 *
 * Returns:	Nonzero if it failed, zero if everything went well.
 *
 * Use:		Souped-up version of `sleep'.
 */

int main(int argc, char *argv[])
{
  struct termios ts;
  unsigned f = 0;
  struct timeval when;

  enum {
    f_bogus = 1u,
    f_timer = 2u,
    f_key = 4u
  };

  /* --- Library initialization --- */

  ego(argv[0]);

  /* --- Parse command line options --- */

  for (;;) {
    static struct option opt[] = {
      { "help",		0,		0,	'h' },
      { "version",	0,		0,	'v' },
      { "usage",	0,		0,	'u' },
      { 0,		0,		0,	0 }
    };
    int i = mdwopt(argc, argv, "hvu", opt, 0, 0, 0);
    if (i < 0)
      break;
    switch (i) {
      case 'h':
	help(stderr);
	exit(0);
      case 'v':
	version(stderr);
	exit(0);
      case 'u':
	usage(stderr);
	exit(0);
      default:
	f |= f_bogus;
	break;
    }
  }

  /* --- Parse a timer spec --- */

  if (!(f & f_bogus) && optind < argc) {
    const char *p =argv[optind++];
    char *q;
    double t = strtod(p, &q);
    switch (*q) {
      case 'd': t *= 24;
      case 'h': t *= 60;
      case 'm': t *= 60;
      case 's':	if (q[1] != 0)
      default:	  t = 0;
      case 0:	break;
    }
    if (t <= 0)
      die(1, "bad time specification `%s'", p);
    gettimeofday(&when, 0);
    TV_ADDL(&when, &when, t, (t - floor(t)) * MILLION);
    f |= f_timer;
  }

  /* --- Report a syntax error --- */

  if (optind < argc)
    f |= f_bogus;
  if (f & f_bogus) {
    usage(stderr);
    exit(1);
  }

  /* --- Set up terminal for single keypresses --- */

  if (tcgetattr(STDIN_FILENO, &ts_old) == 0) {
    static struct { int sig; void (*func)(int); } sigs[] = {
      { SIGINT, sig },
      { SIGQUIT, sig },
      { SIGTERM, sig },
      { SIGTSTP, suspend },
      { 0, 0 }
    };
    int i;

    /* --- Set up the new terminal attributes --- */

    ts = ts_old;
    ts.c_lflag &= ~(ECHO | ICANON | TOSTOP);

    /* --- Set up signal handlers to reset attributes --- */

    for (i = 0; sigs[i].sig; i++) {
      struct sigaction sa;
      sigaction(sigs[i].sig, 0, &sa);
      if (sa.sa_handler != SIG_IGN)
	signal(sigs[i].sig, sigs[i].func);
    }
    signal(SIGTTIN, suspend);

    /* --- Commit the terminal attribute changes --- */

    tcsetattr(STDIN_FILENO, TCSAFLUSH, &ts);
    f |= f_key;
  }

  /* --- Main loop --- */

  for (;;) {
    fd_set fd, *pfd;
    int maxfd;
    struct timeval tv, *ptv;

    /* --- Wait for a keypress --- */

    if (f & f_key) {
      FD_ZERO(&fd);
      FD_SET(STDIN_FILENO, &fd);
      maxfd = STDIN_FILENO + 1;
      pfd = &fd;
    } else {
      maxfd = 0;
      pfd = 0;
    }

    /* --- Wait for the timer to expire --- */

    if (f & f_timer) {
      gettimeofday(&tv, 0);
      TV_SUB(&tv, &when, &tv);
      ptv = &tv;
    } else
      ptv = 0;

    /* --- See what interesting things have happened --- */

    if (select(maxfd, pfd, 0, 0, ptv) < 0) {
      if (errno == EINTR || errno == EAGAIN)
	continue;
      die(1, "error in select: %s", strerror(errno));
    }

    /* --- Check the timer --- */

    if (f & f_timer) {
      gettimeofday(&tv, 0);
      if (TV_CMP(&tv, >=, &when))
	break;
    }

    /* --- Check the key state --- */

    if (f & f_key && FD_ISSET(STDIN_FILENO, &fd))
      break;
  }

  /* --- See what gives --- */

  if (f & f_key)
    tcsetattr(STDIN_FILENO, TCSAFLUSH, &ts_old);
  return (0);
}

/*----- That's all, folks -------------------------------------------------*/