// $Id: vshelper-sync.c,v 1.5 2005/05/05 09:21:21 ensc Exp $    --*- c -*--

// Copyright (C) 2004 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
//  
// This program 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; version 2 of the License.
//  
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "util.h"

#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>
#include <assert.h>

static void
showHelp(int fd, char const *cmd, int res)
{
  WRITE_MSG(fd, "Usage:  ");
  WRITE_STR(fd, cmd);
  WRITE_MSG(fd,
	    " [--] <pipe> <timeout>\n\n"
	    "Please report bugs to " PACKAGE_BUGREPORT "\n");
  exit(res);
}

static void
showVersion()
{
  WRITE_MSG(1,
	    "vshelper-sync " VERSION " -- waits for data from a pipe"
	    "This program is part of " PACKAGE_STRING "\n\n"
	    "Copyright (C) 2004 Enrico Scholz\n"
	    VERSION_COPYRIGHT_DISCLAIMER);
  exit(0);
}

int main(int argc, char *argv[])
{
  int			fd;
  int			idx = 1;
  struct timeval	timeout;

  if (argc>=2) {
    if (strcmp(argv[1], "--help")   ==0) showHelp(1, argv[0], 0);
    if (strcmp(argv[1], "--version")==0) showVersion();
    if (strcmp(argv[1], "--")       ==0) ++idx;
  }

  if (argc<idx+2) {
    WRITE_MSG(2, "Not enough parameters; use '--help' for more information\n");
    return EXIT_FAILURE;
  }

  fd = open(argv[idx], O_RDONLY|O_NONBLOCK, 0);
  if (fd==-1) {
    perror("vshelper-sync: open()");
    return EXIT_FAILURE;
  }

  timeout.tv_sec  = atoi(argv[idx+1]);
  timeout.tv_usec = 0;

  for (;;) {
    char	buf[512];
    ssize_t	len;
    fd_set	fds;

    FD_ZERO(&fds);
    FD_SET(fd, &fds);

#ifndef __linux__
#  error vshelper relies on the Linux select() behavior (timeout holds remaining time)
#endif

    switch (select(fd+1, &fds, 0,0, &timeout)) {
      case 0	:  return EXIT_FAILURE;	// timeout
      case -1	:
	perror("vshelper: select()");
	return EXIT_FAILURE;
      default	:  break;
    }

    assert(FD_ISSET(fd, &fds));

    len = read(fd,buf,sizeof buf);
    if (len==0) break;
    if (len==-1) {
      perror("vshelper-sync: read()");
      return EXIT_FAILURE;
    }
  }

  return EXIT_SUCCESS;
}  
