/* $Id$ */

/* Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the Gnome Top Library.
   Contributed by Martin Baulig <martin@home-of-linux.org>, April 1998.

   The Gnome Top Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The Gnome Top Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <glibtop.h>
#include <glibtop/open.h>
#include <glibtop/xmalloc.h>

/* Opens pipe to gtop server. Returns 0 on success and -1 on error. */

void
glibtop_open (glibtop *server, const char *program_name,
	      const unsigned long features, const unsigned flags)
{
	char	version [BUFSIZ], buffer [BUFSIZ];
	char	*server_command, *server_rsh, *temp;
	char	*server_host, *server_user;

	memset (server, 0, sizeof (glibtop));

	server->name = program_name;

	/* Try to get data from environment. */

	temp = getenv ("LIBGTOP_SERVER") ?
	  getenv ("LIBGTOP_SERVER") : GTOP_SERVER;

	server_command = glibtop_malloc__r (server, strlen (temp) + 1);
	
	strcpy (server_command, temp);

	temp = getenv ("LIBGTOP_RSH") ?
	  getenv ("LIBGTOP_RSH") : "rsh";

	server_rsh = glibtop_malloc__r (server, strlen (temp) + 1);

	strcpy (server_rsh, temp);

	/* Extract host and user information. */

	temp = strstr (server_command, ":");

	if (temp) {
	  *temp = 0;
	  server_host = server_command;
	  server_command = temp+1;

	  temp = strstr (server_host, "@");
	  
	  if (temp) {
	    *temp = 0;
	    server_user = server_host;
	    server_host = temp+1;
	  } else {
	    server_user = NULL;
	  }

	} else {
	  server_host = NULL;
	  server_user = NULL;
	}

	/* Store everything in `server'. */

	server->server_command = server_command;
	server->server_host = server_host;
	server->server_user = server_user;
	server->server_rsh = server_rsh;

	/* Get server features. */

	if (server->server_host)
		glibtop_error__r (server, _("Remote server not yet supported by library\n"));

	server->features = glibtop_server_features;

	/* Fork and exec server. */

	if (pipe (server->input) || pipe (server->output))
		glibtop_error__r (server, _("cannot make a pipe: %s\n"), strerror (errno));

	server->pid  = fork ();

	if (server->pid < 0) {
		glibtop_error__r (server, _("%s: fork failed: %s\n"), strerror (errno));
	} else if (server->pid == 0) {
		close (0); close (1); /* close (2); */
		close (server->input [0]); close (server->output [1]);
		dup2 (server->input [1], 1); /* dup2 (server->input [1], 2); */
		dup2 (server->output [0], 0);

		if (server_host) {
			if (server_user) {
				execl (server->server_rsh, "gtop_server", "-l",
				       server->server_user, server->server_host,
				       server->server_command, NULL);
			} else {
				execl (server->server_rsh, "gtop_server",
				       server->server_host, server_command, NULL);
			}
		} else {
			execl (server->server_command, "gtop_server", NULL);
		}

		_exit (2);
	}

	close (server->input [1]);
	close (server->output [0]);

	sprintf (version, "%s server %s ready.\n", PACKAGE, VERSION);

	glibtop_read__l (server, strlen (version), buffer);

	if (memcmp (version, buffer, strlen (version)))
		glibtop_error__r (server, _("server version is not %s"), VERSION);
}