1/*	$NetBSD: instr.c,v 1.13 2011/08/31 16:24:55 plunky Exp $	*/
2
3/*-
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)instr.c	8.1 (Berkeley) 5/31/93";
36#else
37__RCSID("$NetBSD: instr.c,v 1.13 2011/08/31 16:24:55 plunky Exp $");
38#endif
39#endif /* not lint */
40
41#include <sys/types.h>
42#include <sys/wait.h>
43#include <sys/stat.h>
44
45#include <curses.h>
46#include <err.h>
47#include <fcntl.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <unistd.h>
52#include <errno.h>
53
54#include "deck.h"
55#include "cribbage.h"
56#include "pathnames.h"
57
58void
59instructions(void)
60{
61	int pstat;
62	int fd;
63	pid_t pid;
64	const char *path;
65
66	switch (pid = vfork()) {
67	case -1:
68		err(1, "vfork");
69	case 0:
70		/* Follow the same behaviour for pagers as defined in POSIX.2
71		 * for mailx and man.  We only use a pager if stdout is
72		 * a terminal, and we pass the file on stdin to sh -c pager.
73		 */
74		if (!isatty(1))
75			path = "cat";
76		else {
77			if (!(path = getenv("PAGER")) || (*path == 0))
78				path = _PATH_MORE;
79		}
80		if ((fd = open(_PATH_INSTR, O_RDONLY)) == -1) {
81			warn("open %s", _PATH_INSTR);
82			_exit(1);
83		}
84		if (dup2(fd, 0) == -1) {
85			warn("dup2");
86			_exit(1);
87		}
88		execl("/bin/sh", "sh", "-c", path, (char *) NULL);
89		warn(NULL);
90		_exit(1);
91	default:
92		do {
93			pid = waitpid(pid, &pstat, 0);
94		} while (pid == -1 && errno == EINTR);
95		if (pid == -1 || WEXITSTATUS(pstat))
96			exit(1);
97	}
98}
99