1 /* $NetBSD: instr.c,v 1.14 2011/09/01 07:18:50 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
35 static char sccsid[] = "@(#)instr.c 8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: instr.c,v 1.14 2011/09/01 07:18:50 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
58 void
instructions(void)59 instructions(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