xref: /openbsd/games/cribbage/instr.c (revision 404b540a)
1 /*	$OpenBSD: instr.c,v 1.10 2004/07/10 07:26:23 deraadt Exp $	*/
2 /*	$NetBSD: instr.c,v 1.5 1997/07/10 06:47:30 mikel Exp $	*/
3 
4 /*-
5  * Copyright (c) 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)instr.c	8.1 (Berkeley) 5/31/93";
36 #else
37 static char rcsid[] = "$OpenBSD: instr.c,v 1.10 2004/07/10 07:26:23 deraadt 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 <errno.h>
48 #include <fcntl.h>
49 #include <paths.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include "deck.h"
56 #include "cribbage.h"
57 #include "pathnames.h"
58 
59 void
60 instructions(void)
61 {
62 	int pstat;
63 	int fd;
64 	pid_t pid;
65 	const char *pager;
66 
67 	if ((fd = open(_PATH_INSTR, O_RDONLY)) == - 1)
68 		errx(1, "can't open %s", _PATH_INSTR);
69 
70 	switch (pid = vfork()) {
71 	case -1:
72 		err(1, "vfork");
73 		/* NOTREACHED */
74 	case 0:
75 		setgid(getgid());
76 		if (!isatty(1))
77 			pager = "/bin/cat";
78 		else {
79 			if (!(pager = getenv("PAGER")) || (*pager == 0))
80 				pager = _PATH_MORE;
81 		}
82 		if (dup2(fd, 0) == -1)
83 			err(1, "dup2");
84 		execl(_PATH_BSHELL, "sh", "-c", pager, (char *)NULL);
85 		err(1, "exec sh -c %s", pager);
86 		/* NOTREACHED */
87 	default:
88 		do {
89 			pid = waitpid(pid, &pstat, 0);
90 		} while (pid == -1 && errno == EINTR);
91 		close(fd);
92 		if (pid == -1 || WEXITSTATUS(pstat))
93 			exit(1);
94 		break;
95 	}
96 }
97