xref: /dragonfly/games/cribbage/instr.c (revision 19fe1c42)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)instr.c	8.1 (Berkeley) 5/31/93
34  * $FreeBSD: src/games/cribbage/instr.c,v 1.5 1999/12/12 03:04:15 billf Exp $
35  * $DragonFly: src/games/cribbage/instr.c,v 1.4 2006/09/09 02:21:49 pavalos Exp $
36  */
37 
38 #include <sys/wait.h>
39 #include <sys/stat.h>
40 
41 #include <errno.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "cribbage.h"
48 #include "pathnames.h"
49 
50 void
51 instructions(void)
52 {
53 	struct stat sb;
54 	union wait pstat;
55 	pid_t pid;
56 	const char *pager, *path;
57 
58 	if (stat(_PATH_INSTR, &sb)) {
59 		fprintf(stderr, "cribbage: %s: %s.\n", _PATH_INSTR,
60 		    strerror(errno));
61 		exit(1);
62 	}
63 	switch (pid = vfork()) {
64 	case -1:
65 		fprintf(stderr, "cribbage: %s.\n", strerror(errno));
66 		exit(1);
67 	case 0:
68 		if (!(path = getenv("PAGER")))
69 			path = _PATH_MORE;
70 		if ((pager = rindex(path, '/')) != NULL)
71 			++pager;
72 		pager = path;
73 		execlp(path, pager, _PATH_INSTR, (char *) NULL);
74 		fprintf(stderr, "cribbage: %s.\n", strerror(errno));
75 		_exit(1);
76 	default:
77 		do {
78 			pid = waitpid(pid, (int *)&pstat, 0);
79 		} while (pid == -1 && errno == EINTR);
80 		if (pid == -1 || pstat.w_status)
81 			exit(1);
82 	}
83 }
84