xref: /original-bsd/games/cribbage/instr.c (revision e9b82df0)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)instr.c	5.1 (Berkeley) 06/01/90";
10 #endif /* not lint */
11 
12 #include <sys/types.h>
13 #include <sys/wait.h>
14 #include <sys/errno.h>
15 #include <sys/stat.h>
16 #include <sys/file.h>
17 #include <stdio.h>
18 #include "pathnames.h"
19 
20 instructions()
21 {
22 	extern int errno;
23 	struct stat sb;
24 	union wait pstat;
25 	pid_t pid, waitpid();
26 	char *pager, *path, *getenv(), *rindex(), *strerror();
27 
28 	if (stat(_PATH_INSTR, &sb)) {
29 		(void)fprintf(stderr, "cribbage: %s: %s.\n", _PATH_INSTR,
30 		    strerror(errno));
31 		exit(1);
32 	}
33 	switch(pid = vfork()) {
34 	case -1:
35 		(void)fprintf(stderr, "cribbage: %s.\n", strerror(errno));
36 		exit(1);
37 	case 0:
38 		if (!(path = getenv("PAGER")))
39 			path = _PATH_MORE;
40 		if (pager = rindex(path, '/'))
41 			++pager;
42 		pager = path;
43 		execlp(path, pager, _PATH_INSTR, (char *)NULL);
44 		(void)fprintf(stderr, "cribbage: %s.\n", strerror(errno));
45 		_exit(1);
46 	default:
47 		do {
48 			pid = waitpid(pid, &pstat, 0);
49 		} while (pid == -1 && errno == EINTR);
50 		if (pid == -1 || pstat.w_status)
51 			exit(1);
52 	}
53 }
54