1*7e027cb7Smestre /* $OpenBSD: instr.c,v 1.14 2016/01/10 13:35:09 mestre Exp $ */
298bcabe8Sderaadt /* $NetBSD: instr.c,v 1.5 1997/07/10 06:47:30 mikel Exp $ */
3df930be7Sderaadt
4df930be7Sderaadt /*-
5df930be7Sderaadt * Copyright (c) 1990, 1993
6df930be7Sderaadt * The Regents of the University of California. All rights reserved.
7df930be7Sderaadt *
8df930be7Sderaadt * Redistribution and use in source and binary forms, with or without
9df930be7Sderaadt * modification, are permitted provided that the following conditions
10df930be7Sderaadt * are met:
11df930be7Sderaadt * 1. Redistributions of source code must retain the above copyright
12df930be7Sderaadt * notice, this list of conditions and the following disclaimer.
13df930be7Sderaadt * 2. Redistributions in binary form must reproduce the above copyright
14df930be7Sderaadt * notice, this list of conditions and the following disclaimer in the
15df930be7Sderaadt * documentation and/or other materials provided with the distribution.
167a09557bSmillert * 3. Neither the name of the University nor the names of its contributors
17df930be7Sderaadt * may be used to endorse or promote products derived from this software
18df930be7Sderaadt * without specific prior written permission.
19df930be7Sderaadt *
20df930be7Sderaadt * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21df930be7Sderaadt * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22df930be7Sderaadt * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23df930be7Sderaadt * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24df930be7Sderaadt * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25df930be7Sderaadt * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26df930be7Sderaadt * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27df930be7Sderaadt * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28df930be7Sderaadt * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29df930be7Sderaadt * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30df930be7Sderaadt * SUCH DAMAGE.
31df930be7Sderaadt */
32df930be7Sderaadt
33df930be7Sderaadt #include <sys/wait.h>
34df930be7Sderaadt
351ed0e75dSpjanzen #include <err.h>
3696b46b10Spjanzen #include <errno.h>
3796b46b10Spjanzen #include <fcntl.h>
3896b46b10Spjanzen #include <paths.h>
39df930be7Sderaadt #include <stdlib.h>
40df930be7Sderaadt #include <unistd.h>
41df930be7Sderaadt
42df930be7Sderaadt #include "pathnames.h"
43df930be7Sderaadt
44df930be7Sderaadt void
instructions(void)45ff8320a7Sderaadt instructions(void)
46df930be7Sderaadt {
4796b46b10Spjanzen int pstat;
4896b46b10Spjanzen int fd;
49df930be7Sderaadt pid_t pid;
5096b46b10Spjanzen const char *pager;
51df930be7Sderaadt
5296b46b10Spjanzen if ((fd = open(_PATH_INSTR, O_RDONLY)) == - 1)
5396b46b10Spjanzen errx(1, "can't open %s", _PATH_INSTR);
54b722ed3eSderaadt
55b722ed3eSderaadt switch (pid = vfork()) {
56b722ed3eSderaadt case -1:
571ed0e75dSpjanzen err(1, "vfork");
58b722ed3eSderaadt case 0:
5996b46b10Spjanzen if (!isatty(1))
6096b46b10Spjanzen pager = "/bin/cat";
6196b46b10Spjanzen else {
6296b46b10Spjanzen if (!(pager = getenv("PAGER")) || (*pager == 0))
6396b46b10Spjanzen pager = _PATH_MORE;
6496b46b10Spjanzen }
6596b46b10Spjanzen if (dup2(fd, 0) == -1)
6696b46b10Spjanzen err(1, "dup2");
67c96f6a27Sderaadt execl(_PATH_BSHELL, "sh", "-c", pager, (char *)NULL);
6896b46b10Spjanzen err(1, "exec sh -c %s", pager);
69df930be7Sderaadt default:
70df930be7Sderaadt do {
7196b46b10Spjanzen pid = waitpid(pid, &pstat, 0);
72df930be7Sderaadt } while (pid == -1 && errno == EINTR);
7396b46b10Spjanzen close(fd);
7496b46b10Spjanzen if (pid == -1 || WEXITSTATUS(pstat))
75df930be7Sderaadt exit(1);
7696b46b10Spjanzen break;
77df930be7Sderaadt }
78df930be7Sderaadt }
79