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/* $OpenBSD: instr.c,v 1.14 2016/01/10 13:35:09 mestre Exp $ */
/* $NetBSD: instr.c,v 1.5 1997/07/10 06:47:30 mikel Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdlib.h>
#include <unistd.h>
#include "pathnames.h"
void
instructions(void)
{
int pstat;
int fd;
pid_t pid;
const char *pager;
if ((fd = open(_PATH_INSTR, O_RDONLY)) == - 1)
errx(1, "can't open %s", _PATH_INSTR);
switch (pid = vfork()) {
case -1:
err(1, "vfork");
case 0:
if (!isatty(1))
pager = "/bin/cat";
else {
if (!(pager = getenv("PAGER")) || (*pager == 0))
pager = _PATH_MORE;
}
if (dup2(fd, 0) == -1)
err(1, "dup2");
execl(_PATH_BSHELL, "sh", "-c", pager, (char *)NULL);
err(1, "exec sh -c %s", pager);
default:
do {
pid = waitpid(pid, &pstat, 0);
} while (pid == -1 && errno == EINTR);
close(fd);
if (pid == -1 || WEXITSTATUS(pstat))
exit(1);
break;
}
}
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