usr/src/games/cribbage/instr.c

/*-
 * Copyright (c) 1990 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char sccsid[] = "@(#)instr.c     5.2 (Berkeley) 2/28/91";
#endif /* not lint */

#include <sys/types.h>
#include <sys/wait.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pathnames.h"

instructions()
{
        extern int errno;
        struct stat sb;
        union wait pstat;
        pid_t pid;
        char *pager, *path;

        if (stat(_PATH_INSTR, &sb)) {
                (void)fprintf(stderr, "cribbage: %s: %s.\n", _PATH_INSTR,
                    strerror(errno));
                exit(1);
        }
        switch(pid = vfork()) {
        case -1:
                (void)fprintf(stderr, "cribbage: %s.\n", strerror(errno));
                exit(1);
        case 0:
                if (!(path = getenv("PAGER")))
                        path = _PATH_MORE;
                if (pager = rindex(path, '/'))
                        ++pager;
                pager = path;
                execlp(path, pager, _PATH_INSTR, (char *)NULL);
                (void)fprintf(stderr, "cribbage: %s.\n", strerror(errno));
                _exit(1);
        default:
                do {
                        pid = waitpid(pid, (int *)&pstat, 0);
                } while (pid == -1 && errno == EINTR);
                if (pid == -1 || pstat.w_status)
                        exit(1);
        }
}