games/cribbage/instr.c

   1 /*      $NetBSD: instr.c,v 1.11 2005/02/15 12:56:20 jsm Exp $   */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)instr.c     8.1 (Berkeley) 5/31/93";
  36 #else
  37 __RCSID("$NetBSD: instr.c,v 1.11 2005/02/15 12:56:20 jsm Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <sys/types.h>
  42 #include <sys/wait.h>
  43 #include <sys/stat.h>
  44
  45 #include <curses.h>
  46 #include <err.h>
  47 #include <fcntl.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52 #include <errno.h>
  53
  54 #include "deck.h"
  55 #include "cribbage.h"
  56 #include "pathnames.h"
  57
  58 void
  59 instructions(void)
  60 {
  61         int pstat;
  62         int fd;
  63         pid_t pid;
  64         const char *path;
  65
  66         switch (pid = vfork()) {
  67         case -1:
  68                 err(1, "vfork");
  69         case 0:
  70                 /* Follow the same behaviour for pagers as defined in POSIX.2
  71                  * for mailx and man.  We only use a pager if stdout is
  72                  * a terminal, and we pass the file on stdin to sh -c pager.
  73                  */
  74                 if (!isatty(1))
  75                         path = "cat";
  76                 else {
  77                         if (!(path = getenv("PAGER")) || (*path == 0))
  78                                 path = _PATH_MORE;
  79                 }
  80                 if ((fd = open(_PATH_INSTR, O_RDONLY)) == -1) {
  81                         warn("open %s", _PATH_INSTR);
  82                         _exit(1);
  83                 }
  84                 if (dup2(fd, 0) == -1) {
  85                         warn("dup2");
  86                         _exit(1);
  87                 }
  88                 execl("/bin/sh", "sh", "-c", path, (char *) NULL);
  89                 warn(NULL);
  90                 _exit(1);
  91         default:
  92                 do {
  93                         pid = waitpid(pid, &pstat, 0);
  94                 } while (pid == -1 && errno == EINTR);
  95                 if (pid == -1 || WEXITSTATUS(pstat))
  96                         exit(1);
  97         }
  98 }