1 /* $NetBSD: instr.c,v 1.12 2005/07/02 08:32:32 jmc 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 1.12 2005/07/02 08:32:32 jmc 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 } 99