1 /* $OpenBSD: pwd.c,v 1.14 2015/10/09 01:37:06 deraadt Exp $ */ 2 /* $NetBSD: pwd.c,v 1.22 2011/08/29 14:51:19 joerg Exp $ */ 3 4 /* 5 * Copyright (c) 1991, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/stat.h> 34 35 #include <err.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 40 extern char *__progname; 41 static char *getcwd_logical(void); 42 __dead static void usage(void); 43 44 int 45 main(int argc, char *argv[]) 46 { 47 int ch, lFlag = 0; 48 const char *p; 49 50 if (pledge("stdio rpath", NULL) == -1) 51 err(1, "pledge"); 52 53 while ((ch = getopt(argc, argv, "LP")) != -1) { 54 switch (ch) { 55 case 'L': 56 lFlag = 1; 57 break; 58 case 'P': 59 lFlag = 0; 60 break; 61 default: 62 usage(); 63 } 64 } 65 argc -= optind; 66 argv += optind; 67 68 if (argc != 0) 69 usage(); 70 71 if (lFlag) 72 p = getcwd_logical(); 73 else 74 p = NULL; 75 if (p == NULL) 76 p = getcwd(NULL, 0); 77 78 if (p == NULL) 79 err(EXIT_FAILURE, NULL); 80 81 puts(p); 82 83 exit(EXIT_SUCCESS); 84 } 85 86 static char * 87 getcwd_logical(void) 88 { 89 char *pwd, *p; 90 struct stat s_pwd, s_dot; 91 92 /* Check $PWD -- if it's right, it's fast. */ 93 pwd = getenv("PWD"); 94 if (pwd == NULL) 95 return NULL; 96 if (pwd[0] != '/') 97 return NULL; 98 99 /* check for . or .. components, including trailing ones */ 100 for (p = pwd; *p != '\0'; p++) 101 if (p[0] == '/' && p[1] == '.') { 102 if (p[2] == '.') 103 p++; 104 if (p[2] == '\0' || p[2] == '/') 105 return NULL; 106 } 107 108 if (stat(pwd, &s_pwd) == -1 || stat(".", &s_dot) == -1) 109 return NULL; 110 if (s_pwd.st_dev != s_dot.st_dev || s_pwd.st_ino != s_dot.st_ino) 111 return NULL; 112 return pwd; 113 } 114 115 static void 116 usage(void) 117 { 118 fprintf(stderr, "usage: %s [-LP]\n", __progname); 119 exit(EXIT_FAILURE); 120 } 121