1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993, 1994 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/param.h> 33 #include <sys/stat.h> 34 #include <sys/types.h> 35 36 #include <err.h> 37 #include <errno.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <unistd.h> 41 42 static char *getcwd_logical(void); 43 void usage(void); 44 45 int 46 main(int argc, char *argv[]) 47 { 48 int physical; 49 int ch; 50 char *p; 51 52 physical = 1; 53 while ((ch = getopt(argc, argv, "LP")) != -1) 54 switch (ch) { 55 case 'L': 56 physical = 0; 57 break; 58 case 'P': 59 physical = 1; 60 break; 61 case '?': 62 default: 63 usage(); 64 } 65 argc -= optind; 66 argv += optind; 67 68 if (argc != 0) 69 usage(); 70 71 /* 72 * If we're trying to find the logical current directory and that 73 * fails, behave as if -P was specified. 74 */ 75 if ((!physical && (p = getcwd_logical()) != NULL) || 76 (p = getcwd(NULL, 0)) != NULL) 77 printf("%s\n", p); 78 else 79 err(1, "."); 80 81 exit(0); 82 } 83 84 void __dead2 85 usage(void) 86 { 87 88 (void)fprintf(stderr, "usage: pwd [-L | -P]\n"); 89 exit(1); 90 } 91 92 static char * 93 getcwd_logical(void) 94 { 95 struct stat lg, phy; 96 char *pwd; 97 98 /* 99 * Check that $PWD is an absolute logical pathname referring to 100 * the current working directory. 101 */ 102 if ((pwd = getenv("PWD")) != NULL && *pwd == '/') { 103 if (stat(pwd, &lg) == -1 || stat(".", &phy) == -1) 104 return (NULL); 105 if (lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino) 106 return (pwd); 107 } 108 109 errno = ENOENT; 110 return (NULL); 111 } 112