1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* Copyright (c) 1988 AT&T */ 30 /* All Rights Reserved */ 31 32 33 #pragma weak realpath = _realpath 34 35 #include "synonyms.h" 36 #include <sys/types.h> 37 #include <dirent.h> 38 #include <sys/param.h> 39 #include <limits.h> 40 #include <errno.h> 41 #include <stdlib.h> 42 #include <unistd.h> 43 #include <string.h> 44 45 /* 46 * Canonicalize the path given in file_name, resolving away all symbolic link 47 * components. Store the result into the buffer named by resolved_name, which 48 * must be long enough (MAXPATHLEN bytes will suffice). Returns NULL 49 * on failure and resolved_name on success. On failure, to maintain 50 * compatibility with the past, the contents of file_name will be copied 51 * into resolved_name. 52 */ 53 char * 54 realpath(const char *file_name, char *resolved_name) 55 { 56 char cwd[PATH_MAX]; 57 int len; 58 59 if (file_name == NULL || resolved_name == NULL) { 60 errno = EINVAL; 61 return (NULL); 62 } 63 64 /* 65 * Call resolvepath() to resolve all the symlinks in file_name, 66 * eliminate embedded "." components, and collapse embedded ".." 67 * components. We may be left with leading ".." components. 68 */ 69 if ((len = resolvepath(file_name, resolved_name, PATH_MAX)) < 0) { 70 (void) strlcpy(resolved_name, file_name, PATH_MAX); 71 return (NULL); /* errno set by resolvepath() */ 72 } 73 74 if (len >= PATH_MAX) /* "can't happen" */ 75 len = PATH_MAX - 1; 76 resolved_name[len] = '\0'; 77 78 if (*resolved_name == '/') /* nothing more to do */ 79 return (resolved_name); 80 81 /* 82 * Prepend the current working directory to the relative path. 83 * If the relative path is not empty (or "."), collapse all of the 84 * resulting embedded ".." components with trailing cwd components. 85 * We know that getcwd() returns a path name free of symlinks. 86 */ 87 if (getcwd(cwd, sizeof (cwd)) == NULL) { 88 (void) strlcpy(resolved_name, file_name, PATH_MAX); 89 return (NULL); /* errno set by getcwd() */ 90 } 91 92 if (len != 0 && strcmp(resolved_name, ".") != 0) { 93 char *relpath = resolved_name; 94 char *endcwd = cwd + strlen(cwd); 95 96 /* 97 * Eliminate ".." components from the relative path 98 * left-to-right, components from cwd right-to-left. 99 */ 100 relpath[len++] = '/'; 101 while (len >= 3 && strncmp(relpath, "../", 3) == 0) { 102 relpath += 3; 103 len -= 3; 104 while (*--endcwd != '/') 105 continue; 106 } 107 if (len == 0) { 108 /* the relative path was all ".." components */ 109 *endcwd = '\0'; 110 } else { 111 /* there are non-null components on both sides */ 112 relpath[--len] = '\0'; 113 *endcwd++ = '/'; 114 if (endcwd + len >= cwd + PATH_MAX) { 115 (void) strlcpy(resolved_name, 116 file_name, PATH_MAX); 117 errno = ENAMETOOLONG; 118 return (NULL); 119 } 120 (void) strcpy(endcwd, relpath); 121 } 122 } 123 124 (void) strcpy(resolved_name, cwd); 125 return (resolved_name); 126 } 127