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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#include "lint.h"
#include <sys/types.h>
#include <dirent.h>
#include <sys/param.h>
#include <limits.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
/*
* Canonicalize the path given in file_name, resolving away all symbolic link
* components. Store the result into the buffer named by resolved_name, which
* must be long enough (PATH_MAX bytes will suffice). Returns NULL
* on failure and resolved_name on success. On failure, to maintain
* compatibility with the past, the contents of file_name will be copied
* into resolved_name.
*/
static char *
realpath_impl(const char *file_name, char *resolved_name)
{
char cwd[PATH_MAX];
int len;
if (file_name == NULL) {
errno = EINVAL;
return (NULL);
}
/*
* Call resolvepath() to resolve all the symlinks in file_name,
* eliminate embedded "." components, and collapse embedded ".."
* components. We may be left with leading ".." components.
*/
if ((len = resolvepath(file_name, resolved_name, PATH_MAX)) < 0) {
(void) strlcpy(resolved_name, file_name, PATH_MAX);
return (NULL); /* errno set by resolvepath() */
}
if (len >= PATH_MAX) /* "can't happen" */
len = PATH_MAX - 1;
resolved_name[len] = '\0';
if (*resolved_name == '/') /* nothing more to do */
return (resolved_name);
/*
* Prepend the current working directory to the relative path.
* If the relative path is not empty (or "."), collapse all of the
* resulting embedded ".." components with trailing cwd components.
* We know that getcwd() returns a path name free of symlinks.
*/
if (getcwd(cwd, sizeof (cwd)) == NULL) {
(void) strlcpy(resolved_name, file_name, PATH_MAX);
return (NULL); /* errno set by getcwd() */
}
if (len != 0 && strcmp(resolved_name, ".") != 0) {
char *relpath = resolved_name;
char *endcwd = cwd + strlen(cwd);
/*
* Eliminate ".." components from the relative path
* left-to-right, components from cwd right-to-left.
*/
relpath[len++] = '/';
while (len >= 3 && strncmp(relpath, "../", 3) == 0) {
relpath += 3;
len -= 3;
while (*--endcwd != '/')
continue;
}
if (len == 0) {
/* the relative path was all ".." components */
*endcwd = '\0';
} else {
/* there are non-null components on both sides */
relpath[--len] = '\0';
*endcwd++ = '/';
if (endcwd + len >= cwd + PATH_MAX) {
(void) strlcpy(resolved_name,
file_name, PATH_MAX);
errno = ENAMETOOLONG;
return (NULL);
}
(void) strcpy(endcwd, relpath);
}
}
(void) strcpy(resolved_name, cwd);
return (resolved_name);
}
/*
* Canonicalize the path given in file_name, resolving away all symbolic link
* components. If resolved_name is a null pointer, return a malloc()d
* buffer containing the result, else store the result into resolved_name
* and return resolved_name. Return NULL on failure.
*/
char *
realpath(const char *file_name, char *resolved_name)
{
char buffer[PATH_MAX];
if (resolved_name != NULL)
return (realpath_impl(file_name, resolved_name));
if (realpath_impl(file_name, buffer) != NULL)
return (strdup(buffer));
return (NULL);
}
/*
* GNU extension.
*/
char *
canonicalize_file_name(const char *path)
{
return (realpath(path, NULL));
}
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