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ebfe22bfb9
The link support is no longer limited to the pseudo file system and now covers both soft (symbolic) links and hard links across the VFS. Rename the configuration option PSEUDOFS_SOFTLINKS to the more accurate FS_LINKS and update all references in the source, headers, Kconfig, documentation and board defconfigs accordingly. This is a configuration rename; any out-of-tree defconfig that still selects PSEUDOFS_SOFTLINKS must be updated to FS_LINKS. Signed-off-by: zhengyu16 <zhengyu16@xiaomi.com>
96 lines
3.3 KiB
C
96 lines
3.3 KiB
C
/****************************************************************************
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* libs/libc/unistd/lib_readlinkat.c
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <errno.h>
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#include <unistd.h>
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#include "libc.h"
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#ifdef CONFIG_FS_LINKS
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: readlinkat
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*
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* Description:
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* The readlinkat() system call operates in exactly the same way as
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* readlink(), except for the differences described here.
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*
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* If the pathname given in pathname is relative, then it is interpreted
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* relative to the directory referred to by the file descriptor dirfd
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* (rather than relative to the current working directory of the calling
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* process)
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*
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* If pathname is relative and dirfd is the special value AT_FDCWD, then
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* pathname is interpreted relative to the current working directory of
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* the calling process (like readlink()).
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*
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* If pathname is absolute, then dirfd is ignored.
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*
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* Input Parameters:
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* dirfd - The file descriptor of directory.
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* path - The full path to the symbolic link
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* buf - The user-provided buffer in which to return the path to the
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* link target.
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* bufsize - The size of 'buf'
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*
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* Returned Value:
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* Upon successful completion, readlinkat() will return the count of bytes
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* placed in the buffer. Otherwise, it will return a value of -1, leave the
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* buffer unchanged, and set errno to indicate the error.
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*
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****************************************************************************/
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ssize_t readlinkat(int dirfd, FAR const char *path, FAR char *buf,
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size_t bufsize)
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{
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FAR char *fullpath;
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int ret;
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fullpath = lib_get_pathbuffer();
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if (fullpath == NULL)
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{
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set_errno(ENOMEM);
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return ERROR;
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}
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ret = lib_getfullpath(dirfd, path, fullpath, PATH_MAX);
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if (ret < 0)
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{
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lib_put_pathbuffer(fullpath);
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set_errno(-ret);
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return ERROR;
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}
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ret = readlink(fullpath, buf, bufsize);
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lib_put_pathbuffer(fullpath);
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return ret;
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}
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#endif /* CONFIG_FS_LINKS */
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