incubator-nuttx/libs/libc/unistd/lib_linkat.c

101 lines
3.6 KiB
C

/****************************************************************************
* libs/libc/unistd/lib_linkat.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <errno.h>
#include <unistd.h>
#include "libc.h"
#ifdef CONFIG_PSEUDOFS_SOFTLINKS
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: linkat
*
* Description:
* The linkat() system call operates in exactly the same way as link(),
* except for the differences described here.
*
* If the pathname given in pathname is relative, then it is interpreted
* relative to the directory referred to by the file descriptor dirfd
* (rather than relative to the current working directory of the calling
* process)
* If the pathname given in path1 is relative, then it is interpreted
* relative to the directory referred to by the file descriptor olddirfd
* (rather than relative to the current working directory of the calling
* process, as is done by link() for a relative pathname).
*
* If path1 is relative and olddirfd is the special value AT_FDCWD, then
* oldpath is interpreted relative to the current working directory of the
* calling process (like link()).
*
* If path1 is absolute, then olddirfd is ignored.
*
* The interpretation of path2 is as for path1, except that a relative
* pathname is interpreted relative to the directory referred to by the
* file descriptor newdirfd.
*
* Input Parameters:
* olddirfd - The file descriptor of directory.
* path1 - Points to a pathname naming an existing file.
* newdirfd - The file descriptor of directory.
* path2 - Points to a pathname naming the new directory entry to be
* created.
* flags - ignored.
*
* Returned Value:
* Return zero on success, or -1 if an error occurred (in which case,
* errno is set appropriately).
*
****************************************************************************/
int linkat(int olddirfd, FAR const char *path1,
int newdirfd, FAR const char *path2, int flags)
{
char oldfullpath[PATH_MAX];
char newfullpath[PATH_MAX];
int ret;
ret = lib_getfullpath(olddirfd, path1,
oldfullpath, sizeof(oldfullpath));
if (ret >= 0)
{
ret = lib_getfullpath(newdirfd, path2,
newfullpath, sizeof(newfullpath));
}
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
return link(oldfullpath, newfullpath);
}
#endif /* CONFIG_PSEUDOFS_SOFTLINKS */