incubator-nuttx/libs/libc/dirent/lib_readdir.c

78 lines
2.6 KiB
C

/****************************************************************************
* libs/libc/dirent/lib_readdir.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <dirent.h>
#include <errno.h>
#include <unistd.h>
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: readdir
*
* Description:
* The readdir() function returns a pointer to a dirent structure
* representing the next directory entry in the directory stream pointed
* to by dir. It returns NULL on reaching the end-of-file or if an error
* occurred.
*
* Input Parameters:
* dirp -- An instance of type DIR created by a previous call to opendir();
*
* Returned Value:
* The readdir() function returns a pointer to a dirent structure, or NULL
* if an error occurs or end-of-file is reached. On error, errno is set
* appropriately.
*
* EBADF - Invalid directory stream descriptor dir
*
****************************************************************************/
FAR struct dirent *readdir(DIR *dirp)
{
int ret;
if (!dirp)
{
set_errno(EBADF);
return NULL;
}
ret = read(dirp->fd, &dirp->entry, sizeof(struct dirent));
if (ret <= 0)
{
return NULL;
}
return &dirp->entry;
}