* libs/libc/unistd/lib_pathconf.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 <nuttx/config.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
* Public Functions
****************************************************************************/
* Name: fpathconf/pathconf
*
* Description:
* The fpathconf() and pathconf() functions shall determine the current
* value of a configurable limit or option (variable) that is associated
* with a file or directory.
*
* For pathconf(), the path argument points to the pathname of a file or
* directory.
*
* For fpathconf(), the fildes argument is an open file descriptor.
*
* The name argument represents the variable to be queried relative to that
* file or directory. Implementations shall support all of the variables
* listed in the following table and may support others. The variables in
* the following table come from <limits.h> or <unistd.h> and the symbolic
* constants, defined in <unistd.h>, are the corresponding values used for
* name.
*
* Variable Value of Name
*
* {FILESIZEBITS} _PC_FILESIZEBITS
* {LINK_MAX} _PC_LINK_MAX
* {MAX_CANON} _PC_MAX_CANON
* {MAX_INPUT} _PC_MAX_INPUT
* {NAME_MAX} _PC_NAME_MAX
* {PATH_MAX} _PC_PATH_MAX
* {PIPE_BUF} _PC_PIPE_BUF
* {POSIX2_SYMLINKS} _PC_2_SYMLINKS
* {POSIX_ALLOC_SIZE_MIN} _PC_ALLOC_SIZE_MIN
* {POSIX_REC_INCR_XFER_SIZE} _PC_REC_INCR_XFER_SIZE
* {POSIX_REC_MAX_XFER_SIZE} _PC_REC_MAX_XFER_SIZE
* {POSIX_REC_MIN_XFER_SIZE} _PC_REC_MIN_XFER_SIZE
* {POSIX_REC_XFER_ALIGN} _PC_REC_XFER_ALIGN
* {SYMLINK_MAX} _PC_SYMLINK_MAX
* _POSIX_CHOWN_RESTRICTED _PC_CHOWN_RESTRICTED
* _POSIX_NO_TRUNC _PC_NO_TRUNC
* _POSIX_VDISABLE _PC_VDISABLE
* _POSIX_ASYNC_IO _PC_ASYNC_IO
* _POSIX_PRIO_IO _PC_PRIO_IO
* _POSIX_SYNC_IO _PC_SYNC_IO
*
* Returned Value:
* If name is an invalid value, both pathconf() and fpathconf() shall
* return -1 and set errno to indicate the error.
*
* If the variable corresponding to name has no limit for the path or file
* descriptor, both pathconf() and fpathconf() shall return -1 without
* changing errno. If the implementation needs to use path to determine the
* value of name and the implementation does not support the association of
* name with the file specified by path, or if the process did not have
* appropriate privileges to query the file specified by path, or path does
* not exist, pathconf() shall return -1 and set errno to indicate the
* error.
*
* If the implementation needs to use fildes to determine the value of name
* and the implementation does not support the association of name with the
* file specified by fildes, or if fildes is an invalid file descriptor,
* fpathconf() shall return -1 and set errno to indicate the error.
*
* Otherwise, pathconf() or fpathconf() shall return the current variable
* value for the file or directory without changing errno. The value
* returned shall not be more restrictive than the corresponding value
* available to the application when it was compiled with the
* implementation's <limits.h> or <unistd.h>.
*
* If the variable corresponding to name is dependent on an unsupported
* option, the results are unspecified.
*
****************************************************************************/
long fpathconf(int fildes, int name)
{
* It was originally created to support only the functionality of libcxx
* but can be extended to support as much of the standard POSIX as is
* necessary.
*/
UNUSED(fildes);
switch (name)
{
case _PC_PATH_MAX:
return PATH_MAX;
case _PC_LINK_MAX:
return _POSIX_LINK_MAX;
case _PC_NAME_MAX:
return _POSIX_NAME_MAX;
case _PC_PIPE_BUF:
return _POSIX_PIPE_BUF;
case _PC_MAX_CANON:
return _POSIX_MAX_CANON;
case _PC_MAX_INPUT:
return _POSIX_MAX_INPUT;
case _PC_PRIO_IO:
return _POSIX_PRIO_IO;
case _PC_CHOWN_RESTRICTED:
return _POSIX_CHOWN_RESTRICTED;
case _PC_ALLOC_SIZE_MIN:
return -1;
case _PC_REC_INCR_XFER_SIZE:
return -1;
case _PC_REC_MAX_XFER_SIZE:
return -1;
case _PC_REC_MIN_XFER_SIZE:
return -1;
case _PC_REC_XFER_ALIGN:
return -1;
case _PC_2_SYMLINKS:
return -1;
case _PC_SYNC_IO:
return _POSIX_SYNC_IO;
case _PC_ASYNC_IO:
return _POSIX_ASYNC_IO;
case _PC_NO_TRUNC:
return _POSIX_NO_TRUNC;
default:
if (name >= 0)
{
set_errno(ENOSYS);
}
else
{
set_errno(EINVAL);
}
return ERROR;
}
}
long pathconf(FAR const char *path, int name)
{
UNUSED(path);
return fpathconf(-1, name);
}