platform_bionic/libc/include/dirent.h
Elliott Hughes 02f9f4cfb6 Add documentation to <dirent.h>.
This was a side-effect of something else I was doing. May as well check
this in now though.

Test: treehugger
Change-Id: Ibe8a3640d309c1980fa6e8ef003d4f255384c9e7
2020-03-30 14:26:35 -07:00

243 lines
8.7 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#pragma once
/**
* @file dirent.h
* @brief Directory entry iteration.
*/
#include <stdint.h>
#include <sys/cdefs.h>
#include <sys/types.h>
__BEGIN_DECLS
/** d_type value when the type is not known. */
#define DT_UNKNOWN 0
/** d_type value for a FIFO. */
#define DT_FIFO 1
/** d_type value for a character device. */
#define DT_CHR 2
/** d_type value for a directory. */
#define DT_DIR 4
/** d_type value for a block device. */
#define DT_BLK 6
/** d_type value for a regular file. */
#define DT_REG 8
/** d_type value for a symbolic link. */
#define DT_LNK 10
/** d_type value for a socket. */
#define DT_SOCK 12
#define DT_WHT 14
#if defined(__LP64__)
#define __DIRENT64_INO_T ino_t
#else
#define __DIRENT64_INO_T uint64_t /* Historical accident. */
#endif
#define __DIRENT64_BODY \
__DIRENT64_INO_T d_ino; \
off64_t d_off; \
unsigned short d_reclen; \
unsigned char d_type; \
char d_name[256]; \
/** The structure returned by readdir(). Identical to dirent64 on Android. */
struct dirent { __DIRENT64_BODY };
/** The structure returned by readdir64(). Identical to dirent on Android. */
struct dirent64 { __DIRENT64_BODY };
#undef __DIRENT64_BODY
#undef __DIRENT64_INO_T
/* glibc compatibility. */
#undef _DIRENT_HAVE_D_NAMLEN /* Linux doesn't have a d_namlen field. */
#define _DIRENT_HAVE_D_RECLEN
#define _DIRENT_HAVE_D_OFF
#define _DIRENT_HAVE_D_TYPE
#define d_fileno d_ino
/** The structure returned by opendir()/fopendir(). */
typedef struct DIR DIR;
/**
* [opendir(3)](http://man7.org/linux/man-pages/man3/opendir.3.html)
* opens a directory stream for the directory at `__path`.
*
* Returns null and sets `errno` on failure.
*/
DIR* opendir(const char* __path);
/**
* [fopendir(3)](http://man7.org/linux/man-pages/man3/opendir.3.html)
* opens a directory stream for the directory at `__dir_fd`.
*
* Returns null and sets `errno` on failure.
*/
DIR* fdopendir(int __dir_fd);
/**
* [readdir(3)](http://man7.org/linux/man-pages/man3/readdir.3.html)
* returns the next directory entry in the given directory.
*
* Returns a pointer to a directory entry on success,
* or returns null and leaves `errno` unchanged at the end of the directory,
* or returns null and sets `errno` on failure.
*/
struct dirent* readdir(DIR* __dir);
/**
* [readdir64(3)](http://man7.org/linux/man-pages/man3/readdir.3.html)
* returns the next directory entry in the given directory.
*
* Returns a pointer to a directory entry on success,
* or returns null and leaves `errno` unchanged at the end of the directory,
* or returns null and sets `errno` on failure.
*/
struct dirent64* readdir64(DIR* __dir) __INTRODUCED_IN(21);
int readdir_r(DIR* __dir, struct dirent* __entry, struct dirent** __buffer) __attribute__((__deprecated__("readdir_r is deprecated; use readdir instead")));
int readdir64_r(DIR* __dir, struct dirent64* __entry, struct dirent64** __buffer) __INTRODUCED_IN(21) __attribute__((__deprecated__("readdir64_r is deprecated; use readdir64 instead")));
/**
* [closedir(3)](http://man7.org/linux/man-pages/man3/closedir.3.html)
* closes a directory stream.
*
* Returns 0 on success and returns -1 and sets `errno` on failure.
*/
int closedir(DIR* __dir);
/**
* [rewinddir(3)](http://man7.org/linux/man-pages/man3/rewinddir.3.html)
* rewinds a directory stream to the first entry.
*/
void rewinddir(DIR* __dir);
/**
* [seekdir(3)](http://man7.org/linux/man-pages/man3/seekdir.3.html)
* seeks a directory stream to the given entry, which must be a value returned
* by telldir().
*
* Available since API level 23.
*/
void seekdir(DIR* __dir, long __location) __INTRODUCED_IN(23);
/**
* [telldir(3)](http://man7.org/linux/man-pages/man3/telldir.3.html)
* returns a value representing the current position in the directory
* for use with seekdir().
*
* Returns the current position on success and returns -1 and sets `errno` on failure.
*
* Available since API level 23.
*/
long telldir(DIR* __dir) __INTRODUCED_IN(23);
/**
* [dirfd(3)](http://man7.org/linux/man-pages/man3/dirfd.3.html)
* returns the file descriptor backing the given directory stream.
*
* Returns a file descriptor on success and returns -1 and sets `errno` on failure.
*/
int dirfd(DIR* __dir);
/**
* [alphasort](http://man7.org/linux/man-pages/man3/alphasort.3.html) is a
* comparator for use with scandir() that uses strcoll().
*/
int alphasort(const struct dirent** __lhs, const struct dirent** __rhs);
/**
* [alphasort64](http://man7.org/linux/man-pages/man3/alphasort.3.html) is a
* comparator for use with scandir64() that uses strcmp().
*
* Available since API level 21.
*/
int alphasort64(const struct dirent64** __lhs, const struct dirent64** __rhs) __INTRODUCED_IN(21);
/**
* [scandir(3)](http://man7.org/linux/man-pages/man3/scandir.3.html)
* scans all the directory `__path`, filtering entries with `__filter` and
* sorting them with qsort() using the given `__comparator`, and storing them
* into `__name_list`. Passing NULL as the filter accepts all entries.
*
* Returns the number of entries returned in the list on success,
* and returns -1 and sets `errno` on failure.
*/
int scandir(const char* __path, struct dirent*** __name_list, int (*__filter)(const struct dirent*), int (*__comparator)(const struct dirent**, const struct dirent**));
/**
* [scandir64(3)](http://man7.org/linux/man-pages/man3/scandir.3.html)
* scans all the directory `__path`, filtering entries with `__filter` and
* sorting them with qsort() using the given `__comparator`, and storing them
* into `__name_list`. Passing NULL as the filter accepts all entries.
*
* Returns the number of entries returned in the list on success,
* and returns -1 and sets `errno` on failure.
*
* Available since API level 21.
*/
int scandir64(const char* __path, struct dirent64*** __name_list, int (*__filter)(const struct dirent64*), int (*__comparator)(const struct dirent64**, const struct dirent64**)) __INTRODUCED_IN(21);
#if defined(__USE_GNU)
/**
* [scandirat64(3)](http://man7.org/linux/man-pages/man3/scandirat.3.html)
* scans all the directory referenced by the pair of `__dir_fd` and `__path`,
* filtering entries with `__filter` and sorting them with qsort() using the
* given `__comparator`, and storing them into `__name_list`. Passing NULL as
* the filter accepts all entries.
*
* Returns the number of entries returned in the list on success,
* and returns -1 and sets `errno` on failure.
*
* Available since API level 24.
*/
int scandirat64(int __dir_fd, const char* __path, struct dirent64*** __name_list, int (*__filter)(const struct dirent64*), int (*__comparator)(const struct dirent64**, const struct dirent64**)) __INTRODUCED_IN(24);
/**
* [scandirat(3)](http://man7.org/linux/man-pages/man3/scandirat.3.html)
* scans all the directory referenced by the pair of `__dir_fd` and `__path`,
* filtering entries with `__filter` and sorting them with qsort() using the
* given `__comparator`, and storing them into `__name_list`. Passing NULL as
* the filter accepts all entries.
*
* Returns the number of entries returned in the list on success,
* and returns -1 and sets `errno` on failure.
*
* Available since API level 24.
*/
int scandirat(int __dir_fd, const char* __path, struct dirent*** __name_list, int (*__filter)(const struct dirent*), int (*__comparator)(const struct dirent**, const struct dirent**)) __INTRODUCED_IN(24);
#endif
__END_DECLS