DirHandle.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_DIRHANDLE_H
00023 #define MBED_DIRHANDLE_H
00024 
00025 #if defined(__ARMCC_VERSION) || defined(__ICCARM__)
00026 #   define NAME_MAX 255
00027 typedef int mode_t;
00028 
00029 #else
00030 #   include <sys/syslimits.h>
00031 #endif
00032 
00033 #include "FileHandle.h"
00034 
00035 struct dirent {
00036     char d_name[NAME_MAX+1];
00037 };
00038 
00039 namespace mbed {
00040 
00041 /** Represents a directory stream. Objects of this type are returned
00042  *  by a FileSystemLike's opendir method. Implementations must define
00043  *  at least closedir, readdir and rewinddir.
00044  *
00045  *  If a FileSystemLike class defines the opendir method, then the
00046  *  directories of an object of that type can be accessed by
00047  *  DIR *d = opendir("/example/directory") (or opendir("/example")
00048  *  to open the root of the filesystem), and then using readdir(d) etc.
00049  *
00050  *  The root directory is considered to contain all FileLike and
00051  *  FileSystemLike objects, so the DIR* returned by opendir("/") will
00052  *  reflect this.
00053  */
00054 class DirHandle {
00055 
00056 public:
00057     /** Closes the directory.
00058      *
00059      *  @returns
00060      *    0 on success,
00061      *   -1 on error.
00062      */
00063     virtual int closedir()=0;
00064 
00065     /** Return the directory entry at the current position, and
00066      *  advances the position to the next entry.
00067      *
00068      * @returns
00069      *  A pointer to a dirent structure representing the
00070      *  directory entry at the current position, or NULL on reaching
00071      *  end of directory or error.
00072      */
00073     virtual struct dirent *readdir()=0;
00074 
00075     /** Resets the position to the beginning of the directory.
00076      */
00077     virtual void rewinddir()=0;
00078 
00079     /** Returns the current position of the DirHandle.
00080      *
00081      * @returns
00082      *   the current position,
00083      *  -1 on error.
00084      */
00085     virtual off_t telldir() { return -1; }
00086 
00087     /** Sets the position of the DirHandle.
00088      *
00089      *  @param location The location to seek to. Must be a value returned by telldir.
00090      */
00091     virtual void seekdir(off_t location) { }
00092 
00093     virtual ~DirHandle() {}
00094 };
00095 
00096 } // namespace mbed
00097 
00098 typedef mbed::DirHandle DIR;
00099 
00100 extern "C" {
00101     DIR *opendir(const char*);
00102     struct dirent *readdir(DIR *);
00103     int closedir(DIR*);
00104     void rewinddir(DIR*);
00105     long telldir(DIR*);
00106     void seekdir(DIR*, long);
00107     int mkdir(const char *name, mode_t n);
00108 };
00109 
00110 #endif /* MBED_DIRHANDLE_H */
00111