This is a repository for all my programs or modified programs.
FileHandle.h
- Committer:
- mturner5
- Date:
- 2016-09-11
- Revision:
- 0:72480818e4a9
File content as of revision 0:72480818e4a9:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * Licensed 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. */ #ifndef MBED_FILEHANDLE_H #define MBED_FILEHANDLE_H typedef int FILEHANDLE; #include <stdio.h> #if defined(__ARMCC_VERSION) || defined(__ICCARM__) typedef int ssize_t; typedef long off_t; #else # include <sys/types.h> #endif namespace mbed { /** An OO equivalent of the internal FILEHANDLE variable * and associated _sys_* functions. * * FileHandle is an abstract class, needing at least sys_write and * sys_read to be implmented for a simple interactive device. * * No one ever directly tals to/instanciates a FileHandle - it gets * created by FileSystem, and wrapped up by stdio. */ class FileHandle { public: /** Write the contents of a buffer to the file * * @param buffer the buffer to write from * @param length the number of characters to write * * @returns * The number of characters written (possibly 0) on success, -1 on error. */ virtual ssize_t write(const void* buffer, size_t length) = 0; /** Close the file * * @returns * Zero on success, -1 on error. */ virtual int close() = 0; /** Function read * Reads the contents of the file into a buffer * * @param buffer the buffer to read in to * @param length the number of characters to read * * @returns * The number of characters read (zero at end of file) on success, -1 on error. */ virtual ssize_t read(void* buffer, size_t length) = 0; /** Check if the handle is for a interactive terminal device. * If so, line buffered behaviour is used by default * * @returns * 1 if it is a terminal, * 0 otherwise */ virtual int isatty() = 0; /** Move the file position to a given offset from a given location. * * @param offset The offset from whence to move to * @param whence SEEK_SET for the start of the file, SEEK_CUR for the * current file position, or SEEK_END for the end of the file. * * @returns * new file position on success, * -1 on failure or unsupported */ virtual off_t lseek(off_t offset, int whence) = 0; /** Flush any buffers associated with the FileHandle, ensuring it * is up to date on disk * * @returns * 0 on success or un-needed, * -1 on error */ virtual int fsync() = 0; virtual off_t flen() { /* remember our current position */ off_t pos = lseek(0, SEEK_CUR); if(pos == -1) return -1; /* seek to the end to get the file length */ off_t res = lseek(0, SEEK_END); /* return to our old position */ lseek(pos, SEEK_SET); return res; } virtual ~FileHandle(); }; } // namespace mbed #endif