nothing changed
Fork of mbed by
Diff: FileHandle.h
- Revision:
- 0:a8fa94490a0a
diff -r 000000000000 -r a8fa94490a0a FileHandle.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/FileHandle.h Sat Sep 22 10:32:07 2012 +0000 @@ -0,0 +1,114 @@ +/* mbed Microcontroller Library - FileHandler + * Copyright (c) 2007-2009 ARM Limited. All rights reserved. + */ + +#ifndef MBED_FILEHANDLE_H +#define MBED_FILEHANDLE_H + +typedef int FILEHANDLE; + +#include <stdio.h> +#ifdef __ARMCC_VERSION +typedef int ssize_t; +typedef long off_t; +#else +#include <sys/types.h> +#endif + +namespace mbed { + +/* Class FileHandle + * 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: + + /* Function write + * Write the contents of a buffer to the file + * + * Parameters + * buffer - the buffer to write from + * 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; + + /* Function close + * 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 + * + * Parameters + * buffer - the buffer to read in to + * 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; + + /* Function isatty + * 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 ; + + /* Function lseek + * Move the file position to a given offset from a given location. + * + * Parameters + * offset - The offset from whence to move to + * 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; + + /* Function fsync + * 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; + } + +}; + +} // namespace mbed + +#endif +