Jing Qiu / mbed

nothing changed

Fork of mbed by gokmen ascioglu

FileHandle.h@1:27d81db81dd7, 2015-03-03 (annotated)

Committer:
Jing_Qiu
Date:
Tue Mar 03 00:55:57 2015 +0000
Revision:
1:27d81db81dd7
Parent:
0:a8fa94490a0a 
revise

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gokmenascioglu 0:a8fa94490a0a 1 /* mbed Microcontroller Library - FileHandler
gokmenascioglu 0:a8fa94490a0a 2 * Copyright (c) 2007-2009 ARM Limited. All rights reserved.
gokmenascioglu 0:a8fa94490a0a 3 */
gokmenascioglu 0:a8fa94490a0a 4
gokmenascioglu 0:a8fa94490a0a 5 #ifndef MBED_FILEHANDLE_H
gokmenascioglu 0:a8fa94490a0a 6 #define MBED_FILEHANDLE_H
gokmenascioglu 0:a8fa94490a0a 7
gokmenascioglu 0:a8fa94490a0a 8 typedef int FILEHANDLE;
gokmenascioglu 0:a8fa94490a0a 9
gokmenascioglu 0:a8fa94490a0a 10 #include <stdio.h>
gokmenascioglu 0:a8fa94490a0a 11 #ifdef __ARMCC_VERSION
gokmenascioglu 0:a8fa94490a0a 12 typedef int ssize_t;
gokmenascioglu 0:a8fa94490a0a 13 typedef long off_t;
gokmenascioglu 0:a8fa94490a0a 14 #else
gokmenascioglu 0:a8fa94490a0a 15 #include <sys/types.h>
gokmenascioglu 0:a8fa94490a0a 16 #endif
gokmenascioglu 0:a8fa94490a0a 17
gokmenascioglu 0:a8fa94490a0a 18 namespace mbed {
gokmenascioglu 0:a8fa94490a0a 19
gokmenascioglu 0:a8fa94490a0a 20 /* Class FileHandle
gokmenascioglu 0:a8fa94490a0a 21 * An OO equivalent of the internal FILEHANDLE variable
gokmenascioglu 0:a8fa94490a0a 22 * and associated _sys_* functions
gokmenascioglu 0:a8fa94490a0a 23 *
gokmenascioglu 0:a8fa94490a0a 24 * FileHandle is an abstract class, needing at least sys_write and
gokmenascioglu 0:a8fa94490a0a 25 * sys_read to be implmented for a simple interactive device
gokmenascioglu 0:a8fa94490a0a 26 *
gokmenascioglu 0:a8fa94490a0a 27 * No one ever directly tals to/instanciates a FileHandle - it gets
gokmenascioglu 0:a8fa94490a0a 28 * created by FileSystem, and wrapped up by stdio
gokmenascioglu 0:a8fa94490a0a 29 */
gokmenascioglu 0:a8fa94490a0a 30 class FileHandle {
gokmenascioglu 0:a8fa94490a0a 31
gokmenascioglu 0:a8fa94490a0a 32 public:
gokmenascioglu 0:a8fa94490a0a 33
gokmenascioglu 0:a8fa94490a0a 34 /* Function write
gokmenascioglu 0:a8fa94490a0a 35 * Write the contents of a buffer to the file
gokmenascioglu 0:a8fa94490a0a 36 *
gokmenascioglu 0:a8fa94490a0a 37 * Parameters
gokmenascioglu 0:a8fa94490a0a 38 * buffer - the buffer to write from
gokmenascioglu 0:a8fa94490a0a 39 * length - the number of characters to write
gokmenascioglu 0:a8fa94490a0a 40 *
gokmenascioglu 0:a8fa94490a0a 41 * Returns
gokmenascioglu 0:a8fa94490a0a 42 * The number of characters written (possibly 0) on success, -1 on error.
gokmenascioglu 0:a8fa94490a0a 43 */
gokmenascioglu 0:a8fa94490a0a 44 virtual ssize_t write(const void* buffer, size_t length) = 0;
gokmenascioglu 0:a8fa94490a0a 45
gokmenascioglu 0:a8fa94490a0a 46 /* Function close
gokmenascioglu 0:a8fa94490a0a 47 * Close the file
gokmenascioglu 0:a8fa94490a0a 48 *
gokmenascioglu 0:a8fa94490a0a 49 * Returns
gokmenascioglu 0:a8fa94490a0a 50 * Zero on success, -1 on error.
gokmenascioglu 0:a8fa94490a0a 51 */
gokmenascioglu 0:a8fa94490a0a 52 virtual int close() = 0;
gokmenascioglu 0:a8fa94490a0a 53
gokmenascioglu 0:a8fa94490a0a 54 /* Function read
gokmenascioglu 0:a8fa94490a0a 55 * Reads the contents of the file into a buffer
gokmenascioglu 0:a8fa94490a0a 56 *
gokmenascioglu 0:a8fa94490a0a 57 * Parameters
gokmenascioglu 0:a8fa94490a0a 58 * buffer - the buffer to read in to
gokmenascioglu 0:a8fa94490a0a 59 * length - the number of characters to read
gokmenascioglu 0:a8fa94490a0a 60 *
gokmenascioglu 0:a8fa94490a0a 61 * Returns
gokmenascioglu 0:a8fa94490a0a 62 * The number of characters read (zero at end of file) on success, -1 on error.
gokmenascioglu 0:a8fa94490a0a 63 */
gokmenascioglu 0:a8fa94490a0a 64 virtual ssize_t read(void* buffer, size_t length) = 0;
gokmenascioglu 0:a8fa94490a0a 65
gokmenascioglu 0:a8fa94490a0a 66 /* Function isatty
gokmenascioglu 0:a8fa94490a0a 67 * Check if the handle is for a interactive terminal device
gokmenascioglu 0:a8fa94490a0a 68 *
gokmenascioglu 0:a8fa94490a0a 69 * If so, line buffered behaviour is used by default
gokmenascioglu 0:a8fa94490a0a 70 *
gokmenascioglu 0:a8fa94490a0a 71 * Returns
gokmenascioglu 0:a8fa94490a0a 72 * 1 if it is a terminal, 0 otherwise
gokmenascioglu 0:a8fa94490a0a 73 */
gokmenascioglu 0:a8fa94490a0a 74 virtual int isatty() = 0 ;
gokmenascioglu 0:a8fa94490a0a 75
gokmenascioglu 0:a8fa94490a0a 76 /* Function lseek
gokmenascioglu 0:a8fa94490a0a 77 * Move the file position to a given offset from a given location.
gokmenascioglu 0:a8fa94490a0a 78 *
gokmenascioglu 0:a8fa94490a0a 79 * Parameters
gokmenascioglu 0:a8fa94490a0a 80 * offset - The offset from whence to move to
gokmenascioglu 0:a8fa94490a0a 81 * whence - SEEK_SET for the start of the file, SEEK_CUR for the
gokmenascioglu 0:a8fa94490a0a 82 * current file position, or SEEK_END for the end of the file.
gokmenascioglu 0:a8fa94490a0a 83 *
gokmenascioglu 0:a8fa94490a0a 84 * Returns
gokmenascioglu 0:a8fa94490a0a 85 * New file position on success, -1 on failure or unsupported
gokmenascioglu 0:a8fa94490a0a 86 */
gokmenascioglu 0:a8fa94490a0a 87 virtual off_t lseek(off_t offset, int whence) = 0;
gokmenascioglu 0:a8fa94490a0a 88
gokmenascioglu 0:a8fa94490a0a 89 /* Function fsync
gokmenascioglu 0:a8fa94490a0a 90 * Flush any buffers associated with the FileHandle, ensuring it
gokmenascioglu 0:a8fa94490a0a 91 * is up to date on disk
gokmenascioglu 0:a8fa94490a0a 92 *
gokmenascioglu 0:a8fa94490a0a 93 * Returns
gokmenascioglu 0:a8fa94490a0a 94 * 0 on success or un-needed, -1 on error
gokmenascioglu 0:a8fa94490a0a 95 */
gokmenascioglu 0:a8fa94490a0a 96 virtual int fsync() = 0;
gokmenascioglu 0:a8fa94490a0a 97
gokmenascioglu 0:a8fa94490a0a 98 virtual off_t flen() {
gokmenascioglu 0:a8fa94490a0a 99 /* remember our current position */
gokmenascioglu 0:a8fa94490a0a 100 off_t pos = lseek(0, SEEK_CUR);
gokmenascioglu 0:a8fa94490a0a 101 if(pos == -1) return -1;
gokmenascioglu 0:a8fa94490a0a 102 /* seek to the end to get the file length */
gokmenascioglu 0:a8fa94490a0a 103 off_t res = lseek(0, SEEK_END);
gokmenascioglu 0:a8fa94490a0a 104 /* return to our old position */
gokmenascioglu 0:a8fa94490a0a 105 lseek(pos, SEEK_SET);
gokmenascioglu 0:a8fa94490a0a 106 return res;
gokmenascioglu 0:a8fa94490a0a 107 }
gokmenascioglu 0:a8fa94490a0a 108
gokmenascioglu 0:a8fa94490a0a 109 };
gokmenascioglu 0:a8fa94490a0a 110
gokmenascioglu 0:a8fa94490a0a 111 } // namespace mbed
gokmenascioglu 0:a8fa94490a0a 112
gokmenascioglu 0:a8fa94490a0a 113 #endif
gokmenascioglu 0:a8fa94490a0a 114