Matthew Sims / mbed

Lab 1 Program C

Dependents:   Lab1C

Fork of mbed by -deleted-

FileHandle.h@4:5d1359a283bc, 2008-11-27 (annotated)

Committer:
simon.ford@mbed.co.uk
Date:
Thu Nov 27 16:23:24 2008 +0000
Revision:
4:5d1359a283bc
Parent:
1:6b7f447ca868
Child:
11:1c1ebd0324fa
New version of framework: vectors, environment, platform, base and file system

Who changed what in which revision?

UserRevisionLine numberNew contents of line
simon.ford@mbed.co.uk 0:82220227f4fa 1 /* mbed Microcontroller Library - FileHandle
simon.ford@mbed.co.uk 0:82220227f4fa 2 * Copyright (c) 2007-2008, sford
simon.ford@mbed.co.uk 0:82220227f4fa 3 */
simon.ford@mbed.co.uk 0:82220227f4fa 4
simon.ford@mbed.co.uk 0:82220227f4fa 5 #ifndef MBED_FILEHANDLE_H
simon.ford@mbed.co.uk 0:82220227f4fa 6 #define MBED_FILEHANDLE_H
simon.ford@mbed.co.uk 0:82220227f4fa 7
simon.ford@mbed.co.uk 4:5d1359a283bc 8 typedef int FILEHANDLE;
simon.ford@mbed.co.uk 4:5d1359a283bc 9
simon.ford@mbed.co.uk 4:5d1359a283bc 10 #include <stdio.h>
simon.ford@mbed.co.uk 4:5d1359a283bc 11 #ifdef __ARMCC_VERSION
simon.ford@mbed.co.uk 4:5d1359a283bc 12 typedef int ssize_t;
simon.ford@mbed.co.uk 4:5d1359a283bc 13 typedef long off_t;
simon.ford@mbed.co.uk 4:5d1359a283bc 14 #else
simon.ford@mbed.co.uk 4:5d1359a283bc 15 #include <sys/types.h>
simon.ford@mbed.co.uk 4:5d1359a283bc 16 #endif
simon.ford@mbed.co.uk 4:5d1359a283bc 17
simon.ford@mbed.co.uk 0:82220227f4fa 18 namespace mbed {
simon.ford@mbed.co.uk 0:82220227f4fa 19
simon.ford@mbed.co.uk 4:5d1359a283bc 20 /* Class FileHandle
simon.ford@mbed.co.uk 0:82220227f4fa 21 * An OO equivalent of the internal FILEHANDLE variable
simon.ford@mbed.co.uk 0:82220227f4fa 22 * and associated _sys_* functions
simon.ford@mbed.co.uk 0:82220227f4fa 23 *
simon.ford@mbed.co.uk 0:82220227f4fa 24 * FileHandle is an abstract class, needing at least sys_write and
simon.ford@mbed.co.uk 0:82220227f4fa 25 * sys_read to be implmented for a simple interactive device
simon.ford@mbed.co.uk 0:82220227f4fa 26 *
simon.ford@mbed.co.uk 0:82220227f4fa 27 * No one ever directly tals to/instanciates a FileHandle - it gets
simon.ford@mbed.co.uk 0:82220227f4fa 28 * created by FileSystem, and wrapped up by stdio
simon.ford@mbed.co.uk 0:82220227f4fa 29 */
simon.ford@mbed.co.uk 0:82220227f4fa 30 class FileHandle {
simon.ford@mbed.co.uk 0:82220227f4fa 31
simon.ford@mbed.co.uk 0:82220227f4fa 32 public:
simon.ford@mbed.co.uk 0:82220227f4fa 33
simon.ford@mbed.co.uk 4:5d1359a283bc 34 /* Function write
simon.ford@mbed.co.uk 4:5d1359a283bc 35 * Write the contents of a buffer to the file
simon.ford@mbed.co.uk 0:82220227f4fa 36 *
simon.ford@mbed.co.uk 4:5d1359a283bc 37 * Parameters
simon.ford@mbed.co.uk 0:82220227f4fa 38 * buffer - the buffer to write from
simon.ford@mbed.co.uk 0:82220227f4fa 39 * length - the number of characters to write
simon.ford@mbed.co.uk 0:82220227f4fa 40 *
simon.ford@mbed.co.uk 4:5d1359a283bc 41 * Returns
simon.ford@mbed.co.uk 4:5d1359a283bc 42 * The number of characters written (possibly 0) on success, -1 on error.
simon.ford@mbed.co.uk 0:82220227f4fa 43 */
simon.ford@mbed.co.uk 4:5d1359a283bc 44 virtual ssize_t write(const void* buffer, size_t length) = 0;
simon.ford@mbed.co.uk 0:82220227f4fa 45
simon.ford@mbed.co.uk 4:5d1359a283bc 46 /* Function close
simon.ford@mbed.co.uk 4:5d1359a283bc 47 * Close the file
simon.ford@mbed.co.uk 4:5d1359a283bc 48 *
simon.ford@mbed.co.uk 4:5d1359a283bc 49 * Returns
simon.ford@mbed.co.uk 4:5d1359a283bc 50 * Zero on success, -1 on error.
simon.ford@mbed.co.uk 4:5d1359a283bc 51 */
simon.ford@mbed.co.uk 4:5d1359a283bc 52 virtual int close() = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 53
simon.ford@mbed.co.uk 4:5d1359a283bc 54 /* Function read
simon.ford@mbed.co.uk 4:5d1359a283bc 55 * Reads the contents of the file into a buffer
simon.ford@mbed.co.uk 4:5d1359a283bc 56 *
simon.ford@mbed.co.uk 4:5d1359a283bc 57 * Parameters
simon.ford@mbed.co.uk 0:82220227f4fa 58 * buffer - the buffer to read in to
simon.ford@mbed.co.uk 0:82220227f4fa 59 * length - the number of characters to read
simon.ford@mbed.co.uk 0:82220227f4fa 60 *
simon.ford@mbed.co.uk 4:5d1359a283bc 61 * Returns
simon.ford@mbed.co.uk 4:5d1359a283bc 62 * The number of characters read (zero at end of file) on success, -1 on error.
simon.ford@mbed.co.uk 4:5d1359a283bc 63 */
simon.ford@mbed.co.uk 4:5d1359a283bc 64 virtual ssize_t read(void* buffer, size_t length) = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 65
simon.ford@mbed.co.uk 4:5d1359a283bc 66 /* Function isatty
simon.ford@mbed.co.uk 4:5d1359a283bc 67 * Check if the handle is for a interactive terminal device
simon.ford@mbed.co.uk 4:5d1359a283bc 68 *
simon.ford@mbed.co.uk 4:5d1359a283bc 69 * If so, line buffered behaviour is used by default
simon.ford@mbed.co.uk 4:5d1359a283bc 70 *
simon.ford@mbed.co.uk 4:5d1359a283bc 71 * Returns
simon.ford@mbed.co.uk 4:5d1359a283bc 72 * 1 if it is a terminal, 0 otherwise
simon.ford@mbed.co.uk 4:5d1359a283bc 73 */
simon.ford@mbed.co.uk 4:5d1359a283bc 74 virtual int isatty() = 0 ;
simon.ford@mbed.co.uk 0:82220227f4fa 75
simon.ford@mbed.co.uk 4:5d1359a283bc 76 /* Function lseek
simon.ford@mbed.co.uk 4:5d1359a283bc 77 * Move the file position to a given offset from a given location.
simon.ford@mbed.co.uk 4:5d1359a283bc 78 *
simon.ford@mbed.co.uk 4:5d1359a283bc 79 * Parameters
simon.ford@mbed.co.uk 4:5d1359a283bc 80 * offset - The offset from whence to move to
simon.ford@mbed.co.uk 4:5d1359a283bc 81 * whence - SEEK_SET for the start of the file, SEEK_CUR for the
simon.ford@mbed.co.uk 4:5d1359a283bc 82 * current file position, or SEEK_END for the end of the file.
simon.ford@mbed.co.uk 4:5d1359a283bc 83 *
simon.ford@mbed.co.uk 4:5d1359a283bc 84 * Returns
simon.ford@mbed.co.uk 4:5d1359a283bc 85 * New file position on success, -1 on failure or unsupported
simon.ford@mbed.co.uk 4:5d1359a283bc 86 */
simon.ford@mbed.co.uk 4:5d1359a283bc 87 virtual off_t lseek(off_t offset, int whence) = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 88
simon.ford@mbed.co.uk 4:5d1359a283bc 89 /* Function fsync
simon.ford@mbed.co.uk 4:5d1359a283bc 90 * Flush any buffers associated with the FileHandle, ensuring it
simon.ford@mbed.co.uk 4:5d1359a283bc 91 * is up to date on disk
simon.ford@mbed.co.uk 4:5d1359a283bc 92 *
simon.ford@mbed.co.uk 4:5d1359a283bc 93 * Returns
simon.ford@mbed.co.uk 4:5d1359a283bc 94 * 0 on success or un-needed, -1 on error
simon.ford@mbed.co.uk 4:5d1359a283bc 95 */
simon.ford@mbed.co.uk 4:5d1359a283bc 96 virtual int fsync() = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 97
simon.ford@mbed.co.uk 4:5d1359a283bc 98 virtual off_t flen() {
simon.ford@mbed.co.uk 4:5d1359a283bc 99 /* remember our current position */
simon.ford@mbed.co.uk 4:5d1359a283bc 100 off_t pos = lseek(0, SEEK_CUR);
simon.ford@mbed.co.uk 4:5d1359a283bc 101 if(pos == -1) return -1;
simon.ford@mbed.co.uk 4:5d1359a283bc 102 /* seek to the end to get the file length */
simon.ford@mbed.co.uk 4:5d1359a283bc 103 off_t res = lseek(0, SEEK_END);
simon.ford@mbed.co.uk 4:5d1359a283bc 104 /* return to our old position */
simon.ford@mbed.co.uk 4:5d1359a283bc 105 lseek(pos, SEEK_SET);
simon.ford@mbed.co.uk 4:5d1359a283bc 106 return res;
simon.ford@mbed.co.uk 4:5d1359a283bc 107 }
simon.ford@mbed.co.uk 4:5d1359a283bc 108
simon.ford@mbed.co.uk 0:82220227f4fa 109 };
simon.ford@mbed.co.uk 0:82220227f4fa 110
simon.ford@mbed.co.uk 0:82220227f4fa 111 } // namespace mbed
simon.ford@mbed.co.uk 0:82220227f4fa 112
simon.ford@mbed.co.uk 1:6b7f447ca868 113 #endif
simon.ford@mbed.co.uk 1:6b7f447ca868 114