Matthew Sims / mbed

Lab 1 Program C

Dependents:   Lab1C

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FileHandle.h@44:1c5f591fce58, 2015-09-29 (annotated)

Committer:
mattsims12
Date:
Tue Sep 29 03:04:58 2015 +0000
Revision:
44:1c5f591fce58
Parent:
43:aff670d0d510 
Lab 1 Program C

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rolf.meyer@arm.com 11:1c1ebd0324fa 1 /* mbed Microcontroller Library - FileHandler
rolf.meyer@arm.com 11:1c1ebd0324fa 2 * Copyright (c) 2007-2009 ARM Limited. All rights reserved.
rolf.meyer@arm.com 11:1c1ebd0324fa 3 */
rolf.meyer@arm.com 11:1c1ebd0324fa 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
screamer 43:aff670d0d510 20 /** An OO equivalent of the internal FILEHANDLE variable
screamer 43:aff670d0d510 21 * and associated _sys_* functions.
simon.ford@mbed.co.uk 0:82220227f4fa 22 *
screamer 43:aff670d0d510 23 * FileHandle is an abstract class, needing at least sys_write and
screamer 43:aff670d0d510 24 * sys_read to be implmented for a simple interactive device.
simon.ford@mbed.co.uk 0:82220227f4fa 25 *
screamer 43:aff670d0d510 26 * No one ever directly tals to/instanciates a FileHandle - it gets
screamer 43:aff670d0d510 27 * created by FileSystem, and wrapped up by stdio.
simon.ford@mbed.co.uk 0:82220227f4fa 28 */
simon.ford@mbed.co.uk 0:82220227f4fa 29 class FileHandle {
simon.ford@mbed.co.uk 0:82220227f4fa 30
simon.ford@mbed.co.uk 0:82220227f4fa 31 public:
simon.ford@mbed.co.uk 0:82220227f4fa 32
screamer 43:aff670d0d510 33 /** Write the contents of a buffer to the file
simon.ford@mbed.co.uk 0:82220227f4fa 34 *
screamer 43:aff670d0d510 35 * @param buffer the buffer to write from
screamer 43:aff670d0d510 36 * @param length the number of characters to write
simon.ford@mbed.co.uk 0:82220227f4fa 37 *
screamer 43:aff670d0d510 38 * @returns
screamer 43:aff670d0d510 39 * The number of characters written (possibly 0) on success, -1 on error.
simon.ford@mbed.co.uk 0:82220227f4fa 40 */
simon.ford@mbed.co.uk 4:5d1359a283bc 41 virtual ssize_t write(const void* buffer, size_t length) = 0;
simon.ford@mbed.co.uk 0:82220227f4fa 42
screamer 43:aff670d0d510 43 /** Close the file
simon.ford@mbed.co.uk 4:5d1359a283bc 44 *
screamer 43:aff670d0d510 45 * @returns
screamer 43:aff670d0d510 46 * Zero on success, -1 on error.
simon.ford@mbed.co.uk 4:5d1359a283bc 47 */
simon.ford@mbed.co.uk 4:5d1359a283bc 48 virtual int close() = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 49
screamer 43:aff670d0d510 50 /** Function read
simon.ford@mbed.co.uk 4:5d1359a283bc 51 * Reads the contents of the file into a buffer
simon.ford@mbed.co.uk 4:5d1359a283bc 52 *
screamer 43:aff670d0d510 53 * @param buffer the buffer to read in to
screamer 43:aff670d0d510 54 * @param length the number of characters to read
simon.ford@mbed.co.uk 0:82220227f4fa 55 *
screamer 43:aff670d0d510 56 * @returns
screamer 43:aff670d0d510 57 * The number of characters read (zero at end of file) on success, -1 on error.
simon.ford@mbed.co.uk 4:5d1359a283bc 58 */
simon.ford@mbed.co.uk 4:5d1359a283bc 59 virtual ssize_t read(void* buffer, size_t length) = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 60
screamer 43:aff670d0d510 61 /** Check if the handle is for a interactive terminal device.
screamer 43:aff670d0d510 62 * If so, line buffered behaviour is used by default
simon.ford@mbed.co.uk 4:5d1359a283bc 63 *
screamer 43:aff670d0d510 64 * @returns
screamer 43:aff670d0d510 65 * 1 if it is a terminal,
screamer 43:aff670d0d510 66 * 0 otherwise
simon.ford@mbed.co.uk 4:5d1359a283bc 67 */
simon.ford@mbed.co.uk 4:5d1359a283bc 68 virtual int isatty() = 0 ;
simon.ford@mbed.co.uk 0:82220227f4fa 69
screamer 43:aff670d0d510 70 /** Move the file position to a given offset from a given location.
simon.ford@mbed.co.uk 4:5d1359a283bc 71 *
screamer 43:aff670d0d510 72 * @param offset The offset from whence to move to
screamer 43:aff670d0d510 73 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
simon.ford@mbed.co.uk 4:5d1359a283bc 74 * current file position, or SEEK_END for the end of the file.
simon.ford@mbed.co.uk 4:5d1359a283bc 75 *
screamer 43:aff670d0d510 76 * @returns
screamer 43:aff670d0d510 77 * new file position on success,
screamer 43:aff670d0d510 78 * -1 on failure or unsupported
simon.ford@mbed.co.uk 4:5d1359a283bc 79 */
simon.ford@mbed.co.uk 4:5d1359a283bc 80 virtual off_t lseek(off_t offset, int whence) = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 81
screamer 43:aff670d0d510 82 /** Flush any buffers associated with the FileHandle, ensuring it
simon.ford@mbed.co.uk 4:5d1359a283bc 83 * is up to date on disk
simon.ford@mbed.co.uk 4:5d1359a283bc 84 *
screamer 43:aff670d0d510 85 * @returns
screamer 43:aff670d0d510 86 * 0 on success or un-needed,
screamer 43:aff670d0d510 87 * -1 on error
simon.ford@mbed.co.uk 4:5d1359a283bc 88 */
simon.ford@mbed.co.uk 4:5d1359a283bc 89 virtual int fsync() = 0;
simon.ford@mbed.co.uk 4:5d1359a283bc 90
simon.ford@mbed.co.uk 4:5d1359a283bc 91 virtual off_t flen() {
simon.ford@mbed.co.uk 4:5d1359a283bc 92 /* remember our current position */
simon.ford@mbed.co.uk 4:5d1359a283bc 93 off_t pos = lseek(0, SEEK_CUR);
simon.ford@mbed.co.uk 4:5d1359a283bc 94 if(pos == -1) return -1;
simon.ford@mbed.co.uk 4:5d1359a283bc 95 /* seek to the end to get the file length */
simon.ford@mbed.co.uk 4:5d1359a283bc 96 off_t res = lseek(0, SEEK_END);
simon.ford@mbed.co.uk 4:5d1359a283bc 97 /* return to our old position */
simon.ford@mbed.co.uk 4:5d1359a283bc 98 lseek(pos, SEEK_SET);
simon.ford@mbed.co.uk 4:5d1359a283bc 99 return res;
simon.ford@mbed.co.uk 4:5d1359a283bc 100 }
simon.ford@mbed.co.uk 4:5d1359a283bc 101
simon.ford@mbed.co.uk 0:82220227f4fa 102 };
simon.ford@mbed.co.uk 0:82220227f4fa 103
simon.ford@mbed.co.uk 0:82220227f4fa 104 } // namespace mbed
simon.ford@mbed.co.uk 0:82220227f4fa 105
simon.ford@mbed.co.uk 1:6b7f447ca868 106 #endif
simon.ford@mbed.co.uk 1:6b7f447ca868 107