Micah B / mbed

mbed

Dependents:   DHTSensor_Test K64F_eCompass_OneNET_JW

FileHandle.h@0:2cc6bb4d7fea, 2015-02-25 (annotated)

Committer:
mbotkinl
Date:
Wed Feb 25 20:22:22 2015 +0000
Revision:
0:2cc6bb4d7fea
Working code to read Temperature and Humidity readings

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbotkinl 0:2cc6bb4d7fea 1 /* mbed Microcontroller Library
mbotkinl 0:2cc6bb4d7fea 2 * Copyright (c) 2006-2013 ARM Limited
mbotkinl 0:2cc6bb4d7fea 3 *
mbotkinl 0:2cc6bb4d7fea 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbotkinl 0:2cc6bb4d7fea 5 * you may not use this file except in compliance with the License.
mbotkinl 0:2cc6bb4d7fea 6 * You may obtain a copy of the License at
mbotkinl 0:2cc6bb4d7fea 7 *
mbotkinl 0:2cc6bb4d7fea 8 * http://www.apache.org/licenses/LICENSE-2.0
mbotkinl 0:2cc6bb4d7fea 9 *
mbotkinl 0:2cc6bb4d7fea 10 * Unless required by applicable law or agreed to in writing, software
mbotkinl 0:2cc6bb4d7fea 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbotkinl 0:2cc6bb4d7fea 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbotkinl 0:2cc6bb4d7fea 13 * See the License for the specific language governing permissions and
mbotkinl 0:2cc6bb4d7fea 14 * limitations under the License.
mbotkinl 0:2cc6bb4d7fea 15 */
mbotkinl 0:2cc6bb4d7fea 16 #ifndef MBED_FILEHANDLE_H
mbotkinl 0:2cc6bb4d7fea 17 #define MBED_FILEHANDLE_H
mbotkinl 0:2cc6bb4d7fea 18
mbotkinl 0:2cc6bb4d7fea 19 typedef int FILEHANDLE;
mbotkinl 0:2cc6bb4d7fea 20
mbotkinl 0:2cc6bb4d7fea 21 #include <stdio.h>
mbotkinl 0:2cc6bb4d7fea 22
mbotkinl 0:2cc6bb4d7fea 23 #if defined(__ARMCC_VERSION) || defined(__ICCARM__)
mbotkinl 0:2cc6bb4d7fea 24 typedef int ssize_t;
mbotkinl 0:2cc6bb4d7fea 25 typedef long off_t;
mbotkinl 0:2cc6bb4d7fea 26
mbotkinl 0:2cc6bb4d7fea 27 #else
mbotkinl 0:2cc6bb4d7fea 28 # include <sys/types.h>
mbotkinl 0:2cc6bb4d7fea 29 #endif
mbotkinl 0:2cc6bb4d7fea 30
mbotkinl 0:2cc6bb4d7fea 31 namespace mbed {
mbotkinl 0:2cc6bb4d7fea 32
mbotkinl 0:2cc6bb4d7fea 33 /** An OO equivalent of the internal FILEHANDLE variable
mbotkinl 0:2cc6bb4d7fea 34 * and associated _sys_* functions.
mbotkinl 0:2cc6bb4d7fea 35 *
mbotkinl 0:2cc6bb4d7fea 36 * FileHandle is an abstract class, needing at least sys_write and
mbotkinl 0:2cc6bb4d7fea 37 * sys_read to be implmented for a simple interactive device.
mbotkinl 0:2cc6bb4d7fea 38 *
mbotkinl 0:2cc6bb4d7fea 39 * No one ever directly tals to/instanciates a FileHandle - it gets
mbotkinl 0:2cc6bb4d7fea 40 * created by FileSystem, and wrapped up by stdio.
mbotkinl 0:2cc6bb4d7fea 41 */
mbotkinl 0:2cc6bb4d7fea 42 class FileHandle {
mbotkinl 0:2cc6bb4d7fea 43
mbotkinl 0:2cc6bb4d7fea 44 public:
mbotkinl 0:2cc6bb4d7fea 45 /** Write the contents of a buffer to the file
mbotkinl 0:2cc6bb4d7fea 46 *
mbotkinl 0:2cc6bb4d7fea 47 * @param buffer the buffer to write from
mbotkinl 0:2cc6bb4d7fea 48 * @param length the number of characters to write
mbotkinl 0:2cc6bb4d7fea 49 *
mbotkinl 0:2cc6bb4d7fea 50 * @returns
mbotkinl 0:2cc6bb4d7fea 51 * The number of characters written (possibly 0) on success, -1 on error.
mbotkinl 0:2cc6bb4d7fea 52 */
mbotkinl 0:2cc6bb4d7fea 53 virtual ssize_t write(const void* buffer, size_t length) = 0;
mbotkinl 0:2cc6bb4d7fea 54
mbotkinl 0:2cc6bb4d7fea 55 /** Close the file
mbotkinl 0:2cc6bb4d7fea 56 *
mbotkinl 0:2cc6bb4d7fea 57 * @returns
mbotkinl 0:2cc6bb4d7fea 58 * Zero on success, -1 on error.
mbotkinl 0:2cc6bb4d7fea 59 */
mbotkinl 0:2cc6bb4d7fea 60 virtual int close() = 0;
mbotkinl 0:2cc6bb4d7fea 61
mbotkinl 0:2cc6bb4d7fea 62 /** Function read
mbotkinl 0:2cc6bb4d7fea 63 * Reads the contents of the file into a buffer
mbotkinl 0:2cc6bb4d7fea 64 *
mbotkinl 0:2cc6bb4d7fea 65 * @param buffer the buffer to read in to
mbotkinl 0:2cc6bb4d7fea 66 * @param length the number of characters to read
mbotkinl 0:2cc6bb4d7fea 67 *
mbotkinl 0:2cc6bb4d7fea 68 * @returns
mbotkinl 0:2cc6bb4d7fea 69 * The number of characters read (zero at end of file) on success, -1 on error.
mbotkinl 0:2cc6bb4d7fea 70 */
mbotkinl 0:2cc6bb4d7fea 71 virtual ssize_t read(void* buffer, size_t length) = 0;
mbotkinl 0:2cc6bb4d7fea 72
mbotkinl 0:2cc6bb4d7fea 73 /** Check if the handle is for a interactive terminal device.
mbotkinl 0:2cc6bb4d7fea 74 * If so, line buffered behaviour is used by default
mbotkinl 0:2cc6bb4d7fea 75 *
mbotkinl 0:2cc6bb4d7fea 76 * @returns
mbotkinl 0:2cc6bb4d7fea 77 * 1 if it is a terminal,
mbotkinl 0:2cc6bb4d7fea 78 * 0 otherwise
mbotkinl 0:2cc6bb4d7fea 79 */
mbotkinl 0:2cc6bb4d7fea 80 virtual int isatty() = 0;
mbotkinl 0:2cc6bb4d7fea 81
mbotkinl 0:2cc6bb4d7fea 82 /** Move the file position to a given offset from a given location.
mbotkinl 0:2cc6bb4d7fea 83 *
mbotkinl 0:2cc6bb4d7fea 84 * @param offset The offset from whence to move to
mbotkinl 0:2cc6bb4d7fea 85 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
mbotkinl 0:2cc6bb4d7fea 86 * current file position, or SEEK_END for the end of the file.
mbotkinl 0:2cc6bb4d7fea 87 *
mbotkinl 0:2cc6bb4d7fea 88 * @returns
mbotkinl 0:2cc6bb4d7fea 89 * new file position on success,
mbotkinl 0:2cc6bb4d7fea 90 * -1 on failure or unsupported
mbotkinl 0:2cc6bb4d7fea 91 */
mbotkinl 0:2cc6bb4d7fea 92 virtual off_t lseek(off_t offset, int whence) = 0;
mbotkinl 0:2cc6bb4d7fea 93
mbotkinl 0:2cc6bb4d7fea 94 /** Flush any buffers associated with the FileHandle, ensuring it
mbotkinl 0:2cc6bb4d7fea 95 * is up to date on disk
mbotkinl 0:2cc6bb4d7fea 96 *
mbotkinl 0:2cc6bb4d7fea 97 * @returns
mbotkinl 0:2cc6bb4d7fea 98 * 0 on success or un-needed,
mbotkinl 0:2cc6bb4d7fea 99 * -1 on error
mbotkinl 0:2cc6bb4d7fea 100 */
mbotkinl 0:2cc6bb4d7fea 101 virtual int fsync() = 0;
mbotkinl 0:2cc6bb4d7fea 102
mbotkinl 0:2cc6bb4d7fea 103 virtual off_t flen() {
mbotkinl 0:2cc6bb4d7fea 104 /* remember our current position */
mbotkinl 0:2cc6bb4d7fea 105 off_t pos = lseek(0, SEEK_CUR);
mbotkinl 0:2cc6bb4d7fea 106 if(pos == -1) return -1;
mbotkinl 0:2cc6bb4d7fea 107 /* seek to the end to get the file length */
mbotkinl 0:2cc6bb4d7fea 108 off_t res = lseek(0, SEEK_END);
mbotkinl 0:2cc6bb4d7fea 109 /* return to our old position */
mbotkinl 0:2cc6bb4d7fea 110 lseek(pos, SEEK_SET);
mbotkinl 0:2cc6bb4d7fea 111 return res;
mbotkinl 0:2cc6bb4d7fea 112 }
mbotkinl 0:2cc6bb4d7fea 113
mbotkinl 0:2cc6bb4d7fea 114 virtual ~FileHandle();
mbotkinl 0:2cc6bb4d7fea 115 };
mbotkinl 0:2cc6bb4d7fea 116
mbotkinl 0:2cc6bb4d7fea 117 } // namespace mbed
mbotkinl 0:2cc6bb4d7fea 118
mbotkinl 0:2cc6bb4d7fea 119 #endif