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File.h
1 /* mbed Microcontroller Library
2  * Copyright (c) 2015 ARM Limited
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef FILE_H
18 #define FILE_H
19 
20 #include "features/storage/filesystem/FileSystem.h"
21 #include "platform/FileHandle.h"
22 
23 namespace mbed {
24 /** \addtogroup filesystem */
25 /** @{*/
26 
27 
28 /** File class
29  */
30 class File : public FileHandle {
31 public:
32  /** Create an uninitialized file
33  *
34  * Must call open to initialize the file on a file system
35  */
36  File();
37 
38  /** Create a file on a filesystem
39  *
40  * Creates and opens a file on a filesystem
41  *
42  * @param fs Filesystem as target for the file
43  * @param path The name of the file to open
44  * @param flags The flags to open the file in, one of O_RDONLY, O_WRONLY, O_RDWR,
45  * bitwise or'd with one of O_CREAT, O_TRUNC, O_APPEND
46  */
47  File(FileSystem *fs, const char *path, int flags = O_RDONLY);
48 
49  /** Destroy a file
50  *
51  * Closes file if the file is still open
52  */
53  virtual ~File();
54 
55  /** Open a file on the filesystem
56  *
57  * @param fs Filesystem as target for the file
58  * @param path The name of the file to open
59  * @param flags The flags to open the file in, one of O_RDONLY, O_WRONLY, O_RDWR,
60  * bitwise or'd with one of O_CREAT, O_TRUNC, O_APPEND
61  * @return 0 on success, negative error code on failure
62  */
63  virtual int open(FileSystem *fs, const char *path, int flags = O_RDONLY);
64 
65  /** Close a file
66  *
67  * @return 0 on success, negative error code on failure
68  */
69  virtual int close();
70 
71  /** Read the contents of a file into a buffer
72  *
73  * @param buffer The buffer to read in to
74  * @param size The number of bytes to read
75  * @return The number of bytes read, 0 at end of file, negative error on failure
76  */
77 
78  virtual ssize_t read(void *buffer, size_t size);
79 
80  /** Write the contents of a buffer to a file
81  *
82  * @param buffer The buffer to write from
83  * @param size The number of bytes to write
84  * @return The number of bytes written, negative error on failure
85  */
86  virtual ssize_t write(const void *buffer, size_t size);
87 
88  /** Flush any buffers associated with the file
89  *
90  * @return 0 on success, negative error code on failure
91  */
92  virtual int sync();
93 
94  /** Check if the file in an interactive terminal device
95  *
96  * @return True if the file is a terminal
97  */
98  virtual int isatty();
99 
100  /** Move the file position to a given offset from from a given location
101  *
102  * @param offset The offset from whence to move to
103  * @param whence The start of where to seek
104  * SEEK_SET to start from beginning of file,
105  * SEEK_CUR to start from current position in file,
106  * SEEK_END to start from end of file
107  * @return The new offset of the file
108  */
109  virtual off_t seek(off_t offset, int whence = SEEK_SET);
110 
111  /** Get the file position of the file
112  *
113  * @return The current offset in the file
114  */
115  virtual off_t tell();
116 
117  /** Rewind the file position to the beginning of the file
118  *
119  * @note This is equivalent to file_seek(file, 0, FS_SEEK_SET)
120  */
121  virtual void rewind();
122 
123  /** Get the size of the file
124  *
125  * @return Size of the file in bytes
126  */
127  virtual off_t size();
128 
129  /** Truncate or extend a file.
130  *
131  * The file's length is set to the specified value. The seek pointer is
132  * not changed. If the file is extended, the extended area appears as if
133  * it were zero-filled.
134  *
135  * @param length The requested new length for the file
136  *
137  * @return Zero on success, negative error code on failure
138  */
139  virtual int truncate(off_t length);
140 
141 private:
142  FileSystem *_fs;
143  fs_file_t _file;
144 };
145 
146 
147 /** @}*/
148 } // namespace mbed
149 
150 #endif
mbed::File::~File
virtual ~File()
Destroy a file.
mbed::File::truncate
virtual int truncate(off_t length)
Truncate or extend a file.
mbed::File::sync
virtual int sync()
Flush any buffers associated with the file.
mbed::FileHandle
Class FileHandle.
Definition: FileHandle.h:46
mbed::File::isatty
virtual int isatty()
Check if the file in an interactive terminal device.
mbed::File::rewind
virtual void rewind()
Rewind the file position to the beginning of the file.
mbed::File::size
virtual off_t size()
Get the size of the file.
mbed::File::open
virtual int open(FileSystem *fs, const char *path, int flags=O_RDONLY)
Open a file on the filesystem.
mbed::File
File class.
Definition: File.h:30
mbed::FileSystem
A file system object.
Definition: FileSystem.h:49
mbed::File::read
virtual ssize_t read(void *buffer, size_t size)
Read the contents of a file into a buffer.
mbed::File::File
File()
Create an uninitialized file.
mbed::File::close
virtual int close()
Close a file.
mbed::File::seek
virtual off_t seek(off_t offset, int whence=SEEK_SET)
Move the file position to a given offset from from a given location.
mbed::File::write
virtual ssize_t write(const void *buffer, size_t size)
Write the contents of a buffer to a file.
mbed::File::tell
virtual off_t tell()
Get the file position of the file.
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