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FileHandle Class Reference
[Platform]
Class FileHandle. More...
#include <FileHandle.h>
Inherited by ManagedFile, File, FileLike, LocalFileHandle, and UARTSerial.
Public Member Functions | |
| virtual ssize_t | read (void *buffer, size_t size)=0 |
| Read the contents of a file into a buffer. | |
| virtual ssize_t | write (const void *buffer, size_t size)=0 |
| Write the contents of a buffer to a file. | |
| virtual off_t | seek (off_t offset, int whence=SEEK_SET)=0 |
| Move the file position to a given offset from from a given location. | |
| virtual int | close ()=0 |
| Close a file. | |
| virtual int | sync () |
| Flush any buffers associated with the file. | |
| virtual int | isatty () |
| Check if the file in an interactive terminal device. | |
| virtual off_t | tell () |
| Get the file position of the file. | |
| virtual void | rewind () |
| Rewind the file position to the beginning of the file. | |
| virtual off_t | size () |
| Get the size of the file. | |
| MBED_DEPRECATED_SINCE ("mbed-os-5.4","Replaced by FileHandle::seek") virtual off_t lseek(off_t offset | |
| Move the file position to a given offset from a given location. | |
Detailed Description
Class FileHandle.
An abstract interface that represents operations on a file-like object. The core functions are read, write, and seek, but only a subset of these operations can be provided.
- Note:
- to create a file,
- See also:
- File
- Note:
- Synchronization level: Set by subclass
Definition at line 40 of file FileHandle.h.
Member Function Documentation
| virtual int close | ( | ) | [pure virtual] |
| virtual int isatty | ( | ) | [virtual] |
Check if the file in an interactive terminal device.
- Returns:
- True if the file is a terminal
- False if the file is not a terminal
- Negative error code on failure
Reimplemented in File, and Stream.
Definition at line 98 of file FileHandle.h.
| MBED_DEPRECATED_SINCE | ( | "mbed-os-5.4" | , |
| "Replaced by FileHandle::seek" | |||
| ) |
Move the file position to a given offset from a given location.
- Parameters:
-
offset The offset from whence to move to whence SEEK_SET for the start of the file, SEEK_CUR for the current file position, or SEEK_END for the end of the file.
- Returns:
- new file position on success, -1 on failure or unsupported
| virtual ssize_t read | ( | void * | buffer, |
| size_t | size | ||
| ) | [pure virtual] |
Read the contents of a file into a buffer.
Devices acting as FileHandles should follow POSIX semantics:
* if no data is available, and non-blocking set return -EAGAIN * if no data is available, and blocking set, wait until data is available * If any data is available, call returns immediately
- Parameters:
-
buffer The buffer to read in to size The number of bytes to read
- Returns:
- The number of bytes read, 0 at end of file, negative error on failure
| virtual void rewind | ( | ) | [virtual] |
Rewind the file position to the beginning of the file.
- Note:
- This is equivalent to seek(0, SEEK_SET)
Reimplemented in File, and Stream.
Definition at line 118 of file FileHandle.h.
| virtual off_t seek | ( | off_t | offset, |
| int | whence = SEEK_SET |
||
| ) | [pure virtual] |
Move the file position to a given offset from from a given location.
- Parameters:
-
offset The offset from whence to move to whence The start of where to seek SEEK_SET to start from beginning of file, SEEK_CUR to start from current position in file, SEEK_END to start from end of file
- Returns:
- The new offset of the file, negative error code on failure
| off_t size | ( | ) | [virtual] |
Get the size of the file.
- Returns:
- Size of the file in bytes
Reimplemented in File, and Stream.
Definition at line 22 of file FileHandle.cpp.
| virtual int sync | ( | ) | [virtual] |
Flush any buffers associated with the file.
- Returns:
- 0 on success, negative error code on failure
Reimplemented in File, and Stream.
Definition at line 87 of file FileHandle.h.
| virtual off_t tell | ( | ) | [virtual] |
Get the file position of the file.
- Note:
- This is equivalent to seek(0, SEEK_CUR)
- Returns:
- The current offset in the file, negative error code on failure
Reimplemented in File, and Stream.
Definition at line 109 of file FileHandle.h.
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