FileSystemWritableFileStream.truncate()
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The truncate() method of the
FileSystemWritableFileStream interface resizes the file associated with
the stream to be the specified size in bytes.
If the size specified is larger than the current file size this pads the file with
null bytes, otherwise it truncates the file.
The file cursor is also updated when truncate() is called. If the offset
is smaller than the size, it remains unchanged. If the offset is larger than size, the
offset is set to that size. This ensures that subsequent writes do not error.
No changes are written to the actual file on disk until the stream has been closed. Changes are typically written to a temporary file instead.
Syntax
FileSystemWritableFileStream.truncate().then(...);
Parameters
- size
-
An
unsigned longof the amount of bytes to resize the stream to.
Return value
A Promise which returns undefined.
Exceptions
- NotAllowedError
-
If the
PermissionStateis not 'granted'. - TypeError
-
If the size is undefined or not an unsigned long.
Examples
// todo
Specifications
| Specification |
|---|
| File System Access # dom-filesystemwritablefilestream-truncate |
Browser compatibility
BCD tables only load in the browser