Usage in Deno
import { read } from "node:fs";
read<TBuffer extends ArrayBufferView>(fd: number,buffer: TBuffer,offset: number,length: number,position: ReadPosition | null,callback: (err: ErrnoException | null,bytesRead: number,buffer: TBuffer,) => void,): void
Read data from the file specified by fd
.
The callback is given the three arguments, (err, bytesRead, buffer)
.
If the file is not modified concurrently, the end-of-file is reached when the number of bytes read is zero.
If this method is invoked as its util.promisify()
ed version, it returns
a promise for an Object
with bytesRead
and buffer
properties.
buffer: TBuffer
The buffer that the data will be written to.
position: ReadPosition | null
Specifies where to begin reading from in the file. If position
is null
or -1
, data will be read from the current file position, and the file position will be updated. If
position
is an integer, the file position will be unchanged.
void
read<TBuffer extends ArrayBufferView>(fd: number,options: ReadAsyncOptions<TBuffer>,callback: (err: ErrnoException | null,bytesRead: number,buffer: TBuffer,) => void,): void
Similar to the above fs.read
function, this version takes an optional options
object.
If not otherwise specified in an options
object,
buffer
defaults to Buffer.alloc(16384)
,
offset
defaults to 0
,
length
defaults to buffer.byteLength
, - offset
as of Node 17.6.0
position
defaults to null
options: ReadAsyncOptions<TBuffer>
void