read
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.
Since
v0.0.2
Parameters
The buffer that the data will be written to.
The position in buffer
to write the data to.
The number of bytes to read.
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.
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
Since
v12.17.0, 13.11.0