filehandle.read(buffer[, options])
buffer
<Buffer> | <TypedArray> | <DataView> 将填充读取的文件数据的缓冲区。options
<Object>- 返回: <Promise> 成功时将使用具有以下两个属性的对象履行:
bytesRead
<integer> 读取的字节数buffer
<Buffer> | <TypedArray> | <DataView> 对传入的buffer
参数的引用。
从文件中读取数据,并将其存储在给定的缓冲区中。
如果未同时修改文件,当读取的字节数为零时,则到达文件末尾。
buffer
<Buffer> | <TypedArray> | <DataView> A buffer that will be filled with the file data read.options
<Object>offset
<integer> The location in the buffer at which to start filling. Default:0
length
<integer> The number of bytes to read. Default:buffer.byteLength - offset
position
<integer> The location where to begin reading data from the file. Ifnull
, data will be read from the current file position, and the position will be updated. Ifposition
is an integer, the current file position will remain unchanged. Default::null
- Returns: <Promise> Fulfills upon success with an object with two properties:
bytesRead
<integer> The number of bytes readbuffer
<Buffer> | <TypedArray> | <DataView> A reference to the passed inbuffer
argument.
Reads data from the file and stores that in the given buffer.
If the file is not modified concurrently, the end-of-file is reached when the number of bytes read is zero.