filehandle.read(buffer, offset, length, position)

• buffer <Buffer> | <TypedArray> | <DataView> 将填充读取的文件数据的缓冲区。

  ¥buffer <Buffer> | <TypedArray> | <DataView> A buffer that will be filled with the file data read.

• offset <integer> 缓冲区中开始填充的位置。默认值：0

  ¥offset <integer> The location in the buffer at which to start filling. Default: 0

• length <integer> 读取的字节数。默认值：buffer.byteLength - offset

  ¥length <integer> The number of bytes to read. Default: buffer.byteLength - offset

• position <integer> | <bigint> | <null> 从文件开始读取数据的位置。如果是 null 或 -1，将从当前文件位置读取数据，并更新该位置。如果 position 是非负整数，则当前文件位置将保持不变。Default::null

  ¥position <integer> | <bigint> | <null> The location where to begin reading data from the file. If null or -1, data will be read from the current file position, and the position will be updated. If position is a non-negative integer, the current file position will remain unchanged. Default:: null

• 返回：<Promise> 成功时将使用具有以下两个属性的对象履行：

  ¥Returns: <Promise> Fulfills upon success with an object with two properties:

  • bytesRead <integer> 读取的字节数

    ¥bytesRead <integer> The number of bytes read

  • buffer <Buffer> | <TypedArray> | <DataView> 对传入的 buffer 参数的引用。

    ¥buffer <Buffer> | <TypedArray> | <DataView> A reference to the passed in buffer argument.

从文件中读取数据，并将其存储在给定的缓冲区中。

¥Reads data from the file and stores that in the given buffer.

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。

¥If the file is not modified concurrently, the end-of-file is reached when the number of bytes read is zero.