ReadFile

Reads bytes from a file or I/O device.

Module: Windows

Microsoft documentation: ReadFile

Signature

func ReadFile(file: *opaque, buffer: *opaque,
    numberOfBytesToRead: uint32, numberOfBytesRead: *uint32,
    overlapped: *opaque) -> bool32;

Parameters

Name	Description
file	Open readable handle.
buffer	Writable destination buffer.
numberOfBytesToRead	Maximum requested byte count.
numberOfBytesRead	Receives the actual count for synchronous I/O.
overlapped	Overlapped state, or null for synchronous I/O.

Returns

bool32 — nonzero on completed success or zero on failure/pending overlapped I/O. A successful synchronous read can return fewer bytes than requested; zero bytes can indicate end of file.

See also

• WriteFile — write bytes
• File I/O — file API overview