readFixedSizeAsync
Note
This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information.
Read a fixed amount of data
public function readFixedSizeAsync(
int $size,
?int $timeout_ns = NULL,
): Awaitable<string>;
Will fail with EPIPE if the file is closed before that much data is
available.
It is possible for this to never return, e.g. if called on a pipe or or socket which the other end keeps open forever. Set a timeout if you do not want this to happen.
Parameters
int $size?int $timeout_ns = NULL