IsEndOfFile

:::info[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. :::

If we are known to have reached the end of the file

public function isEndOfFile(): bool;

This function is best-effort: true is reliable, but false is more of 'maybe'. For example, if called on an open socket with no data available, it will return false; it is then possible that a future read will:

• return data if the other send sends some more
• block forever, or until timeout if set
• return the empty string if the socket closes the connection

Additionally, helpers such as readUntil may fail with EPIPE.

Returns

• bool