Skip to main content

lseek

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.

Reposition the current file offset

namespace HH\Lib\OS;

function lseek(
  FileDescriptor $fd,
  int $offset,
  SeekWhence $whence,
): int;

See man 2 lseek for details. On error, an ErrnoException will be thrown.

Parameters​

  • FileDescriptor $fd
  • int $offset
  • SeekWhence $whence

Returns​

  • int