dio_truncate Truncates file descriptor fd to offset bytes &reftitle.description; booldio_truncate resourcefd intoffset dio_truncate truncates a file to at most offset bytes in size. If the file previously was larger than this size, the extra data is lost. If the file previously was shorter, it is unspecified whether the file is left unchanged or is extended. In the latter case the extended part reads as zero bytes. &reftitle.parameters; fd The file descriptor returned by dio_open. offset The offset in bytes. &reftitle.returnvalues; &return.success; &reftitle.notes; ¬e.no-windows;