PHP. Руководство по PHP. 2005
dio_truncate
dio_truncate
Описание
bool dio_truncate (resource fd, int offset)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.
Замечание: Для Windows-платформ
эта функция не реализована.
