ориентированный (визуальный) редактор отображения (oriented (visual) display editor)
Стандартный ввод (Stdin)
If standard input is not a terminal device, the results are
undefined. The standard input consists of a series of commands
and input text, as described in the EXTENDED DESCRIPTION section.
If a read from the standard input returns an error, or if the
editor detects an end-of-file condition from the standard input,
it shall be equivalent to a SIGHUP asynchronous event.
