библиотека программных диалогов с интерактивными программами (programmed dialogue library with interactive programs)
MULTIPLEXING
By default, the expect functions block inside of a read on a
single file descriptor. If you want to wait on patterns from
multiple file descriptors, use select, poll, or an event manager.
They will tell you what file descriptor is ready to read.
When a file descriptor is ready to read, you can use the expect
functions to do one and only read by setting timeout to 0.
