CharDeviceInfo uses syscall.Stat to test if the path exists, is a character device (mode has S_IFCHR), parses the major and minor numbers out of syscall.Stat_t.Rdev and finally determines the TermType value based on the major and minor values.

ParseDims extracts terminal dimensions (width x height) from the provided buffer.

SetWinSz sets the width and height for the given tty fd.