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A-Shell Reference

FKEYWAIT=<# ms>

Example:  FKEYWAIT=50

(Unix Only) Most "function keys" send multiple bytes. In order to distinguish between a true multi-byte sequence and a series of individual single-byte keystrokes, A-Shell considers the time delay between the first byte (the "leadin") and the following byte. In practice, this means that whenever A-Shell sees a byte that could be a "leadin" (typically Escape or Ctrl+A), it does a timed input operation for the next byte. If one or more bytes arrive within the specified interval, then it is considered a multi-byte sequence, otherwise the initial byte is treated as a stand-alone character. Under normal circumstances, the default five milliseconds wait is sufficient, but still short enough that you don’t notice the delay. However, in some cases, the delay between the "leadin" and the following bytes can be substantially longer. One example of this occurs when using rlogin instead of telnet to log into a remote system. In that case, you may need to specify a much longer delay, perhaps as much as 200 ms.

If the FKEYWAIT value is too short, function keys may stop working properly, and will instead typically put some kind of garbage on the screen. However, the longer the wait, the longer you have to wait before an individual Escape or Ctrl+A is acted on. For example, in VUE, the Escape character switches between edit and command mode. If you like to switch quickly between these modes, you may find that a 200 ms delay in response to the Escape key is unbearable. So the advice is to use experimentation to get the FKEYWAIT value as low as possible without causing your function keys to break up.

Since the required FKEYWAIT value may change from terminal to terminal, you may also change this on a job-by-job value at runtime using SET; type SET /? from the A-Shell prompt to display help info.