The KEYTRAP statement defines trap keys for use with INPUT @.
KEYTRAP (action, key), (action, key), ...
A negative action value removes the key binding specified by key.
The KEYTRAP statement defines one or more keys that will terminate an INPUT @ statement. When any of these keys in pressed the INPUT @ returns with the original value of the input variable. The STATUS() function will return the value defined by action for the key.
See the KEYEXIT statement for a method to return the input data as entered up to the moment when this key was used.
Example of a multi-byte key sequence
The F2 key of a vt100 terminal using the vt100-at definition with AccuTerm sends a three character sequence of "Esc O Q". The hexadecimal values of these characters are 1B, 4F, 51. The key value is formed by concatenating bytes with these character values in reverse order and adding 160. The simplest way to do this is
KEY = XTD('514F1B') + 160