InputWait

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Here's a subroutine to mimic the INPUT WAITING capability that exists in Unidata. It has all the functionality including duplicating the behaviour of the underscore and colon when specifying the maximum string length. For example, if you want to input three characters for variable THIS, waiting for 10 seconds, requiring a carriage return to signify input but without a line feed, and defaulting to the string "zip"; you would code:

CALL INPUTWAIT(THIS, '3_:', '10', 'zip' )

     SUBROUTINE INPUTWAIT(STR, MAX, TIM, DEF)
     * S[[/R]] - KRJ - Duplicates INPUT... WAITING mechanism on UNIDATA
     * which doesn't exist in UNIVERSE
     *
     * STR is the string being input
     * MAX is the maximum string length (can have underline and colon)
     * TIM is the delay in seconds
     * DEF is the default if nothing is entered
     *
     * This matches up with the format
     * INPUT STR,MAX FOR TIM ELSE STR = DEF
     * PT standard setup
     $OPTIONS PICK.FORMAT CASE FORMAT.OCONV TIME.MILLISECOND PERF.EQ.EXEC
     $OPTIONS ONGO.RANGE -READ.RETAIN
     * See whether a colon or underline is in the string MAX
     * COL shows that the cursor is to be held on the line
     * UND shows that a carriage return is required input
     *
     IF INDEX(MAX, ':', 1) THEN COL = @TRUE ELSE COL = @FALSE
     IF INDEX(MAX, '_', 1) THEN UND = @TRUE ELSE UND = @FALSE
  *
     MAX = OCONV(MAX, 'MCN')
     STR = ''
     NUM = 0
     CHR = ''
     LOOP
        TAB = @FALSE
        BEG = SYSTEM(12)
        EOW = @FALSE
        LOOP
  * Check whether there is anything in the type-ahead buffer (TAB)
           INPUT TAB, -1
           NOW = SYSTEM(12)
  * Check how long we've been waiting for input
           IF NOW LT BEG THEN EOW = @TRUE
           IF ((NOW-BEG)/1000) GE TIM THEN EOW = @TRUE
        UNTIL TAB OR EOW DO NAP 100 REPEAT
  * We've either got something or we have waited too long. check TAB
        IF TAB THEN
           CHR = KEYIN()
  * A carriage return or linefeed is an <ENTER>
           IF CHR = CHAR(10) OR CHR = CHAR(13) THEN CHR = ''
           IF CHR NE '' THEN
  * Check for a backspace, but we must have something to backspace over!
              IF CHR = CHAR(8) THEN
                 IF NUM THEN
                    CRT @(-9):' ':@(-9):
                    STR = STR[1, LEN(STR)-1]
                    NUM -= 1
                 END
              END ELSE
  * Check for maximum length
                 IF NOT(MAX) OR NUM LT MAX THEN
  * We could parse out control chars here, but UNIDATA don't
                    STR := CHR
                    NUM += 1
                    CRT CHR:
                 END
  * Check for any maximum length
                 IF NOT(UND) AND MAX AND NUM GE MAX THEN CHR = ''
              END
           END
        END ELSE CHR = ''
     UNTIL CHR = '' DO REPEAT
  * On the way out - see if we had to wait too long
     IF EOW THEN STR = DEF ELSE
  * If we didn't we may have to do the carriage return / line feed
        IF COL ELSE CRT
     END
     RETURN