basic/readline.in.bas

   1 EOF=0
   2
   3 REM READLINE(A$) -> R$
   4 READLINE:
   5   EOF=0
   6   PROMPT$=A$
   7   PRINT PROMPT$;
   8   CH$="": LINE$="": CH=0
   9   READCH:
  10     GET CH$: IF CH$="" THEN READCH
  11     CH=ASC(CH$)
  12     IF (CH=4 OR CH=0) THEN EOF=1: GOTO RL_DONE: REM EOF
  13     IF (CH=127) THEN GOSUB RL_BACKSPACE
  14     IF (CH=127) THEN GOTO READCH
  15     IF (CH<32 OR CH>127) AND CH<>13 THEN READCH
  16     IF LEN(LINE$)<255 AND CH$<>CHR$(13) THEN LINE$=LINE$+CH$
  17     IF LEN(LINE$)<255 AND CH$<>CHR$(13) THEN GOTO READCH
  18   RL_DONE:
  19     R$=LINE$
  20     RETURN
  21
  22   REM Assumes LINE$ has input buffer
  23   RL_BACKSPACE:
  24   IF LEN(LINE$)=0 THEN RL_BACKSPACE_ONCE:
  25     PRINT CHR$(157) + CHR$(157) + "  " + CHR$(157) + CHR$(157);
  26     LINE$=LEFT$(LINE$, LEN(LINE$)-1)
  27     RETURN
  28   RL_BACKSPACE_ONCE:
  29     PRINT CHR$(157) + " " + CHR$(157);
  30     RETURN