lib/ack/libm2/Terminal.mod

   1 #
   2 (*
   3   (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4   See the copyright notice in the ACK home directory, in the file "Copyright".
   5 *)
   6
   7 (*$R-*)
   8 IMPLEMENTATION MODULE Terminal;
   9 (*
  10   Module:       Input/Output to/from terminals
  11   Author:       Ceriel J.H. Jacobs
  12   Version:      $Header$
  13
  14   Implementation for Unix.
  15 *)
  16   FROM  SYSTEM IMPORT   ADR;
  17 #ifdef __USG
  18   FROM  Unix IMPORT     read, write, open, fcntl;
  19 #else
  20   FROM  Unix IMPORT     read, write, open, ioctl;
  21 #endif
  22   VAR fildes: INTEGER;
  23       unreadch: CHAR;
  24       unread: BOOLEAN;
  25       tty: ARRAY[0..8] OF CHAR;
  26
  27   PROCEDURE Read(VAR ch: CHAR);
  28   BEGIN
  29         IF unread THEN
  30                 ch := unreadch;
  31                 unread := FALSE
  32         ELSE
  33                 IF read(fildes, ADR(ch), 1) < 0 THEN
  34                         ;
  35                 END;
  36         END;
  37         unreadch := ch;
  38   END Read;
  39
  40   PROCEDURE BusyRead(VAR ch: CHAR);
  41     VAR l: INTEGER;
  42   BEGIN
  43         IF unread THEN
  44                 ch := unreadch;
  45                 unread := FALSE
  46         ELSE
  47 #ifdef __USG
  48                 l := fcntl(fildes, (*FGETFL*) 3, 0);
  49                 IF fcntl(fildes,
  50                               (* FSETFL *) 4,
  51                               l + (*ONDELAY*) 2) < 0 THEN
  52                         ;
  53                 END;
  54                 IF read(fildes, ADR(ch), 1) = 0 THEN
  55                         ch := 0C;
  56                 ELSE
  57                         unreadch := ch;
  58                 END;
  59                 IF fcntl(fildes, (*FSETFL*)4, l) < 0 THEN
  60                         ;
  61                 END;
  62 #else
  63 #ifdef __BSD4_2
  64                 IF ioctl(fildes, INTEGER(ORD('f')*256+127+4*65536+40000000H), ADR(l)) < 0 THEN
  65 #else
  66                 IF ioctl(fildes, INTEGER(ORD('f')*256+127), ADR(l)) < 0 THEN
  67 #endif
  68                         ;
  69                 END;
  70
  71                 IF l = 0 THEN
  72                         ch := 0C;
  73                 ELSE
  74                         IF read(fildes, ADR(ch), 1) < 0 THEN
  75                                 ;
  76                         END;
  77                         unreadch := ch;
  78                 END;
  79 #endif
  80         END;
  81   END BusyRead;
  82
  83   PROCEDURE ReadAgain;
  84   BEGIN
  85         unread := TRUE;
  86   END ReadAgain;
  87
  88   PROCEDURE Write(ch: CHAR);
  89   BEGIN
  90         IF write(fildes, ADR(ch), 1) < 0 THEN
  91                 ;
  92         END;
  93   END Write;
  94
  95   PROCEDURE WriteLn;
  96   BEGIN
  97         Write(12C);
  98   END WriteLn;
  99
 100   PROCEDURE WriteString(s: ARRAY OF CHAR);
 101     VAR i: CARDINAL;
 102   BEGIN
 103         i := 0;
 104         WHILE (i <= HIGH(s)) & (s[i] # 0C) DO
 105                 Write(s[i]);
 106                 INC(i)
 107         END
 108   END WriteString;
 109
 110 BEGIN
 111         tty := "/dev/tty";
 112         fildes := open(ADR(tty), 2);
 113         unread := FALSE;
 114 END Terminal.