lib/ack/libp/rdi.c

   1 /* $Header$ */
   2 /*
   3  * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4  *
   5  *          This product is part of the Amsterdam Compiler Kit.
   6  *
   7  * Permission to use, sell, duplicate or disclose this software must be
   8  * obtained in writing. Requests for such permissions may be sent to
   9  *
  10  *      Dr. Andrew S. Tanenbaum
  11  *      Wiskundig Seminarium
  12  *      Vrije Universiteit
  13  *      Postbox 7161
  14  *      1007 MC Amsterdam
  15  *      The Netherlands
  16  *
  17  */
  18
  19 /* Author: J.W. Stevenson */
  20
  21 #include        <pc_file.h>
  22 #include        <pc_err.h>
  23
  24 extern          _trp();
  25 extern          _rf();
  26 extern          _incpt();
  27
  28 _skipsp(f) struct file *f; {
  29         while ((*f->ptr == ' ') || (*f->ptr == '\t'))
  30                 _incpt(f);
  31 }
  32
  33 int _getsig(f) struct file *f; {
  34         int sign;
  35
  36         if ((sign = (*f->ptr == '-')) || *f->ptr == '+')
  37                 _incpt(f);
  38         return(sign);
  39 }
  40
  41 int _fstdig(f) struct file *f; {
  42         int ch;
  43
  44         ch = *f->ptr - '0';
  45         if ((unsigned) ch > 9) {
  46                 _trp(EDIGIT);
  47                 ch = 0;
  48         }
  49         return(ch);
  50 }
  51
  52 int _nxtdig(f) struct file *f; {
  53         int ch;
  54
  55         _incpt(f);
  56         ch = *f->ptr - '0';
  57         if ((unsigned) ch > 9)
  58                 return(-1);
  59         return(ch);
  60 }
  61
  62 int _getint(f) struct file *f; {
  63         int is_signed,i,ch;
  64
  65         is_signed = _getsig(f);
  66         ch = _fstdig(f);
  67         i = 0;
  68         do
  69                 i = i*10 - ch;
  70         while ((ch = _nxtdig(f)) >= 0);
  71         return(is_signed ? i : -i);
  72 }
  73
  74 int _rdi(f) struct file *f; {
  75         _rf(f);
  76         _skipsp(f);
  77         return(_getint(f));
  78 }