git.distorted.org.uk Git - u/mdw/catacomb/blob - mptext-string.c

   1 /* -*-c-*-
   2  *
   3  * $Id: mptext-string.c,v 1.3 2000/08/04 23:23:44 mdw Exp $
   4  *
   5  * Reading and writing large integers on strings
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: mptext-string.c,v $
  33  * Revision 1.3  2000/08/04 23:23:44  mdw
  34  * Various <ctype.h> fixes.
  35  *
  36  * Revision 1.2  1999/12/22 15:56:21  mdw
  37  * Make the buffer passed to `put' op constant.
  38  *
  39  * Revision 1.1  1999/11/17 18:02:16  mdw
  40  * New multiprecision integer arithmetic suite.
  41  *
  42  */
  43
  44 /*----- Header files ------------------------------------------------------*/
  45
  46 #include <string.h>
  47
  48 #include "mptext.h"
  49
  50 /*----- Main code ---------------------------------------------------------*/
  51
  52 /* --- Operations table --- */
  53
  54 static int get(void *p)
  55 {
  56   mptext_stringctx *c = p;
  57   if (c->buf >= c->lim)
  58     return (EOF);
  59   return ((unsigned char)*c->buf++);
  60 }
  61
  62 static void unget(int ch, void *p)
  63 {
  64   mptext_stringctx *c = p;
  65   if (ch != EOF)
  66     c->buf--;
  67 }
  68
  69 static int put(const char *s, size_t sz, void *p)
  70 {
  71   mptext_stringctx *c = p;
  72   int rc = 0;
  73   if (sz > c->lim - c->buf) {
  74     sz = c->lim - c->buf;
  75     rc = EOF;
  76   }
  77   if (sz) {
  78     memcpy(c->buf, s, sz);
  79     c->buf += sz;
  80   }
  81   return (rc);
  82 }
  83
  84 const mptext_ops mptext_stringops = { get, unget, put };
  85
  86 /* --- Convenience functions --- */
  87
  88 mp *mp_readstring(mp *m, const char *p, char **end, int radix)
  89 {
  90   mptext_stringctx c;
  91   c.buf = (char *)p;
  92   c.lim = c.buf + strlen(p);
  93   m = mp_read(m, radix, &mptext_stringops, &c);
  94   if (end)
  95     *end = c.buf;
  96   return (m);
  97 }
  98
  99 int mp_writestring(mp *m, char *p, size_t sz, int radix)
 100 {
 101   mptext_stringctx c;
 102   int rc;
 103   if (!sz)
 104     return (0);
 105   c.buf = p;
 106   c.lim = p + sz - 1;
 107   rc = mp_write(m, radix, &mptext_stringops, &c);
 108   *c.buf = 0;
 109   return (rc);
 110 }
 111
 112 /*----- That's all, folks -------------------------------------------------*/