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

   1 /* -*-c-*-
   2  *
   3  * $Id: mptext-string.c,v 1.5 2004/04/08 01:36:15 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 /*----- Header files ------------------------------------------------------*/
  31
  32 #include <string.h>
  33
  34 #include "mptext.h"
  35
  36 /*----- Main code ---------------------------------------------------------*/
  37
  38 /* --- Operations table --- */
  39
  40 static int get(void *p)
  41 {
  42   mptext_stringctx *c = p;
  43   if (c->buf >= c->lim)
  44     return (EOF);
  45   return ((unsigned char)*c->buf++);
  46 }
  47
  48 static void unget(int ch, void *p)
  49 {
  50   mptext_stringctx *c = p;
  51   if (ch != EOF)
  52     c->buf--;
  53 }
  54
  55 static int put(const char *s, size_t sz, void *p)
  56 {
  57   mptext_stringctx *c = p;
  58   int rc = 0;
  59   if (sz > c->lim - c->buf) {
  60     sz = c->lim - c->buf;
  61     rc = EOF;
  62   }
  63   if (sz) {
  64     memcpy(c->buf, s, sz);
  65     c->buf += sz;
  66   }
  67   return (rc);
  68 }
  69
  70 const mptext_ops mptext_stringops = { get, unget, put };
  71
  72 /* --- Convenience functions --- */
  73
  74 mp *mp_readstring(mp *m, const char *p, char **end, int radix)
  75 {
  76   mptext_stringctx c;
  77   c.buf = (/*unconst */ char *)p;
  78   c.lim = c.buf + strlen(p);
  79   m = mp_read(m, radix, &mptext_stringops, &c);
  80   if (end)
  81     *end = c.buf;
  82   return (m);
  83 }
  84
  85 int mp_writestring(mp *m, char *p, size_t sz, int radix)
  86 {
  87   mptext_stringctx c;
  88   int rc;
  89   if (!sz)
  90     return (0);
  91   c.buf = p;
  92   c.lim = p + sz - 1;
  93   rc = mp_write(m, radix, &mptext_stringops, &c);
  94   *c.buf = 0;
  95   return (rc);
  96 }
  97
  98 /*----- That's all, folks -------------------------------------------------*/