stk/Mp/gmp-1.3.2/mpz_inp_str.c

106 lines
2.3 KiB
C

/* mpz_inp_str(dest_integer, stream, base) -- Input a number in base
BASE from stdio stream STREAM and store the result in DEST_INTEGER.
Copyright (C) 1991, 1993 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
The GNU MP Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the GNU MP Library; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <stdio.h>
#include <ctype.h>
#include "gmp.h"
#include "gmp-impl.h"
static int
char_ok_for_base (c, base)
int c;
int base;
{
if (isdigit (c))
return (unsigned) c - '0' < base;
if (islower (c))
return (unsigned) c - 'a' + 10 < base;
if (isupper (c))
return (unsigned) c - 'A' + 10 < base;
return 0;
}
void
#ifdef __STDC__
mpz_inp_str (MP_INT *dest, FILE *stream, int base)
#else
mpz_inp_str (dest, stream, base)
MP_INT *dest;
FILE *stream;
int base;
#endif
{
char *str;
size_t str_size;
size_t i;
int c;
int negative = 0;
str_size = 100;
str = (char *) (*_mp_allocate_func) (str_size);
c = getc (stream);
if (c == '-')
{
negative = 1;
c = getc (stream);
}
/* If BASE is 0, try to find out the base by looking at the initial
characters. */
if (base == 0)
{
base = 10;
if (c == '0')
{
base = 8;
c = getc (stream);
if (c == 'x' || c == 'X')
{
base = 16;
c = getc (stream);
}
}
}
for (i = 0; char_ok_for_base (c, base); i++)
{
if (i >= str_size)
{
size_t old_str_size = str_size;
str_size = str_size * 3 / 2;
str = (char *) (*_mp_reallocate_func) (str, old_str_size, str_size);
}
str[i] = c;
c = getc (stream);
}
ungetc (c, stream);
str[i] = 0;
_mpz_set_str (dest, str, base);
if (negative)
dest->size = -dest->size;
(*_mp_free_func) (str, str_size);
}