1  /* mpf_out_str (stream, base, n_digits, op) -- Print N_DIGITS digits from
       2     the float OP to STREAM in base BASE.  Return the number of characters
       3     written, or 0 if an error occurred.
       4  
       5  Copyright 1996, 1997, 2001, 2002, 2005, 2011 Free Software Foundation, Inc.
       6  
       7  This file is part of the GNU MP Library.
       8  
       9  The GNU MP Library is free software; you can redistribute it and/or modify
      10  it under the terms of either:
      11  
      12    * the GNU Lesser General Public License as published by the Free
      13      Software Foundation; either version 3 of the License, or (at your
      14      option) any later version.
      15  
      16  or
      17  
      18    * the GNU General Public License as published by the Free Software
      19      Foundation; either version 2 of the License, or (at your option) any
      20      later version.
      21  
      22  or both in parallel, as here.
      23  
      24  The GNU MP Library is distributed in the hope that it will be useful, but
      25  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      26  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      27  for more details.
      28  
      29  You should have received copies of the GNU General Public License and the
      30  GNU Lesser General Public License along with the GNU MP Library.  If not,
      31  see https://www.gnu.org/licenses/.  */
      32  
      33  #define _GNU_SOURCE    /* for DECIMAL_POINT in langinfo.h */
      34  
      35  #include "config.h"
      36  
      37  #include <stdio.h>
      38  #include <string.h>
      39  
      40  #if HAVE_LANGINFO_H
      41  #include <langinfo.h>  /* for nl_langinfo */
      42  #endif
      43  
      44  #if HAVE_LOCALE_H
      45  #include <locale.h>    /* for localeconv */
      46  #endif
      47  
      48  #include "gmp-impl.h"
      49  #include "longlong.h"
      50  
      51  
      52  size_t
      53  mpf_out_str (FILE *stream, int base, size_t n_digits, mpf_srcptr op)
      54  {
      55    char *str;
      56    mp_exp_t exp;
      57    size_t written;
      58    TMP_DECL;
      59  
      60    TMP_MARK;
      61  
      62    if (base == 0)
      63      base = 10;
      64    if (n_digits == 0)
      65      MPF_SIGNIFICANT_DIGITS (n_digits, base, op->_mp_prec);
      66  
      67    if (stream == 0)
      68      stream = stdout;
      69  
      70    /* Consider these changes:
      71       * Don't allocate memory here for huge n_digits; pass NULL to mpf_get_str.
      72       * Make mpf_get_str allocate extra space when passed NULL, to avoid
      73         allocating two huge string buffers.
      74       * Implement more/other allocation reductions tricks.  */
      75  
      76    str = (char *) TMP_ALLOC (n_digits + 2); /* extra for minus sign and \0 */
      77  
      78    mpf_get_str (str, &exp, base, n_digits, op);
      79    n_digits = strlen (str);
      80  
      81    written = 0;
      82  
      83    /* Write sign */
      84    if (str[0] == '-')
      85      {
      86        str++;
      87        fputc ('-', stream);
      88        written = 1;
      89        n_digits--;
      90      }
      91  
      92    {
      93      const char  *point = GMP_DECIMAL_POINT;
      94      size_t      pointlen = strlen (point);
      95      putc ('0', stream);
      96      fwrite (point, 1, pointlen, stream);
      97      written += pointlen + 1;
      98    }
      99  
     100    /* Write mantissa */
     101    {
     102      size_t fwret;
     103      fwret = fwrite (str, 1, n_digits, stream);
     104      written += fwret;
     105    }
     106  
     107    /* Write exponent */
     108    {
     109      int fpret;
     110      fpret = fprintf (stream, (base <= 10 ? "e%ld" : "@%ld"), exp);
     111      written += fpret;
     112    }
     113  
     114    TMP_FREE;
     115    return ferror (stream) ? 0 : written;
     116  }