mes/lib/mes/ntoab.c

/* -*-comment-start: "//";comment-end:""-*-
 * GNU Mes --- Maxwell Equations of Software
 * Copyright © 2016,2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
 *
 * This file is part of GNU Mes.
 *
 * GNU Mes 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 3 of the License, or (at
 * your option) any later version.
 *
 * GNU Mes 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 GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <libmes.h>

char const*
ntoab (long x, int base, int signed_p)
{
  static char itoa_buf[20];
  char *p = itoa_buf + 11;
  *p-- = 0;

  int sign = 0;
  unsigned long u = x;
  if (signed_p && x < 0)
    {
      sign = 1;
      u = -x;
    }

  do
     {
       long i = u % base;
       *p-- = i > 9 ? 'a' + i - 10 : '0' + i;
       u = u / base;
     } while (u);

  if (sign && *(p + 1) != '0')
    *p-- = '-';

  return p+1;
}