stdlib/l64a.c

   1 /* Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <stdlib.h>
  21
  22 /* Conversion table.  */
  23 static const char conv_table[64] =
  24 {
  25   '.', '/', '0', '1', '2', '3', '4', '5',
  26   '6', '7', '8', '9', 'A', 'B', 'C', 'D',
  27   'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L',
  28   'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
  29   'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b',
  30   'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
  31   'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r',
  32   's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
  33 };
  34
  35 char *
  36 l64a (n)
  37      long int n;
  38 {
  39   static char result[7];
  40   int cnt;
  41
  42   if (n <= 0l)
  43     /* The value for N == 0 is defined to be the empty string.  When a
  44        negative value is given the result is undefined.  We will
  45        return the empty string.  */
  46     return (char *) "";
  47
  48   result[6] = '\0';
  49
  50   for (cnt = 5; n > 0; --cnt)
  51     {
  52       result[cnt] = conv_table[n & 0x3f];
  53       n >>= 6;
  54     }
  55
  56   return &result[n + 1];
  57 }