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/* l64a - convert long to radix-64 ascii string

 *

 * Conversion is performed on at most 32-bits of input value starting

 * from least significant bits to the most significant bits.

 *

 * The routine splits the input value into groups of 6 bits for up to

 * 32 bits of input.  This means that the last group may be 2 bits

 * (bits 30 and 31).

 *

 * Each group of 6 bits forms a value from 0-63 which is converted into

 * a character as follows:

 *         0 = '.'

 *         1 = '/'

 *         2-11 = '0' to '9'

 *        12-37 = 'A' to 'Z'

 *        38-63 = 'a' to 'z'

 *

 * When the remaining bits are zero or all 32 bits have been translated,

 * a nul terminator is appended to the resulting string.  An input value of

 * 0 results in an empty string.

 */

#include <_ansi.h>

#include <stdlib.h>

#include <reent.h>

static const char R64_ARRAY[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

char *

_DEFUN (l64a, (value),

     long value)

{

  return _l64a_r (_REENT, value);

}

char *

_DEFUN (_l64a_r, (rptr, value),

     struct _reent *rptr _AND

     long value)

{

  char *ptr;

  char *result;

  int i, index;

  unsigned long tmp = (unsigned long)value & 0xffffffff;

  _REENT_CHECK_MISC(rptr);

  result = _REENT_L64A_BUF(rptr);

  ptr = result;

  for (i = 0; i < 6; ++i)

    {

      if (tmp == 0)

        {

          *ptr = '\0';

          break;

        }

      index = tmp & (64 - 1);

      *ptr++ = R64_ARRAY[index];

      tmp >>= 6;

    }

  return result;

}