uuid/unparse.c

   1 /*
   2  * unparse.c -- convert a UUID to string
   3  *
   4  * Copyright (C) 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, and the entire permission notice in its entirety,
  12  *    including the disclaimer of warranties.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote
  17  *    products derived from this software without specific prior
  18  *    written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  21  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
  23  * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
  24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  26  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  27  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  30  * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
  31  * DAMAGE.
  32  * %End-Header%
  33  */
  34
  35 #include <stdio.h>
  36
  37 #include "uuid.h"
  38
  39 void uuid_unparse(const uuid_t uu, char *out)
  40 {
  41         const uint8_t *uuid_array = (const uint8_t *)uu;
  42         unsigned int uuid_index;
  43         static const char *fmt = "0123456789ABCDEF";
  44
  45         for ( uuid_index = 0; uuid_index < sizeof(uuid_t); ++uuid_index ) {
  46                 // insert '-' after the 4th, 6th, 8th, and 10th uuid byte
  47                 switch (uuid_index) {
  48                 case 4:
  49                 case 6:
  50                 case 8:
  51                 case 10:
  52                         *out++ = '-';
  53                         break;
  54                 }
  55                 // insert uuid byte as two hex characters
  56                 *out++ = fmt[*uuid_array >> 4];
  57                 *out++ = fmt[*uuid_array++ & 0xF];
  58         }
  59         *out = 0;
  60 }