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/**
* \file guid.c
* \brief GUID creation and validation.
* \author Copyright (c) 2002-2008 Jason Perkins and the Premake project
*/
#include <stdio.h>
#include <string.h>
#include "premake.h"
#include "guid.h"
#include "platform/platform.h"
#include "base/buffers.h"
static void stringify(char* src, char* dst, int count);
/**
* Create a new GUID, with the format "4E67EBCE-BC8B-4058-9AA9-48EE5E003683".
* \returns The new GUID.
*/
const char* guid_create()
{
char guid[16];
char* result = buffers_next();
/* get a GUID as an array of 16 bytes */
platform_create_guid(guid);
/* convert that array to a string in the usual format */
stringify(guid, result, 4);
result[8] = '-';
stringify(guid + 4, result + 9, 2);
result[13] = '-';
stringify(guid + 6, result + 14, 2);
result[18] = '-';
stringify(guid + 8, result + 19, 2);
result[23] = '-';
stringify(guid + 10, result + 24, 6);
result[36] = '\0';
return result;
}
/**
* Validate the format of a GUID, which should use the form "4E67EBCE-BC8B-4058-9AA9-48EE5E003683".
* \param value The guid to validate.
* \returns True if valid, zero otherwise.
*/
int guid_is_valid(const char* value)
{
int i, n;
/* make sure it is the right size */
if (strlen(value) != 36)
return 0;
/* check for dashes in the right places */
if (value[8] != '-' ||
value[13] != '-' ||
value[18] != '-' ||
value[23] != '-')
{
return 0;
}
/* make sure only [0-9A-F-] are present; count the number of dashes on the way */
n = 0;
for (i = 0; i < 36; ++i)
{
if (value[i] == '-')
{
++n;
}
else if ((value[i] < '0' || value[i] > '9') &&
(value[i] < 'A' || value[i] > 'F') &&
(value[i] < 'a' || value[i] > 'f'))
{
return 0;
}
}
/* make sure I've got the right number of dashes */
if (n != 4)
{
return 0;
}
return 1;
}
/**
* Convert an array of bytes to a string.
* \param src The source array of bytes.
* \param dst The destination string buffer.
* \param count The number of bytes to convert.
*/
static void stringify(char* src, char* dst, int count)
{
int i;
for (i = 0; i < count; ++i)
{
unsigned value = (unsigned char)src[i];
sprintf(dst, "%02X", value);
dst += 2;
}
}
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