typedef struct _GUID {
DWORD data 1；
WORD Data2
WORD Data3
Byte data 4 [8];
} GUID
For example:
Suppose the format of a GUID is 6b29fc40-ca47-1067-b31d-00dd010662da.
Among them, Data 1 is 32 bits, which can be regarded as eight four-digit hexadecimal numbers, corresponding to the above 6B29FC40.
Where Data2 is 16, which can be regarded as four four-digit hexadecimal numbers, corresponding to CA47 above.
Data3 is 16 bit, which can be regarded as four four-digit hexadecimal numbers, corresponding to 1067 above.
Among them, Data4 is special, 8 bytes, which can be regarded as 16 four-digit hexadecimal number.
Take data4 [0] and data4 [1] to form four four-digit hexadecimal numbers, corresponding to B3 1D above.
Take data4 [2] and data4 [3] to form four four-digit hexadecimal numbers, corresponding to the above 00DD.
Take data4 [4] and data4 [5] to form four four-digit hexadecimal numbers, corresponding to 0 106 above.
Take data4 [6] and data4 [7] to form four four-digit hexadecimal numbers, corresponding to the above 62DA.
* Note: Four hexadecimal digits correspond to one GUID character.
The function of generating GUID is provided under Windows. You need to use the header file "objbase.h" and the link library ole32.lib
HRESULT cocreate GUID(GUID * pguid)；
Under Linux, you need to download the corresponding library files and header files first.
If you are a Debian user, you can easily get related resources through the apt command.
Apt-get installs uuid-dev
After the installation, you will find that
There is a uuid folder under /usr/include/, which contains the header file uuid.h
There are several libuuid* link library files under /usr/lib/, including static and dynamic link libraries.
Open uuid.h and you will find a function declaration of uuid _ uuid_generate(uuid_t out). We can generate UUID by calling this function.
uuid _ generate(reinterpret _ cast & lt； Unsigned character *> (& guid));
Is GUID easy to generate? Yes, because we don't need to implement the generated algorithm, we are standing on the shoulders of our predecessors, so we should thank them.
The following are general programs under WINDOWS and LINUX.
// uuid_test.cpp
# include & lt string & gt
# include & ltstdio.h & gt
# include & ltiostream & gt
# contains "uuid_test.hpp"
#ifdef WIN32
# include & ltobjbase.h & gt
# Otherwise
# include & ltuuid/uuid . h & gt；
#endif
Use namespace std
Namespace ChinuxTeam
{
GUID CreateGuid()
{
GUID guid
#ifdef WIN32
CoCreateGuid(& amp； guid)；
# Otherwise
uuid _ generate(reinterpret _ cast & lt； Unsigned character *> (& guid));
#endif
Return guid
}
string GUID tostring(const GUID & amp； guid)
{
char buf[64]= { 0 }；
#ifdef __GNUC__
snprintf(
# Otherwise // MSVC
_snprintf_s(
#endif
buf，
sizeof(buf)，
" { % 08X-% 04X-% 04X-% 02X % 02X-% 02X % 02X % 02X % 02X % 02X % 02X } "，
guid。 Data 1, guid. Data 2, guid. Data 3,
guid。 Data 4[0], guid. Data 4[ 1],
guid。 Data 4[2], guid. Data 4[3],
guid。 Data 4[4], guid. Data 4[5],
guid。 Data 4[6], guid. data 4[7])；
Returns STD:: string (buf);
}
}
Corresponding header file
// uuid_test.hpp "
# include & lt string & gt
# include & ltstdio.h & gt
# include & ltiostream & gt
typedef struct _GUID
{
Unsigned long data1;
Unsigned short data 2;
Unsigned short data 3;
Unsigned character data 4 [8];
} UUID GUID；
Namespace ChinuxTeam
{
GUID create GUID()；
string GUID tostring(const GUID & amp； guid)；
}//namespace ChinuxTeam
The last GuidToString () is explained a little bit, which is used to output GUIDs as a standard String with a fixed format.
According to different calls of compiler, different string printing functions are called.
Attach a simple test function.
# include & lt string & gt
# include & ltstdio.h & gt
# include & ltiostream & gt
#ifdef WIN32
# contains "objbase.h"
# Otherwise
typedef struct _GUID
{
Unsigned long data1;
Unsigned short data 2;
Unsigned short data 3;
Unsigned character data 4 [8];
} UUID GUID；
#endif
Namespace ChinuxTeam{
GUID create GUID()；
string GUID tostring(const GUID & amp； guid)；
}
After running, a GUID will be generated and printed on the console with standard output.