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creating_20a_20globally_20unique_20identifier
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This shows you the differences between two versions of the page.
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creating_20a_20globally_20unique_20identifier [2018/03/31 13:19] 127.0.0.1 external edit |
creating_20a_20globally_20unique_20identifier [2018/04/17 15:23] tbest3112 Added syntax highlighting |
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| {A8A8D3E5-713D-4C00-897E-F3B225E3A3AF} | {A8A8D3E5-713D-4C00-897E-F3B225E3A3AF} | ||
| GUIDs are used for a number of purposes in Windows, most notably to identify a **COM interface** (IID) or **class** (CLSID); in those cases you must discover the correct value to use from Microsoft's documentation.\\ \\ GUIDs are also useful whenever you need to identify something uniquely. For example in the article [[/Detecting%20a%20second%20instance%20of%20a%20program|Detecting a second instance of a program]] it is suggested that a GUID be used as the **UniqueLockName**. In such cases it is up to you to create a GUID for the purpose.\\ \\ There is no guarantee that a GUID is genuinely unique, but statistically the likelihood of any two being the same is small. Whilst you could simply make up your own 128-bit number 'at random' (whatever that means) it is far better to use one of the means provided specially for the purpose. One is the following website, which will create a new GUID on request: http://www.famkruithof.net/uuid/uuidgen.\\ \\ An alternative method is to use your own program. The code below will generate a new GUID whenever you need one:\\ \\ | GUIDs are used for a number of purposes in Windows, most notably to identify a **COM interface** (IID) or **class** (CLSID); in those cases you must discover the correct value to use from Microsoft's documentation.\\ \\ GUIDs are also useful whenever you need to identify something uniquely. For example in the article [[/Detecting%20a%20second%20instance%20of%20a%20program|Detecting a second instance of a program]] it is suggested that a GUID be used as the **UniqueLockName**. In such cases it is up to you to create a GUID for the purpose.\\ \\ There is no guarantee that a GUID is genuinely unique, but statistically the likelihood of any two being the same is small. Whilst you could simply make up your own 128-bit number 'at random' (whatever that means) it is far better to use one of the means provided specially for the purpose. One is the following website, which will create a new GUID on request: http://www.famkruithof.net/uuid/uuidgen.\\ \\ An alternative method is to use your own program. The code below will generate a new GUID whenever you need one:\\ \\ | ||
| + | <code bb4w> | ||
| SYS "LoadLibrary", "OLE32.DLL" TO ole32% | SYS "LoadLibrary", "OLE32.DLL" TO ole32% | ||
| SYS "GetProcAddress", ole32%, "CoCreateGuid" TO CoCreateGuid% | SYS "GetProcAddress", ole32%, "CoCreateGuid" TO CoCreateGuid% | ||
| Line 13: | Line 14: | ||
| SYS "WideCharToMultiByte", 0, 0, guidw%, -1, guida%, 40, 0, 0 | SYS "WideCharToMultiByte", 0, 0, guidw%, -1, guida%, 40, 0, 0 | ||
| PRINT $$guida% | PRINT $$guida% | ||
| + | </code> | ||
| The GUID is available as a 128-bit number in the structure **guid{}**, as a Unicode (16-bit) string at **guidw%** and as a NUL-terminated ANSI (8-bit) string at **guida%**. | The GUID is available as a 128-bit number in the structure **guid{}**, as a Unicode (16-bit) string at **guidw%** and as a NUL-terminated ANSI (8-bit) string at **guida%**. | ||
creating_20a_20globally_20unique_20identifier.txt ยท Last modified: 2018/04/17 15:23 by tbest3112
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