SAMPLE: Wsscanf.exe Replaces sscanf in Windows DLLs (76684)

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The following file is available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.

The sscanf(), fprintf(), and scanf() functions are not available for Windows DLLs.

There are two factors that cause these functions to be incompatible:

1. These functions rely on near pointers.
2. These functions expect SS == DS.

Because neither of these conditions is true when a function in a DLL uses data from an application, these functions are not available.

The WSSCANF file in the Microsoft Download Center contains the source code to a wsscanf() function that can serve as a limited replacement for the sscanf function. It does not support floating point. The wsscanf() code is based on the sscanf() source code in the Microsoft C 6.0a run-time library. The source code has been modified to work correctly in a DLL, and requires that all parameters are specified as FAR pointers. The following code demonstrates using the wsscanf() function:

    char   szBuf[] = "1 3 b000:0200";
   int    nValue1, nValue2;
   LPSTR  lpPtr;

   wsscanf(szBuf, "%d %d %p", (int FAR *)&nValue1,
            (int FAR *)&nValue2, (LPSTR FAR *)&lpPtr);
				

NOTE: The first two parameters are not explicitly typecast in the function call. The function prototype typecasts the first two parameters automatically; however, the application must typecast each subsequent parameter. If the application does not typecast each parameter, when the application calls wsscanf an unrecoverable application error (UAE) occurs.

The wsscanf() function does not support floating point numbers (the %f, %g, and %e format specifiers).