Microsoft KB Archive/167326

= FIX: Intrinsic Version of strcmp May Return Incorrect Result =

Article ID: 167326

Article Last Modified on 12/10/2003

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APPLIES TO


 * Microsoft Visual C++ 5.0 Enterprise Edition
 * Microsoft Visual C++ 6.0 Enterprise Edition
 * Microsoft Visual C++ 5.0 Professional Edition
 * Microsoft Visual C++ 6.0 Professional Edition
 * Microsoft Visual C++ 6.0 Standard Edition

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This article was previously published under Q167326



SYMPTOMS
Explicitly referencing the Null character in the second argument of strcmp causes the intrinsic version of strcmp to incorrectly report the two arguments are not equal. Please see the sample code below.



RESOLUTION
Use one of the following two workarounds:


 * Do not explicitly reference the Null character.
 * Do not use the intrinsic version of strcmp.

Please see the "MORE INFORMATION" section and sample code below.



STATUS
Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.



MORE INFORMATION
You can enable intrinsic functions either by using of the /Oi compiler switch or #pragma intrinsic. To disable intrinsic functions, remove the /Oi compiler switch, add /Oi-, or use #pragma function to force a function call on a function by function basis. Please see the sample code below for use of the #pragma function.

Sample Code
/* Build Options: /Oi */ #include   #include    // uncomment the following line for workaround #2 //#pragma function(strcmp)

int main(void) {     char somestr [15]  = "Some String";

somestr[1] = 0;

// change the following to strcmp(somestr,"S") for workaround #1 if (strcmp(somestr,"S\0") == 0) printf("match: correct\n"); else printf("no match: incorrect\n"); return 0; } Note that a more common use of an embedded Null character may be to compare a string to "\0" to see if it is an empty string. For the first workaround above, compare it to "" instead.

Keywords: kbbug kbfix kbnoupdate kbprogramming kbcode KB167326

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