How to use _CRT_SECURE_NO_WARNINGS

Question

I have compile error in my simple MFC window application generated from wizard with several lines of code:

error C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

I set Configuration Properties>>C/C++>>Preporocessor>>Preprocessor Definitions>> _CRT_NONSTDC_NO_WARNINGS

But this does't helped. I have another very close project that generates only warning in this place and it has no _CRT_NONSTDC_NO_WARNINGS definition.

Only difference between projects is several different options in wizard.

Why _CRT_NONSTDC_NO_WARNINGS does not helps in first project and why second project compiles without problems without this definition?

Answer 1

Under "Project -> Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions" add _CRT_SECURE_NO_WARNINGS

Answer 2

Add by

Configuration Properties>>C/C++>>Preporocessor>>Preprocessor Definitions>> _CRT_SECURE_NO_WARNINGS

Answer 3

If your are in Visual Studio 2012 or later this has an additional setting 'SDL checks' Under Property Pages -> C/C++ -> General

Additional Security Development Lifecycle (SDL) recommended checks; includes enabling additional secure code generation features and extra security-relevant warnings as errors.

It defaults to YES - For a reason, I.E you should use the secure version of the strncpy. If you change this to NO you will not get a error when using the insecure version.

SDL checks in vs2012 and later