fopen deprecated warning

Question

On Visual Studio 2005 C++ compiler, I get the following warning when my code uses the fopen and such calls.

1>foo.cpp(5) : warning C4996: 'fopen' was declared deprecated
1>        c:\program files\microsoft visual studio 8\vc\include\stdio.h(234) : see declaration of 'fopen'
1>        Message: 'This function or variable may be unsafe. Consider using fopen_s instead. To disable deprecation, use _CRT_SECURE_NO_DEPRECATE. See online help for details.'

How do I prevent this?

Answer 1

It looks like Microsoft has deprecated lots of calls which use buffers to improve code security. However, the solutions they're providing aren't portable. Anyway, if you aren't interested in using the secure version of their calls (like fopen_s), you need to place a definition of _CRT_SECURE_NO_DEPRECATE before your included header files. For example:

#define _CRT_SECURE_NO_DEPRECATE
#include <stdio.h>

The preprocessor directive can also be added to your project settings to effect it on all the files under the project. To do this add _CRT_SECURE_NO_DEPRECATE to Project Properties -> Configuration Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions.