C++ 'strcpy' gives a Warning (C4996)

Question

I am getting this warning but all functions working properly .

what does this really means?

\'strcpy\': This function or variable may be unsafe. 
Con         


        

Answer 1

use Secure Template Overloads or define wrapper functions not work for dynamically allocated buffers, so this attempt is futile.
Either modify source to use secure replacement, or just ignore it.

if the codes are writing by yourself, you had better change such strcpy to strcpy_s etc. if the modules are imported from trusted soures, you may choose to ignore the warning.

ignore method 1: project globle scope: add _CRT_SECURE_NO_WARNINGS
ignore method 2: ignore particular module: if only one or two of them, then you could simplely forbit warning for these modules when include them:

#pragma warning(push)
#pragma warning(disable: 4996)
#include <sapi.h>  //legacy module
#include <sphelper.h> //legacy module
#pragma warning(pop)

Answer 2

This function (strcpy) is considered unsafe due to the fact that there is no bounds checking and can lead to buffer overflow. (Actually strcpy is infamous for overflow exploits and all programmers avoid it-or at least should avoid it). The advice is to use a safe function which takes into account the size of the destination buffer to avoid overflow. You could also use strncpy (BUT with caution!). There is no problem with your code, i.e. the functions will run as you say but try giving as input a buffer that is larger than the destination buffer. The function will overflow the destination buffer. Check this also link text

Answer 3

Since you’re programming C++, the correct solution is to ban C-style char* strings from your code where possible, and replace them by std::string (or another appropriate string type).

Do not use functions such as strcpy or strcpy_s or strncpy. Use the copy constructor or assignment operator of the string class. Or if you really need to copy buffers, use std::copy.