Setting up the name of a file in the executable directory

I have to create a buffer to hold the the name of a license file which is in the executable directory. This is my klugy solution (I'm not a C programmer):

Code:

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  char buffer[MAX_PATH] = "";
  GetModuleFileName(NULL, buffer, MAX_PATH);
  int len = (int) strlen(buffer);
  buffer[len-7] = '\0';
  strcat(buffer,"license.lic");

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Note I know the name of the executable is net.exe - 7 chars, so I'm cheating.

Firstly is this code safe? I got a compiler warning about using strcat saying I should use strcat_s, but I couldn't get that working.

Secondly how do I get the correct length of the executable name?

> Firstly is this code safe?
No.
- you don't check GetModuleFileName for success (I really hope this code goes nowhere near XP, which broke GetModuleFileName)
- len is unnecessarily an int - make it size_t
- len-7 risks potential underflow if the (ab)user can manipulate the name of your program
- strcat risks potential overflow for the same reason.

> Note I know the name of the executable is net.exe
Today maybe, but what if some wally moves your program to C:\x.exe ?

> I got a compiler warning about using strcat saying I should use strcat_s, but I couldn't get that working.
That doesn't tell us much. You need to show your attempt if you want diagnosis as to how you got it wrong.

> Secondly how do I get the correct length of the executable name?
You could use p = strrchr(buff,'\\');
If successful, p will point to the last '\' in buff.



If you just want to get going and ignore issues, then put this on line 1 of your code.

Code:

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#define _CRT_SECURE_NO_DEPRECATE

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