[RESOLVED] Does not recognize CreateSymbolicLink function

[mov_ebx]

Hello guys,
i wanted to use the CreateSymbolicLink function of WinAPI.
Here is my code:

#include <windows.h>
#include <tchar.h>
#include <stdio.h>
 
int _tmain(int argc, LPTSTR argv[]) {
 
    if (argc != 3) {
        _ftprintf(stderr, _T("Usage: symhard srcfile destfile"));
        return EXIT_FAILURE;
    }
 
    if(!CreateSymbolicLink(argv[2], argv[1], SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE)) {
        _ftprintf(stdout, _T("Creating symboliclink failed: %lx"), GetLastError());
        return 1;
    }
 
    return 0;
}

I'm using MSYS2 and clang version 5.0.0:

clang -Wall -Werror -pedantic -std=c99 -c symbolic_vs_hardlink.c

I always get the following output:

$ clang -Wall -Werror -pedantic -std=c99 -c symboliclink.c
symboliclink.c:12:6: error: implicit declaration of function 'CreateSymbolicLink' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
        if(!CreateSymbolicLink(argv[2], argv[1], SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE)) {
            ^
symboliclink.c:12:43: error: use of undeclared identifier 'SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE'
        if(!CreateSymbolicLink(argv[2], argv[1], SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE)) {
                                                 ^
2 errors generated.

It seems it does not know of the CreateSymbolicLink function nor the constant.
When trying the same code with Visual Studio 2017 it works and it also finds the function.

What am I doing wrong here?

[mov_ebx]

Why can't I edit my post? Here is the well formated code:

#include <windows.h>
#include <tchar.h>
#include <stdio.h>
 
int _tmain(int argc, LPTSTR argv[]) {
 
    if (argc != 3) {
        _ftprintf(stderr, _T("Usage: symhard srcfile destfile"));
        return EXIT_FAILURE;
    }
 
    if(!CreateSymbolicLink(argv[2], argv[1], SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE)) {
        _ftprintf(stdout, _T("Creating symboliclink failed: %lx"), GetLastError());
        return 1;
    }
 
    return 0;
}

[2kaud]

You can't edit the post as you need a certain number of posts (10?) before this facility is enabled. I'd edited your original post for this.

Sorry I can't help you as I don't use clang, just VS.

[mov_ebx]

If anybody is interested in the solution:
I had to modify _WIN32_WINNT. After adding

#define _WIN32_WINNT 0x600

before including the windows header file, it works!
The function is only available in Vista+ and VS compiler seems to add this defines automatically.

https://msdn.microsoft.com/en-us/library/6sehtctf.aspx

[VictorN]

Glad you have resolved your problem!
So I mark this thread as resolved!