WinAPI - Create .ini file if it doesn't exist

Question

Possible Duplicate:
c++ how to create a directory from a path

I'm trying to create an .ini file in the application data folder so I can use settings. I gave it a try, but I couldn't figure out how to check if it already exists, and if not, create the subdirectory and .ini file.

When I get the last error message it says "The system cannot find the path specified."

#include <string>
using namespace std;

#include <Windows.h>
#include <Shlwapi.h>
#include <ShlObj.h>
#pragma comment(lib, "shlwapi.lib")

namespace Settings
{
    CIni        Ini;
    bool        Available = false;
    char        Directory[MAX_PATH];
    const char *IniFileName = "Settings.ini";

    void CheckError() {
        LPVOID lpMsgBuf;
        LPVOID lpDisplayBuf;
        DWORD dw = GetLastError(); 

        FormatMessage(
            FORMAT_MESSAGE_ALLOCATE_BUFFER | 
            FORMAT_MESSAGE_FROM_SYSTEM |
            FORMAT_MESSAGE_IGNORE_INSERTS,
            NULL, dw,
            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
            (LPTSTR)&lpMsgBuf, 0, NULL
        );

        string msg = (LPTSTR)lpMsgBuf;
        Error(msg); // MessageBox
    }

    void Initialize() {
        // Get AppData directory
        if (SHGetFolderPath(0, CSIDL_COMMON_APPDATA, 0, 0, Directory) >= 0) {
            string fullpath;
            string subDir = "\\MyCompany\\MyProgram\\1.0\\";

            PathAppend(Directory, subDir.c_str());
            fullpath = Directory;
            fullpath += IniFileName;

            // If directory doesn't exist, create it.
            DWORD attrib = GetFileAttributes(Directory);
            if (!(attrib != INVALID_FILE_ATTRIBUTES && (attrib & FILE_ATTRIBUTE_DIRECTORY))) {

                if (CreateDirectory(Directory, NULL)) {
                    HANDLE file = CreateFile(
                        fullpath.c_str(), GENERIC_WRITE, 0, 0,
                        CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0
                    );

                    if (file != INVALID_HANDLE_VALUE) {
                        CloseHandle(file);
                    } else {
                        CheckError();
                        return;
                    }
                } else {
                    CheckError();
                    return;
                }
            }

            Ini.SetPathName(fullpath.c_str());
            Available = true;
        }
    }
}

I checked and my call to CreateDirectory() is returning false. How can I check if the file and directory exists, and if not then create them?

score 1 · Answer 1 · answered Oct 11 '12 at 12:12

1

You need to create the sub folders one level at a time.

i.e. create "MyCompany" then "MyProgram" then "1.0".. You can write a function to do this, similar to VCL's ForceDirectories.

Additionally, be aware that common app data is not writable on windows7 unless running with admin priviledges. Unless your application installer creates a sub-folder and sets the appropriate security ACLs on it to allow access. Avoid if you can and use the user app data folder.

answered Oct 11 '12 at 12:12

Pete

4,784
26
33

How do I get the user AppData folder? Because I would like to avoid having to get admin privileges. – Brandon Miller Oct 11 '12 at 12:16
Oh, `CSIDL_APPDATA` or `CSIDL_APPDATA_LOCAL`? Or will either do? – Brandon Miller Oct 11 '12 at 12:18
`CSIDL_APPDATA`. That's the one that works with roaming profiles. – David Heffernan Oct 11 '12 at 12:28
+1 for CSIDL_APPDATA, I'm trying not to require elevation. – Brandon Miller Oct 11 '12 at 12:48

Andriy · Accepted Answer · 2012-10-11T12:22:47.610

1

if (SHCreateDirectoryEx(NULL, Directory, NULL) || 
    GetLastError() == ERROR_ALREADY_EXISTS) 
   {
   HANDLE file = CreateFile(
      fullpath.c_str(), GENERIC_WRITE, 0, 0,
      CREATE_NEW, FILE_ATTRIBUTE_NORMAL, 0);

   if (file != INVALID_HANDLE_VALUE) 
     {
     CloseHandle(file);
     } 
     else if (GetLastError() != ERROR_FILE_EXISTS) 
       {
       CheckError();
       return;
       }
   } 
   else 
   {
   CheckError();
   return;
   }

edited Oct 11 '12 at 12:22

answered Oct 11 '12 at 12:17

Andriy

8,486
3
27
51

Took me awhile to see what all you changed, so basically I just need to use `CREATE_NEW`? Because `CreateDirectory` is what is returning false and that is not changed in your code. – Brandon Miller Oct 11 '12 at 12:22
Another change is the check for GetLastError() == ERROR_ALREADY_EXISTS after trying to create the dir. And I just replaced `CreateDirectory` with `SHCreateDirectoryEx` – Andriy Oct 11 '12 at 12:24
+1 for example code and `CREATE_NEW` correction. But I would like it to work on older versions of Windows. So I'll make the subdirs one at a time. – Brandon Miller Oct 11 '12 at 12:31
@BrandonMiller: older than Win2000? – Andriy Oct 11 '12 at 12:32
I thought SHCreateDirectoryEx was XP SP2 or later, I saw that on the possible duplicate that Frédéric suggested. – Brandon Miller Oct 11 '12 at 12:34
@BrandonMiller: MSDN documentation says differently. – Andriy Oct 11 '12 at 12:36
Oh, I forgot to +1. And I see, well I'm going to test that out real quick. – Brandon Miller Oct 11 '12 at 12:38
Now I am getting the error: `The specified module could not be found.` – Brandon Miller Oct 11 '12 at 12:42
Oh, I forgot to change it to `CREATE_NEW` – Brandon Miller Oct 11 '12 at 12:42

WinAPI - Create .ini file if it doesn't exist

2 Answers2