Christof

/**
* elevate (sudo for windows)
* @version 0.2
* @filename elevate.c
* @author Christof Germishuizen <christofg@gmail.com>
*
* Copyright (C) 2009 Christof Germishuizen <christofg@gmail.com>
*    copying and distribution of this file, with or without modification,
*    are permitted in any medium without royalty provided the copyright
*    notice and this notice are preserved.  This file is offered as-is,
*    without any warranty.
*/

#ifndef UNICODE
#define UNICODE
#endif
#include <windows.h>
#include <shellapi.h>
#include <wchar.h>

LPWSTR *mergestrings(LPWSTR *left, LPCWSTR right)
{
    size_t size = ( 1 + lstrlen(*left) + lstrlen(right) ) * sizeof(LPWSTR*);

    if ( *left ) {
        LPWSTR leftcopy = _wcsdup(*left);
        *left = (LPWSTR)realloc(*left, size);
        *left = lstrcpy(*left, leftcopy);
        *left = lstrcat(*left, right);
        free( leftcopy );

    } else *left = _wcsdup(right);

    return left;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevInstance, LPSTR lpcommand, int nShowCmd)
{
    DWORD result = 0x2a; // Life, the Universe, Everything.
    LPWSTR *argv = NULL;
    int argc = 0;

    if ( argv = CommandLineToArgvW(GetCommandLineW(), &argc) ) {

        if ( argc < 2 ) {

            LPWSTR usagemsg = NULL;
            usagemsg = *mergestrings(&usagemsg, argv[0]);
            usagemsg = *mergestrings(&usagemsg, TEXT(" <command_to_run> [arguments]"));
            MessageBox(NULL, usagemsg, TEXT("Usage:"), MB_OK | MB_ICONEXCLAMATION );

            LocalFree( argv );
            free( usagemsg );

            return ERROR_BAD_ARGUMENTS;

        // argv is populated with at least a <command_to_run>
        } else {

            LPWSTR command = argv[1];
            LPWSTR arguments = NULL;
            int c;

            for ( c = 2; c < argc; c++ ) {
                arguments = *mergestrings(&arguments, argv[c]);
                arguments = *mergestrings(&arguments, TEXT(" "));
            }

            result = (DWORD)ShellExecute(NULL, TEXT("runas"), command, arguments, NULL, SW_SHOWNORMAL);

            LocalFree( argv );
            if ( arguments ) free( arguments );

            // translate ShellExecute()'s wacky return codes to something more meaningful.
            switch ( result )
            {
                case 0: /* "The operating system is out of memory or resources." */
                    result = ERROR_OUTOFMEMORY;
                    break;

                case 27: /* SE_ERR_ASSOCINCOMPLETE */
                case 31: /* SE_ERR_NOASSOC */
                    result = ERROR_NO_ASSOCIATION;
                    break;

                case 28: /* SE_ERR_DDETIMEOUT */
                case 29: /* SE_ERR_DDEFAIL */
                case 30: /* SE_ERR_DDEBUSY */
                    result = ERROR_DDE_FAIL;
                    break;

                case 32: /* SE_ERR_DLLNOTFOUND */
                    result = ERROR_DLL_NOT_FOUND;
                    break;

                // ShellExecute() succeeded if it returns > 32.
                default:
                    if ( result > 32 ) result = 0x2a;
            }
        }
    // CommandLineToArgvW() failed in a strange way. Let's get its error code.
    } else result = GetLastError();

    if (result != 0x2a) {

        LPWSTR errormsg = NULL;
        FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,
                      NULL, result, 0, (LPWSTR)&errormsg, 0, NULL);

        MessageBox(NULL, errormsg, TEXT("Error:"), MB_OK | MB_ICONERROR);
        LocalFree( errormsg );

        return result;

    // It all went fine. :)
    }  else return NO_ERROR;
}