Thread: Problem using reg.exe

Hi, I'm trying to make a program (in C) that performs certain tweaks within windows. Here's an extract that sets the interval time between windows update reboot nags

Code:

char command[256];
int interval = 1440;

system("reg add HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU /v RebootRelaunchTimeoutEnabled /t REG_DWORD /d 00000001 /f");
sprintf(command, "reg add HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU /v RebootRelaunchTimeout /t REG_DWORD /d %08x /f", interval);
system(command);

the output I get is:

The operation completed successfully
Error: Invalid command-line parameters

I can't work out why the second command is invalid.
Also... I'd rather not have the output printed on the screen, would this be the right way to do it? :

system("@echo off\n...second command...");

Thanks for any advice

you didnt include an end of line marker or zero termination. add "\n\0" to the end of the sprintf string and you should be fine.

...and using system() instead of REG apis is horrible.

...and using system() instead of REG apis is horrible.

It will behoove you to learn the Windows API's if you plan on writing code for the Windows environment. It'll make life a lot easier in the long run.

Code:

	
Code:
	
#pragma comment( lib, "advapi32.lib" )
#include <windows.h>
#include <stdio.h>

int main(void)
{
	HKEY hk; 
	DWORD dwData, dwDisp; 
	char szKey[] = {"SOFTWARE\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU"};

	dwData = 1;
	if (RegCreateKeyEx(HKEY_LOCAL_MACHINE, szKey, 
		0, NULL, REG_OPTION_NON_VOLATILE,
		KEY_WRITE, NULL, &hk, &dwDisp)) 
		printf("Could not create (open) the szKey registry key."); 
	else
	{
		if (RegSetValueEx(hk,      // subkey handle 
			"RebootRelaunchTimeoutEnabled",  // value name 
			0,                 // must be zero 
			REG_DWORD,         // value type 
			(LPBYTE) &dwData,  // pointer to value data 
			sizeof(DWORD)))    // length of value data 
			printf("Could not set RebootRelaunchTimeoutEnabled."); 
		dwData = 1440;
		if (RegSetValueEx(hk,      // subkey handle 
			"RebootRelaunchTimeout",  // value name 
			0,                 // must be zero 
			REG_DWORD,         // value type 
			(LPBYTE) &dwData,  // pointer to value data 
			sizeof(DWORD)))    // length of value data 
			printf("Could not set RebootRelaunchTimeout."); 
		RegCloseKey(hk);    
	}
	return 0;
}

Hi, thanks for your help. I sort of knew using system() was probably a bad way of doing it, but I didn't know any better way. I tried using your example code and it worked fine... so I'll stick to that method in future.