Change system property in com.apple.wifi.plist - ios

Question

I have been developing an app to programmatically enable/disable Wi-Fi interface of my iphone. I have tried to use the Apple 80211( apple's private service) on my jail broken Iphone 4s (iOS 5.1.1) to make it work. However, thing does not work out as I expected.
I can successfully scan and get the status of Wi-Fi connection however, the method Apple80211SetPower to enable/disable WiFi seems does not work on iOS 5.
As I found out from SBsetting's WiFi toggle, It might also require to change the system property of WiFi at "/var/preferences/systemconfiguration/com.apple.wifi.plist". However, my app is failed to change system property in that file, I suspected the problem resulted from file property and ownership. Therefore, I imitated the file property of SBsetting's WiFi toggle, Still, it did not change a thing.
does anyone know how I could change the system property of this file? this is the code that I used. thanks and regards
NSMutableDictionary *plistDict =
[NSMutableDictionary dictionaryWithContentsOfFile:#"/var/preferences/SystemConfiguration/com.apple.wifi.plist"];
BOOL wifiState = [[plistDict objectForKey:#"AllowEnable"] boolValue];
NSLog(wifiState ? #"Yes" : #"No");
if (value == YES)
{
[plistDict setValue:[NSNumber numberWithBool:YES] forKey:#"AllowEnable"];
[plistDict writeToFile:#"/var/preferences/SystemConfiguration/com.apple.wifi.plist"
atomically: YES];
}
else if (value== NO)
{
[plistDict setValue:[NSNumber numberWithBool:NO] forKey:#"AllowEnable"];
[plistDict writeToFile:#"/var/preferences/SystemConfiguration/com.apple.wifi.plist"
atomically: YES];
}

Answer 1

On my phone (iOS 5.0.1, not 5.1.1), I see this in the SystemConfiguration directory:
iPhone4:/var/preferences/SystemConfiguration mobile$ ls -altr
total 144
drwxr-xr-x 3 root wheel 136 Dec 25 2007 ..
-rw-r--r-- 1 root wheel 181 Jul 26 2009 OSThermalStatus.plist
-rw-r--r-- 1 root wheel 79 Jan 10 2012 com.apple.mobilegestalt.plist
-rw-r--r-- 1 root wheel 60 Sep 30 00:47 com.apple.radios.plist
-rw-r--r-- 1 root wheel 1162 Sep 30 15:50 NetworkInterfaces.plist
-rw-r--r-- 1 root wheel 57087 Sep 30 15:51 com.apple.network.identification.plist
-rw-r--r-- 1 root wheel 127 Oct 1 01:04 com.apple.PowerManagement.plist
-rw-r--r-- 1 root wheel 7323 Oct 1 01:18 preferences.plist
-rw-r--r-- 1 root wheel 31648 Oct 1 01:18 com.apple.wifi.plist
-rw-r--r-- 1 root wheel 1223 Oct 1 01:18 com.apple.AutoWake.plist
drwxr-xr-x 2 root wheel 374 Oct 1 01:18 .
So, it looks like the user mobile (which is the user the apps normally run as) would not be able to write that file, with only read privileges.
You can take a look here at how to give your app root privileges.