Question

I’m developing an app for jailbroken phones. I’m new to Obj-c. I want to:

1. Read a plist file in /var/mobile/Library/Preferences [specifically com.apple.assistant.plist] (Jailbroken, remember?)

2. Change the string for the key, “Hostname”.

3. Save the plist file.

Then I plan to throw the code in a IBAction and link it to a button in IB.

Does anyone know how to achieve this? Can you post the code for it?

Answer 1

I assume you’re mainly wondering about how to read/write the plist. Here’s an example of doing that:

NSString* filename = @"/var/mobile/Library/Preferences/com.apple.assistant.plist";
NSMutableDictionary* prefs = [[NSMutableDictionary alloc] initWithContentsOfFile: filename];
NSString* hostnamePref = (NSString*)[prefs valueForKey: @"Hostname"];
NSLog(@"current hostname is %@", hostnamePref);

[prefs setValue: @"Some New Value Here" forKey: @"Hostname"];

[prefs writeToFile: filename atomically: YES];
[prefs release];  // not needed if you use Automatic Reference Counting in your project

Edit: If your dictionary (plist) is actually a dictionary of dictionaries, you might use something like this:

NSMutableDictionary* prefs = [[NSMutableDictionary alloc] initWithContentsOfFile: filename];
NSString* nestedKeyname = @"124-37HGSH-CF12-67TY";
NSMutableDictionary* nestedPrefs = (NSMutableDictionary*)[prefs valueForKey: nestedKeyname];
NSString* hostnamePref = (NSString*)[nestedPrefs valueForKey: @"Hostname"];
NSLog(@"current hostname is %@", hostnamePref);

[nestedPrefs setValue: @"Some New Value Here" forKey: @"Hostname"];
[prefs setValue: nestedPrefs forKey: nestedKeyname];

The above code should work for any path that user mobile has permission to read and write.