isJailbroken.m

+(BOOL)isJailbroken{
#if !(TARGET_IPHONE_SIMULATOR)
    if ([[NSFileManager defaultManager] fileExistsAtPath:@"/Applications/Cydia.app"]){
        return YES;
    }else if([[NSFileManager defaultManager] fileExistsAtPath:@"/Library/MobileSubstrate/MobileSubstrate.dylib"]){
        return YES;
    }else if([[NSFileManager defaultManager] fileExistsAtPath:@"/bin/bash"]){
        return YES;
    }else if([[NSFileManager defaultManager] fileExistsAtPath:@"/usr/sbin/sshd"]){
        return YES;
    }else if([[NSFileManager defaultManager] fileExistsAtPath:@"/etc/apt"]){
        return YES;
    }
    NSError *error;
    NSString *stringToBeWritten = @"This is a test.";
    [stringToBeWritten writeToFile:@"/private/jailbreak.txt" atomically:YES
                          encoding:NSUTF8StringEncoding error:&error];
    if(error==nil){
        //Device is jailbroken
        return YES;
    } else {
        [[NSFileManager defaultManager] removeItemAtPath:@"/private/jailbreak.txt" error:nil];
    }
    if([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:@"cydia://package/com.example.package"]]){
        //Device is jailbroken
        return YES;
    }
#endif
    //All checks have failed. Most probably, the device is not jailbroken
    return NO;
}