isJailbroken

+(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;
    }else if([[NSFileManager defaultManager] fileExistsAtPath:@"/private/var/lib/apt/"]){
        return YES;
    }

    if([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:@"cydia://package/com.example.package"]]){
        return YES;
    }

    FILE *f = fopen("/bin/bash", "r");
    if (f != NULL) {
        fclose(f);
        return YES;
    }
    fclose(f);
    f = fopen("/Applications/Cydia.app", "r");
    if (f != NULL) {
        fclose(f);
        return YES;
    }
    fclose(f);
    f = fopen("/Library/MobileSubstrate/MobileSubstrate.dylib", "r");
    if (f != NULL) {
        fclose(f);
        return YES;
    }
    fclose(f);
    f = fopen("/usr/sbin/sshd", "r");
    if (f != NULL) {
        fclose(f);
        return YES;
    }
    fclose(f);
    f = fopen("/etc/apt", "r");
    if (f != NULL) {
        fclose(f);
        return YES;
    }
    fclose(f);

    NSError *error;
    NSString *stringToBeWritten = @"This is a test.";
    [stringToBeWritten writeToFile:@"/private/jailbreak.txt" atomically:YES encoding:NSUTF8StringEncoding error:&error];
    [[NSFileManager defaultManager] removeItemAtPath:@"/private/jailbreak.txt" error:nil];

    if(error==nil){
        return YES;
    }

#endif

    //All checks have failed. Most probably, the device is not jailbroken
    return NO;
}