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iosobjective-cjailbreaktheos

Why does NSLog not output aString parameter?

I have the following code in Tweak.xm:

%hook NSString
- (BOOL)isEqualToString:(NSString *) aString {
    NSLog(@"%@", [NSString stringWithFormat:@"isEqualToString for : %@ with: %@", aString, self]);

    return %orig;
}
%end

However the syslog output shows self but not aString (should be after for :), example:

Apr 9 20:46:32 remini CitrixReceiver-iPad[7972] <Warning>: isEqualToString for : with: /var/mobile/Containers/Data/Application/42123BED-A507-4CE0-97B0-20DFFD9BB78C Apr 9 20:46:32 remini CitrixReceiver-iPad[7972] <Warning>: isEqualToString for : with: /Applications/Cydia.app Apr 9 20:46:32 remini CitrixReceiver-iPad[7972] <Warning>: isEqualToString for : with: /private/var/lib/apt/ Apr 9 20:46:32 remini CitrixReceiver-iPad[7972] <Warning>: isEqualToString for : with: /var/mobile/Containers/Data/Application/42123BED-A507-4CE0-97B0-20DFFD9BB78C

Why is aString not outputted?

Solution

  • I would hazard a guess that the string is either nil or empty. Check against that at the beginning of the method. i.e.

    if (aString == nil || [aString length] == 0) 
{
    ...
}