Progress? We're not making any progress! or Are We There Yet? A common need in programs is the need to display the progress of an operation. Displaying progress can tell the user: the program is still alive; what percentage done the program is; when the activity might complete. Another type of report commonly, but incorrectly, called "progress" is the spinning wheel. A similar one is the "Cylon" activity bar. Such indicators would more properly be called "activity indicators". These are not covered in this post. Progress can be defined: "forward or onward movement toward a destination". An activity indicator does not, and cannot, indicate progress, because it does not indicate that "forward" or "onward" movement is being made! Thus, for a file transfer, a beep every second doesn't indicate progress, but a beep every 1024 bytes of data transferred would indicate progress (although po
The #IAmRoot flaw The recent "I Am Root" bug in MacOS (#1) brings to mind two of my favorite topics: functional results, and function naming. (Although this post is C-oriented, the concepts apply to any programming language.) The bug: In some circumstances, perhaps a few less than many news report implied, a non-privileged user could obtain root access on Macs running the HighSierra version of macOS. An analysis from http://www.theregister.co.uk/2017/11/29/apple_macos_high_sierra_root_bug_patch reads, in part: ... the security daemon opendirectoryd calls an internal function called odm_RecordVerifyPassword . ... Seeing as that shadow hash lookup failed, opendirectoryd next tries to retrieve and check a crypt password for the account using od_verify_crypt_password . Weirdly, that function returns the value 0x1, signaling it was successful, and rather than bail out and deny access, the code falls through to function calls that upgrade the crypt password to a sh