The Most Expensive One-Byte Mistake
An anonymous reader writes "Poul-Henning Kamp looks back at some of the bad decisions made in language design, specifically the C/Unix/Posix use of NUL-terminated text strings. 'The choice was really simple: Should the C language represent strings as an address + length tuple or just as the address with a magic character (NUL) marking the end? ... Using an address + length format would cost one more byte of overhead than an address + magic_marker format, and their PDP computer had limited core memory. In other words, this could have been a perfectly typical and rational IT or CS decision, like the many similar decisions we all make every day; but this one had quite atypical economic consequences.'"
I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. But I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.
"First they came for the slanderers and i said nothing."