[KenWittlief]

stupidest programming mistake I ever made

when I was in college I took a course in the language LISP. This language is all functions, and you can define or change the definition of any function, even the core default ones built into the language.

I was entering code on a terminal at the computer center, and the terminal wacked out for a second. I thought the mainframe was crashing so I typed

EXIT <return>

which is how you get out of the LISP program space.

But then the terminal was ok, it did not exit, it just kept running. So I finished up my project, printed the listing and entered

EXIT <return>

and nothing happened - I was still in LISP - it wouldnt stop running.

Then I realized just before the terminal wacked out I was defining a new function, so what I had really done was enter

Define EXIT <return>

which in LISP means: define the function 'EXIT' to be nothing!

I had to sit at the terminal for 30 minutes to wait for the mainframe to timeout my link and kick me off.