DWIM

/dwim/ [acronym, "Do What I Mean" (not what I say)] 1. Able to

guess, sometimes even correctly, the result intended when

bogus input was provided.

2. The BBNLISP/INTERLISP function that attempted to accomplish

this feat by correcting many of the more common errors. See

hairy.

3. Occasionally, an interjection hurled at a balky computer,

especially when one senses one might be tripping over

legalisms (see legalese).

Warren Teitelman originally wrote DWIM to fix his typos and

spelling errors, so it was somewhat idiosyncratic to his

style, and would often make hash of anyone else's typos if

they were stylistically different. Some victims of DWIM thus

claimed that the acronym stood for "Damn Warren's Infernal

Machine!'.

In one notorious incident, Warren added a DWIM feature to the

command interpreter used at Xerox PARC. One day another

hacker there typed "delete *$" to free up some disk space.

(The editor there named backup files by appending "$" to the

original file name, so he was trying to delete any backup

files left over from old editing sessions.) It happened that

there weren't any editor backup files, so DWIM helpfully

reported "*$ not found, assuming you meant 'delete *'". It

then started to delete all the files on the disk! The hacker

managed to stop it with a Vulcan nerve pinch after only a

half dozen or so files were lost.

The disgruntled victim later said he had been sorely tempted

to go to Warren's office, tie Warren down in his chair in

front of his workstation, and then type "delete *$" twice.

DWIM is often suggested in jest as a desired feature for a

complex program; it is also occasionally described as the

single instruction the ideal computer would have. Back when

proofs of program correctness were in vogue, there were also

jokes about "DWIMC" (Do What I Mean, Correctly). A related

term, more often seen as a verb, is DTRT (Do The Right Thing);

see Right Thing.

[Jargon File]