Dictionary.net

/dwim/ [acronym, "Do What I Mean" (not what I say)] 1. Able toguess, sometimes even correctly, the result intended whenbogus input was provided.2. The BBNLISP/INTERLISP function that attempted to accomplishthis feat by correcting many of the more common errors. Seehairy.3. Occasionally, an interjection hurled at a balky computer,especially when one senses one might be tripping overlegalisms (see legalese).Warren Teitelman originally wrote DWIM to fix his typos andspelling errors, so it was somewhat idiosyncratic to hisstyle, and would often make hash of anyone else's typos ifthey were stylistically different. Some victims of DWIM thusclaimed that the acronym stood for "Damn Warren's InfernalMachine!'.In one notorious incident, Warren added a DWIM feature to thecommand interpreter used at Xerox PARC. One day anotherhacker there typed "delete *$" to free up some disk space. (The editor there named backup files by appending "$" to theoriginal file name, so he was trying to delete any backupfiles left over from old editing sessions.) It happened thatthere weren't any editor backup files, so DWIM helpfullyreported "*$ not found, assuming you meant 'delete *'". Itthen started to delete all the files on the disk! The hackermanaged to stop it with a Vulcan nerve pinch after only ahalf dozen or so files were lost.The disgruntled victim later said he had been sorely temptedto go to Warren's office, tie Warren down in his chair infront of his workstation, and then type "delete *$" twice.DWIM is often suggested in jest as a desired feature for acomplex program; it is also occasionally described as thesingle instruction the ideal computer would have. Back whenproofs of program correctness were in vogue, there were alsojokes about "DWIMC" (Do What I Mean, Correctly). A relatedterm, more often seen as a verb, is DTRT (Do The Right Thing);see Right Thing.