Printf sets errno to 25?

[Tim Smith]

> Could someone please explain to me why the printf() family of
> functions cause errno to be set to 25 (not a typewritter) when output
> is redirected to either a file or a pipe. I know that the problem comes

Because a file or a pipe is not a typewriter?
-- 
Tim Smith       sdcrdcf!ism780c!tim || ima!ism780!tim || ihnp4!cithep!tim