stdio buffering considered harmful

[Mike Lutz]

I disagree with Doug Gwyn's suggestion that programmers should be responsible
for fflush()ing "relevant" output before doing input; what is more, I don't
think it's a question of sloppiness/neatness.  Taken to an extreme, the use of
libraries at all is sloppy (printf is the lazy way of getting around number
conversions, and the window package is a crutch for those too indolent to keep
track of what's on the screen).  I don't think Doug meant to be so pedantic as
to forbid all library routines, but I also believe the issues in an I/O
package's functional design are subtle.

If programmers embed flushing decisions in their code, users are denied the
option of solving the buffering problem THEIR way.  Second, every programmer
has a slightly different notion of when to call fflush(), so the behavior of
commands in a pipeline will be even more unpredictable than now.  (One could
invent "standards" for the use of fflush(), but then why not relieve the
programmer of an unnecessary burden and implement the standard as part of the
library?) Finally, who has the time or patience to go through every program on
the system inserting calls to fflush()?

All of this is not to suggest that I have the ultimate answer to the buffering
problem; I don't (and I have reservations about the proposals that have been
made).  However, if and when a suitable answer becomes available, I hope it's
part and parcel of the standard I/O package.

Mike Lutz
{allegra,seismo}!rochester!ritcv!mjl