Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!apple!ames!haven!mimsy!chris
From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.unix.questions
Subject: Re: printf implementation again
Message-ID: <22267@mimsy.umd.edu>
Date: 3 Feb 90 20:36:32 GMT
References: <29039@amdcad.AMD.COM>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 29

In article <29039@amdcad.AMD.COM> srini@diablo.amd.com writes:
>Does vprintf call _doprnt? From what I have found so far, _doprnt
>is called, _flsbuf is called to flush buffer, and a memory copy
>(memcpy) is done to copy from buffer to file.

If you were to trace my stdio, you would see:
	1. printf/fprintf/sprintf
	2. vfprintf
	3. __spstr (someday, a static symbol)
	4. (if buffer fills) __swrite + write

You would also find that there is no function called `_doprnt'.

>If all these are implementation dependent, then let me rephrase my
>original question. What are the factors that are assumed or 
>considered to implement printf or in the already existing printf
>implementation(s)?

All the details are implementation dependent: I suspect neither
__spstr nor __swrite appear in any other stdio, nor will I say what
their call sequence is.  In my implementation, vfprintf() (with
funopen(), a new function that opens functions to do I/O) gives you
everything you need.

The factors that are assumed and considered are those outlined in
the ANSI standard or the SVID or some other applicable standard.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris