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From: leichter@venus.ycc.yale.EDU ("Jerry Leichter")
Newsgroups: comp.os.vms
Subject: re: VAX C V2.3, VMS V4.6
Message-ID: <8711012020.AA13211@ucbvax.Berkeley.EDU>
Date: Thu, 29-Oct-87 11:34:00 EST
Article-I.D.: ucbvax.8711012020.AA13211
Posted: Thu Oct 29 11:34:00 1987
Date-Received: Thu, 5-Nov-87 20:54:58 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: "Jerry Leichter" <leichter@venus.ycc.yale.edu>
Organization: The ARPA Internet
Lines: 40


	The on-line release notes of VAX C V2.3 say:

	      o  The printf and scanf functions now perform  formatted  output
	         and  input respectively with the addition of three new format
	         flags (#, +, space) and the following new format  specifiers:
	         i, p, and n.

	    Who can tell what the new specifiers are supposed to do?
	    I did not find them in the VAX C V2.3 RTL manual, or in online
	    HELP.

These specifiers are from the ANSI Draft Standard; apparently the documenters
of VAX C didn't quite manage to keep up with the implementors.

Here - in summary - is what Harbison and Steele list for these flags and
specifiers:

	+	Always produce a sign, either plus or minus
	SPACE	Produce either a minus sign or a space
	#	Use a variant of the main conversion operation; depends
		on the conversion operation.  Applies to eEfgGoxX only.
			#o	- insert leading 0
			#x,X	- insert leading 0x or 0X
			#f,e,E 	- always include ".", even if trailing
			#g,G	- as above plus some sort of 0-stripping

	i	Same as d on output.  On input, reads a generic C integer
		constant (e.g., allows a leading 0x).  Does NOT accept a
		size marker (e.g., trailing L) in the INPUT, only in the
		format string.
	p	Prints a generic pointer (a (void *)) in an implementation-
		specific format.  Reads said format back on input.
	n	Argument must be an (int *), which receives as a value the
		number of bytes output (or read) so far.  Produces no output
		and doesn't increment the value returned by xscanf.

							-- Jerry

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