ISO/ IEC JTC1/SC22/WG14 N701


			    Document Number: WG14 N701/X3J11 97-064


			       C9X Revision Proposal
			       =====================

       Title: ____vscanf___________________________________________
       Author: _____________Larry Jones____________________________
       Author Affiliation: _SDRC___________________________________
       Postal Address: _____2000 Eastman Dr, Milford, OH 45150_____
       E-mail Address: _____larry.jones@sdrc.com___________________
       Telephone Number: ___513-576-2070___________________________
       Fax Number: _________513-576-2843___________________________
       Sponsor: ____________Larry Jones____________________________
       Date: _______________22 May 1997____________________________
       Proposal Category:
	  __ Editorial change/non-normative contribution
	  __ Correction
	  X_ New feature
	  __ Addition to obsolescent feature list
	  __ Addition to Future Directions
	  __ Other (please specify)
       Area of Standard Affected:
	  __ Environment
	  __ Language
	  __ Preprocessor
	  X_ Library
	     __ Macro/typedef/tag name
	     X_ Function
	     __ Header
	  __ Other (please specify)  ______________________________
       Prior Art: HP-UX, GNU libc, 4.4BSD, others__________________
       Target Audience: C Programmers______________________________
       ____________________________________________________________
       ____________________________________________________________
       Related Documents (if any): ________________________________
       ____________________________________________________________
       ____________________________________________________________
       Proposal Attached: X_ Yes __ No, but what's your interest?

       Abstract:

	Although the standard library provides va_list versions
	of the printf family of functions, it does not provide
	them for the scanf family.  Although the scanf versions
	are not needed nearly as often, they are exceedingly
	difficult for the user to implement whereas the
	implementor need only make very minor changes to the
	existing scanf functions to provide them.

       Proposal

	In subclause 7.1.1 Definitions of terms, paragraph [#3]
	The decimal-point character, revise the footnote [109] to
	read:

		109.  The functions that make use of the
		decimal-point character are localeconv, fprintf,
		fscanf,  printf, scanf, sprintf, sscanf,
		vfprintf, vfscanf, vprintf, vscanf, vsprintf,
		vsscanf, atof, strtod, fwprintf, fwscanf,
		wprintf, wscanf, swprintf, swscanf, vfwprintf,
		vfwscanf, vwprintf, vwscanf, vswprintf, and
		vswscanf.

	[[Editorial note: the wide-character versions were not
	listed in draft 9, but presumably should be.]]

	In subclause 7.12.1 Introduction (Input/output
	<stdio.h>), paragraph [#6], revise the first bullet to
	read:

		The wide-character input functions - those 
		functions described in this subclause that
		perform input into wide characters and wide
		strings: fgetwc,  fgetws, getwc, getwchar,
		fwscanf, wscanf, vfwscanf, and vwscanf.


	Revise the last bullet to read:

		The byte input/output functions - those 
		functions described in this subclause that
		perform input/output: fgetc, fgets, fprintf,
		fputc, fputs, fread, fscanf, fwrite, getc,
		getchar, gets, printf, putc, putchar, puts,
		scanf, ungetc, vfprintf, vfscanf, vprintf, and
		vscanf.


	In subclause 7.12.6.7 The vfprintf function, paragraph
	[#2], change the footnote [186] to:

		186.  As the functions vfprintf, vfscanf,
		vprintf, vscanf, vsprintf, and vsscanf invoke the
		va_arg macro, the value of arg after the return
		is indeterminate.

	In subclause 7.12.6 Formatted input/output functions, add
	new subclauses:

		7.12.6.X  The vfscanf function

		Synopsis

			#include <stdarg.h>
			#include <stdio.h>
			int vfscanf(FILE * restrict stream,
				const char * restrict format,
				va_list arg);

		Description

		The vfscanf function is equivalent to fscanf,
		with the variable argument list replaced by arg,
		which shall have been initialized by the va_start
		macro (and possibly subsequent va_arg calls). 
		The vfscanf does not invoke the va_end macro.186

		Returns

		The vfscanf function returns the value of the
		macro EOF if an input failure occurs before any
		conversion.  Otherwise, the vfscanf function
		returns the number of input items assigned,
		which can be fewer than provided for, or even
		zero, in the event of an early matching failure.

		7.12.6.X  The vscanf function

		Synopsis

			#include <stdarg.h>
			#include <stdio.h>
			int vscanf(const char * restrict format,
				va_list arg);

		Description

		The vscanf function is equivalent to scanf, with
		the variable argument list replaced by arg,
		which shall have been initialized by the
		va_start macro (and possibly subsequent va_arg
		calls).  The vfscanf does not invoke the va_end
		macro.186

		Returns

		The vscanf function returns the value of the
		macro EOF if an input failure occurs before any
		conversion.  Otherwise, the vscanf function
		returns the number of input items assigned,
		which can be fewer than provided for, or even
		zero, in the event of an early matching failure.

		7.12.6.X  The vsscanf function

		Synopsis

			#include <stdarg.h>
			#include <stdio.h>
			int vsscanf(const char * restrict s,
				const char * restrict format,
				va_list arg);

		Description

		The vsscanf function is equivalent to sscanf,
		with the variable argument list replaced by arg,
		which shall have been initialized by the va_start
		macro (and possibly subsequent va_arg calls). 
		The vsscanf does not invoke the va_end macro.186

		Returns

		The vsscanf function returns the value of the
		macro EOF if an input failure occurs before any
		conversion.  Otherwise, the vsscanf function
		returns the number of input items assigned,
		which can be fewer than provided for, or even
		zero, in the event of an early matching failure.


	In subclause 7.18.2.7 The vfwprintf function, paragraph
	[#2], change the footnote [222] to:

		222.  As the functions vfwprintf, vfwscanf,
		vwprintf, vwscanf, vswprintf, and vswscanf
		invoke the va_arg macro, the value of arg after
		the return is indeterminate.

	In subclause 7.18.2 Formatted wide-character
	input/output functions, add new subclauses:

		7.18.2.X  The vfwscanf function

		Synopsis

			#include <stdarg.h>
			#include <stdio.h>
			#include <wchar.h>
			int vfwscanf(FILE * restrict stream,
				const wchar_t * restrict format,
				va_list arg);

		Description

		The vfwscanf function is equivalent to fwscanf,
		with the variable argument list replaced by arg,
		which shall have been initialized by the
		va_start macro (and possibly subsequent va_arg
		calls).  The vfwscanf does not invoke the va_end
		macro.222

		Returns

		The vfwscanf function returns the value of the
		macro EOF if an input failure occurs before any
		conversion.  Otherwise, the vfwscanf function
		returns the number of input items assigned,
		which can be fewer than provided for, or even
		zero, in the event of an early matching failure.

		7.18.2.X  The vwscanf function

		Synopsis

			#include <stdarg.h>
			#include <stdio.h>
			#include <wchar.h>
			int vwscanf(const wchar_t * restrict format,
				va_list arg);

		Description

		The vwscanf function is equivalent to wscanf,
		with the variable argument list replaced by arg,
		which shall have been initialized by the
		va_start macro (and possibly subsequent va_arg
		calls).  The vfwscanf does not invoke the va_end
		macro.222

		Returns

		The vwscanf function returns the value of the
		macro EOF if an input failure occurs before any
		conversion.  Otherwise, the vwscanf function
		returns the number of input items assigned,
		which can be fewer than provided for, or even
		zero, in the event of an early matching failure.

		7.18.2.X  The vswscanf function

		Synopsis

			#include <stdarg.h>
			#include <stdio.h>
			#include <wchar.h>
			int vswscanf(const wchar_t * restrict s,
				const wchar_t * restrict format,
				va_list arg);

		Description

		The vswscanf function is equivalent to swscanf,
		with the variable argument list replaced by arg,
		which shall have been initialized by the
		va_start macro (and possibly subsequent va_arg
		calls).  The vswscanf does not invoke the va_end
		macro.222

		Returns

		The vswscanf function returns the value of the
		macro EOF if an input failure occurs before any
		conversion.  Otherwise, the vswscanf function
		returns the number of input items assigned,
		which can be fewer than provided for, or even
		zero, in the event of an early matching failure.

	In subclause 7.18.3.9 The ungetwc function, paragraph
	[#3], first sentence, change ``(fwscanf or wscanf)'' to
	``(fwscanf, wscanf, vfwscanf, or vwscanf)''.

	Add the corresponding entries to Annex D Library summary.