Re: vfscanf in newlib

[Charles Wilson <cwilson at ece dot gatech dot edu>]

"J. Johnston" wrote:
> 
> "Charles S. Wilson" wrote:
> >
> > Is there a reason, other than 'nobody has gotten round tuit yet', that
> > vfscanf is not implemented in newlib?
> >
> 
> It's a glibc extension.  Nobody thus far has asked for it in newlib.
> 
> > newlib/libc/stdio/vfscanf.c contains a function "__svfscanf()" that is
> > used as the guts of scanf(), fscanf(), and sscanf(). It seems to me as
> > though vfscanf() would be a trivial wrapper around __svfscanf() -- or am
> > I missing something?
> >
> 
> No, you are correct; they are straightforward to add.  I will do so when I get the chance.

How's this? (see attached patch to libc/include/stdio.h,
libc/stdio/Makefile.am, libc/stdio/Makefile.in, libc/stdio/vfscanf.c,
plus new files libc/stdio/vscanf.c and libc/stdio/vsscanf.c)

Note: these modifications compile -- but I have not (can not) test
them.  I'm using a cygwin system, which incorporates newlib.  So, to
test changes to newlib, I have to build a new cygwin kernel -- but
something seems to have broken *in cygwin* recently and I'm having
trouble building cygwin, but libc.a(newlib) builds okay.  Thus, I can't
test these additions to newlib since my runtime (cygwin) already
includes (the old) newlib.  Perhaps someone on a different platform can
test these additions to newlib?

I followed the pattern I saw in the scanf family, including the
_function_r reentrant versions -- however, I am not sure that the
functions _vfscanf_r, vscanf_r, and _vsscanf_r are truly reentrant --
again, perhaps someone more knowledgable give the code a look.

I'm providing the patches and new files in the hopes that they will save
somebody (Jeff?) some time, when it comes to adding these six functions
to newlib.

Wed Apr 18 23:45:00 2001  Charles Wilson  <cwilson@ece.gatech.edu>

	* libc/include/stdio.h: add declarations for new functions
	vfscanf, vscanf, vsscanf, _vfscanf_r, _vscanf_r, and _vsscanf_r
	* libc/stdio/Makefile.am: add new files vscanf.c and vsscanf.c
	to the build list; also, add vfscanf.def to the list of doc 
	files to be generated (yes, I added documentation on the
	six new v?scanf() functions to vfscanf.c).  Finally, add
	entries for vscanf.o and vsscanf.o in the dependency list --
	they depend on local.h
	* libc/stdio/Makefile.in: replicate changes in Makefile.am,
	also add vscanf.o and vsscanf.o to the OBJ list.
	* libc/stdio/vfscanf.c: add documentation for vfscanf(),
	vscanf(), and vsscanf(), as well as _vfscanf_r(), _vscanf_r(),
	and _vsscanf_r().
	* libc/stdio/vfscanf.c (vfscanf): new function 
	* libc/stdio/vfscanf.c (_vfscanf_r): new function
	* libc/stdio/vscanf.c: new file, contains implementations for
	vscanf and _vscanf_r.
	* libc/stdio/vsscanf.c: new file, contains implementations for
	vsscanf and _vsscanf_r.

--Chuck

vfscanf-newlib.tar.gz