Re: Bug in "cmp" man page: missing exit status value

[David Booth]

On Sat, 2011-10-08 at 20:32 -0700, Micah Cowan wrote:
> (2011年10月08日 19:14), David Booth wrote:
> > Hi Micah & Bruce,
> >
> > Thanks for your attention to this.
> >
> > My version of cmp:
> > [[
> > $ cmp -version
> > cmp (GNU diffutils) 2.8.1
> > Copyright (C) 2002 Free Software Foundation, Inc.
> >
> > This program comes with NO WARRANTY, to the extent permitted by law.
> > You may redistribute copies of this program
> > under the terms of the GNU General Public License.
> > For more information about these matters, see the file named COPYING.
> >
> > Written by Torbjorn Granlund and David MacKenzie.
> > ]]
> >
> > My version of the cmp man page:
> > [[
> > diffutils 2.8.1                   April 2002
> > CMP(1)
> > ]]
> >
> > Note that my version of the cmp man page refers the reader to the *diff*
> > info page:
> 
> <snip>
> 
> > I assumed that was intentional -- perhaps sharing the same code base --
> > but now I'm wondering if that is also a bug.  In any case, I *did* check
> > the info page for diff (attached), and it also fails to say anything
> > about the exit status values.  But even worse, the end of the info page
> > unhelpfully refers back to itself:
> 
> <snip>
> 
> That's a sure-fire symptom that info is viewing the manpage, not the
> info documentation. This will tend to happen when the diff infopages are
> not actually installed. This can happen as a result of improper
> installation from a source package; but assuming that you simply
> installed your OS vendor's packages, the most common explanation would
> be that you're on some variant of Debian (such as Ubuntu, or Debian
> itself), 

Very sorry I forgot to mention: I'm on Ubuntu 10.04.

> which is the only GNUish OS I'm aware of that has the habit of
> separating the documentation from the binaries (ironically, this is due
> to a slightly different understanding of what "free" means, which causes
> them to consider many documents covered by the GNU FDL to be "unfree",
> and therefore carried under a separate category of package than the
> GPL-covered "free" program itself).
> 
> If you're on such a system, try "sudo apt-get install diffutils-doc" to
> obtain and install the info docs.

Done.  Now "info diff" gives me the actual info page, and it does
mention the exit status values.

> 
> As to "info diff", I believe this is incorrect; "info diff" and "info
> cmp" both get me to the same actual info documentation; but one brings
> me to the section talking about the diff program specifically, the other
> brings me to the section on cmp.

Yes, that is the behavior I now see, now that I have installed
diffutils-doc.

> 
> Fortunately, it looks like this was changed to "info cmp" in GNU
> diffutils 3.1, so there's no fix needed (as far as GNU's concerned). You
> may wish to file a bug report with your OS (Debian or Ubuntu?) for them
> to patch their version of diffutils 2.8 accordingly (but note that both
> distributions are currently using 3.0 now in their latest versions -
> fixes the "no exit status" issue, but still says "info diff" in the cmp
> manpage).

Sorry, I'm not sure I understand.  Are you saying that the man page
problem (failure to state the exit status) is already fixed in diffutils
3.1?

Thanks

-- 
David Booth, Ph.D.
http://dbooth.org/

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