[Openmcl-devel] OSX install difficulties

[Gary Byers]

On Wed, 29 Sep 2004, Dan Knapp wrote:

> >>  This morning I couldn't expand with "tar xvzf" an archive downloaded
> >> by
> >> ftp in "text" mode ( Mac Os 10.3.5 ) as I had read it was the way to
> >>  go, then downloaded in "Binary" mode and could "tar xvzf" the
> >> archive !
> >
> > Um... I'd expect that, wouldn't you expect that? Downloading something
> > as text will typically do end-of-line marker conversion. Why under
> > 10.3.5 that doesn't mean converting LFs to LFs, I wouldn't know, but a
> > tarred, gzipped archive is binary and any conversion would probably be
> > bad. Again, if this was a surprise for you let me know and I might put
> > a note in the docs, to some degree this may be another discrepancy
> > between a Linux->Mac OS X transitioner's POV vs. a long-standing Mac
> > person's POV, worth noting for other Mac people who aren't used to
> > tarring.
>
>    Clearly it was a surprise. :)  Also as I said in my last email, I do
> think it's appropriate to
> document this, I'm just not quite sure where or what to say.

There are a couple of sources of possible confusion here.

Some traditional Mac unarchivers (Stuffit variants certainly, some
older standalone GUI tar programs) offered the option to automatically
detect text files and convert LF to CR in them.  If the files are
actually text files, this is mostly harmless (as long as editors and
compilers and READ-LINE and ... can deal with CR-terminated files), if
the file is actually a text file.  If the file isn't a text file, this
is mostly harmful, and I don't think that unarchiving programs have
ever claimed to be able to do this conversion perfectly.  (I haven't
checked recently, but even if the C compiler and OpenMCL can deal
with CR-terminated files perfectly, the assembler and "make" and
"m4" programs may find them puzzling.)

The other issue is so obvious that it doesn't really need to be stated
(unless of course you've been burned by it recently ...): .tar archives
(and especially compressed .tar.gz archives) are binary  files and
should be transferred in binary mode.  Most command-line FTP clients
default to binary mode these days, though there are exceptions (which
can cause you to lose hours downloading Solaris .iso images as text
files, to name a particularly painful example that happens to come to
mind.)  Only an idiot would have done this ... oh, a week or so ago.

I'm not sure that it's really the job of the OpenMCL documentation
to go into great depth in discussing these issues; there are probably
entire websites devoted to helping people who are unfamiliar with
them.  It might suffice to say something like "the files
available here should be transferred in binary mode and archive
contents should be extracted without line conversion or other loss
of information.  If you don't have any idea what this means, see
<http://helpful-web-site.org>"