rsync silently changes special files to regular ones!
jw at pegasys.ws
Tue Sep 16 20:49:45 EST 2003
On Tue, Sep 16, 2003 at 12:12:04PM +0200, Paul Slootman wrote:
> On Fri 12 Sep 2003, jw schultz wrote:
> > >
> > > i did: "rsync localhost::rsync/readme /dev/stdout" given the hype
> > > "rsync(1) is an improved cp(1)" (which it is, no doubt about that)
> > I don't know where you got that idea. You keep repeating it
> > despite its obvious incorrectness. I certainly would not
> > describe rsync as an improved cp. An improvement on rcp,
> > sure, but not an improved rcp either. I see nothing in the
> > manpage or web site to indicate that its general behaviour
> > bears any equivalence to cp.
> >From the manpage:
> You can also use rsync in local-only mode, where both the source and
> destination don´t have a ´:´ in the name. In this case it behaves like
> an improved copy command.
> For me it's quite understandable that people then get the idea that
> "rsync(1) is an improved cp(1)".
I saw that line but couldn't make that extreme a conclusion.
That is jumping from analogy of a generic term to simile of
a specific. I suppose it could do with a rewrite for those
for whom English is a second language.
Perhaps "When used in this way rsync behaves superficially
like a copy command" or "This way rsync can be used for
a safer and in some cases more efficient file copying"
would be an improvement.
Aside from numerous other weaknesses that have crept into
the manpage i do note that there doesn't seem to be any
point where it is mentioned that rsync replaces destination
files rather than updating them in-place. I'm not sure
where it would go in the current manpage.
I'm no writer but i have been toying with the idea of a
practical "how the rsync utility works for the
non-mathematician" document. This wouldn't be a how-to but
would instead describe in broad terms what the rsync
internals are doing, the three processes involved and a
general sketch of the protocol. Something that wouldn't be
obsoleted by enhancements.
J.W. Schultz Pegasystems Technologies
email address: jw at pegasys.ws
Remember Cernan and Schmitt
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