On 8 Nov 2000, Todd Robinson <[EMAIL PROTECTED]> wrote:
> > That's pretty strange, for two reasons: as far as I knew, everything
> > ought to go to stderr, stdout, or the log file. When you say
> > "console", do you mean it comes out in your current window, or it goes
> > to the actual VGA adapter/serial console of the server?
>
> In the current window the rsync was executed from, even if you redirect
> stderr someplace else. For instance, I run something just like this:
>
> > rsync -avvvz /tmp/rsync-2.4.6/lib fdops3::marktg 2>&1 >
> > /rsync.txt
Ah, OK. This is because stderr is not actually redirected!
The construct 2>&1 means ``send fd2 (stderr) to wherever fd1 (stdout)
is pointing *at the moment*''. Since redirections are evaluated in
order left-to-right, this sends stderr to the terminal (probably where
it was already going), and then sends stdout to the file. From the
bash man page:
Note that the order of redirections is significant. For
example, the command
ls > dirlist 2>&1
directs both standard output and standard error to the
file dirlist, while the command
ls 2>&1 > dirlist
directs only the standard output to file dirlist, because
the standard error was duplicated as standard output
before the standard output was redirected to dirlist.
I still remember the `ah-ha!' moment when this sunk in a few years
ago.
Regards,
--
Martin Pool, Linuxcare, Inc.
+61 2 6262 8990
[EMAIL PROTECTED], http://www.linuxcare.com/
Linuxcare. Support for the revolution.
PGP signature
