The >
(right angle bracket) operator redirects the standard output of a
process to a file.
It doesn't affect the standard error.
If you're logged in and can see any messages written to standard error,
that's okay:
%nroff -ms report.ms > report.out &
[1] 10316 ...Later... nroff: can't open file /hoem/jpeek/report.data
But if you log out and leave the job running, you'll never see those errors
unless you use the csh operator >&
.
It redirects both standard output and standard error to a file.
For example:
make | % |
---|
You might also use the >&
operator while you're logged in - and watch
the output file with
tail -f (25.16).
If you don't want the errors mixed with other output, you can split them
to two files; see article
13.1.
The C shell also has a pipe operator, |&
, that redirects both
standard output and standard error.
It's great for running a job in the background, or on another computer,
and
mailing (1.33)
any output to me:
%make |& mailx -s "'make bigprog' output" jpeek@jpeek.com &
[1] 29182 29183
If I'd used plain |
instead of |&
, any text on the standard
error wouldn't go into the mail message.
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