Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. It only takes a minute to sign up.
Sign up to join this community
I run the following command:
pkg_add emacs-23.4,2.tbz 2> output.log
The output still displays in the terminal. When I press ↑, I get
pkg_add emacs-23.4,2.tbz 2 > output.log
with a space before the 2.
I did not originally put this. I try
pkg_add emacs-23.4,2.tbz > output.log 2>&1
Again, when I press ↑, spaces have been added.
Why is this happening to me?
I am running csh on FreeBSD.
I'm not sure if you are trying to hide STDERR or redirect it to STDOUT.
To redirect STDOUT to a file:
pkg_add emacs-23.4,2.tbz > stdout.log
To redirect STDOUT and STDERR to a file:
pkg_add emacs-23.4,2.tbz > & stdxxx.log
To redirect STDOUT to a file and hide STDERR:
( pkg_add emacs-23.4,2.tbz > stdout.log ) > & /dev/null
To redirect STDOUT to console and hide STDERR:
( pkg_add emacs-23.4,2.tbz > /dev/tty ) > & /dev/null
To redirect STDOUT to console and STDERR to a file:
( pkg_add emacs-23.4,2.tbz > /dev/tty ) > & stderr.log
To redirect STDOUT to a file and STDERR to a file:
( pkg_add emacs-23.4,2.tbz > stdout.log ) > & stderr.log
EDIT: The reason why this works is that the action in the ()'s happens first; Ergo, if we've redirected STDOUT, then it will no longer be available outside of the ()'s. This leaves us with just STDERR, and then we can redirect that as desired.
The 2> redirect does not work with csh or tcsh.
Use the chsh command to change your shell to /bin/sh or /usr/local/bin/bash in order to use the 2> style redirect. Note: Do not change root's shell to /usr/local/bin/bash
csh and tcsh cannot redirect standard out and error separately, but >& will redirect the combined output to a file.
pkg_add on FreeBSD, so I'm assuming this is for the root user (/bin/csh is the default for root on FreeBSD). In this case you should not change the shell to /usr/local/bin/bash. /bin/sh is acceptable. You could also just switch to another shell after logging in as root.
Apr 6, 2012 at 23:21
I know how to do it in Csh, but using 2 shells:
csh -c 'SOME_COMMAND 1>/dev/null' |& tee file.txt
Such a way allows to redirect only stderr to file.txt, without stdout - namely what you wanted.
In regards to nikc's answer, to achieve the same behavior of Bourne shells, instead of /dev/tty, use a FIFO.
To redirect STDOUT to console and hide STDERR:
mkfifo stdout
( pkg install -y emacs > stdout ) >& /dev/null & cat stdout
To redirect STDERR to console and hide STDOUT:
pkg install -y emacs > /dev/null
