On 04/27/2012 05:12 AM, Stefan Berger wrote:
On 04/26/2012 05:13 PM, Eric Blake wrote:
On 04/23/2012 06:20 AM, Stefan Berger wrote:
+ if [ -n "${cmd}" ]; then + eval "${cmd}" 2>&1 1>/dev/null This says output any errors from command to our stdout, and to ignore normal output of $cmd. Is that what you meant, or did you want to ignore both output and errors from $cmd, in which case you should swap the redirection operators?
The intention was to not get any output from running those test commands. Above unfortunately only solved this for stdout but not for suppressing stderr, so 'ipset: command not found' was still printed. Now I changed this line to
eval "${cmd}" 2>/dev/null 1>/dev/null
and everything is quiet. Not quite sure why the previous notation didn't work...
Using '2>&1 1>/dev/null' says: start with stdout (1) and stderr (2) inherited from the parent change fd 2 to be copied from the current fd 1 (the parents stdout) change fd 1 to be /dev/null now the child discards output, and sends errors into the parent's stdout Using '2>/dev/null 1>/dev/null' says: start with stdout and stderr inherited from the parent change fd 2 to be /dev/null change fd 1 to be /dev/null now the child discards everything Swapping the order, and using '>/dev/null 2>&1' says: start with stdout (1) and stderr (2) inherited from the parent change fd 1 to be /dev/null change fd 2 to be copied from the current fd 1 (/dev/null) now the child discards everything In other words, all you did wrong was forgetting that redirections are honored left-to-right.
I will post a V2. For this patch to go in I'll also need an ACK for the somewhat longer patch for ipset support:
http://www.redhat.com/archives/libvir-list/2012-April/msg01226.html
Yep, on my list to review. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org