Re: [libvirt] [PATCH 4/4] remote: Detect 'nc' version incompatibilities

On Mon, Feb 15, 2010 at 09:39:31AM -0500, Cole Robinson wrote: > On 02/15/2010 06:11 AM, Daniel P. Berrange wrote: >> On Fri, Feb 12, 2010 at 10:32:17AM -0500, Cole Robinson wrote: >>> This ugly thing is a shell script to detect availability of >>> the -q option for 'nc': debian and suse based distros need this >>> flag to ensure the remote nc will exit on EOF, so it will go away >>> when we close the tunnel. If it doesn't go away, a useless 'nc' >>> process is left sitting on the remote host. >>> >>> Fedora's 'nc' doesn't have this option, so we can't blindly pass -q. >>> More info here: >> >> I don't really like this approach. Shouldn't it be sufficient to >> just explicit SIGKILL the ssh client, rather than relying on the >> exit-on-EOF behaviour of nc. >> > > kill() helps prevent virt-manager from hanging, but it doesn't address the > dangling 'nc' process on the remote host that requires -q. Every connection > will leave an 'nc' process hanging. It does when I try it. Killing the SSH client connection results in SIGHUP for the process running on the remote host & nc exits on SIGHUP.