December 18, 2007

Cygwin ssh-agent Control

[Edited: 10/6/08 Remove temporary files before starting a new agent]

Another little annoyance gone: all Cygwin processes now share a single ssh-agent instance, which is started up automatically as required. I picked this tip up from a now-forgotten blog. the only change required to that recipe being to re-order the redirections for the ssh-agent command. Since it took me a while to find (low Google-fu today?) I take the liberty of repeating it here so I don't forget it.

In your ~/.bashrc file add the following:

export SSH_AUTH_SOCK=/tmp/.ssh-socket

ssh-add -l >/dev/null 2>&1
if [ $? = 2 ]; then
# Exit status 2 means couldn't connect to ssh-agent; start one now
rm -rf /tmp/.ssh-*
ssh-agent -a $SSH_AUTH_SOCK >/tmp/.ssh-script
. /tmp/.ssh-script
echo $SSH_AGENT_PID >/tmp/.ssh-agent-pid
fi


function kill-agent {
pid=`cat /tmp/.ssh-agent-pid`
kill $pid
}



You can use Start | My Computer | Properties | Advanced | Environment Variables to add an environment variable called SSH_AUTH_SOCK whose value is /tmp/.ssh-socket to make the agent available to other Cygwin-aware processes you run under Windows.

That's better!

For some reason a number of posts were stuck in the blog as drafts. This one is from October last year.

3 comments:

nickhansen said...

Nice post. Very useful.

Anonymous Lee said...

I've been looking for something like this myself and this works like a charm, thanks! Though I didn't need to set a Windows environment variable to have the agent available to subsequent rxvts.

Steve said...

Glad you found it useful. I have since given up on rxvt, having found mintty to be a much more satisfactory alternative.