Use ssh-add to check if agent is started as ps does not always work

functions/__ssh_agent_is_started.fish

@@ -7,6 +7,8 @@ function __ssh_agent_is_started -d "check if ssh agent is already started"
 		return 1
 	end
 
-	ps -ef | grep $SSH_AGENT_PID | grep -v grep | grep -q ssh-agent
-	return $status
+	ssh-add -l > /dev/null
+	if [ $status -eq 2 ]
+	    return 1
+	end
 end