Start ssh-agent when needed

.profile

@@ -7,14 +7,33 @@
 # the default umask is set in /etc/profile; for setting the umask
 # for ssh logins, install and configure the libpam-umask package.
 #umask 022
+VISUAL=vim
+EDITOR=vim
 
-eval "$(ssh-agent)"
+SSH_ENV="$HOME/.ssh/environment"
+function start_agent {
+     echo "Initialising new SSH agent..."
+     /usr/bin/ssh-agent | sed 's/^echo/#echo/' > "${SSH_ENV}"
+     echo "succeeded"
+     chmod 600 "${SSH_ENV}"
+     . "${SSH_ENV}" > /dev/null
+}
+
+# source SSH settings, if applicable
+if [ -f "${SSH_ENV}" ]; then
+     . "${SSH_ENV}" > /dev/null
+     ps -ef | grep ${SSH_AGENT_PID} | grep ssh-agent$ > /dev/null || {
+         start_agent;
+     }
+else
+     start_agent;
+fi
 
 # if running bash
 if [ -n "$BASH_VERSION" ]; then
     # include .bashrc if it exists
     if [ -f "$HOME/.bashrc" ]; then
-	. "$HOME/.bashrc"
+        . "$HOME/.bashrc"
     fi
 fi