Added get-ssh-agent.

functions/get-ssh-agent

@@ -0,0 +1,35 @@
+## get-ssh-agent
+# A pretty simple function intended to convince multiple shell sessions to connect to the same
+# ssh-agent instance.
+
+AGENT_FILE_NAME='ssh-agent.env'
+# XDG runtime path by default is /run/user/$UID
+default_runtime_path="/run/user/$UID"
+
+if [[ "$XDG_RUNTIME_DIR" ]]; then
+	ssh_agent_env_file="${XDG_RUNTIME_DIR}/${AGENT_FILE_NAME}"
+else
+	ssh_agent_env_file="${default_runtime_path}/${AGENT_FILE_NAME}"
+fi
+
+function _start_new_ssh_agent () {
+	killall ssh-agent
+	# start a new ssh-agent and write its output to the env file.
+	ssh-agent | grep -v echo >&"$ssh_agent_env_file"
+	echo "New ssh-agent started."
+	ssh-add
+}
+
+if [[ -e "$ssh_agent_env_file" ]]; then
+	# determine if the pid in the env file is still alive
+	if [[ "$(source "$ssh_agent_env_file"; ps -ef | grep "$SSH_AGENT_PID")" ]]; then
+		source "$ssh_agent_env_file"
+		echo "Existing ssh-agent environment configured with pid ${SSH_AGENT_PID}."
+	else
+		echo "Existing ssh-agent appears to be dead."
+		_start_new_ssh_agent
+	fi
+else
+	echo "No existing ssh-agent found."
+	_start_new_ssh_agent
+fi