An exciting bash function for extending the default capability of ssh-agent

ssh_agent_systemwide is for making ssh-agent even cooler

#!/bin/bash
# Currently, I only have used this on RH/Fedora-based systems, so....
# The way *I* use this: I put the function into /etc/profile.d/reusessh.sh
# or something like that, and then call it from each user's ~/.bash_profile

# Reuse SSH Agent -- handles a per-user system-wide reusable ssh-agent
# This just sets up a function; you still need to call it from ~/.bash_profile
# (or simply run on demand, as a replacement for running 'ssh-agent bash')

function ssh_agent_systemwide
{
  # This block checks for already running ssh-agent
  local SSH_AGENT_CACHE=/tmp/ssh_agent_`whoami`
  if [[ -f $SSH_AGENT_CACHE ]]; then
    eval `cat $SSH_AGENT_CACHE` &>/dev/null
    kill -0 $SSH_AGENT_PID &>/dev/null && echo "[Reusing existing ssh-agent]" \
      || { local dead=1; rm -f $SSH_AGENT_CACHE; }
  fi

  # This block starts a new ssh-agent if necessary
  if [[ ! -f $SSH_AGENT_CACHE ]]; then
    [[ $dead = 1 ]] && echo "[Started new ssh-agent]"
    ssh-agent >$SSH_AGENT_CACHE
    chmod 400 $SSH_AGENT_CACHE
    eval `cat $SSH_AGENT_CACHE` &>/dev/null
  fi
}