use [zeus](https://github.com/burke/zeus) as a shim

zeus_shim.sh

# Usage: 
# 
# Paste these functions into your `.*shrc`, and re-open a new session. Then 
# you can use `rails`, `rake`, `rspec` to launch their zeus equivalance. If you 
# need to invoke a bash script contains those commands, you'll have to call it
# by `source xxxx.sh`.
#
# It works under rbenv. But not tested under rvm (rvm use shell functions, so it may
# not be compliant with these functions)
#

export rake() { 
  if [[ -S .zeus.sock ]]; then
    echo using zeus!!!
    if [[ $1 == "test" ]]; then 
      zeus "$@"
    else 
      zeus rake "$@"
    fi
  else
    command rake "$@"
  fi
}

export rails() {
  if [[ -S .zeus.sock ]]; then
    echo using zeus!!!
    zeus $@
  else
    command rails "$@"
  fi
}


export rspec() {
  if [[ -S .zeus.sock ]]; then
    echo using zeus!!!
    zeus test spec $@
  else
    command rspec "$@"
  fi
}

export bundle() {
  if [[ -S .zeus.sock && $1 == "exec" && ($2 == "rake" || $2 == "rails" || $2 == "rspec") ]]; then
    shift
    $@
  else
    command bundle "$@"
  fi
}