#!/bin/sh
#
#  SSH Agent Wrapper script: SAW v0.1
#
#  This is a simple script to wrapper a command by starting an SSH agent 
#  for just that command, then kill it.  To use it, simply prepend "saw"
#  to the command.
#
#  Usage:
#    saw <cmd> <args>
#
#  Example:
#      saw svn ci -m "blah"  
#
#  If you fix something, please send the updated version to
#  Paul Millar <paul.millar@desy.de>

likely_identity_files="id_dsa id_rsa identity"

if [ $# -lt 1 ]; then
  echo "saw <cmd> [<args>]"
  echo "  Runs command <cmd> by first starting an ssh-agent, running <cmd>, then killing the agent"
  exit 0
fi

if [ -r "$SSH_FILE" ]; then
  echo "Ignoring file $SSH_FILE as it cannot be read."
  unset SSH_FILE
fi

if [ -z "$SSH_FILE" ]; then
  for id_file in $likely_identity_files; do
    if [ -r ~/.ssh/${id_file} -a -r ~/.ssh/${id_file}.pub ]; then
      SSH_FILE=$id_file
    fi
  done
fi

if [ -z "$SSH_FILE" ]; then
  echo "Cannot find a likely identity file: please specify one with SSH_FILE"
  exit 1
fi

eval `ssh-agent -s` > /dev/null

if [ $? -ne 0 ]; then
  echo "Failed to start ssh-agent, stopping."
  exit 1
fi

ssh-add ~/.ssh/$SSH_FILE

if [ $? -ne 0 ]; then
  echo "Failed to add the identity, stopping."
  eval `ssh-agent -k` > /dev/null
  exit 1
fi

cmd="$1"
shift

$cmd "$@"

rc=$?

eval `ssh-agent -k` >/dev/null

exit $rc