sshconf

#!/bin/bash
command=$1
ssh_config_dir=~/.ssh
ssh_configs_dir=${ssh_config_dir}/conf.d
ssh_config_file=${ssh_config_dir}/config
ssh_base_config_file=${ssh_configs_dir}/config

function usage()
{
    echo "Usage: `basename $0` [update [go]] [add user@ipaddress alias]"
}

function generate()
{
  cat ${ssh_base_config_file} ${ssh_configs_dir}/*.conf > ${ssh_config_file}.new
}

function diff_w_new()
{
  diff -uN ${ssh_config_file} ${ssh_config_file}.new
}

function update()
{
    cp ${ssh_config_file} ${ssh_config_file}.old
    cp ${ssh_config_file}.new ${ssh_config_file}
}

if [ -z "$command" ]; then
  generate
  diff_w_new && exit
  while true; do
    read -p "Do you wish to overwrite ${ssh_config_file}? [Y] " yn
    case $yn in
      [Yy]* ) update; break;;
      * ) exit;;
    esac
  done
  exit
fi

case $command in
  update)
    generate
    update
    ;;
  *)
    usage
    ;;
esac