ramdisk-target.sh

#!/bin/bash
# Overwrite ./target with a tmpfs ramdisk. Prompts for sudo.

function usage() {
  echo 'Usage: `ramdisk-target.sh recreate|restore`'
}

if [ ! -f "project.clj" ]; then
  echo "Not in Clojure project."
  exit 2
fi

function remove-old() {
  if mountpoint -q ./target; then
    if fuser --mount ./target; then
      echo "Processes are currently using the ramdisk!"
      exit 2
    fi
    echo "Unmounting ./target"
    sudo umount ./target || exit 1
  fi
  if [ "`stat --format="%F" ./target`" = 'directory' ]; then
    echo "Deleting ./target directory"
    rm -rf ./target || exit 1
  fi
}

## Primitives

function restore() {
  remove-old
  mkdir ./target
}

function mount-on-point() {
  group=`stat --format='%G' .`
  user=`stat --format='%U' .`
  echo "Creating mount point with ownership $user:$group"
  sudo mount -t tmpfs -o size=400M tmpfs ./target
  sudo chown $group:$user ./target
}

## Actions

function become-mounted() {
  # Remove any existing target so that we don't end up with old stuff
  # exposed when we umount.
  restore
  mount-on-point
}

## Dispatch

case "$1" in
  recreate)
    become-mounted
    ;;
  restore)
    restore
    ;;
  *)
    usage
    exit 0
    ;;
esac