Bash script to watch Compass project dir using inotifywait and compile on changes. Uses Bundler if project dir has Gemfile.

compass-watch.sh

#!/bin/bash
# Watch Compass project dir for changes using inotifywait,
#+which is more sustainable in the long run than 'compass watch'.
#
# In Debian: apt-get install inotify-tools

# First parameter is the project dir
project_dir="${1?Compass project dir expected as first parameter}"
# Rest of the arguments will be passed to compile command
shift
args="${@}"

# Will watch changes only in the Sass directory (and subdirs)
watch_dir="${project_dir%/}"/sass
echo "Watching for changes in ${watch_dir}"

# Routine checks
if [[ ! -d "${project_dir}" ]]
then
  echo "${project_dir} does not exist or is not a directory."
  exit 1
elif [[ ! -d "${watch_dir}" ]]
then
  echo "${watch_dir} does not exist or is not a directory."
  exit 1
fi

# If Gemfile exists in the project dir, use 'bundle exec' to compile.
# Otherwise go with plain 'compass compile'.
[[ -e "${project_dir}"/Gemfile ]] && cmd="bundle" || cmd="compass"

# For bundler, change to project dir.
[[ "${cmd}" == "bundle" ]] && cd "${project_dir}"

echo "Ctrl-C to quit"
while true
do
  # Wait.
  change=$(inotifywait -q --exclude .# -r -e close_write,moved_to,create "${watch_dir}")
  if [[ -n "${change}" ]]
  then
    # Act.
    echo $(date)
    if [[ "${cmd}" == "bundle" ]]
    then
      bundle exec compass compile $args
    else
      compass compile $args "${project_dir}"
    fi
  fi
done

exit 0

Calls to inotifywait, bundle and compass should be made more robust...