#!/usr/bin/env bash
#
# Run commands when a folder content changes.
#

# Parameters
BASENAME="`basename $0`"
WATCHED="$1"
COMMAND="$2"

# Listened inotify events
#
# See inotifywait(0) for the full list and description of all supported events.
#
# By default, exclude "access", "close", "close_write", "close_nowrite", "open"
# from the list of events
INOTIFY_EVENTS="-e modify -e attrib -e moved_to -e moved_from -e move -e move_self -e create -e delete -e delete_self -e unmount"

# Check
if [ -z "$COMMAND" ]; then
  echo "usage: $BASENAME <folder> <command> [args]"
  exit 1
elif [ ! -e "$WATCHED" ]; then
  echo "error: file or folder not found: $WATCHED"
  exit 1
fi

# Shift
shift 2

# Normalize folder name
if [ -d "$WATCHED" ]; then
  WATCHED="`cd $WATCHED &> /dev/null && pwd`"
fi

# UX
echo "Watching $WATCHED to exec \"$COMMAND $*\" upon changes..."

# Dispatch
# Excluding any .git folder from being watched
while inotifywait $INOTIFY_EVENTS --exclude '.*.git.*' -r $WATCHED; do
  $COMMAND $*
done