do something when a file is modified, e.g. convert markdown to pdf: $ inotify-action foo.md pandoc -o foo.pdf foo.md

inotify-action.sh

#!/usr/bin/env bash

declare -a watches

while [[ -n $1 && $1 != "--" ]]
do
  watches+=("$1")
  shift
done

# check if we have something to watch
if [[ ${#watches[@]} -eq 0 ]]
then
  echo "usage: $(basename "$0") FILE... -- command" >&2
  exit 1
fi

# shift away the double dashes
shift

# check if we have a command
if [[ -z $1 ]]
then
  echo "usage: $(basename "$0") FILE... -- command" >&2
  exit 1
fi

# start command once
"$@"

# now wait for changes and then start command
while inotifywait -qr -e modify "${watches[@]}" &> /dev/null
do
  "$@"
done