Usage: watcher.sh <watched files> -- <command>; watcher then will execute the given command whenever a write has occured to one of the watched files

watcher.sh

#!/bin/bash
INDEX=0
IS_PARSING_WATCHED_FILES="y"

declare -a WATCHED_FILES
declare -a COMMAND

while [[ $# > 0 ]]
do
  if [ "$1" == "--" ]
  then
    IS_PARSING_WATCHED_FILES="n"
    INDEX=0
  else
    if [ "$IS_PARSING_WATCHED_FILES" = "y" ]
    then
      WATCHED_FILES[$INDEX]=$1
    else
      COMMAND[$INDEX]=$1
    fi
  fi
  INDEX=$((INDEX + 1))
  shift
done

if [ ${#COMMAND[@]} -lt 1 ]
then
  echo "Usage: watcher.sh <watched files> -- <command>"
  exit 1
fi

while inotifywait -e close_write ${WATCHED_FILES[*]}
do
  ${COMMAND[*]}
done

echo "Watching: ${WATCHED_FILES[*]}"
echo "Executing: ${COMMAND[*]}"

This script is based on the answer of http://superuser.com/questions/181517/how-to-execute-a-command-whenever-a-file-changes

BTW: requires inotify-tools on arch/manjaro