Watch File or Files changed in a folder to run a command

watchdo.sh

#!/bin/bash

# watchdo "rake" .rb

command="$1"
shift
fileSpec="$@"
sentinel=/tmp/t.$$

touch -t197001010000 $sentinel
while :
do
  files=$(find . -newer $sentinel -a '(' -name "*$fileSpec" ')')
  if [ $? != 0 ]; then
    exit 1;
  fi
  #echo $files
  if [ "$files" != "" ]; then
    $command
    touch $sentinel
  fi
  sleep 0.5 
done

watchdoit.sh

#!/bin/bash

# watchdoit "ruby" .rb

command="$1"
shift
fileSpec="$@"
sentinel=/tmp/t.$$

touch -t197001010000 $sentinel
while :
do
  files=$(find . -newer $sentinel -a '(' -name "*$fileSpec" ')')
  if [ $? != 0 ]; then
    exit 1;
  fi
  #echo $files
  if [ "$files" != "" ]; then
    $command $files
    touch $sentinel
  fi
  sleep 0.5 
done

It was inspired by https://gist.github.com/derekwyatt/3577440