File watcher

watcher.sh

#!/bin/bash

normal=$(tput sgr0)
yellow=$(tput setaf 3)
green=$(tput setaf 2)

FOLDER="."
PATTERN=".*"
COMMAND="ls"

spinner() {
    SPIN='|/-\'
    echo ""
    while true
    do
        TMP=${SPIN#?}
        tput sc
        printf "${yellow}waiting...${normal} [${yellow}%c${normal}] " "$SPIN"
        SPIN=$TMP${SPIN%"$TMP"}
        sleep 0.5
        tput rc
    done
}

while getopts 'f:p:x:h' opt
do
  case "$opt" in
    f)
      FOLDER=$OPTARG
      ;;
    p)
      PATTERN=$OPTARG
      ;;
    x)
      COMMAND=$OPTARG
      ;;
    h)
      echo "Usage: $(basename $0) [-f FOLDER] [-p PATTERN] [-x COMMAND]"
      exit 1
      ;;
  esac
done

if ! hash inotifywait 2>&1 >/dev/null
then
  echo "inotifywait not found"
  exit 1
fi

clear

while true
do
  # eval command
  clear
  printf "${green}${COMMAND}${normal}\n"
  eval $COMMAND

  # start spinner
  spinner &
  pid=$!

  # waiting for an event
  inotifywait -q -r -P -I -e modify,delete $FOLDER --include "${PATTERN}" >/dev/null 2>&1

  # kill spinner
  kill $pid
done