watch-directory

#!/bin/bash

# Bash Utility to watch any directory for changes and runs a supplied custom command on the event


scriptAbsolutePath=;
helpText=;
directory=;
commandEntry=;

function displayHowToUse() {
  helpText=$(cat << EOF



            watch-directory
            Version: 1.0.0
            Usage:
              watch-directory [OPTIONS]

            Options:
              <-d | --directory directoryName>
              <-c | --command commandEntry>
              <-h | --help>

            Synopsis:
              Purpose: To watch a directory for changes and also runs a command whenever a change is observed

              Options:
                -d | --directory: This option receives the name of the directory to watch.

                -c | --command: This option receives the name of the command to run whenever a change happens in the directory.

                -h | --help: This option displays this help page.




            Author: Daniel Okwufulueze [https://github.com/DOkwufulueze]
            Date: 02/05/2018

EOF
);
}

function getAbsolutePathOfSelf() {
  pushd $(dirname "$0") > /dev/null;
  scriptAbsolutePath="$(pwd -P)";
  popd > /dev/null;
}

function beginWatch() {
  fswatch -0 "${directory}" | while read -d "" event
    do
      [[ -f "${event}" ]] && $(${commandEntry} -f ${event});
      # [[ -f "${event}" ]] && echo "${commandEntry} -f ${event}";
    done
}

if [[ $# -gt 0 ]]; then
  while [[ "$1" != "" ]]; do
    case "$1" in
      -d | --directory )
        shift;
        directory="$1";
      ;;

      -c | --command )
        shift;
        commandEntry="$*";
      ;;

      -h | --help )
        displayHowToUse;
        echo "${helpText}" | less;
        exit;
      ;;

      * )
        echo "Invalid entry in watch-directory invocation.";
        exit;
      ;;
    esac

    [[ -n "${commandEntry}" && -n "${directory}" ]] && break;
    shift;
  done
fi


getAbsolutePathOfSelf;

firstDirectoryCharacter=$(echo "${directory}" | head -c 1);

[[ -n "${firstDirectoryCharacter}" && "${firstDirectoryCharacter}" != "/" ]] && directory="${scriptAbsolutePath}/${directory}";

beginWatch;