Directory Watcher for linux about file changes

dir-watcher.sh

#!/bin/bash

# @Author: Alexander 'Delta' Diller
# @Date:   2022-11-29 23:32:48
# @Description Monitor a folder recursiveley and sents an email notification

# inotifywait 3.14
# Wait for a particular event on a file or set of files.
# Usage: inotifywait [ options ] file1 [ file2 ] [ file3 ] [ ... ]
# Options:
#         -h|--help       Show this help text.
#         @<file>         Exclude the specified file from being watched.
#         --exclude <pattern>
#                         Exclude all events on files matching the
#                         extended regular expression <pattern>.
#         --excludei <pattern>
#                         Like --exclude but case insensitive.
#         -m|--monitor    Keep listening for events forever.  Without
#                         this option, inotifywait will exit after one
#                         event is received.
#         -d|--daemon     Same as --monitor, except run in the background
#                         logging events to a file specified by --outfile.
#                         Implies --syslog.
#         -r|--recursive  Watch directories recursively.
#         --fromfile <file>
#                         Read files to watch from <file> or `-' for stdin.
#         -o|--outfile <file>
#                         Print events to <file> rather than stdout.
#         -s|--syslog     Send errors to syslog rather than stderr.
#         -q|--quiet      Print less (only print events).
#         -qq             Print nothing (not even events).
#         --format <fmt>  Print using a specified printf-like format
#                         string; read the man page for more details.
#         --timefmt <fmt> strftime-compatible format string for use with
#                         %T in --format string.
#         -c|--csv        Print events in CSV format.
#         -t|--timeout <seconds>
#                         When listening for a single event, time out after
#                         waiting for an event for <seconds> seconds.
#                         If <seconds> is 0, inotifywait will never time out.
#         -e|--event <event1> [ -e|--event <event2> ... ]
#                 Listen for specific event(s).  If omitted, all events are
#                 listened for.

# Exit status:
#         0  -  An event you asked to watch for was received.
#         1  -  An event you did not ask to watch for was received
#               (usually delete_self or unmount), or some error occurred.
#         2  -  The --timeout option was given and no events occurred
#               in the specified interval of time.

# Events:
#         access          file or directory contents were read
#         modify          file or directory contents were written
#         attrib          file or directory attributes changed
#         close_write     file or directory closed, after being opened in
#                         writable mode
#         close_nowrite   file or directory closed, after being opened in
#                         read-only mode
#         close           file or directory closed, regardless of read/write mode
#         open            file or directory opened
#         moved_to        file or directory moved to watched directory
#         moved_from      file or directory moved from watched directory
#         move            file or directory moved to or from watched directory
#         create          file or directory created within watched directory
#         delete          file or directory deleted within watched directory
#         delete_self     file or directory was deleted
#         unmount         file system containing file or directory unmounted

ACTION=${1:-HELP}
FOLDER=${2:-"/root"} # Folder to watch
EMAIL=${3:-"Delta@ugx-mods.com"}        # Email to send notification to

ID=$(echo -n "$FOLDER" | md5sum | cut -d ' ' -f 1)
AUDIT_FILE=/root/watcher-audit-${ID}.log

# --- color helpers ---
red=$(tput setaf 1)
green=$(tput setaf 2)
yellow=$(tput setaf 3)
cyan=$(tput setaf 6)
reset=$(tput sgr0)

# --- LOGIC ---

type -P inotifywait &>/dev/null || {
	echo "${red}Install ionotify${reset} | ${yellow}apt-get install inotify-tools"
	exit 1
}

if [ -z "$FOLDER" ]; then
	echo "${red}Folder param is missing!"
	exit 1
fi

function is_already_running {
	if [ "$(pgrep -a inotifywait | grep -c "$FOLDER")" -gt 0 ]; then
		return
	fi

	false
}

function start {

	if is_already_running; then
		echo "${red}A process monitoring ${yellow}$FOLDER${red} is already running:"
		echo "${cyan}$(pgrep -a inotifywait | grep "$FOLDER")"
		exit 1
	fi

	if [ -z "$EMAIL" ]; then
		echo "${red}EMAIL is missing!"
		exit 1
	fi

	if [ -d "$FOLDER" ]; then
		echo "${green}Monitoring folder (recursively) ${yellow}$FOLDER${green} for changes - sending alerts to ${cyan}$EMAIL"

		while inotifywait -r -e create -e modify -e attrib -e move -e delete "$FOLDER" -o "$AUDIT_FILE"; do
			sleep 1
			changes="$(cat "${AUDIT_FILE}")"
			echo "The following changes occured at $FOLDER : $changes" | mail -s "[WATCHER] Change in $FOLDER" "$EMAIL"
			rm "$AUDIT_FILE"
			touch "$AUDIT_FILE"
		done
	else
		echo "Error: Folder $FOLDER not found!"
	fi
}

function status {
	if is_already_running; then
		echo "${green}Monitoring is running${reset} for ${yellow}$FOLDER${reset} [${cyan}$ID${reset}]"
	else
		echo "${red}Monitoring is NOT running${reset} for ${yellow}$FOLDER${reset} [${cyan}$ID${reset}]"
	fi
}

function stop {
	# if a inotifywait for this file is already running
	if ! is_already_running; then

		echo "${red}A process monitoring ${yellow}$FOLDER${red} is not running"
		if [ -z "$AUDIT_FILE" ]; then
			echo "${yellow}Audit file ${cyan}$AUDIT_FILE${yellow} does exist though, you might want to delete it manually (kept in case you need it)"
			exit 1
		fi

		exit 1
	fi

	kill -9 "$(pgrep -f "inotifywait.*${FOLDER}")"
	rm "$AUDIT_FILE"
	echo "${green}Process stopped and audit file removed"
}

case "$ACTION" in
"start")
	start
	exit 0
	;;

"status")
	status
	exit 0
	;;

"stop")
	stop
	exit 0
	;;

*)
	echo "Usage dir-watcher.sh <action=start|stop|status> <dir> <email>"
	exit 1
	;;
esac

⚠️ Script has some default parm values set, like email and folder! Either remove or change (you don't want to send me your changes 🤣)

usage: dir-watcher.sh <action> <path> <email>

start: dir-watcher.sh start /some/folder email@example.de (or omit params after action to use default values)
status: dir-watcher.sh status /some/folder
stop: dir-watcher.sh stop /some/folder

To keep it in background, use screen

start sceen: screen -S MyTask -dm bash -c "dir-watcher.sh /some/folder email@example.de"
stop screen: screen -S MyTask -X quit