Automate Linux File Sync with inotify and rsync

Overview

This guide shows how to combine inotify-tools and rsync to automatically sync files when a directory changes on Linux. It is useful for continuous deployment or keeping backup copies up to date.

Installing inotify-tools

On a system with yum, install the utilities with: yum install inotify-tools The package provides two commands: inotifywait (used for waiting on events) and inotifywatch (for statistics). The tutorial focuses on inotifywait.

Monitoring command and options

To watch a directory (e.g., /usr/local/src) continuously and output concise event information, run:

/usr/local/bin/inotifywait -mrq --timefmt '%d/%m/%y %H:%M' --format '%T %w %f %e' -e modify,delete,create,attrib /usr/local/src

Key options: -m: keep listening after the first event -r: watch directories recursively -q: suppress non‑essential messages -e: specify which events to monitor (modify, delete, create, attrib) --timefmt: format for the timestamp, e.g.,

'%d/%m/%y %H:%M'

--format

: customize output using placeholders: %T – time according to

--timefmt

%w

– directory where the event occurred %f – file name %e – event type

Example output

Creating a file 1.txt in the watched directory produces:

22/03/18 17:22 /usr/local/src/ 1.txt CREATE
22/03/18 17:22 /usr/local/src/ 1.txt ATTRIB

Shell script for handling events

The following script loops on events and runs a user‑specified script whenever a file is created, modified, or deleted:

#!/bin/sh
# Monitored file or directory
filename=$1
# Script to execute on change
script=$2

inotifywait -mrq --format '%e' --event create,delete,modify $filename | while read event
do
    case $event in
        MODIFY|CREATE|DELETE) bash $script ;;
    esac
done

Running the script in the background

Use nohup to detach the script from the terminal and redirect output: nohup sh test.sh > out.txt & This setup enables continuous, automated file synchronization without manual intervention.