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--- directory:run_a_command_upon_files_or_directories_changes [2021/01/26 09:49] – peter
+++ directory:run_a_command_upon_files_or_directories_changes [2021/01/26 10:53] (current) – removed peter
@@ Line 1: / Line 1: @@
-====== Directory - Run a Command Upon Files or Directories Changes ======
-Use either inotifywait or iwatch.
-----
-===== Using inotifywait =====
-==== Install inotify-tools ====
-<code bash>
-sudo apt install inotify-tools
-</code>
-----
-==== Test inotifywait ====
-In a shell enter:
-<code bash>
-while true; do
-  res=`inotifywait -r thedirtowatch/ --format %f`;
-  echo "RESULT=$res";
-done
-</code>
-returns:
-<code bash>
-Setting up watches.  Beware: since -r was given, this may take a while!
-Watches established.
-</code>
-<WRAP info>
-**NOTE:**  The **<nowiki>%f**</nowiki> refers to the filename in the event.
-See http://manpages.ubuntu.com/manpages/focal/man1/inotifywait.1.html for options.
-</WRAP>
-----
-In a 2nd shell, go to that directory being watched.
-<code bash>
-touch test1
-</code>
-**NOTE:**  Back on the 1st shell this should show you output:
-<code bash>
-RESULT=test1
-</code>
-----
-<WRAP info>
-**NOTE:**  An additional **-e** option can be added to the inotifywait to only listen for certain events.
-For example:
-<code bash>
-while true; do res=`inotifywait -e create, open, close, modify, moved_to, moved_from -r thedirtowatch/ --format '%e %f'` ; echo "RESULT=$res\n"; done
-</code>
-The **<nowiki>--format</nowiki>** option is changed to include showing **%e** which is the actual event.  Obviously change as needed.
-See http://manpages.ubuntu.com/manpages/focal/man1/inotifywait.1.html for options.
-</WRAP>
-----
-===== More =====
-<code bash>
-inotifywait -m -e modify,create -r /yourpath && \
-chmod 644 file; && \
-chown blah:blah file;
-</code>
-<WRAP info>
-**NOTE:**
-  * **-m, --monitor**:  Instead of exiting after receiving a single event, execute indefinitely.  The default behavior is to exit after the first event occurs.
-  * **-r, --recursive**:  Watch all sub-directories of any directories passed as arguments.   Watches will be set up recursively to an unlimited depth.
-    * Symbolic  links  are  not  traversed.  Newly created sub-directories will also be watched.
-</WRAP>
-----
-===== Using a BASH Script =====
-<file bash after-change.sh>
-#!/bin/bash
-#
-# Monitor the input directory and if any change occurs run the provided command:
-#
-# Usage:
-#   after-change.sh /tmp ls -al %f
-if [ $# -lt 3 ]; then
-  echo "Usage: $0 dir cmd "
-  exit 1
-fi
-which inotifywait 2>&1 >/dev/null
-if [ "$?" == "1" ]; then
-  echo "ERROR:  inotifywait not installed."
-  exit 1
-fi
-dir=$1
-shift
-cmd=$1
-shift
-options=$*
-inotifywait -q -r -m $dir $options
-eval $cmd
-</file>
-----
-===== References =====
-http://manpages.ubuntu.com/manpages/focal/man1/inotifywait.1.html