How to find if there are new files in a directory every 2 minutes in shell script?

Question

I have a directory called /home/user/local. Every two minutes or so, a new file is dumped into this directory. I need to check this directory every 2 minutes to see if a new file/files have landed in there. And if there are new files, I need to put a list of it into a variable to use later on. How do I do this shell script?

Answer 1

#! /usr/bin/env bash

FILELIST=/tmp/filelist
MONITOR_DIR=/home/usr/local

[[ -f ${FILELIST} ]] || ls ${MONITOR_DIR} > ${FILELIST}

while : ; do
    cur_files=$(ls ${MONITOR_DIR})
    diff <(cat ${FILELIST}) <(echo $cur_files) || \
         { echo "Alert: ${MONITOR_DIR} changed" ;
           # Overwrite file list with the new one.
           echo $cur_files > ${FILELIST} ;
         }

    echo "Waiting for changes."
    sleep $(expr 60 \* 2)
done

a quick & dirty way. :) It'll monitor the directory for changes, not only when there's new file dumped in, but also if some file is missing/deleted.

File list is stored in variable $cur_files.

Answer 2

inotifywait is exactly what you are looking for: http://linux.die.net/man/1/inotifywait