Monitor folder for new files using unix ksh shell script or perl script and trigger perl script

If I understand correctly, you just want something like this?

#!/usr/bin/perl

use strict;
use warnings;

use File::Copy

my $poll_cycle = 5;
my $dest_dir = "/pri/vate";

while (1) {
    sleep $poll_cycle;

    my $dirname = '/exam/ple';

    opendir my $dh, $dirname 
        or die "Can't open directory '$dirname' for reading: $!";

    my @files = readdir $dh;
    closedir $dh;

    if ( grep( !/^[.][.]?$/, @files ) > 0 ) {
        print "Dir is not empty\n";

        foreach my $target (@files) {
            # Move file
            move("$dirname/$target", "$dest_dir/$target");

            # Trigger external Perl script
            system('./my_script.pl');
    }
}

File::ChangeNotify allows you to monitor files and directories for changes.

https://metacpan.org/pod/File::ChangeNotify

I'm late to the party, I know, but in the interests of completeness and providing info to future visitors;

#!/bin/ksh
# Check a File path for any new files
# And execute another script if any are found

POLLPATH="/path/to/files"
FILENAME="*.txt" # Or can be a proper filename without wildcards
ACTION="executeScript.sh argument1 argument2"
LOCKFILE=`basename $0`.lock

# Make sure we're not running multiple instances of this script
if [ -e /tmp/$LOCKFILE ] ; then 
     exit 0
else
     touch /tmp/$LOCKFILE
fi

# check the dir for the presence of our file
# if it's there, do something, if not exit

if [ -e $POLLPATH/$FILENAME ] ; then
     exec $ACTION
else
     rm /tmp/$LOCKFILE
     exit 0
fi

Run it from cron;

*/1 7-22/1 * * * /path/to/poll-script.sh >/dev/null 2>&1

You'd want to use the lockfile in your subsequent script ( $ACTION ), and then clean it up on exit, just so you don't have any stacking processes.

$ python autocmd.py /exam/ple .txt,.html /pri/vate some_script.pl

Advantages:

• easier to install than incron due to pyinotify is pure Python
• event-driven -- less impact than the perl script

autocmd.py:

#!/usr/bin/env python
"""autocmd.py 

Adopted from autocompile.py [1] example.

[1] http://git.dbzteam.org/pyinotify/tree/examples/autocompile.py

Dependencies:

Linux, Python, pyinotify
"""
import os, shutil, subprocess, sys

import pyinotify
from pyinotify import log

class Handler(pyinotify.ProcessEvent):
    def my_init(self, **kwargs):
        self.__dict__.update(kwargs)

    def process_IN_CLOSE_WRITE(self, event):
        # file was closed, ready to move it
        if event.dir or os.path.splitext(event.name)[1] not in self.extensions:
           # directory or file with uninteresting extension
           return # do nothing

        try:
            log.debug('==> moving %s' % event.name)
            shutil.move(event.pathname, os.path.join(self.destdir, event.name))
            cmd = self.cmd + [event.name]
            log.debug("==> calling %s in %s" % (cmd, self.destdir))
            subprocess.call(cmd, cwd=self.destdir)
        except (IOError, OSError, shutil.Error), e:
            log.error(e)

    def process_default(self, event):
        pass


def mainloop(path, handler):
    wm = pyinotify.WatchManager()
    notifier = pyinotify.Notifier(wm, default_proc_fun=handler)
    wm.add_watch(path, pyinotify.ALL_EVENTS, rec=True, auto_add=True)
    log.debug('==> Start monitoring %s (type c^c to exit)' % path)
    notifier.loop()


if __name__ == '__main__':
    if len(sys.argv) < 5:
       print >> sys.stderr, "USAGE: %s dir ext[,ext].. destdir cmd [args].." % (
           os.path.basename(sys.argv[0]),)
       sys.exit(2)

    path = sys.argv[1] # dir to monitor
    extensions = set(sys.argv[2].split(','))
    destdir = sys.argv[3]
    cmd = sys.argv[4:]

    log.setLevel(10) # verbose

    # Blocks monitoring
    mainloop(path, Handler(path=path, destdir=destdir, cmd=cmd,
                           extensions=extensions))

This will result in a fair bit of io - stat() calls and the like. If you want rapid notification without the runtime overhead (but more upfront effort), take a look at FAM/dnotify: link text or link text

I don't use ksh but here's how i do it with sh. I'm sure it's easily adapted to ksh.

#!/bin/sh
trap 'rm .newer' 0
touch .newer
while true; do
  (($(find /exam/ple -maxdepth 1 -newer .newer -type f -name '*.txt' -print \
      -exec mv {} /pri/vate \; | wc -l))) && found-some.pl &
  touch .newer
  sleep 10
done

#!/bin/ksh
while true
do
    for file in `ls /exam/ple/*.txt`
    do
          # mv -f /exam/ple/*.txt /pri/vate
          # changed to
          mv -f  $file  /pri/vate

    done
    sleep 30
done