Shell Programming and Scripting

Hi Guys.

I am a complete shell scripting newbie with some syntax and commands understanding. I'm more of a win admin. With that said: I need to write a shell script to monitor a directory '/Mon_Dir' for new occurrences of files with .xx extension. Once a new file is detected in the directory, a command 'str_xx -i file.xx' must be executed against that file. This script should be running as a service with 'sleep' statement or as a Cron job.

My understanding is that this shouldn't be much of a challenge for someone with scripting knowledge, which I don't have.

Any help will be greatly appreciated.

Based on what you gave, here is a start, sleeping for 30 seconds, looping forever:

Code:

#!/bin/ksh
cd /Mon_dir
while true
do
    for file in `ls *.xx`
    do
          /path/to/str_xx -i $file
    done
    sleep 30
done

--> process, hide, delay, all over again ...

Thanks guys. This helps.
I used Jim's post and it works fine.
but looking at botao's post I realize that this might be something that Is more viable.

Scenario: After the file is found in the directory and the command is ran against the file. How will I then avoid running the same command against the same file again. Could the name of the file that the command ran agains be moved into a text file which the script will check before running the command again?

This would be most helpfull as I would like to avoid looping the command against the same files along with the new ones added to the directory.


BTW: you guys are awsome. Thanks a bunch.

#!/bin/ksh
#
# UNIX Monitor New File Script
# Purpose: Monitors the new files in a directory
# Notifies via e-mail
# Outputs: Email
# Author : Steven Koh
#*********************************************************
#

if test $# -lt 1; then
echo "Usage: $0 <DIR TO MONITOR FOR NEW FILES> <FILENAME to exclude, delimited by |>"
echo "Example: $0 /var/tmp \"Test1|Test2\""
echo

exit 0;
fi

MONITOR_DIR=$1
IGNORE_LIST=$2

OS=`uname -s`

CONF_FILE=/usr/local/scripts/monitor.conf
SCRIPTDIR=`grep "SCRIPTDIR" $CONF_FILE | awk -F= '{print $NF}'`

LOCK=/tmp/${LOGNAME}.mon_new_file.lock
if test -f $LOCK; then
echo "${LOCK} exists. Exiting this job now ... " | mailx -s "$0" ${LOGNAME}
exit
fi

touch ${LOCK}

# The directory this script resides in
ADMINDIR=$SCRIPTDIR/monitorNEWFiles
#IGNORE_LIST=$ADMINDIR/ignore.List

MAILADD=${LOGNAME}@localhost

# Define the hostname of the server
SRVNM=`uname -n`

# Define the hostname of the SNMP server
SNMP_SRV=`grep "SNMP_SRV" $CONF_FILE | awk -F= '{print $NF}'`
SEND_TRAP=`grep "SEND_TRAP" $CONF_FILE | awk -F= '{print $NF}'`


echo ${MONITOR_DIR}
DIR_ID=`echo ${MONITOR_DIR} | sed 's/\//_/'g`
NEW_LOG="/tmp/${SRVNM}_${LOGNAME}_${DIR_ID}_mon_new_file.log"
OLD_LOG="/tmp/${SRVNM}_${LOGNAME}_${DIR_ID}_mon_new_file.old"
DIFF_FILE="/tmp/${SRVNM}_${LOGNAME}_${DIR_ID}_mon_new_file.same"

touch ${NEW_LOG}
mv ${NEW_LOG} ${OLD_LOG}

echo "============= `date` =============" | tee $NEW_LOG
unalias ls
ls -tr ${MONITOR_DIR} | tee -a ${NEW_LOG}


if test $# -eq 1; then
egrep -vf ${OLD_LOG} ${NEW_LOG} | grep -v "=============" > ${DIFF_FILE} 2>&1
else
egrep -vf ${OLD_LOG} ${NEW_LOG} | egrep -v "(${IGNORE_LIST})" | grep -v "=============" > ${DIFF_FILE} 2>&1
fi

if test `wc -l < ${DIFF_FILE}` -gt 0; then
echo "UNIX Monitor New Files - Monitor new files in ${MONITOR_DIR}"
echo "New Files for past 2 runs"
echo "=================================="
echo
cat ${DIFF_FILE}
echo

################
### Sending Mail
mail ${MAILADD} <<EOF
From: $0
To: $MAILADD
Subject: UNIX Monitor New Files - Monitor new files in ${MONITOR_DIR}

New Files for past 2 runs
==================================

`cat ${DIFF_FILE}`

EOF

fi

rm ${LOCK}