Hide files while being transfered via scp

Question

I'm reading into a local folder where various files are written, if file match a pattern I send those files to a remote server via a second script (transfer_file.sh), if transfer is completed successfully (via SCP) I then use rsync to move the processed file to a local folder as local backup using --remove-source-files flag which removes the file from the monitoring folder. It could be that there are a huge number of files being transferred hence rsync hasn't completed, after sleep is done the first cycle it may retry to send the files which already read in previous loop. How to unlist or not process files already passed to transfer_file.sh ? I have increased the sleep time, but need to have a more cleaner solution in case suddenly I processed hundreds of files.

if [ -d $MONITOR_FOLDER ] ; then
        while [ 1 ]; do
            echo "$(date +%c) monitor() |Main| Monitoring local repository"
            for LOG_FILE in `ls $MONITOR_FOLDER$LOG_PATTERN 2> /dev/null`
                do              
                    sh transfer_file.sh $LOG_FILE &
                done
            sleep 10
        done
    fi

Answer 1

Edit transfer.sh so that will keep track of the files being processed. Use a tmp folder and tmp file for each file being processed:

After reading the parameter $LOG_FILE (change the solution when LOG_FILE has a path, something like tr "/" "_", and when LOG_FILE has spaces in the name):

tmpdir=/tmp/transfer_in_process
tmpfile=${tmpdir}/${LOG_FILE}.tmp
if [ -f "${tmpfile}" ]; then
   echo "File already being transferred"
   exit 0
fi

touch "${tmpfile}"
... (transfer code)
rm -f "${tmpfile}"

After this you should thing of some error handling: When do you remove the tmp files of transfers that were started but never finished?