Bash Script to Remove Day old Files in /tmp directory that has no open file handles

clean_tmp_files.sh

#!/bin/bash
  
# Meant to be run nightly by a cron job on this box. This script will: 
# - find a list of files that are 1 day old and has no current file handles attached
# - log these files into a: deleted.<day_of_the_month>.log file so we have a max log count (no need to clean up)
# - delete the files from disk

DRY_RUN=${DRY_RUN:-'0'}
CLR_TMP_DIR=${CLR_TMP_DIR:-'/tmp'}
CLR_TMP_LOG=${CLR_TMP_LOG:-"${HOME}/clr_tmp"}
CLR_ACTIVE_LOG=${CLR_ACTIVE:-"${CLR_TMP_LOG}/active_handles.log"}
rem_dt=$(date +'%d')
CLR_REM_LOG=${CLR_REM_LOG:-"${CLR_TMP_LOG}/remove_files_${rem_dt}.target"}

echo '===================================================='
echo "Starting at $(date)"
if [ "${DRY_RUN}" != '0' ]; then
    echo 'DRY RUN!'
fi

echo '----before----'
du -sh "${CLR_TMP_DIR}"
echo '--------------'
echo "Cleaning orphan files in: '${CLR_TMP_DIR}' using log path -> '${CLR_TMP_LOG}'"
mkdir -p $CLR_TMP_LOG

# build a list of all files with active handles
lsof +D $CLR_TMP_DIR | awk '{ if(NR>1)print $9 }' | sort | uniq > "${CLR_ACTIVE_LOG}"
# remove the files from the above list from this list of all files that re created -1 days ago
find $CLR_TMP_DIR -mtime +1 -type f | grep -v -f "${CLR_ACTIVE_LOG}" > "${CLR_REM_LOG}"
# remove all entries in file with this pattern matched
grep -v "snap" "${CLR_REM_LOG}" > "${CLR_REM_LOG}.tmp" && mv "${CLR_REM_LOG}.tmp" "${CLR_REM_LOG}"

rem_count=$(wc -l "${CLR_REM_LOG}" | tr ' ' '\n' | head -1)
echo "List of files to be removed: '${CLR_REM_LOG}' @ ${rem_count} files"

if [ "${rem_count}" != "0" ]; then
    echo "Removing fies from list now"
    if [ "${DRY_RUN}" != '0' ]; then
        echo "Dry Run Only!"
    fi
    rem_count=0
    rem_done="${CLR_REM_LOG}.log"
    echo $(date) > "${rem_done}"
    echo '=================================' >> "${rem_done}"
    # load the target list file and loop through each line (should be a full file path)
    while IFS= read -r line; do
        if [ "${DRY_RUN}" = '0' ]; then
            # if not dry run, actually delete the file!
            rm -f "${line}"
        fi
        rem_count=$(expr $rem_count + 1)
        # log each deleted file into a log
        echo "${line}" >> "${rem_done}"
    done < "${CLR_REM_LOG}"
    echo "DONE: See all ${rem_count} removed files here: '${rem_done}'"
    echo '----after----'
    du -sh "${CLR_TMP_DIR}"
    echo '--------------'
else
    echo "SKIP: Nothing to remove!"
fi

echo "Ended at $(date)"
echo ''