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we have a log rotation stub in a cron job as given below, say $1 is /var/tmp/abc.log, MAX_LOG_SIZE_IN_BYTE is 5000 (i.e 5 KB), MAX_LOG_COUNT is 5 which says the expectation is to append logs to existing log file and if log file size crosses 5 KB, rotate log files and thus arrange logs in new files /var/tmp/abc.log.1, /var/tmp/abc.log.2 till /var/tmp/abc.log.5, and logs over 25 KB gets flushed and always recent logs are written to /var/tmp/abc.log

function LOG_ROTATE () {
    local LOG_FILE=$1
    fileSizeInBytes=$(stat -c%s "$LOG_FILE")
    if [ "$fileSizeInBytes" -ge "$MAX_LOG_SIZE_IN_BYTE" ]
        then
        # Deletes old log file
        if [ -f $LOG_FILE ] ; then
            CNT=$MAX_LOG_COUNT
            P_CNT=$(($CNT-1))
            if [ -f ${LOG_FILE}.$MAX_LOG_COUNT ] ; then
                rm -f ${LOG_FILE}.$MAX_LOG_COUNT
            fi
            # Renames logs .1 trough .$MAX_LOG_COUNT
            while [[ $CNT > 1 ]] ; do
                if [ -f ${LOG_FILE}.${P_CNT} ] ; then
                    mv ${LOG_FILE}.${P_CNT} ${LOG_FILE}.${CNT}
                fi
                CNT=$(($CNT-1))
                P_CNT=$(($P_CNT-1))
            done
            # Renames current log to .1
            mv $LOG_FILE ${LOG_FILE}.1
            touch $LOG_FILE
        fi
    fi
}

But whenever cron job is run, contents of /var/tmp/abc.log are being replaced with new logs and no rotation is taking place. Help to append logs instead of replacing and thus if old logs are preserved, rotation will also take place.

hitesh adabala
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  • Why do you want to keep logs in first log file? They are already moved into the second log file. Isn't it logical, starting to a clean first log file? – Mert Mertce Feb 03 '22 at 21:35
  • I cant see any second log files too. No rotation is taking place. Within same cron job, if size exceeds threshold, rotation is taking place but if new session of cron task takes place, only that particular session logs are seen, though size will not meet all files filling thresholds in single run. No previous logs at all. – hitesh adabala Feb 04 '22 at 03:55

0 Answers0