Count lines in all logs

Find the biggest log files by line count

find /var/log -name '*.log' -exec wc -l {} + | sort -rn | head -20

More linux commands

Follow multiple log files

tail -f /var/log/syslog /var/log/auth.log

Stream multiple log files interleaved in one terminal
Search compressed logs

zgrep -i 'error' /var/log/syslog.*.gz

grep inside .gz files without manual decompression
Rotate logs manually

logrotate -f /etc/logrotate.conf

Force log rotation regardless of schedule
List cron jobs system-wide

for u in $(cut -f1 -d: /etc/passwd); do crontab -l -u $u 2>/dev/null | grep -v '^#' | sed "s|^|$u: |"; done

Print active cron lines for every user
Cron expression tester

systemd-analyze calendar '*/5 * * * *'

Parse and show next 5 trigger times for a cron expression