MAILTO and PATH header

Cron PATH is minimal; set PATH/MAILTO at top or jobs fail silently

crontab - <<'EOF' MAILTO=ops@example.com PATH=/usr/local/bin:/usr/bin:/bin 0 3 * * * backup.sh EOF
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cron8 commands
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More cron commands

  • Test run-parts dry run
    run-parts --test /etc/cron.daily

    List which scripts would execute without running them; debugging cron.daily

  • systemd timer alternative
    systemd-run --on-calendar='*-*-* 03:00:00' --unit=backup /opt/backup.sh

    modern: transient OnCalendar timer with logs/retries; replaces a crontab line

  • One-shot job with at
    at now + 1 hour <<< 'systemctl restart nginx'

    Schedule a single deferred command; inspect queue with atq, cancel with atrm

  • Defer until load is low
    batch <<< '/opt/heavy-reindex.sh'

    Run only when load avg drops below 1.5; note: atd must be running

  • Dump another user's crontab
    crontab -l -u <name> 2>/dev/null || echo 'no crontab'

    Inspect a service account's jobs as root; note: -u needs root or sudo

all 8 cron commands