# /etc/cron.d/ddns-client SHELL=/usr/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root # * * * * * user command to execute # | | | | | # | | | | | # | | | | |_______________ day of week (0 - 6) (0 to 6 are Sunday to Saturday, or use names; 7 is Sunday, the same as 0) # | | | |______________________ month (1 - 12) # | | |_____________________________ day of month (1 - 31) # | |____________________________________ hour (0 - 23) # |___________________________________________ min (0 - 59) # */5 * * * * root if [ -d '/run/systemd/system' ]; then exit 0; fi; if '/usr/lib/ddns-client/check_condition'; then '/usr/lib/ddns-client/start_update'; fi; #