CRONTAB(5) CRONTAB(5) (NAME) crontab - (DESCRIPTION) crontab cron(8) : << >>. crontab . crontab crontab . Uucp News crontab su(1) cron . . (#) . cron . . crontab cron. : name = value (=) value name . value ( ) . cron(8) . SHELL /bin/sh LOGNAME HOME crontab /etc/passwd . HOME SHELL crontab (override) LOGNAME . (: LOGNAME BSD USER ). LOGNAME HOME SHELL cron(8) MAILTO crontab . MAILTO ( ) . MAILTO (MAILTO="") . crontab . /usr/lib/sendmail /bin/mail . /bin/mail (aliasing) UUCP . MAILFROM ( ) (envelope sender) . crond . (: MAILFROM MAILTO : MAILFROM=cron-$USER@cron.com $USER ). cron 'Content-Type:' 'text/plain' 'charset=' 'charmap/codeset' (locale) crond(8) ( LC_* ) LC_* ( locale(7)). CONTENT_TYPE CONTENT_TRANSFER_ENCODING crontab cron . CRON_TZ cron . . (log) . MLS_LEVEL (security context) SELinux crontab . cron SELinux crontab . . SELinux MLS/MCS selinux(8) crontab . MLS_LEVEL SELinux SELinux . crond . crontab(1) -s. RANDOM_DELAY . cron . cron V7 . ( crontab ) . cron(8) <<>> <<>> << >> <<>> (<< >> << >>) ( <<>> ). << >> << >> . ( ) . cron(8) cron . : ----- -------------- 0-59 0-23 1-31 1-12 ( ) 0-7 (0 7 ) (*) <<->> ( ) . . . . 8-11 <<>> 8 9 10 11 . . . (~) . . 6~15 <<>> 6 15 . crontab . . . ~ <<>> 0 59 . . ( ) . : "1,2,5,9" "0-4,8-12". (step) . <>>> . "0-23/2" <<>> ( V7 "0,2,4,6,8,10,12,14,16,18,20,22"). "*/2" . . "*/23" 0 23 . <<>> . <<>> << >> . ( ). . : "mon,wed,fri" "jan-mar". UID 0 (root) crontab "-" . syslog cron . <<>> ( ) . "%" /bin/sh SHELL cron . "%" (\) % . : -- << >> << >>. ( "*" ) . : "30 4 1,15 * 5" 4:30 . crontab -T . crontab(1) . (EXAMPLE CRON FILE) # /bin/sh /etc/passwd SHELL=/bin/sh # `paul' crontab MAILTO=paul # CRON_TZ=Japan # 5 0 * * * $HOME/bin/daily.job >> $HOME/tmp/out 2>&1 # 2:15 -- paul 15 14 1 * * $HOME/bin/monthly # 10 0 22 * * 1-5 mail -s "It's 10pm" joe%Joe,%%Where are your kids?% 23 0-23/2 * * * echo "run 23 minutes after midn, 2am, 4am ..., everyday" 5 4 * * sun echo "run at 5 after 4 every sunday" /etc/cron.d/ (JOBS IN /etc/cron.d/) cron.d /etc/crontab . MAILTO . /etc/cron.d/job (EXAMPLE OF A JOB IN /etc/cron.d/job) # root # ( vim) MAILTO=root * * * * * root touch /tmp/file (NOTES) . "0/35" crontab 35 0 35 . : * * * * * if [ $(expr \( $(date +%s) / 60 \) % 58) = 0 ]; then echo this runs every 58 minutes; fi 0 * * * * if [ $(expr \( $(date +%s) / 3600 \) % 23) = 0 ]; then echo this runs every 23 hours on the hour; fi date(1) "+%s" . SELinux (SELinux WITH MULTI LEVEL SECURITY - MLS) crontab crontab -s crontab . /etc/selinux/targeted/seusers . crontab MLS : - / - / . SELINUX MLS (EXAMPLE FOR SELINUX MLS) # root newrole -r sysadm_r mkdir /tmp/SystemHigh chcon -l SystemHigh /tmp/SystemHigh crontab -e # crontab MLS_LEVEL=SystemHigh 0-59 * * * * id -Z > /tmp/SystemHigh/crontest (FILES) /etc/crontab crontab . /var/spool/cron/ crontab . /etc/cron.d/ crontab . (SEE ALSO) cron(8) crontab(1) (EXTENSIONS) '@' : @reboot : . @yearly : "0 0 1 1 *". @annually : "0 0 1 1 *". @monthly : "0 0 1 * *". @weekly : "0 0 * * 0". @daily : "0 0 * * *". @hourly : "0 * * * *". (CAVEATS) crontab . -p crond . inotify crontab cron . cron SIGHUP crontab . (API) inotify . cron crontab . crontab ( EOF ) cron crontab ( ) . syslog . (AUTHORS) Paul Vixie cronie 2012-11-22 CRONTAB(5)