glenda.party
term% ls -F
term% pwd
$home/manuals/9front/8/cron
term% cat index.txt
CRON(8)                     System Manager's Manual                    CRON(8)



NAME
       cron - clock daemon

SYNOPSIS
       auth/cron [ -c ]

DESCRIPTION
       Cron  executes  commands  at specified dates and times according to in‐
       structions in the files /cron/user/cron.  It runs only on an  authenti‐
       cation  server.   Option  -c  causes  cron  to  create  /cron/user  and
       /cron/user/cron for the current user; it can be run from any Plan 9 ma‐
       chine.

       Blank lines and lines beginning with # in these files are ignored.  En‐
       tries are lines with fields

              minute hour day month weekday host command

       Command is a string, which may contain spaces, that  is  passed  to  an
       rc(1) running on host for execution.  The first five fields are integer
       patterns for

              minute         0-59

              hour           0-23

              day of month   1-31

              month of year  1-12

              day of week    0-6; 0=Sunday

       The syntax for these patterns is

              time  : '*'
                    | range
              range : number
                    | number '-' number
                    | range ',' range

       Each number must be in the appropriate range.  Hyphens  specify  inclu‐
       sive ranges of valid times; commas specify lists of valid time ranges.

       To  run  the  job,  cron calls host and authenticates remote execution,
       equivalent to running rx host command (see con(1)).  The user's profile
       is run with $service set to rx.  If host is set to local, cron will run
       the command as user on the local machine without using rx.

       Cron is not a reliable service.  It skips commands if it  cannot  reach
       host  within  two  minutes, or if the cron daemon is not running at the
       appropriate time.

EXAMPLES
       Here is the job that mails system news.

              % cat /cron/upas/cron
              # send system news
              15 8-17,21 * * *    helix     /mail/lib/mailnews
              %

FILES
       /cron/lock
              lock file to prevent multiple crons running

SOURCE
       /sys/src/cmd/auth/cron.c

SEE ALSO
       con(1), rc(1)



                                                                       CRON(8)