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CRONTAB(5)                    File Formats Manual                   CRONTAB(5)

       crontab - table of jobs to be performed by cron

       /var/opt/name/lib/crontab  (Minix-vmd only)

       The  cron(8)  daemon  runs  jobs  at regular intervals.  These jobs are
       listed in crontab files.  The format of entries in a crontab  file  are
       five  fields  of numbers specifying the minute (0-59), hour (0-23), day
       of the month (1-31), month (1-12), and day of the week (0-6  with  0  =
       Sunday)  that a task must be executed.  The task to be executed follows
       as a shell command.

       The time numbers can be given as  a  comma  separated  list  of  simple
       numbers,  ranges  ("2-5"  is the same as "2,3,4,5"), and repeats ("2:5"
       means "2,7,12,17,22" in the hour field).  A repeat  is  cyclic  affair,
       i.e.  2:5  and  12:5 are the same thing.  A single "*" can be used in a
       field to indicate all valid numbers in that field, so it translates  to
       "always".   In  the minute field you can use "?" for the current minute
       that the crontab file is loaded.  It can be  used  in  a  repeat,  i.e.
       "?:10"  for  every  10  minutes.   This  keeps  machines with identical
       crontabs from executing tasks at exactly the same time, causing a burst
       of traffic if anything is done over a network.

       If a given time is valid in all five fields then a command is executed.
       Here are a few examples that illustrate the possibilities:

       # min hour mday mon wday command
          ?   3    *    *   *   /usr/etc/daily  # Daily system cleanup
          0   *    *    *   *   date            # Print date on the hour
         30   4    *    *  2-6  /var/etc/backup # After workdays on 4:30
          0   9   25   12   *   -u ast sing     # Andy sings on Xmas morning
          0   0   13    *   5   echo Beware!    # For the superstitious

       The command may optionally be prefixed by  -u  user  to  specify  under
       which  user  the  command should be run.  Commands from crontabs in the
       spool directory are always run under the id of the crontab's owner, the
       -u flag is ignored.

       A  command can be placed on the same line as the time fields, or on the
       next line indented by one TAB character.  (A TAB,  not  eight  spaces.)
       More TAB indented lines can be added for a multiline command.  The tabs
       are removed from the command when passed to the shell.  If a command is
       put  on  the  same  line as the time fields then percent characters are
       changed into newlines, this is not done for  a  TAB  indented  command.
       The following three entries give the same output:

              0 12  *  *  *   echo 'Hello'; echo '  World!'
              0 12  *  *  *   echo 'Hello%  World!'  #2
              0 12  *  *  *        #3
                      cat <<EOF    #4

       Comments  start  with  a  "#" character and continue until end of line.
       They, excess whitespace, and empty lines are ignored.  Of the  comments
       in  the  example above #1 and #3 are ignored by cron, but #2 and #4 are
       not recognized as comments, but are seen as part of a command  and  are
       passed  to  the  shell  who  then  happens to ignore them.  There is no
       interpretation of command  characters  other  than  the  percent  in  a
       oneliner.  The time fields must all be on the same line.

       /usr/lib/crontab         Main MINIX 3 crontab file.

       /usr/local/lib/crontab   Local jobs for all systems in an organization.

       /var/lib/crontab         System specific jobs.

                                Per package jobs for Minix-vmd.

       /usr/lib/packages        List of installed packages.

       /usr/spool/crontabs/user Per user jobs.

       crontab(1), cron(8).

       The  "?"  in  the  minute  field,  the  repeat  field (e.g. "2:5"), TAB
       indented multiline commands and the -u option are unique to  this  cron
       implementation.   This  doesn't  mean you shouldn't use these features,
       but just that you  should  be  aware  of  the  differences  with  other
       systems.   You  are  even  advised  to use these features and avoid the
       percent hack for multiline commands.

       Other crons allow one to specify input to a job in some way,  something
       this  cron  can't.   Simply use the << shell feature to do that.  Other
       crons often choke on empty lines.

       It is a common bug to use 0 for Sunday instead of 7.  This  cron,  like
       most other crons out there accepts this without comment.

       A  job is not reissued until a previous instance of it has exited.  The
       next time to execute is computed from the previous time it ran.  If job
       issuing  lags behind on the system time then the next time to run it is
       computed from the current system time.

       Kees J. Bot (