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       fcrontab - tables for driving fcron


       A fcrontab is a file containing all tables used by the fcron(8) daemon.
       In other words, it is the means for a user to tell the daemon  "execute
       this  command  at  this  moment". Each user has his own fcrontab, whose
       commands are executed as his owner (only root can run a job as  another
       using the option runas (see below)).

       Blank  lines,  line  beginning by a hash sign (#) (which are considered
       comments), leading blanks and tabs are ignored. Each line in a fcrontab
       file can be either

       · an environment setting,

       · an option setting,

       · entries based on elapsed system up time,

       · entries based on absolute time (like normal crontab entries), or

       · entries run periodically.

       Any  logical  line  (an  entry  or  an  assignment) can be divided into
       several real lines (the lines which end  by  a  newline  character)  by
       placing a backslash (\) before the newline character (\n).

       The environment settings are of the form

              name = value

       where  the  blanks  around  equal-sign  (=)  are  ignored and optional.
       Trailing blanks are also ignored, but you can place the value in quotes
       (simple or double, but matching) to preserve any blanks in the value.

       When  fcron executes a command, it always sets USER, HOME, and SHELL as
       defined in /etc/passwd for the owner of the  fcrontab  from  which  the
       command  is  extracted. HOME and SHELL may be overridden by settings in
       the fcrontab, but USER may not.  Every  other  environment  assignments
       defined  in  the  user  fcrontab  are  then  made,  and  the command is

       Plus, the special variable MAILTO allows you to tell fcron to  whom  it
       has  to  mail  the  command’s  output.  Note  that  MAILTO  is  in fact
       equivalent to a global declaration of the option mailto (see below). It
       is  only  used for backward compatibility, so you should use the option
       mailto directly.

       The entries of commands which have to be run once every  m  minutes  of
       fcron’s  execution (which is normally the same as m minutes of system’s
       execution) are of the form

       @options frequency command

       where    frequency    is    a    time     value     of     the     form
       value*multiplier+value*multiplier+...+value-in-minutes  as  "12h02"  or
       "3w2d5h1".  The first means "12 hours and 2 minutes of fcron execution"
       while  the second means "3 weeks, 2 days, 5 hours and 1 minute of fcron
       execution". The only valid multipliers are:  "VALID  TIME  MULTIPLIERS"
       meaning:  multipliers:       months (4 weeks): m      weeks (7 days): w
       days (24 hours): d      hours (60 minutes): h  seconds: s

       In place of options, user can put a time value: it will be  interpreted
       as @first(<time>). If first option is not set, the value of "frequency"
       is used.

       This kind of entry does not guarantee a time and date of execution  (as
       the  job  is  delayed  at  each  startup  by the time elapsed since the
       shutdown), but should be useful for jobs depending  on  the  number  of
       things done by the users (for instance, the filesystem should better be
       checked after a certain amount of use by the users rather than every  x
       days,  as  the  system  may run from 1 day to x days during that x days

       The time remaining before next execution is saved  every  1800  seconds
       (to  limit damages caused by a crash) and when fcron exits after having
       received a SIGTERM signal, i.e. when systems go down. Thus,  this  kind
       of entries is particularly useful for systems that don’t run regularly.
       The syntax being very simple, it may also useful for tasks which  don’t
       need to be run at a specific time and date.

       See  also:  options  first, mail, nolog, serial, lavg, nice, runas (see

       # Get our mails every 30 minutes
       @ 30 getmails -all

       # make some security tests every 48 hours of system up time,
       # force a mail to be sent to root even if there is no output
       @mailto(root),forcemail 2d /etc/security/msec/cron-sh/

       The second type of fcrontab’s entries begins by an optional "&",  which
       can  be  immediately  followed  by  an  optional  number  defining  the
       frequency of execution (this is equivalent  to  option  runfreq)  or  a
       declaration  of  options; it has five time and date fields, and a shell
       command :

       &options min hrs day-of-month month day-of-week command

       Note that the shell command may be preceded by a user  name,  which  is
       equivalent   to   runas(<user>):  as  it  is  only  here  for  backward
       compatibility you should use option  runas  (see  below)  instead.  The
       frequency  is interpreted as: "run this command after x matches of time
       and date fields". The time and date fields are: "TIME AND DATE  FIELDS"
       field:  allowed  values:       minute: 0-59      hour: 0-23      day of
       month: 1-31      month: 1-12 (or names, see below)       day  of  week:
       0-7 (0 and 7 are both Sunday, or names)

       A  field  is  always  filled  by  either an asterisk (*), which acts as
       "first-last" range, a single number or a list.

       List are numbers or range separated  with  commas  (,).  For  instance:

       Ranges  of  number  are  of the form "<begin>-<end>", where "begin" and
       "end" are included. For example, "3-5" specifies the values 3, 4 and 5.
       You  can  also  add  an optional "/number" to a range, where the number
       specifies skips of the number’s value through the range.  For  example,
       "0-23/2"  can  be  used in the hours field to specify command execution
       every other hour. Finally, one or several "~number"  can  be  added  to
       turn  off  some  specific  values in a range. For example, "5-8~6~7" is
       equivalent to "5,8". The final form of a field is:


       where the letters are integers.

       You can also use an asterisk (*) in a field. It acts for  "first-last".
       For  example, a "*" in the field minute means all minutes from minute 0
       down to minute 59.

       Ranges can be included in a list as  a  single  number.  For  instance:

       Names  can also be used for the "month" and "day of week" fields. To do
       so, use the first three letters of the particular day  or  month  (case
       doesn’t  matter).  Please  note that names are used exactly as numbers:
       you can use them in a list or a range.

       If a day of month and a day of week are given, the command will execute
       only when both match with the current time and date unless option dayor
       is set. For example, with the line

       5 10 31 * 7 echo ’’
       echo will only be executed days which are  a  Sunday  AND  a  31th,  at

       See  also:  options dayor, bootrun, runfreq, mail, nolog, serial, lavg,
       nice, runas (see below).

       # run mycommand at 12:05, 12:35, 13:05, 13:35,
       # 14:05 *and* 14:35 everyday
       & 05,35 12-14 * * * mycommand -u me -o file

       # get mails every hour past 20, 21, 22, and 24 minutes.
       20-24~23 * * * * getmail

       # save our work of the day every night at 03:45 with a low priority
       # unless we are sunday, mail the output to jim and run that job
       # at startup if computer was down at 03:45
       &nice(10),mailto(jim),bootrun 45 03 * * *~0 "save --our work"

       The third type of fcrontab’s entries begin by  a  "%",  followed  by  a
       keyword from one of 3 different lists, and optional options.

       Those keywords are:

       hourly , daily , monthly , weekly

       Those keywords tell fcron to run the command once from the beginning of
       the corresponding time interval to the end of  that  time  interval.  A
       time  interval is, for example, the time from Monday 16:20 to Wednesday
       01h43.  For instance, the keyword weekly tells fcron to run  a  command
       once between Monday and Sunday each week.

       With  this  two kind of keywords, user must give the needed time fields
       (as defined in "Entries based on time and date" (see above)) to specify
       when the command should be run during each time interval:

       "NEEDED TIME FIELDS FOR EACH KEYWORD" Keywords: must be followed by the
       fields:  hourly, midhourly:  minutes. daily, middaily, nightly, weekly,
       midweekly:  minutes and hours. monthly, midmonthly:  minutes, hours and

       They are similar to the "*ly" ones:

       midhourly , middaily , nightly , midmonthly , midweekly

       They work  exactly  has  the  "*ly"  keywords,  except  that  the  time
       intervals  are defined from middle to middle of the corresponding "*ly"
       intervals:  midweekly  will  run  a  command  once  from  Thursday   to
       Wednesday. Note that nightly is equivalent to middaily.

       For example:

       %nightly,mail(no) * 21-23,3-5 echo "a nigthly entry"

       will run the command once each night either between 21:00 and 23:59, or
       between 3:00 and 5:59 (it will run as soon as possible. To change that,
       use  option  random) and won’t send mail (because option mail is set to

       See also: options lavg,  noticenotrun,  strict,  mail,  nolog,  serial,
       nice, runas, random (see below).

       They are:

       mins , hours , days , mons , dow

       Those keywords act differently, as follows:

       run this command once during EACH time interval specified, ignoring the
       fields below the keyword in  the  time  interval  definition  (a  hours
       prevents  the  mins  field  to be considered as a time interval, but it
       will be used to determine  when  the  line  should  be  run  during  an
       interval: see the note below) (dow means "day of week").

       Such  a  keyword is followed by 5 time and date fields (the same fields
       used for a line based on absolute time (see above)). Furthermore, there
       must be some non-matching time and dates in the lines with that kind of
       keyword (i.e. the following is not allowed :

       %hours * 0-23 * * * echo "INCORRECT line!"

       %hours * 0-22 * * * echo "Ok."
       is allowed).


              a single number in a field is considered as a time interval:

              %mins 15 2-4 * * * echo
              will run at 2:15, 3:15 AND 4:15 every day.

              But all fields below the keywords are ignored in  time  interval

              %hours 15 2-4 * * * echo
              will run only ONCE either at 2:15, 3:15 OR 4:15.

       See also: option random (see below).

       The  options  can be set either for every line below the declaration or
       for an individual line. In the first case, the setting  is  done  on  a
       whole  line immediately after an exclamation mark (!), while it is done
       after a "&", a "%" or a "@" depending on the type of scheduling in  the
       second  case.  Note  that an option declaration in a schedule overrides
       the global declaration of that same option.

       Options are separated by commas (,) and their arguments,  if  any,  are
       placed  in parentheses ("(" and ")") and separated by commas. No spaces
       are allowed. A declaration of options is of the form


       where option is either the name of an option or its  abbreviation.  The
       options  are  (default  value  in  parentheses):  "VALID  OPTIONS  IN A


       b      boolean(false)

              Run a &-line at fcron’s startup if it should have be run  during
              system down time.

       dayand boolean(true)

              Perform a logic AND between week and month day.

              See also: options dayor.

       dayor  boolean(false)

              Perform a logic OR between week and month day.

              See also: options dayand.

       exesev boolean(false)

              Can a job be executed several times simultaneously ?

              See also: options serialonce, lavgonce.


       f      time-value

              Delay  before  first  execution of a job based on system up time
              ("@"-lines). Useful in the following case: you have several jobs
              running,  say,  every hour. By setting different first value for
              each job, you can avoid them to  run  simultaneously  everytime.
              You  can  also  set  it  to  0,  which  is  useful  when used in
              conjunction with option volatile.


              Mail output even if zero-length.

              See also: options mail, mailto, nolog.

       lavg   real(0) real(0) real(0)

              Set the values of the 1, 5 and 15-minute (in this order)  system
              load  average  values below which the job should run. The values
              have a maximum of 1 decimal (i.e. "2.3"): if there are more than
              1  decimal,  the  value  will  be round off. Set a value to 0 to
              ignore the corresponding load average (or all of the  values  to
              run the job regardless of the load average).

              See also: options lavg1, lavg5, lavg15, until, lavgonce, lavgor,
              lavgand, strict, noticenotrun.



       lavg15 real(0)

              Set the threshold of, respectively,  the  1,  5  or  15  minutes
              system  load  average  value. Set one of them to 0 to ignore the
              corresponding load average.

              See also: options lavg.


              Perform a logic AND between the 1, 5 and 15 minutes system  load
              average values.

              See also: options lavg, lavgor.


              Can  a job be queued several times in lavg queue simultaneously?

              See also: options lavg.

       lavgor boolean(false)

              Perform a logic OR between the 1, 5 and 15 minutes  system  load
              average values.

              See also: options lavg, lavgand.


       m      boolean(true)

              Mail output (if any) or not.

              See also: options mailto, forcemail, nolog.

       mailto email-address(name of file’s owner)

              Mail  output  (if needed) to "email-address". It can be either a
              single user-name or a fully qualified email  address.  A  mailto
              declared and empty (string "") is equivalent to "mail(false)".

              See also: options mail, forcemail, nolog.


       n      nice-value

              Change  job  priority.  A  nice-value  is  an  integer  from -20
              (highest priority) to 19 (lowest) (only root is allowed to use a
              negative value with this option).

       nolog  boolean(false)

              If  set  to  true, log only errors for the corresponding job(s).
              May be useful for jobs running very often, and/or to reduce disk
              access on a laptop.

              See also: options mail, mailto, forcemail.


              Should fcron mail user to report the non-execution of a %-job or
              a &-job? (because of system down state for both or  a  too  high
              system load average for the latter)

              See also: options lavg, strict.

       random boolean(false)

              In  a  line  run periodically, this option answers the question:
              should this job be run as soon as possible in its time  interval
              of  execution  (safer),  or  should  fcron  set a random time of
              execution in that time interval? Note that  if  this  option  is
              set,  the  job  may  not  run if fcron is not running during the
              whole execution interval. Besides, you must know that the random
              scheme  may be quite easy to guess for skilled people: thus, you
              shouldn’t rely on this option to make important  things  secure.
              However, it shouldn’t be a problem for most uses.

       reset  boolean

              Reset all the options to default.

       runas  user-name

              Run  with  "user-name" permissions and environment (only root is
              allowed to use this option).


       r      integer

              Run every "runfreq" matches of time and date.  (this  option  is
              ignored for lines based on elapsed system up time).


       s      boolean(false)

              Fcron  runs  at  most  1  serial  jobs (ie. for which the option
              serial is set to true), and the same number of lavg serial  jobs
              (ie. for which both option serial and lavg (or lavg1 or lavg5 or
              lavg15) are set to  true)  simultaneously.  This  value  may  be
              modified  by fcron’s option -m. This option is especially useful
              when used with big jobs in order to limit the system overload.

              See also: options serialonce, lavg.


              Can  a  job  be   queued   several   times   in   serial   queue

              See also: options exesev, lavgonce.

       stdout boolean(false)

              If  fcron is running in the foreground, then also let jobs print
              to stderr/stdout instead of mailing or discarding it.

              See also: fcron’s option --once in fcron(8).

       strict boolean(true)

              When a lavg %-job is at the end of a time interval of execution,
              should  it  be removed from the lavg queue (strict(true), so the
              job is not run) or be let there until the  system  load  average
              allows its execution (strict(false))?

              See also: options lavg, noticenotrun.

              timezone-name(time zone of the system)

              Run  the  job  in the given time zone. timezone-name is a string
              which  is  valid  for  the  environment  variable  TZ:  see  the
              documentation  of  your  system  for more details. For instance,
              "Europe/Paris" is valid on a Linux system. This  option  handles
              daylight saving time changes correctly.

              Please   note  that  if  you  give  an  erroneous  timezone-name
              argument, it will be SILENTLY ignored, and the job will  run  in
              the time zone of the system.

              WARNING:   do  *not*  use  option  timezone  and  option  tzdiff
              simultaneously! There is no need  to  do  so,  and  timezone  is
              cleverer than tzdiff.

              See also: options tzdiff.

       tzdiff integer(0)

              WARNING: this option is deprecated: use option timezone instead!

              Time zone difference (in hours, between -24 and 24) between  the
              system  time, and the local real time. This option allows a user
              to define its & and %-lines in the local time.  Note  that  this
              value  is  set  for  a  whole  fcrontab  file, and only the last
              definition is taken into account. tzdiff  is  quite  stupid:  it
              doesn’t  handle  daylight  saving changes, while option timezone
              does, so you should use the latter.

              See also: options timezone.

       until  time-value(0)

              Set the timeout of the waiting of the wanted system load average
              values.  If  the timeout is exceeded, the job runs no matter the
              load average. Set until to 0 to remove the timeout.

              See also: options lavg.


              When set to true, the job is based on  a  "volatile"  system  up
              time, i.e. restart counting each time fcron is started, which is
              useful when fcron is started  by  a  script  running  only,  for
              instance,  during  a dialup connection: the "volatile" system up
              time then refers to the dialup connection  time.  You  may  also
              want to use option first if you use fcron that way.

              See  also:  options first, stdout, lines based on elapsed system
              up time, fcron’s option --once in fcron(8).

       A boolean argument can be non-existent, in which case  parentheses  are
       not used and it means true; the string "true", "yes" or 1 to mean true;
       and the string "false",  "no"  or  0  to  mean  false.  See  above  for
       explanations about time value (section "entries based on elapsed system
       up time").

       Note that dayand and dayor are in fact the same option: a  false  value
       to  dayand  is  equivalent to a true to dayor, and reciprocally a false
       value to dayor is equivalent a true value to dayand. It is the same for
       lavgand and lavgor.

       Note  a  special  case  to be handled: A job should be entered into the
       serial queue, *but* the previous  entry  for  this  job  has  not  been
       completed  yet,  because  of  high  system load or some external event.
       Option serialonce answers the question: should the new entry of the job
       be ignored? This way one can distinguish between jobs required to run a
       certain number of times, preferably at specified times, and tasks to be
       performed  irrespective  of  their  number (-> serialonce(true)), which
       make the system respond faster.

       The same considerations apply for the load average queue,  and  can  be
       expressed with option lavgonce.

       Moreover,  if  the  serial or the lavg queue contains respectively more
       than 30 and 30 jobs, any new job is refused and not  run  to  avoid  an
       overwhelming  of  system  resources.  In this case, an error message is
       logged through syslog.

       Finally, if jobs remain in the lavg or serial queues when fcron  stops,
       they  will  be  put  once  in the corresponding queue on startup (their
       order may not be conserved).



       # use /bin/bash to run commands, ignoring what /etc/passwd says

       # mail output to thib, no matter whose fcrontab this is

       # define a variable which is equivalent to " Hello thib and paul! "
       # here the newline characters are escaped by a backslash (\)
       # and quotes are used to force to keep leading and trailing blanks
       TEXT= " Hello\
        thib and\
        paul! "

       # we want to use serial but not bootrun:

       # run after five minutes of execution the first time,
       # then run every hour
       @first(5) 1h   echo "Run every hour"

       # run every day
       @ 1d echo "fcron daily"

       # run once between in the morning and once in the afternoon
       #  if systems is running at any moment of these time intervals
       %hours * 8-12,14-18 * * * echo "Hey boss, I’m working today!"

       # run once a week during our lunch
       %weekly * 12-13 echo "I left my system on at least once \
        at lunch time this week."

       # run every Sunday and Saturday at 9:05
       5 9 * * sat,sun echo "Good morning Thibault!"

       # run every even days of march at 18:00, except on 16th
       0 18 2-30/2~16 Mar * echo "It’s time to go back home!"

       # the line above is equivalent to
       & 0 18 2-30/2~16 Mar * echo "It’s time to go back home!"

       # reset options to default and set runfreq for lines below

       # run once every 7 matches (thanks to the declaration above),
       # so if system is running every day at 10:00, this will be
       # run once a week
       & 0 10 * * * echo "if you got this message last time 7 days ago,\
        this computer has been running every day at 10:00 last week.\
        If you got the message 8 days ago, then the system has been down \
        one day at 10:00 since you got it, etc"

       # wait every hour for a 5 minutes load average under 0.9
       @lavg5(0.9) 1h echo "The system load average is low"

       # wait a maximum of 5 hours every day for a fall of the load average
       @lavgand,lavg(1,2.0,3.0),until(5h) 1d echo "Load average is going down"

       # wait for the best moment to run a heavy job
       @lavgor,lavg(0.8,1.2,1.5),nice(10) 1w echo "This is a heavy job"

       # run once every night between either 21:00 and 23:00 or
       #   between 3:00 and 6:00
       %nightly,lavg(1.5,2,2) * 21-23,3-6 echo "It’s time to retrieve \
        the latest release of Mozilla!"


              Configuration file for fcron, fcrontab  and  fcrondyn:  contains
              paths (spool dir, pid file) and default programs to use (editor,
              shell, etc). See fcron.conf(5) for more details.

              Users allowed to use fcrontab and fcrondyn (one name  per  line,
              special name "all" acts for everyone)

              Users  who  are  not  allowed to use fcrontab and fcrondyn (same
              format as allow file)

       /etc/pam.d/fcron (or /etc/pam.conf)
              PAM configuration file for fcron. Take a look at pam(8) for more







       If  you’re  learning  how to use fcron from scratch, I suggest that you
       read the HTML version of the documentation (if your are not reading  it
       right  now! :) ): the content is the same, but it is easier to navigate
       thanks to the hyperlinks.


       Thibault Godouet <>