 @@ -1,256 +1,346 @@
-.\"	$NetBSD: crontab.5,v 1.12 2009/04/04 16:05:10 perry Exp $
+.\"	$NetBSD: crontab.5,v 1.13 2009/04/04 17:29:59 wiz Exp $
 .\"
 .\"/* Copyright 1988,1990,1993,1994 by Paul Vixie
 .\" * All rights reserved
 .\" *
 .\" * Distribute freely, except: don't remove my name from the source or
 .\" * documentation (don't take credit for my work), mark your changes (don't
 .\" * get me blamed for your possible bugs), don't alter or remove this
 .\" * notice.  May be sold if buildable source is provided to buyer.  No
 .\" * warrantee of any kind, express or implied, is included with this
 .\" * software; use at your own risk, responsibility for damages (if any) to
 .\" * anyone resulting from the use of this software rests entirely with the
 .\" * user.
 .\" *
 .\" * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
 .\" * I'll try to keep a version up to date.  I can be reached as follows:
 .\" * Paul Vixie          <paul@vix.com>          uunet!decwrl!vixie!paul
 .\" */
 .\"
 .\" Id: crontab.5,v 2.4 1994/01/15 20:43:43 vixie Exp
 .\"
-.TH CRONTAB 5 "24 January 1994"
+.Dd April 4, 2009
-.UC 4
+.Dt CRONTAB 5
-.SH NAME
+.Os
-crontab \- tables for driving cron
+.Sh NAME
-.SH DESCRIPTION
+.Nm crontab
 .Nd tables for driving cron
 .Sh DESCRIPTION
+A
-.I crontab
+.Nm
 file contains instructions to the
-.IR cron (8)
+.Xr cron 8
-daemon of the general form: ``run this command at this time on this date''.
+daemon of the general form:
-Each user has their own crontab, and commands in any given crontab will be
+.Dq run this command at this time on this date .
-executed as the user who owns the crontab.  Uucp and News will usually have
+Each user has their own crontab, and commands in any given crontab
-their own crontabs, eliminating the need for explicitly running
+will be executed as the user who owns the crontab.
-.IR su (1)
+Uucp and News will usually have their own crontabs, eliminating
 the need for explicitly running
 .Xr su 1
 as part of a cron command.
-.PP
+.Pp
-Blank lines and leading spaces and tabs are ignored.  Lines whose first
+Blank lines and leading spaces and tabs are ignored.
-non-space character is a pound-sign (#) are comments, and are ignored.
+Lines whose first non-space character is a pound-sign
 .Pq Sq #
 are comments, and are ignored.
 Note that comments are not allowed on the same line as cron commands, since
-they will be taken to be part of the command.  Similarly, comments are not
+they will be taken to be part of the command.
 Similarly, comments are not
 allowed on the same line as environment variable settings.
-.PP
+.Pp
-An active line in a crontab will be either an environment setting or a cron
+An active line in a crontab will be either an environment setting
-command.  An environment setting is of the form,
+or a cron command.
-.PP
+An environment setting is of the form,
 .Bd -literal
     name = value
-.PP
+.Ed
-where the spaces around the equal-sign (=) are optional, and any subsequent
+where the spaces around the equal-sign
-non-leading spaces in
+.Pq Sq =
-.I value
+are optional, and any subsequent non-leading spaces in
 .Ar value
 will be part of the value assigned to
-.IR name .
+.Ar name .
 The
-.I value
+.Ar value
-string may be placed in quotes (single or double, but matching) to preserve
+string may be placed in quotes (single or double, but matching) to
-leading or trailing blanks.  The
+preserve leading or trailing blanks.
-.I name
+The
-string may also be placed in quotes (single or double, but matching) to preserve
+.Ar name
-leading, trailing or inner blanks.
+string may also be placed in quotes (single or double, but matching)
-.PP
+to preserve leading, trailing or inner blanks.
-Several environment variables are set up
+.Pp
-automatically by the
+Several environment variables are set up automatically by the
-.IR cron (8)
+.Xr cron 8
 daemon.
-SHELL is set to /bin/sh, and LOGNAME and HOME are set from the /etc/passwd
+.Ev SHELL
 is set to
 .Pa /bin/sh ,
 and
 .Ev LOGNAME
 and
 .Ev HOME
 are set from the
 .Pa /etc/passwd
 line of the crontab's owner.
-HOME and SHELL may be overridden by settings in the crontab; LOGNAME may not.
+.Ev HOME
-.PP
+and
-(Another note: the LOGNAME variable is sometimes called USER on BSD systems...
+.Ev SHELL
-on these systems, USER will be set also.)
+may be overridden by settings in the crontab;
-.PP
+.Ev LOGNAME
-In addition to LOGNAME, HOME, and SHELL,
+may not.
-.IR cron (8)
+.Pp
-will look at MAILTO if it has any reason to send mail as a result of running
+(Another note: the
-commands in ``this'' crontab.  If MAILTO is defined (and non-empty), mail is
+.Ev LOGNAME
-sent to the user so named.  If MAILTO is defined but empty (MAILTO=""), no
+variable is sometimes called
-mail will be sent.  Otherwise mail is sent to the owner of the crontab.  This
+.Ev USER
-option is useful if you decide on /bin/mail instead of /usr/lib/sendmail as
+on BSD systems...  on these systems,
-your mailer when you install cron -- /bin/mail doesn't do aliasing, and UUCP
+.Ev USER
-usually doesn't read its mail.
+will be set also.)
-.PP
+.Pp
 In addition to
 .Ev LOGNAME ,
 .Ev HOME ,
 and
 .Ev SHELL ,
 .Xr cron 8
 will look at
 .Ev MAILTO
 if it has any reason to send mail as a result of running commands in
 .Dq this
 crontab.
 If
 .Ev MAILTO
 is defined (and non-empty), mail is sent to the user so named.
 If
 .Ev MAILTO
 is defined but empty
 .Pq Ev MAILTO Ns = Ns \&"" ,
 no mail will be sent.
 Otherwise mail is sent to the owner of the crontab.
 This option is useful if you decide on
 .Xr mail 1
 instead of
 .Xr sendmail 1
 as your mailer when you install cron --
 .Xr mail 1
 doesn't do aliasing, and UUCP usually doesn't read its mail.
 .Pp
 In order to provide finer control over when jobs execute, users
-can also set the environment variables CRON_TZ and CRON_WITHIN.
+can also set the environment variables
-The CRON_TZ variable can be set to an alternate time zone in order
+.Ev CRON_TZ
-to affect when the job is run.  Note that this only affects the
+and
-scheduling of the job, not the time zone that the job perceives
+.Ev CRON_WITHIN .
-when it is run.  If CRON_TZ is defined but empty (CRON_TZ=""), jobs
+The
-are scheduled with respect to the local time zone.
+.Ev CRON_TZ
-.PP
+variable can be set to an alternate time zone in order to affect
-The CRON_WITHIN variable should indicate the number of seconds
+when the job is run.
-within a job's scheduled time that it should still be run.  On a
+Note that this only affects the scheduling of the job, not the time
-heavily loaded system, or on a system that has just been "woken
+zone that the job perceives when it is run.
-up", jobs will sometimes start later than originally intended, and
+If
-by skipping non-critical jobs because of delays, system load can
+.Ev CRON_TZ
-be lightened.  If CRON_WITHIN is defined but empty (CRON_WITHIN="") or
+is defined but empty
-set to some non-positive value (0, a negative number, or a non-numeric
+.Pq Ev CRON_TZ Ns = Ns \&"" ,
-string), it is treated as if it was unset.
+jobs are scheduled with respect to the local time zone.
-.PP
+.Pp
-The format of a cron command is very much the V7 standard, with a number of
+The
-upward-compatible extensions.  Each line has five time and date fields,
+.Ev CRON_WITHIN
-followed by a user name if this is the system crontab file,
+variable should indicate the number of seconds within a job's
-followed by a command.  Commands are executed by
+scheduled time that it should still be run.
-.IR cron (8)
+On a heavily loaded system, or on a system that has just been
-when the minute, hour, and month of year fields match the current time,
+.Dq woken up ,
-.I and
+jobs will sometimes start later than originally intended, and by
 skipping non-critical jobs because of delays, system load can be
 lightened.
 If
 .Ev CRON_WITHIN
 is defined but empty
 .Pa Ev CRON_WITHIN Ns = Ns \&""
 or set to some non-positive value (0, a negative number, or a
 non-numeric string), it is treated as if it was unset.
 .Pp
 The format of a cron command is very much the V7 standard, with a
 number of upward-compatible extensions.
 Each line has five time and date fields, followed by a user name
 if this is the system crontab file, followed by a command.
 Commands are executed by
 .Xr cron 8
 when the minute, hour, and month of year fields match the current
 time,
 .Em and
 when at least one of the two day fields (day of month, or day of week)
-match the current time (see ``Note'' below).
+match the current time (see
-.IR cron (8)
+.Dq Note
 below).
 .Xr cron 8
 examines cron entries once every minute.
 The time and date fields are:
-.IP
+.Bl -column -offset indent "day of month" "0-7 (0 or 7 is Sun, or use names)"
-.ta 1.5i
+.It Em field Ta Em allowed values
-field	allowed values
+.It minute Ta 0-59
-.br
+.It hour Ta 0-23
------	--------------
+.It day of month Ta 1-31
-.br
+.It month Ta 1-12 (or names, see below)
-minute	0-59
+.It day of week Ta 0-7 (0 or 7 is Sun, or use names)
-.br
+.El
-hour	0-23
+.Pp
-.br
+A field may be an asterisk
-.\" changed from 0-31 to 1-31: mouse, 1997-07-13
+.Pq Sq * ,
-day of month	1-31
+which always stands for
-.br
+.Dq first\-last .
-.\" changed from 0-12 to 1-12: mouse, 1997-07-13
+.Pp
-month	1-12 (or names, see below)
+Ranges of numbers are allowed.
-.br
+Ranges are two numbers separated with a hyphen.
-day of week	0-7 (0 or 7 is Sun, or use names)
+The specified range is inclusive.
-.br
+For example,
-.PP
+.Dq 8-11
-A field may be an asterisk (*), which always stands for ``first\-last''.
+for an
-.PP
+.Dq hours
-Ranges of numbers are allowed.  Ranges are two numbers separated
+entry specifies execution at hours 8, 9, 10, and 11.
-with a hyphen.  The specified range is inclusive.  For example,
+.Pp
--11 for an ``hours'' entry specifies execution at hours 8, 9, 10
+A field may begin with a question mark
-and 11.
+.Pq Sq ? ,
-.PP
+which indicates a single value randomly selected when the crontab
-A field may begin with a question mark (?), which indicates a
+file is read.
 single value randomly selected when the crontab file is read.
 If the field contains only a question mark, the value is randomly
 selected from the range of all possible values for the field.
 If the question mark precedes a range, the value is randomly selected
 from the range.
-For example, ``? ?2-5 * * *'' specifies that a task will be performed
+For example,
-daily between 2:00am and and 5:59am at a time randomly selected when
+.Dq ? ?2-5 * * *
-the crontab file is first read.
+specifies that a task will be performed daily between 2:00am and
 and 5:59am at a time randomly selected when the crontab file is
 first read.
 As just one example, this feature can be used to prevent a large
 number of hosts from contacting a server simultaneously and
-overloading it by staggering the time at which a download script is
+overloading it by staggering the time at which a download script
-executed.
+is executed.
-.PP
+.Pp
-Lists are allowed.  A list is a set of numbers (or ranges)
+Lists are allowed.
-separated by commas.  Examples: ``1,2,5,9'', ``0-4,8-12''.
+A list is a set of numbers (or ranges) separated by commas.
-.PP
+Examples:
-Step values can be used in conjunction with ranges.  Following
+.Dq 1,2,5,9 ,
-a range with ``/\*[Lt]number\*[Gt]'' specifies skips of the number's value
+.Dq 0-4,8-12 .
-through the range.  For example, ``0-23/2'' can be used in the hours
+.Pp
-field to specify command execution every other hour (the alternative
+Step values can be used in conjunction with ranges.
-in the V7 standard is ``0,2,4,6,8,10,12,14,16,18,20,22'').  Steps are
+Following a range with
-also permitted after an asterisk, so if you want to say ``every two
+.Dq / Ns Aq number
-hours'', just use ``*/2''.
+specifies skips of the number's value through the range.
-.PP
+For example,
-Names can also be used for the ``month'' and ``day of week''
+.Dq 0-23/2
-fields.  Use the first three letters of the particular
+can be used in the hours field to specify command execution every
-day or month (case doesn't matter).  Ranges or
+other hour (the alternative in the V7 standard is
-lists of names are not allowed.
+.Dq 0,2,4,6,8,10,12,14,16,18,20,22 ) .
-.PP
+Steps are also permitted after an asterisk, so if you want to say
-The ``sixth'' field (the rest of the line) specifies the command to be
+.Dq every two hours ,
-run.
+just use
-The entire command portion of the line, up to a newline or %
+.Dq */2 .
-character, will be executed by /bin/sh or by the shell
+.Pp
-specified in the SHELL variable of the cronfile.
+Names can also be used for the
-Percent-signs (%) in the command, unless escaped with backslash
+.Dq month
-(\\), will be changed into newline characters, and all data
+and
-after the first % will be sent to the command as standard
+.Dq day of week
-input.
+fields.
-.PP
+Use the first three letters of the particular day or month (case
-Note: The day of a command's execution can be specified by two
+doesn't matter).
-fields \(em day of month, and day of week.  If both fields are
+Ranges or lists of names are not allowed.
-restricted (ie, aren't *), the command will be run when
+.Pp
-.I either
+The
-field matches the current time.  For example,
+.Dq sixth
-.br
+field (the rest of the line) specifies the command to be run.
-``30 4 1,15 * 5''
+The entire command portion of the line, up to a newline or percent
-would cause a command to be run at 4:30 am on the 1st and 15th of each
+signs
-month, plus every Friday.
+.Pq Sq % ,
-.\" Everything from here to .SH EXAMPLE CRON FILE added: mouse, 1997-07-13
+will be executed by
-.PP
+.Xr sh 1
 or by the shell specified in the
 .Ev SHELL
 variable of the cronfile.
 Percent signs
 .Pq Sq %
 in the command, unless escaped with backslash
 .Pq Sq \e ,
 will be changed into newline characters, and all data after the
 first % will be sent to the command as standard input.
 .Pp
 .Em Note :
 The day of a command's execution can be specified by two fields
 \(em day of month, and day of week.
 If both fields are restricted (i.e., aren't *), the command will
 be run when
 .Em either
 field matches the current time.
 For example,
 .Dq 30 4 1,15 * 5
 would cause a command to be run at 4:30 am on the 1st and 15th of
 each month, plus every Friday.
 .Pp
 Instead of the first five fields, one of eight special strings may appear:
-.IP
+.Bl -column -offset indent "@annually" "Run once a month, 0 0 1 * *."
-.ta 1.5i
+.It Sy string Ta Sy meaning
-string	meaning
+.It @reboot Ta Run once, at startup.
-.br
+.It @yearly Ta Run once a year, Dq 0 0 1 1 * .
-------	-------
+.It @annually Ta (same as @yearly)
-.br
+.It @monthly Ta Run once a month, Dq 0 0 1 * * .
-@reboot	Run once, at startup.
+.It @weekly Ta Run once a week, Dq 0 0 * * 0 .
-.br
+.It @daily Ta Run once a day, Dq 0 0 * * * .
-@yearly	Run once a year, "0 0 1 1 *".
+.It @midnight Ta (same as @daily)
-.br
+.It @hourly Ta Run once an hour, Dq 0 * * * * .
-@annually	(same as @yearly)
+.El
-.br
+.Ss EXAMPLE CRON FILE
-@monthly	Run once a month, "0 0 1 * *".
+.Bd -literal
 .br
 @weekly	Run once a week, "0 0 * * 0".
 .br
 @daily	Run once a day, "0 0 * * *".
 .br
 @midnight	(same as @daily)
 .br
 @hourly	Run once an hour, "0 * * * *".
 .br
 .SH EXAMPLE CRON FILE
 .nf
 # use /bin/sh to run commands, no matter what /etc/passwd says
 SHELL=/bin/sh
 # mail any output to `paul', no matter whose crontab this is
 MAILTO=paul
+#
 # run five minutes after midnight, every day
 0 * * *       $HOME/bin/daily.job \*[Gt]\*[Gt] $HOME/tmp/out 2\*[Gt]\*[Am]1
 # run at 2:15pm on the first of every month -- output mailed to paul
 14 1 * *     $HOME/bin/monthly
 # run at 10 pm on weekdays, annoy Joe
 22 * * 1-5    mail -s "It's 10pm" joe%Joe,%%Where are your kids?%
 0-23/2 * * * echo "run 23 minutes after midn, 2am, 4am ..., everyday"
 4 * * sun     echo "run at 5 after 4 every sunday"
 ? ?2-4 1,15 * * echo "random between 2am-4:59am on the 1st and 15th"
-.fi
+.Ed
-.SH SEE ALSO
+.Sh SEE ALSO
-cron(8), crontab(1)
+.Xr crontab 1 ,
-.SH EXTENSIONS
+.Xr cron 8
-When specifying day of week, both day 0 and day 7 will be considered Sunday.
+.Sh STANDARDS
 When specifying day of week, both day 0 and day 7 will be considered
 Sunday.
 BSD and ATT seem to disagree about this.
-.PP
+.Pp
-Lists and ranges are allowed to co-exist in the same field.  "1-3,7-9" would
+Lists and ranges are allowed to co-exist in the same field.
-be rejected by ATT or BSD cron -- they want to see "1-3" or "7,8,9" ONLY.
+.Dq 1-3,7-9
-.PP
+would be rejected by ATT or BSD cron -- they want to see
-Ranges can include "steps", so "1-9/2" is the same as "1,3,5,7,9".
+.Dq 1-3
-.PP
+or
 .Dq 7,8,9
 ONLY.
 .Pp
 Ranges can include
 .Dq steps ,
 so
 .Dq 1-9/2
 is the same as
 .Dq 1,3,5,7,9 .
 .Pp
 Names of months or days of the week can be specified by name.
-.PP
+.Pp
-Environment variables can be set in the crontab.  In BSD or ATT, the
+Environment variables can be set in the crontab.
-environment handed to child processes is basically the one from /etc/rc.
+In BSD or ATT, the environment handed to child processes is basically
-.PP
+the one from
-Command output is mailed to the crontab owner (BSD can't do this), can be
+.Pa /etc/rc .
-mailed to a person other than the crontab owner (SysV can't do this), or the
+.Pp
-feature can be turned off and no mail will be sent at all (SysV can't do this
+Command output is mailed to the crontab owner (BSD can't do this),
-either).
+can be mailed to a person other than the crontab owner (SysV can't
-.\" This next paragraph added: mouse, 1997-07-13
+do this), or the feature can be turned off and no mail will be sent
-.PP
+at all (SysV can't do this either).
-All of the `@' commands that can appear in place of the first five fields
+.Pp
-are extensions.
+All of the
-.SH AUTHOR
+.Sq @
-.nf
+commands that can appear in place of the first five fields are
-Paul Vixie \*[Lt]paul@vix.com\*[Gt]
+extensions.
 .Sh AUTHORS
 .An Paul Vixie Aq paul@vix.com