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author | ru <ru@FreeBSD.org> | 2004-07-02 23:13:00 +0000 |
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committer | ru <ru@FreeBSD.org> | 2004-07-02 23:13:00 +0000 |
commit | 6294018a208cf7742b1c021a9b75c26962505571 (patch) | |
tree | 502f17eb951b74c914af346cd4dbff252350c082 /usr.sbin/cron | |
parent | 3f44360851448f8816c22f6b72e8dd5c9924c27f (diff) | |
download | FreeBSD-src-6294018a208cf7742b1c021a9b75c26962505571.zip FreeBSD-src-6294018a208cf7742b1c021a9b75c26962505571.tar.gz |
Mechanically kill hard sentence breaks.
Diffstat (limited to 'usr.sbin/cron')
-rw-r--r-- | usr.sbin/cron/cron/cron.8 | 9 | ||||
-rw-r--r-- | usr.sbin/cron/crontab/crontab.5 | 71 |
2 files changed, 54 insertions, 26 deletions
diff --git a/usr.sbin/cron/cron/cron.8 b/usr.sbin/cron/cron/cron.8 index 8ad0622..31b579f 100644 --- a/usr.sbin/cron/cron/cron.8 +++ b/usr.sbin/cron/cron/cron.8 @@ -57,7 +57,8 @@ The .Nm utility then wakes up every minute, examining all stored crontabs, checking each -command to see if it should be run in the current minute. When executing +command to see if it should be run in the current minute. +When executing commands, any output is mailed to the owner of the crontab (or to the user named in the .Ev MAILTO @@ -71,9 +72,11 @@ the modification time on has changed, and if it has, .Nm will then examine the modification time on all crontabs and reload those -which have changed. Thus +which have changed. +Thus .Nm -need not be restarted whenever a crontab file is modified. Note that the +need not be restarted whenever a crontab file is modified. +Note that the .Xr crontab 1 command updates the modification time of the spool directory whenever it changes a crontab. diff --git a/usr.sbin/cron/crontab/crontab.5 b/usr.sbin/cron/crontab/crontab.5 index d1eaa4a..0d9f9e7 100644 --- a/usr.sbin/cron/crontab/crontab.5 +++ b/usr.sbin/cron/crontab/crontab.5 @@ -30,19 +30,23 @@ file contains instructions to the .Xr cron 8 daemon of the general form: ``run this command at this time on this date''. Each user has their own crontab, and commands in any given crontab will be -executed as the user who owns the crontab. Uucp and News will usually have +executed as the user who owns the crontab. +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 -Blank lines and leading spaces and tabs are ignored. Lines whose first +Blank lines and leading spaces and tabs are ignored. +Lines whose first non-space character is a pound-sign (#) 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 An active line in a crontab will be either an environment setting or a cron -command. An environment setting is of the form, +command. +An environment setting is of the form, .Bd -literal name = value .Ed @@ -102,7 +106,8 @@ and will look at .Ev MAILTO if it has any reason to send mail as a result of running -commands in ``this'' crontab. If +commands in ``this'' crontab. +If .Ev MAILTO is defined (and non-empty), mail is sent to the user so named. @@ -112,7 +117,9 @@ by seperating recipient users with a comma. If .Ev MAILTO is defined but empty (MAILTO=""), no -mail will be sent. Otherwise mail is sent to the owner of the crontab. This +mail will be sent. +Otherwise mail is sent to the owner of the crontab. +This option is useful if you decide on .Pa /bin/mail instead of @@ -124,11 +131,13 @@ doesn't do aliasing, and UUCP usually doesn't read its mail. .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, +upward-compatible extensions. +Each line has five time and date fields, followed by a user name (with optional ``:<group>'' and ``/<login-class>'' suffixes) if this is the system crontab file, -followed by a command. Commands are executed by +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 @@ -149,25 +158,35 @@ day of week 0-7 (0 or 7 is Sun, or use names) .Pp A field may be an asterisk (*), which always stands for ``first\-last''. .Pp -Ranges of numbers are allowed. Ranges are two numbers separated -with a hyphen. The specified range is inclusive. For example, +Ranges of numbers are allowed. +Ranges are two numbers separated +with a hyphen. +The specified range is inclusive. +For example, 8-11 for an ``hours'' entry specifies execution at hours 8, 9, 10 and 11. .Pp -Lists are allowed. A list is a set of numbers (or ranges) -separated by commas. Examples: ``1,2,5,9'', ``0-4,8-12''. +Lists are allowed. +A list is a set of numbers (or ranges) +separated by commas. +Examples: ``1,2,5,9'', ``0-4,8-12''. .Pp -Step values can be used in conjunction with ranges. Following +Step values can be used in conjunction with ranges. +Following a range with ``/<number>'' specifies skips of the number's value -through the range. For example, ``0-23/2'' can be used in the hours +through the range. +For example, ``0-23/2'' can be used in the hours field to specify command execution every other hour (the alternative -in the V7 standard is ``0,2,4,6,8,10,12,14,16,18,20,22''). Steps are +in the V7 standard is ``0,2,4,6,8,10,12,14,16,18,20,22''). +Steps are also permitted after an asterisk, so if you want to say ``every two hours'', just use ``*/2''. .Pp Names can also be used for the ``month'' and ``day of week'' -fields. Use the first three letters of the particular -day or month (case doesn't matter). Ranges or +fields. +Use the first three letters of the particular +day or month (case doesn't matter). +Ranges or lists of names are not allowed. .Pp The ``sixth'' field (the rest of the line) specifies the command to be @@ -185,10 +204,12 @@ after the first % will be sent to the command as standard input. .Pp 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 +fields \(em day of month, and day of week. +If both fields are restricted (ie, aren't *), the command will be run when .Em either -field matches the current time. For example, +field matches the current time. +For example, ``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. @@ -234,7 +255,8 @@ and .Tn ATT seem to disagree about this. .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. +"1-3,7-9" would be rejected by .Tn ATT or @@ -245,7 +267,8 @@ Ranges can include "steps", so "1-9/2" is the same as "1,3,5,7,9". .Pp Names of months or days of the week can be specified by name. .Pp -Environment variables can be set in the crontab. In +Environment variables can be set in the crontab. +In .Bx or .Tn ATT , @@ -269,11 +292,13 @@ are extensions. .Sh BUGS If you're in one of the 70-odd countries that observe Daylight Savings Time, jobs scheduled during the rollback or advance will be -affected. In general, it's not a good idea to schedule jobs during +affected. +In general, it's not a good idea to schedule jobs during this period. .Pp For US timezones (except parts of IN, AZ, and HI) the time shift occurs at -2AM local time. For others, the output of the +2AM local time. +For others, the output of the .Xr zdump 8 program's verbose .Fl ( v ) |