Differences between version 3 and previous revision of crontab(5).
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| Newer page: | version 3 | Last edited on Tuesday, January 21, 2003 9:31:52 pm | by CraigBox | Revert |
| Older page: | version 2 | Last edited on Tuesday, January 21, 2003 9:29:10 pm | by CraigBox | Revert |
@@ -2,9 +2,9 @@
crontab - tables for driving cron
!!DESCRIPTION
-A ''crontab'' file contains instructions to the cron(8) daemon of the general form: ``
run this command at this time on this date''.
+A ''crontab'' file contains instructions to the 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 their own crontabs, eliminating the need for explicitly running su(1) as part of a cron command.
Blank lines and leading spaces and tabs are ignored. Lines whose first non-space character is a hash-sign (#) are comments, and are
@@ -25,9 +25,9 @@
(Another note: the LOGNAME variable is sometimes called USER on BSD systems... on these systems, USER will be set also.)
In addition to LOGNAME, HOME, and SHELL, cron(8) will look at MAILTO if it has any reason to send mail as a result of running commands
-in ``
this'' crontab. If MAILTO is defined (and non-empty), mail is sent to the user so named. If MAILTO is defined but empty
+in ''
this'' crontab. If MAILTO is defined (and non-empty), mail is sent to the user so named. If MAILTO is defined but empty
(MAILTO=""), no mail will be sent. Otherwise mail is sent to the owner of the crontab.
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 command, followed by a newline character ('0). The system crontab (/etc/crontab) uses the same format,
@@ -36,9 +36,9 @@
be executed.
Commands are executed by cron(8) when the minute, hour, and month of year fields match the current time, ''and'' when at least one of
-the two day fields (day of month, or day of week) match the current time (see ``
Note'' below). cron(8) examines cron entries once
+the two day fields (day of month, or day of week) match the current time (see ''
Note'' below). cron(8) examines cron entries once
every minute. The time and date fields are:
field allowed values
----- --------------
@@ -48,30 +48,30 @@
month 1-12 (or names, see below)
day of week 0-7 (0 or 7 is Sun, or use names)
-A field may be an asterisk (*), which always stands for ``
first-last''.
+A field may be an asterisk (*), which always stands for ''
first-last''.
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.
+an ''
hours'' entry specifies execution at hours 8, 9, 10 and 11.
-Lists are allowed. A list is a set of numbers (or ranges) separated by commas. Examples: ``
1,2,5,9'', ``
-4,8-12''.
+Lists are allowed. A list is a set of numbers (or ranges) separated by commas. Examples: ''
1,2,5,9'', ''
-4,8-12''.
-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, ``
-23/2'' can be used in the hours field to specify command execution every other hour (the
-alternative in the V7 standard is ``
,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''.
+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, ''
-23/2'' can be used in the hours field to specify command execution every other hour (the
+alternative in the V7 standard is ''
,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''.
-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
+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 lists of names are not allowed.
-The ``
sixth'' field (the rest of the line) specifies the command to be run. The entire command portion of the line, up to a newline or
+The ''
sixth'' field (the rest of the line) specifies the command to be run. The entire command portion of the line, up to a newline or
% character, will be executed by /bin/sh or by the shell specified in the SHELL variable of the cronfile. Percent-signs (%) in the
command, unless escaped with backslash (), will be changed into newline characters, and all data after the first % will be sent to the
command as standard input.
Note: The day of a command's execution can be specified by two fields -- day of month, and day of week. If both fields are restricted
-(ie, aren't *), the command will be run when ''either'' field matches the current time. For example, ``
30 4 1,15 * 5'' would cause a
+(ie, aren't *), the command will be run when ''either'' 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.
Instead of the first five fields, one of eight special strings may appear:
