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neysx 06/01/04 11:22:18 |
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|
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Modified: xml/htdocs/doc/en cron-guide.xml |
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Log: |
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#117683 explain cronbase |
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|
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Revision Changes Path |
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1.7 +99 -39 xml/htdocs/doc/en/cron-guide.xml |
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|
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file : http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/doc/en/cron-guide.xml?rev=1.7&content-type=text/x-cvsweb-markup&cvsroot=gentoo |
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plain: http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/doc/en/cron-guide.xml?rev=1.7&content-type=text/plain&cvsroot=gentoo |
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diff : http://www.gentoo.org/cgi-bin/viewcvs.cgi/xml/htdocs/doc/en/cron-guide.xml.diff?r1=1.6&r2=1.7&cvsroot=gentoo |
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|
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Index: cron-guide.xml |
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=================================================================== |
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RCS file: /var/cvsroot/gentoo/xml/htdocs/doc/en/cron-guide.xml,v |
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retrieving revision 1.6 |
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retrieving revision 1.7 |
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diff -u -r1.6 -r1.7 |
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--- cron-guide.xml 1 Jan 2006 11:51:43 -0000 1.6 |
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+++ cron-guide.xml 4 Jan 2006 11:22:18 -0000 1.7 |
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@@ -1,5 +1,5 @@ |
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<?xml version='1.0' encoding="UTF-8"?> |
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-<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/cron-guide.xml,v 1.6 2006/01/01 11:51:43 neysx Exp $ --> |
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+<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/cron-guide.xml,v 1.7 2006/01/04 11:22:18 neysx Exp $ --> |
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<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> |
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|
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<guide link="/doc/en/cron-guide.xml"> |
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@@ -20,8 +20,8 @@ |
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<!-- See http://creativecommons.org/licenses/by-sa/2.5 --> |
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<license/> |
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|
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-<version>1.4</version> |
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-<date>2005-07-25</date> |
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+<version>1.5</version> |
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+<date>2005-01-04</date> |
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|
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<chapter> |
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<title>Cron basics</title> |
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@@ -51,7 +51,14 @@ |
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Portage. All of them offer a similar interface, namely the use of |
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<c>crontab</c> or a similar command. There is also a related utility called |
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Anacron which is meant to work with cron on systems that are not continuously |
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-running. |
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+running. |
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+</p> |
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+ |
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+<p> |
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+It is also worth noting that all three of the available cron packages depend on |
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+<c>sys-process/cronbase</c>. This package is not technically depended on by any |
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+of the cron packages, but it does provide cron-like functionality that most |
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+users can appreciate. |
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</p> |
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|
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<p> |
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@@ -115,13 +122,13 @@ |
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</p> |
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|
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<ul> |
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-<li> |
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- Fast, simple and free of unnecessary features |
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-</li> |
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-<li> |
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- Access to <c>crontab</c> is limited to the cron group, i.e. it doesn't rely on |
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- any external faculties |
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-</li> |
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+ <li> |
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+ Fast, simple and free of unnecessary features |
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+ </li> |
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+ <li> |
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+ Access to <c>crontab</c> is limited to the cron group, i.e. it doesn't rely on |
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+ any external faculties |
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+ </li> |
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</ul> |
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|
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</body> |
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@@ -144,29 +151,25 @@ |
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</p> |
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|
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<ul> |
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-<li> |
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- Designed to work on systems that are not continuously running, i.e. it can run |
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- a job after restarting if it was missed |
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-</li> |
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-<li> |
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- Setting of environment variables and many other options in crontabs |
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-</li> |
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-<li> |
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- Each user can have his own crontab, access is controlled by cron.allow and |
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- cron.deny |
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-</li> |
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-<li> |
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- Enhanced crontab syntax with support for many new features |
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-</li> |
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+ <li> |
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+ Designed to work on systems that are not continuously running, i.e. it can |
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+ run a job after restarting if it was missed |
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+ </li> |
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+ <li>Setting of environment variables and many other options in crontabs</li> |
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+ <li> |
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+ Each user can have his own crontab, access is controlled by cron.allow and |
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+ cron.deny |
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+ </li> |
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+ <li>Enhanced crontab syntax with support for many new features</li> |
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</ul> |
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|
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- |
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</body> |
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</section> |
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|
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<section> |
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<title>Anacron</title> |
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<body> |
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+ |
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<p> |
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Anacron is not a cron daemon, it is something that usually works in |
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conjunction with one. It executes commands at intervals specified in days and |
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@@ -174,8 +177,8 @@ |
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that were missed while the system was down. Anacron usually relies on a cron |
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daemon to run it each day. |
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</p> |
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-</body> |
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|
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+</body> |
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</section> |
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</chapter> |
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|
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@@ -208,22 +211,23 @@ |
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|
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</body> |
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</section> |
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-<section> |
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+<section id="systemtab"> |
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<title>System crontab</title> |
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<body> |
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|
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<p> |
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The post install messages from some of these cron packages tell you to run |
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<c>crontab /etc/crontab</c>. The <path>/etc/crontab</path> file is your |
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-<e>system crontab</e>. A default Gentoo installation uses it to run the |
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-scripts in <path>/etc/cron.{daily,hourly,weekly,monthly}</path>. Note that |
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+<e>system crontab</e>. A cron installation can use it in conjunction with |
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+<c>sys-process/cronbase</c> to run the scripts in |
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+<path>/etc/cron.{daily,hourly,weekly,monthly}</path>. Note that only |
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Vixie-cron schedules jobs in <path>/etc/crontab</path> automatically. Dcron and |
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Fcron users will need to run <c>crontab /etc/crontab</c> every time they make |
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changes to <path>/etc/crontab</path>. |
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</p> |
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|
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<p> |
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-Please note that jobs scheduled in the system crontab will not show up in the |
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+Please note that jobs scheduled in the system crontab might not show up in the |
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list of cron-jobs displayed by <c>crontab -l</c>. |
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</p> |
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|
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@@ -339,36 +343,41 @@ |
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<table> |
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<tr> |
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<th>Version</th> |
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- <th>Edit command</th> |
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- <th>Remove command</th> |
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- <th>New command</th> |
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- <th>List command</th> |
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+ <th>Edit crontab</th> |
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+ <th>Remove crontab</th> |
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+ <th>New crontab</th> |
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+ <th>List cron-jobs</th> |
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</tr> |
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<tr> |
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<ti>dcron</ti> |
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<ti><c>crontab -e</c></ti> |
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- <ti><c>crontab -d</c></ti> |
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+ <ti><c>crontab -d <e>[user]</e></c></ti> |
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<ti><c>crontab <e>file</e></c></ti> |
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<ti><c>crontab -l</c></ti> |
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</tr> |
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<tr> |
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<ti>fcron</ti> |
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<ti><c>fcrontab -e</c></ti> |
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- <ti><c>fcrontab -r</c></ti> |
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+ <ti><c>fcrontab -r <e>[user]</e></c></ti> |
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<ti><c>fcrontab <e>file</e></c></ti> |
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<ti><c>fcrontab -l</c></ti> |
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</tr> |
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<tr> |
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<ti>vixie-cron</ti> |
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<ti><c>crontab -e</c></ti> |
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- <ti><c>crontab -r</c></ti> |
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+ <ti><c>crontab -r <e>[user]</e></c></ti> |
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<ti><c>crontab <e>file</e></c></ti> |
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<ti><c>crontab -l</c></ti> |
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</tr> |
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</table> |
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|
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<note> |
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-Fcron also makes a symlink to <c>crontab</c>. |
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+When using the remove command, if no argument is supplied, it deletes the |
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+current user's crontab. |
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+</note> |
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+ |
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+<note> |
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+Fcron also has a symlink from <c>crontab</c> to <c>fcrontab</c>. |
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</note> |
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|
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<p> |
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@@ -567,6 +576,57 @@ |
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</chapter> |
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|
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<chapter> |
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+<title>Using cronbase</title> |
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+<section> |
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+<body> |
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+ |
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+<p> |
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+As mentioned earlier, all three of the available cron packages depend on |
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+<c>sys-process/cronbase</c>. The cronbase package creates |
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+<path>/etc/cron.{hourly,daily,weekly,monthly}</path>, and a script called |
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+<c>run-crons</c>. You might have noticed that the default |
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+<path>/etc/crontab</path> contains something like this: |
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+</p> |
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+ |
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+<pre caption="Default system crontab"> |
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+*/15 * * * * test -x /usr/sbin/run-crons && /usr/sbin/run-crons |
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+0 * * * * rm -f /var/spool/cron/lastrun/cron.hourly |
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+0 3 * * * rm -f /var/spool/cron/lastrun/cron.daily |
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+15 4 * * 6 rm -f /var/spool/cron/lastrun/cron.weekly |
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+30 5 1 * * rm -f /var/spool/cron/lastrun/cron.monthly |
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+</pre> |
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+ |
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+<p> |
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+To avoid going into much detail, we can just assume that these commands will |
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+effectively run your hourly, daily, weekly and monthly scripts. This method of |
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+scheduling cron-jobs has some important advantages: |
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+</p> |
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+ |
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+<ul> |
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+ <li> |
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+ They will run even if your computer was off when they were scheduled to run |
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+ </li> |
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+ <li> |
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+ It is easy for package maintainers to place scripts in those well defined |
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+ places |
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+ </li> |
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+ <li> |
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+ You know exactly where your cron-jobs and your crontab are stored, making |
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+ it easy for you to backup and restore this part of your system |
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+ </li> |
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+</ul> |
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+ |
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+<note> |
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+Again, it is useful to point out that Vixie cron automatically reads |
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+<path>/etc/crontab</path>, while dcron and fcron do not. Please read the <uri |
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+link="#systemtab">System crontab</uri> section to read more about this. |
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+</note> |
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+ |
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+</body> |
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+</section> |
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+</chapter> |
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+ |
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+<chapter> |
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<title>Final Notes</title> |
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<section> |
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<title>Troubleshooting</title> |
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|
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|
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|
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-- |
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