Writing Customized Expressions

You can enter custom expressions for an ACL. Select this option only if you are familiar with the syntax and structure of ACL files. A few features are available only by editing the ACL file or creating custom expressions. For example, you can restrict access to your server depending on the time of day, day of the week, or both.

The following customized expression shows how you could restrict access by time of day and day of the week. This example assumes you have two groups in your LDAP directory. The Regular group gets access Monday through Friday, 8:00 am to 5:00 pm. The Critical group gets access all the time.

allow (read){(group=regular and dayofweek=”mon,tue,wed,thu,fri”);
(group=regular and (timeofday>=0800 and timeofday<=1700));(group=critical)}

For more information about valid syntax and ACL files, see Chapter 18, ACL File Syntax.