Руководство Пользователя для Cisco Cisco Email Security Appliance X1070
Chapter 5 Using Message Filters to Enforce Email Policies
5-298
Cisco IronPort AsyncOS 7.1 for Email Advanced Configuration Guide
OL-22164-02
Regular Expressions in Rules
Several of the atomic tests used to define rules use regular expression matching.
Regular expressions can become complex. Use the following table as a guide for
the applying of regular expressions within message filter rules:
Regular expressions can become complex. Use the following table as a guide for
the applying of regular expressions within message filter rules:
Table 5-3
Regular Expression in Rules
Regular expression (
abc
)
Regular expressions in filter rules match a string if the
sequence of directives in the regular expression match
any part of the string.
sequence of directives in the regular expression match
any part of the string.
For example, the regular expression
Georg
matches the
string
George Of The Jungle
, the string
Georgy Porgy
,
the string
La Meson Georgette
as well as
Georg
.
Carat (
^
)
Dollar sign (
$
)
Rules containing the dollar sign character ($) only
match the end of the string, and rules containing the
caret symbol (
match the end of the string, and rules containing the
caret symbol (
^
) only match the beginning of the string.
For example, the regular expression
^Georg$
only
matches the string
Georg
.
Searching for an empty header would look like this:
"^$"
Letters, white space and
the at sign (
the at sign (
@
) character
Rules containing characters, white space, and the at
sign character (
sign character (
@
) only match themselves explicitly.
For example, the regular expression
^George@admin$
only matches the string
George@admin
.
Period character (
.
)
Rules containing a period character (
.
) match any
character (except a new line).
For example, the regular expression
^...admin$
matches the string
macadmin
as well as the string
sunadmin
but not
win32admin
.