Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

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 in filter rules match a string if the 
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

. 

Rules containing the dollar sign character ($) only 
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: 

"^$"

Rules containing characters, white space, and the at 
sign character (

@

) only match themselves explicitly. 

For example, the regular expression 

^George@admin$

 

only matches the string 

George@admin

. 

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

.