Cisco Cisco Email Security Appliance C160 Mode D'Emploi

When matching an empty string, do not use 

“”

 as that actually matches all strings. Instead use 

“^$”

. For 

an example, see the second example in 

.

It is also important to remember that if you want to match a literal period, you must use an escaped period 
in the regular expression. For example, the regular expression 

sun.com

 matches the string 

thegodsunocommando

, but the regular expression 

^sun\.com$

 only matched the string 

sun.com.

Technically, the style of regular expressions used are Python re Module style regular expressions. For 
a more detailed discussion of Python style regular expressions, consult the Python Regular Expression 
HOWTO, accessible from

:

 

http://www.python.org/doc/howto/

In some languages, the concepts of a word or word boundary, or case do not exist. 

Complex regular expressions that depend on concepts like what is or is not a character that would 
compose a word (represented as “

\w

” in regex syntax) cause problems when the locale is unknown or if 

the encoding is not known for certain. 

Regular expressions can be tested for matching using the sequence 

==

 and for non-matching using the 

sequence 

!=

. For example: 

Unless otherwise noted, regular expressions are case-sensitive. Thus, if your regular expression is 
searching for 

foo

, it does not match the pattern 

FOO

 or even 

Foo

.

rcpt-to == "^goober@dev\\.null\\....$" (matching)

rcpt-to != "^goober@dev\\.null\\....$" (non-matching)