Barracuda Networks SSL VPN, Administrator'S Manual

Page: 107 / 124

Regular Expressions 107
Appendix B
Regular Expressions
The Barracuda SSL VPN allows you to use regular expressions when creating Content Filtering
policies. Regular Expressions allow you to flexibly describe text so that a wide range of possibilities
can be matched.
When using regular expressions:
• Be careful when using special characters such as |, *, '.' in your text. For more information, refer
to
Using Special Characters in Expressions on page 108.
• All matches are not case sensitive.
Table B.1 describes the most common regular expressions supported by the Barracuda SSL VPN.
Table B.1: Common Regular Expressions
Expression Matches...
Operators
* Zero or more occurrences of the character immediately preceding
+ One or more occurrences of the character immediately preceding
? Zero or one occurrence of the character immediately preceding
| Either of the characters on each side of the pipe
( ) Characters between the parenthesis as a group
Character Classes
. Any character except new line
[ac] Letter 'a' or letter 'c'
[^ac] Anything but letter 'a' or letter 'c'
[a-z] Letters 'a' through 'z'
[a-z.] Letters 'a' through 'z' or 'A' through 'Z' or a dot
[a-z\-] Letters 'a' through 'z' or 'A' through 'Z' or a dash
\d Digit, shortcut for [0-9]
[^\d] Non-digit
\a Digit, shortcut for [0-9]
\w Part of word: shortcut for [A-Za-z0-9_]
[^\w] Non-word character