Cisco Cisco Firepower Management Center 4000

escaped characters that allow you to use the metacharacters as literal characters

six character classes

Metacharacters are literal characters that have special meaning within regular expressions. The 
following table describes the metacharacters you can use when defining a custom data pattern.

You must use a backslash to escape the characters in the following table for the sensitive data 
preprocessor to interpret them correctly as literal characters.

The following table describes the character classes you can use when defining a custom sensitive data 
pattern.

?

Matches zero or one occurrence of the preceding 
character or escape sequence; that is, the preceding 
character or escape sequence is optional.

colou?r

 matches 

color

 or 

colour

{n}

Matches the preceding character or escape sequence 

 times.

For example,

 

\d{2}

 matches 

55

, 

12

, and 

so on;

 

\l{3}

 matches 

AbC

, 

www

, and 

so on;

 

\w{3}

 matches 

a1B

, 25C, 

and so on; 

 

x{5}

 matches 

xxxxx

\

Allows you to use metacharacters as actual characters 
and is also used to specify a predefined character 
class. See the 

 table for a description of the character classes 

you can use in sensitive data patterns.

\?

 matches a question mark,

 

\\

 matches a backslash, 

 

\d

 matches numeric 

characters, and so on

\?

?

\{

{

\}

}

\\

\

\d

Matches any numeric ASCII character 0-9

0-9

\D

Matches any byte that is not a numeric ASCII character not 0-9

\l (lowercase “ell”) Matches any ASCII letter

a-zA-Z

\L

Matches any byte that is not an ASCII letter

not a-zA-Z