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Fortinet 678 FortiWeb 5.0 Patch 6 Administration Guide
See also
• What are back-references?
• Cookbook regular expressions
• Language support
• Rewriting & redirecting
• Defining custom data leak & attack signatures
• Configuring URL interpreters
• Configuring custom suspicious request URLs
What are back-references?
A back-reference is a regular expression token such as $0 or $1 that refers to whatever part of
the text was matched by the capture group in that position within the regular expression.
Back-references are used whenever you want the output/interpretation to resemble the original
match
: they insert a substring of the original matching text. Like other regular expression
features, back-references help to ensure that you do not have to maintain a large, cumbersome
{} Quantifies the number of times the previous
ch
arac
ter or capture group may be repeated
continuously.
To define a varying number repetitions, delimit it
with
a comma.
Text: 1234567890
Regu
lar expression: \d{3}
Matche
s: 123
Tex
t: www.example.com
Regu
lar expression: w{1,4}
Ma
tches: www
If th
e string were a typo such as
“ww ” or “wwww”, it
would also
match that.
Table 61:Popular FortiWeb regular expression syntax
Notation Function Sample Matches