User Guide

Input Validation with cfform Controls 143
Expression examples
The following examples show some regular expressions and describe what they
match:
Resources
An excellent reference on regular expressions is Mastering Regular Expressions by
Jeffrey E.F. Friedl, published by O’Reilly & Associates, Inc.
Expression Description
[\?&]value=
Any string containing a URL parameter
value.
^[A-Z]:(\\[A-Z0-9_]+)+$
An uppercase DOS/Windows directory
path that is not the root of a drive and has
only letters, numbers, and underscores in
its text.
^(\+|-)?[1-9][0-9]*$
An integer that does not begin with a zero
and has an optional sign.
^(\+|-)?[1-9][0-9]*(\.[0-9]*)?$
A real number.
^(\+|-)?[1-9]\.[0-9]*E(\+|-)?[0-9]+$
A real number in engineering notation.
a{2,4}
A string containing two to four
occurrences of ’a’: aa, aaa, aaaa; for
example aardvark, but not automatic.
(ba){2,}
A string containing least two ’ba’ pairs; for
example Ali baba, but not Ali Baba.