Using escape sequences

Escape sequences are special characters in regular expressions preceded by a backslash (\). You typically use escape sequences to represent special characters within a regular expression. For example, the escape sequence \t represents a tab character within the regular expression, and the \d escape sequence specifies any digit, similar to [0-9]. In ColdFusion the escape sequences are case-sensitive.

The following table lists the escape sequences supported in ColdFusion:

Escape Sequence	Description
\b	Specifies a boundary defined by a transition from an alphanumeric character to a nonalphanumeric character, or from a nonalphanumeric character to an alphanumeric character. For example, the string " Big" contains boundary defined by the space (nonalphanumeric character) and the "B" (alphanumeric character). The following example uses the \b escape sequence in a regular expression to locate the string "Big" at the end of the search string and not the fragment "big" inside the word "ambiguous". reFindNoCase("\bBig\b", "Don't be ambiguous about Big.") <!--- The value of IndexOfOccurrence is 26 ---> When used inside of a character set (e.g. [\b]), it specifies a backspace
\B	Specifies a boundary defined by no transition of character type. For example, two alphanumeric character in a row or two nonalphanumeric character in a row; opposite of \b.
\A	Specifies a beginning of string anchor, much like the ^ special character. However, unlike ^, you cannot combine \A with (?m) to specify the start of newlines in the search string.
\Z	Specifies an end of string anchor, much like the $ special character. However, unlike $, you cannot combine \Z with (?m) to specify the end of newlines in the search string.
\n	Newline character
\r	Carriage return
\t	Tab
\f	Form feed
\d	Any digit, similar to [0-9]
\D	Any nondigit character, similar to [^0-9]
\w	Any alphanumeric character, similar to [[:alnum:]]
\W	Any nonalphanumeric character, similar to [^[:alnum:]]
\s	Any whitespace character including tab, space, newline, carriage return, and form feed. Similar to [ \t\n\r\f].
\S	Any nonwhitespace character, similar to [^ \t\n\r\f]
\xdd	A hexadecimal representation of character, where d is a hexadecimal digit
\ddd	An octal representation of a character, where d is an octal digit, in the form \000 to \377

Escape

Sequence

Description

Specifies a boundary defined by a transition from an alphanumeric character to a nonalphanumeric character, or from a nonalphanumeric character to an alphanumeric character.

For example, the string " Big" contains boundary defined by the space (nonalphanumeric character) and the "B" (alphanumeric character).

The following example uses the \b escape sequence in a regular expression to locate the string "Big" at the end of the search string and not the fragment "big" inside the word "ambiguous".

reFindNoCase("\bBig\b", "Don't be ambiguous about Big.")

<!--- The value of IndexOfOccurrence is 26 --->

When used inside of a character set (e.g. [\b]), it specifies a backspace

Specifies a boundary defined by no transition of character type. For example, two alphanumeric character in a row or two nonalphanumeric character in a row; opposite of \b.

Specifies a beginning of string anchor, much like the ^ special character.

However, unlike ^, you cannot combine \A with (?m) to specify the start of newlines in the search string.

Specifies an end of string anchor, much like the $ special character.

However, unlike $, you cannot combine \Z with (?m) to specify the end of newlines in the search string.

Newline character

Carriage return

Tab

Form feed

Any digit, similar to [0-9]

Any nondigit character, similar to [^0-9]

Any alphanumeric character, similar to [[:alnum:]]

Any nonalphanumeric character, similar to [^[:alnum:]]

Any whitespace character including tab, space, newline, carriage return, and form feed. Similar to [ \t\n\r\f].

Any nonwhitespace character, similar to [^ \t\n\r\f]

\xdd

A hexadecimal representation of character, where d is a hexadecimal digit

\ddd

An octal representation of a character, where d is an octal digit, in the form \000 to \377

Version 6.1

Comments are no longer accepted for ColdFusion MX 6.1. ColdFusion 8 is the current version.

Comments

isaac dealey said on Nov 9, 2003 at 2:56 PM :

Why are there escape sequences for digit, nondigit, alphanumeric and nonalphanumeric, but _not_ for alpha and nonalpha. Is this a documentation bug or do these escape sequences not exist in cfmx?

Steve said on Aug 6, 2004 at 9:19 AM :

How do you do a ^(full word) ?

Something like this:

<cfset somestring='<cfquery datasource="dsn" name="myQuery"'>
<cfset getvalue=refindnocase('<cfquery^(name)name="([^"]*)"',somestring,1,"true")>

Adam Cameron said on Dec 27, 2004 at 7:11 PM :

\w is actually equivalent to :word: not :alnum:. The difference being that \w matches underscore (like :word: does), whereas :alnum: only matches alphanumeric values.

Current page: http://livedocs.adobe.com/coldfusion/6.1/htmldocs/regexp12.htm


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