# about_Regular_Expressions

Applies To: Windows PowerShell 2.0

```
TOPIC
about_Regular_Expressions
SHORT DESCRIPTION
Describes regular expressions in Windows PowerShell.
LONG DESCRIPTION
Windows PowerShell supports the following regular expression characters.
Format Logic Example
-------- ------------------------------- -----------------------
value Matches exact characters "book" -match "oo"
anywhere in the original value.
. Matches any single character. "copy" -match "c..y"
[value] Matches at least one of the "big" -match "b[iou]g"
characters in the brackets.
[range] Matches at least one of the "and" -match "[a-e]nd"
characters within the range.
The use of a hyphen (–) allows
you to specify an adjacent
character.
[^] Matches any characters except "and" -match "[^brt]nd"
those in brackets.
^ Matches the beginning "book" -match "^bo"
characters.
$ Matches the end characters. "book" -match "ok$"
* Matches any instances "baggy" -match "g*"
of the preceding character.
? Matches one instance "baggy" -match "g?"
of the preceding character.
\ Matches the character that "Try$" -match "Try\$"
follows as an escaped character.
Windows PowerShell supports the character classes available in
Microsoft .NET Framework regular expressions.
Format Logic Example
-------- ------------------------------- -----------------------
\p{name} Matches any character in the "abcd defg" -match "\p{Ll}+"
named character class specified
by {name}. Supported names are
Unicode groups and block
ranges such as Ll, Nd,
Z, IsGreek, and IsBoxDrawing.
\P{name} Matches text not included in 1234 -match "\P{Ll}+"
the groups and block ranges
specified in {name}.
\w Matches any word character. "abcd defg" -match "\w+"
Equivalent to the Unicode (this matches abcd)
character categories [\p{Ll}
\p{Lu}\p{Lt}\p{Lo}\p{Nd}\p{Pc}].
If ECMAScript-compliant behavior
is specified with the ECMAScript
option, \w is equivalent to
[a-zA-Z_0-9].
\W Matches any nonword character. "abcd defg" -match "\W+"
Equivalent to the Unicode (This matches the space)
categories [^\p{Ll}\p{Lu}\p{Lt}
\p{Lo}\p{Nd}\p{Pc}].
\s Matches any white-space "abcd defg" -match "\s+"
character. Equivalent to the
Unicode character categories
[\f\n\r\t\v\x85\p{Z}].
\S Matches any non-white-space "abcd defg" -match "\S+"
character. Equivalent to the
Unicode character categories
[^\f\n\r\t\v\x85\p{Z}].
\d Matches any decimal digit. 12345 -match "\d+"
Equivalent to \p{Nd} for
Unicode and [0-9] for non-
Unicode behavior.
\D Matches any nondigit. "abcd" -match "\D+"
Equivalent to \P{Nd} for
Unicode and [^0-9] for non-
Unicode behavior.
Windows PowerShell supports the quantifiers available in .NET Framework
regular expressions. The following are some examples of quantifiers.
Format Logic Example
-------- ------------------------------- -----------------------
* Specifies zero or more matches; "abc" -match "\w*"
for example, \w* or (abc)*.
Equivalent to {0,}.
+ Matches repeating instances of "xyxyxy" -match "xy+"
the preceding characters.
? Specifies zero or one matches; "abc" -match "\w?"
for example, \w? or (abc)?.
Equivalent to {0,1}.
{n} Specifies exactly n matches; "abc" -match "\w{2}"
for example, (pizza){2}.
{n,} Specifies at least n matches; "abc" -match "\w{2,}"
for example, (abc){2,}.
{n,m} Specifies at least n, but no "abc" -match "\w{2,3}"
more than m, matches.
All the comparisons shown in the preceding table evaluate to true.
Notice that the escape character for regular expressions, a backslash (\),
is different from the escape character for Windows PowerShell. The
escape character for Windows PowerShell is the backtick character (`)
(ASCII 96).
For more information, see the "Regular Expression Language Elements" topic
in the Microsoft Developer Network (MSDN) library
at http://go.microsoft.com/fwlink/?LinkId=133231.
SEE ALSO
about_Comparison_Operators
about_Operators
```