Windows .NET Powershell - Overview
## Here I offer the reader a bit of output from the Microsoft Windows DotNet ( .NET ) Powershell. Powershell is available for windows uders to download for no cost, as a facility for interfacing with many .NET functions, as well as some typical Windows Shell (cmd.exe) functions; some interesting enhancements to the functionality of The OS and available .NET Framework components which may be able to do some heavy lifting, as its said, for the user in a fraction of the time and effort which may be required through other means.
## Plesae note that it is for the express purpose of DEMONSTRATION ONLY, so the reader might make his or her own decisions about the subject, as this author makes no claim here regarding the quality of the software itself or the operation thereof, his fascination with the software notwithstanding. NoviceNotes™ encourages you, the reader, to develop your own opinions and share your feelings in the comments below. We hot that such texts are educational, insightful, and balanced.
as output, verbatim from Windows PowerShell™, the following shows a query instance of “get-help about_*”, where the last few cmdlet items are shown, then I specifiy precisely “get-help about_regular”, where Powershell was intuitive enough to display that which I wanted: more information on the available Windows .Net Powershell Regular Expression syntax
about_property HelpFile Using object propertie...
about_provider HelpFile Windows PowerShell pro...
about_pssnapins HelpFile A Windows PowerShell s...
about_quoting_rules HelpFile Rules for setting the ...
about_redirection HelpFile Redirecting output fro...
about_ref HelpFile How to create and use ...
about_regular_expression HelpFile Using regular expressi...
about_reserved_words HelpFile Words in the Windows P...
about_scope HelpFile The visibility a funct...
about_script_block HelpFile Grouping statements an...
about_shell_variable HelpFile Variables that are cre...
about_signing HelpFile Describes the Windows ...
about_special_characters HelpFile The special characters...
about_switch HelpFile Using a switch to hand...
about_system_state HelpFile Data maintained by the...
about_types HelpFile Extending the .NET typ...
about_where HelpFile Filter objects based o...
about_while HelpFile A language statement f...
about_wildcard HelpFile Using wildcards in Cmd...
SEE ALSO
For information about the match comparison operator, enter the
following command at the PowerShell command prompt:
help about_comparison_operators
See the MSDN Documentation on Regular Expression Language Elements
PS C:\> get-help about_regular
TOPIC
Regular expressions
SHORT DESCRIPTION
Using regular expressions in Cmdlet parameters in the Windows PowerShell
LONG DESCRIPTION
PowerShell supports a number of the 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
specification of contiguous
character.
[^] Matches any character except “and” -match “[^brt]nd”
those in brackets
^ Matches the beginning “book” -match “^bo”
characters
$ Matches the end characters “book” -match “ok$”
* Matches zero or more instances “baggy” -match “g*”
of the preceding character
? Matches zero or one instance “baggy” -match “g?”
of the preceding character
\ Matches the character that “Try$” -match “Try\$”
follows as an escaped character
PowerShell supports the character classes available in .NET 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. For example, Ll, Nd,
Z, IsGreek, IsBoxDrawing.
\P{name} Matches text not included in 1234 -match “\P{Ll}+”
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.
PowerShell supports the quantifiers available in .NET 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 of the comparisons shown in the above examples in the table
above evaluate to true.
Note that the escape character for regular expressions is different
than that of the PowerShell. The character escape for regular
expressions is the backslash “\”.
SEE ALSO
For information about the match comparison operator, enter the
following command at the PowerShell command prompt:
help about_comparison_operators
See the MSDN Documentation on Regular Expression Language Elements
PS C:\>
