Mastering Windows PowerShell Scripting - Third Edition

The ValidatePattern attribute

ValidatePattern is used to test that a string, or the elements in an array of strings, matches the supplied pattern:

function Test-ValidatePattern {    [CmdletBinding()]    param (        [ValidatePattern('^Hello')]        [String]$Parameter1    )}

In addition to the pattern argument, ValidatePattern accepts RegexOptions using the Options named parameter, for example:

function Test-ValidatePattern {    [CmdletBinding()]    param (        [ValidatePattern('^Hello', Options = 'Multiline')]        [String]$Parameter1    )}

The possible values for Options are described by the System.Text.RegularExpressions.RegexOptions enumeration, which is documented in the .NET reference (https://docs.microsoft.com/en-us/dotnet/api/system.text.regularexpressions.regexoptions?view=netframework-4.7.2 ...