Find-NthIndexOf.ps1
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<#PSScriptInfo
.Version 1.1 .Guid a4de76e8-d5c6-4592-8b04-324acbe17355 .Author Thomas Malkewitz @dotps1 .Tags Regex, Index .ProjectUri https://github.com/dotps1/PSFunctions .ReleaseNotes Move escaping the regex value from begin block to the process block to handle better pipeline support. #> <# .Synopsis Finds the nth index of a char in a string. .Description Finds the nth index of a char in a string, returns -1 if the char does not exist, or if nth is out of range. .Inputs System.Int System.String .Outputs System.Int .Parameter Target System.String The string to evaluate. .Parameter Value System.String The character to locate. .Parameter Nth System.Int the occurrence of the character to find. .Parameter IgnoreCase Preforms a case insensitive regex match. .Example PS C:\> Find-NthIndexOf -Target "CN=me,OU=Users,DC=domain,DC=org" -Value "=" -Nth 2 8 .Example PS C:\> ($dn = "CN=dotps1,OU=Users,DC=domain,DC=org").SubString((Find-NthIndexOf -Target $dn -Value "=" -Nth 2) - 2) OU=Users,DC=domain,DC=org .Example PS C:\> Find-NthIndexOf -Target "Hello World." -Value "w" -IgnoreCase 6 .Notes Returns -1 if the char does not exist, or if nth is out of range. .Link http://stackoverflow.com/questions/186653/c-sharp-indexof-the-nth-occurrence-of-a-string .Link https://dotps1.github.io .Link https://www.powershellgallery.com/packages/Find-NthIndexOf .Link https://grposh.github.io #> [CmdletBinding()] [OutputType( [Int] )] param ( [Parameter( Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true )] [String[]] $Target, [Parameter( Mandatory = $true, ValueFromPipelineByPropertyName = $true )] [ValidateLength( 1,1 )] [ValidateNotNullOrEmpty()] [String] $Value, [Parameter( ValueFromPipelineByPropertyName = $true )] [Int] $Nth = 1, [Parameter()] [Switch] $IgnoreCase ) process { $Value = [Regex]::Escape( $Value ) foreach ($targetValue in $Target) { $regex = "(($Value).*?){$Nth}" if ($IgnoreCase.IsPresent) { $regex = $regex.Insert( 0, "(?i)" ) } $match = [Regex]::Match( $targetValue, $regex ) if ($match.Success) { Write-Output -InputObject $match.Groups[2].Captures[$Nth - 1].Index } else { Write-Output -InputObject -1 } } } |