Use-RegEx.ps1
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function Use-RegEx { <# .Synopsis Uses a saved regular expression. .Description Uses a saved regular expression, or an expression provided with -Parameter. Use-RegEx is normally called with an alias that is the name of a saved RegEx, for example: ?<Digits> .Link Get-RegEx .Link Write-RegEx .Example "abc" | Use-RegEx -Pattern '.' .Example 'true', 'false', 'neither' | ?<TrueOrFalse> # ?<TrueOrFalse> is a saved RegEx and alias to Use-RegEx .Example $txt = "true or false or true or false" $m = $txt | ?<TrueOrFalse> -Count 1 do { $m $m = $m | ?<TrueOrFalse> -Count 1 -Scan } while ($m) # Looping over each match until non are found. ?<TrueOrFalse> is an alias to Use-RegEx #> [CmdletBinding(DefaultParameterSetName='Pattern')] [OutputType([Text.RegularExpressions.Match], [string], [PSObject])] [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSPossibleIncorrectComparisonWithNull", "", Justification="This is explicitly checking for null (lazy -If would miss 0)")] [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSAvoidAssignmentToAutomaticVariable", "", Justification="Risk understood and behavior is desired")] param( # One or more strings to match. [Parameter(Mandatory=$true,ParameterSetName='Text',ValueFromPipeline,Position=0)] [Parameter(ParameterSetName='Pattern',Position=0,ValueFromPipelineByPropertyName)] [Alias('InputObject','Text', 'Matches','Value')] [string[]]$Match, # If set, will return a boolean indicating if the regular expression matched [switch]$IsMatch, # If set, will measure the number of matches. [switch]$Measure, # The count of matches to return, or the number of matches split or replaced. [Alias('Number')] [int]$Count = 0, # The starting position of the match [Parameter(ValueFromPipelineByPropertyName)] [Alias('StartingAt')] [int]$StartAt = 0, # If set, will remove the regular expression matches from the text. [switch]$Remove, # If set, will replace the text with a replacement string. # For more information about replacement strings, see: # https://docs.microsoft.com/en-us/dotnet/standard/base-types/substitutions-in-regular-expressions [string]$Replace, [switch]$Scan, # If provided, will replace the match if any of the conditions exist. [ValidateScript({ foreach ($kv in $_.GetEnumerator()) { if ($kv.Key -isnot [ScriptBlock]) { throw "Keys must be ScriptBlocks" } } return $true })] [Collections.IDictionary] $ReplaceIf, # If provided, will each match will be passed to the Replacer ScriptBlock. # The values returned from this script block will replace the match. [Alias('Replacer','Evaluator')] [ScriptBlock]$ReplaceEvaluator, # If set, will split the input text according to the expression. [switch]$Split, # If set, will get the text until the expression. [switch]$Until, # If -IncludeMatch and -Until are provided, will include the match with the result of -Until. # If -IncludeMatch and -Split are provided, will include the matches with the result of -Split. # If neither -Split or -Until is provided, this parameter is ignored. [Alias('IncludingMatch')] [switch]$IncludeMatch, # If set, will trim returned strings. [switch]$Trim, # If set, will extract capture groups into a custom object. [switch]$Extract, # If provided, will transform each match with a replacement string. # For more information about replacement strings, see: # https://docs.microsoft.com/en-us/dotnet/standard/base-types/substitutions-in-regular-expressions [string]$Transform, # If provided, will cast named capture groups to a given type. This implies -Extract. [ValidateScript({ foreach ($kv in $_.GetEnumerator()) { if ($kv.Key -isnot [string]) { throw "Keys must be a string" } if ($kv.Value -isnot [type] -and $kv.Value -isnot [ScriptBlock]) { throw "Values must be a type or Script Block" } } return $true })] [Alias('Cast')] [Collections.IDictionary]$Coerce, # If provided, will filter the extracted data of a match. [ScriptBlock] $Where, # One or more conditions. If the condition is true, the value will be returned. # If the value is a script block, it will be executed. # If the value is a string, it will be treated as a Replacement string (like -Transform). [ValidateScript({ foreach ($kv in $_.GetEnumerator()) { if ($kv.Key -isnot [ScriptBlock]) { throw "Keys must be ScriptBlocks" } } return $true })] [Collections.IDictionary]$If, # The regular expression options, by default, IgnoreCase and IgnorePatternWhitespace [Alias('Options')] [Text.RegularExpressions.RegexOptions] $Option = 'IgnoreCase, IgnorePatternWhitespace', # If set, will go from right to left, instead of left to right. [switch] $RightToLeft, # The match timeout. By default, five seconds. [Timespan] $Timeout = "00:00:05", # Indicates that the cmdlet makes matches case-sensitive. By default, matches are not case-sensitive. [switch]$CaseSensitive, # A regular expression. [Parameter(ParameterSetName='Pattern',ValueFromPipelineByPropertyName)] [Alias('Expression')] [string]$Pattern, # A pattern generator. This script will generate a regular expression [ScriptBlock] $Generator, # Named parameters for the regular expression. These are only valid if the regex is a Generator. [Alias('ExpressionParameters')] [Collections.IDictionary] $ExpressionParameter = @{}, # A list of arguments. These are only valid if the regex is using a Generator script. [Alias('ExpressionArguments','ExpressionArgs')] [PSObject[]]$ExpressionArgumentList = @() ) dynamicParam { $myInv = $MyInvocation # If we didn't have a regex library if (-not $script:_RegexLibrary -or -not $script:_RegexLibrary.Count) { # it could be because we're invoke in a place where $script: variables aren't accessible. if ($myInv.MyCommand.Module) { # If that's the case, and this command is within a module $script:_RegexLibrary = @{} # then we can try to look at the RegexLibraryMetadata to reconstruct out regex liberary $regexMetadata = . $myInv.MyCommand.Module {$_RegexLibraryMetadata} if ($regexMetadata -and $regexMetadata.getEnumerator) { # If we found metadata foreach ($kv in $regexMetadata.GetEnumerator()) { # Walk over each piece of metadata $script:_RegexLibrary[$kv.Key] = # the key format is the same for RegexLibrary. # If the value has a pattern, it's a RegEx if ($kv.Value.Pattern) { [Regex]::new($kv.Value.Pattern, 'IgnoreCase,IgnorePatternWhitespace','00:00:05') } # If the path was like *.ps1, it's a RegEx Generator. elseif ($kv.Value.Path -like '*.ps1') { $ExecutionContext.SessionState.InvokeCommand.GetCommand($kv.Value.Path, 'ExternalScript') } } } } if (-not $script:_RegexLibrary) { $script:_RegexLibrary = @{} } } # Then, determine what the name of the pattern in the library would be. $mySafeName = if ('.', '&' -contains $myInv.InvocationName -and ( $myInv.Line.Substring($MyInvocation.OffsetInLine) -match '^\s{0,}\?\<(?<Name>\w+)\>' ) -or ( $myInv.Line.Substring($MyInvocation.OffsetInLine) -match '^\s{0,}\$\{\?\<(?<Name>\w+)\>\}' ) ) { $matches.Name } else { $myInv.InvocationName -replace '\W', '' } # Find the regex in the library. $regex = $script:_RegexLibrary[$mySafeName] $DynamicParameterNames = @() if ($regex -isnot [Management.Automation.ExternalScriptInfo]) { return } $generator = $regex $generatorMetaData = [Management.Automation.CommandMetaData]$generator $DynamicParameters = [Management.Automation.RuntimeDefinedParameterDictionary]::new() foreach ($kv in $generatorMetaData.Parameters.GetEnumerator()) { $DynamicParameters.Add($kv.Key, [Management.Automation.RuntimeDefinedParameter]::new( $kv.Value.Name, $kv.Value.ParameterType, $kv.Value.Attributes ) ) } $DynamicParameterNames = $DynamicParameters.Keys -as [string[]] return $DynamicParameters } begin { if ($DynamicParameterNames) { foreach ($dynamicParameterName in $DynamicParameterNames) { if ($PSBoundParameters.ContainsKey($DynamicParameterName)) { $ExpressionParameter[$dynamicParameterName] = $PSBoundParameters[$dynamicParameterName] } } } # Now figure out if we'll be extracting later $isExtracting = $MyInvocation.InvocationName -eq '.' -or $Extract -or $coerce.Count -or $If.Count # If -Where or -If was provided, we need to recreate the script blocks for $_ to work. if ($Where) { $where = [ScriptBlock]::Create($Where) } # In order for $_ to work correctly, # we need to recreate any script block parameters passed within dictionaries. # Rather than write this three times, let's loop over each collection foreach ($coll in $if, $ReplaceIf, $Coerce) { if (-not $coll) { continue } foreach ($k in @($coll.Keys)) { $v = $coll[$k] if ($v -is [ScriptBlock]) { $v = [ScriptBlock]::Create($v) } $coll.Remove($k) if ($k -is [ScriptBlock]) { $k = [ScriptBlock]::Create($k) } $coll[$k] = $v } } #region [ScriptBlock]$ExtractMatch $extractMatch = { process { $m = $_ $xm = [Ordered]@{} foreach ($g in $m.Groups) { if ($g.Name -as [int] -ge 1) { continue } $gcv = foreach ($gc in $g.Captures) { $gc.Value } if ($Coerce -and $Coerce.$($g.Name) -is [type]) { $xm[$g.Name] = foreach ($v in $gcv) { $v -as $Coerce.$($g.Name) } } elseif ($Coerce -and $Coerce.$($g.Name) -is [ScriptBlock]) { $xm[$g.Name] = foreach ($v in $gcv) { $_ = $v; & $Coerce.$($g.Name) $v } } else { $xm[$g.Name] = $gcv # set it in $matches } } $xm.Match = $m $xm.PSTypeName = 'Irregular.Match.Extract' [PSCustomObject]$xm } } #endregion [ScriptBlock]$ExtractMatch #region [ScriptBlock]$FilterMatches $FilterMatches = { process { if ($_ -is [Boolean] -or $_ -is [string]) { return $_ } $currentMatch = $_ $MatchMetaData = [Ordered]@{ StartIndex = $_.Index EndIndex = $_.Index + $_.Length Input = $_.Result('$_') } if ($isExtracting -or $Where) { $xm = $currentMatch | & $extractMatch } if ($where) { $this = $_ = $xm $IsThere = . $where $in if (-not $IsThere) { return } $_ = $currentMatch } if ($transform) { return . $decorateString $currentMatch.Result($transform) $matchMetaData } if ($if.Count) { $in = $_ = $xm foreach ($ifCondition in $if.GetEnumerator()) { $ifResult = & $ifCondition.Key $in if ($ifResult) { if ($ifCondition.Value -is [ScriptBlock]) { $_ = $xm . $ifCondition.Value $in } elseif ($ifCondition.Value -is [string]) { . $decorateString $currentMatch.Result($ifCondition.Value) $matchMetaData } else { $ifCondition.Value } } } return } if ($isextracting) { return $xm } if ($currentMatch.psobject.properties['EndIndex'] -isnot [PSScriptProperty]) { # add on two script properties we might want: $currentMatch.psobject.properties.Remove('EndIndex') # EndIndex $currentMatch.psobject.properties.add([PSScriptProperty]::new('EndIndex', { $this.Index + $this.Length })) } if ($currentMatch.psobject.properties['Input'] -isnot [PSScriptProperty]) { $currentMatch.psobject.properties.Remove('Input') $currentMatch.psobject.properties.add([PSScriptProperty]::new('Input', { $this.Result('$_') })) # and Input. } if ($inputObject -and $inputObject -ne $currentMatch.Input) { $currentMatch.psobject.Properties.Remove('InputObject') $currentMatch.psobject.properties.add([PSNoteProperty]::new('InputObject', $inputObject)) } else { $currentMatch.psobject.Properties.Remove('InputObject') $currentMatch.psobject.properties.add([PSAliasProperty]::new('InputObject', 'Input')) } return $currentMatch } } #endregion [ScriptBlock]$FilterMatches #region [ScriptBlock]$DecorateString $DecorateString = { param( [string]$string, [Collections.IDictionary]$property = @{}) if ($trim) { $string = $string.Trim() } $psString = [PSObject]::new($string) foreach ($kv in $property.GetEnumerator()) { $psString.psobject.properties.add([PSNoteProperty]::new($kv.Key, $kv.Value)) } $psString } #endregion [ScriptBlock]$DecorateString } process { #region Prepare Input $in = $inputObject = $_ if ($_.Input) { # First we want to see if the piped in object had an input property. $match = $_.Input # If it did, we're using it to cheat in the value to -Match. } if ($in -is [IO.FileInfo]) { # If the input was a file, $match = [IO.File]::ReadAllText($in.FullName) # we want to match the file contents } if ($in -is [Management.Automation.ExternalScriptInfo]) { # If we were passed an external script $match = "{$($in.ScriptContents)}" # we want to match it's contents. } if ($in -is [Management.Automation.FunctionInfo]) { # If we're passed a function, $match = "function $($in.Name) {$($in.ScriptBlock)}" # we want to match the definition. } if ($in -is [ScriptBlock]) { $match = "{$in}" } if ($_ -is [Text.RegularExpressions.Match] -and -not $StartAt) { # If the input was a [Match] and we don't have a start if (-not $_.psobject.properties['EndIndex']) { # add on two script properties we might want: $_.psobject.properties.add( # EndIndex [PSScriptProperty]::new('EndIndex', { $this.Match.Index + $this.Match.Length }) ) } if (-not $_.psobject.properties['Input']) { $_.psobject.properties.add( # and Input. [PSScriptProperty]::new('Input', { $this.Match.Result('$_') }) ) } if ($Scan) { $startAt = $_.Index + $_.Length } } #endregion Prepare Input #region Initialize Regular Expression # If the saved RegEx is a generator if ($regex -is [Management.Automation.ExternalScriptInfo] -or $regex -is [ScriptBlock]) { if ($generator -and $mySafeName -and $mySafeName -ne ($MyInvocation.MyCommand.Name -replace '\W', '')) { Write-Error "Will not override ?<$mySafeName>" -ErrorId RegEx.No.Override -Category InvalidOperation return } $Generator = if ($regex -is [Management.Automation.ExternalScriptInfo]) { $regex.ScriptBlock } else { $regex } } if ($Generator) { # (or one was provided) $regex = & $Generator @ExpressionArgumentList @ExpressionParameter # run the generator. if ($regex -and $mySafeNAme -and -not "$regex".StartsWith("(?<$mySafeName") -and -not $mySafeName -eq 'UseRegEx') { $regex = "(?<$mySafeName>$($regex;[Environment]::NewLine;))" } } if ($Pattern) { # If we've been provided a pattern # and it would overriding something if ($mySafeName -and $mySafeName -ne ($MyInvocation.MyCommand.Name -replace '\W', '')) { Write-Error "Will not override ?<$mySafeName>" -ErrorId RegEx.No.Override -Category InvalidOperation return } if ($pattern -match '^\?\<(?<Name>\w+)\>' -and $script:_RegexLibrary) { $pattern = $script:_RegexLibrary.($matches.Name) } # If we didn't have to warn them, we've propably piped in a [Regex] or the output of Write-Regex. $regex = [Regex]::new($Pattern, 'IgnoreCase,IgnorePatternWhitespace') } if (-not $regex) { return } # If for any reason our regex is invalid, return. if ($RightToLeft) { # If we're going RightToLeft $Option = $Option -bor 'RightToLeft' # adjust the Regex options if ($StartAt -and $_.EndIndex -eq $startAt -and $_.Index -ne $null) { # and adjust the start if needed. $startAt = $_.Index } if (-not $startAt -and $_.EndIndex) { return } } if ($CaseSensitive) { # If we're using CaseSensitive, $option = $option -bxor 'IgnoreCase' # adjust the RegEx options. } # Then recreate the regex with the new options and timeout $regex = [Regex]::new("$regex", $Option, $Timeout) if (-not $regex) { return } # If for any reason our regex is invalid, return. #endregion Initialize Regular Expression if (-not $Match) { # If we haven't been given any text to match $regex.pstypenames.add('Irregular.Regular.Expression') # decorate the Regex for the formatter. return $regex # and return it. This will let "true" -match (?<TrueOrFalse>) be valid PowerShell. } $OriginalStartAt = $StartAt foreach ($m in $Match) { # Walk over each text we're supposed to match $$, $methodArgs = $null, $null if ($RightToLeft -and -not $OriginalStartAt) { $startAt = $m.Length } if ($until) { # If we're matching until that point $matches = $regex.Match($m, $StartAt) # find the first match after StartAt. if (-not $matches.Success) { continue } # If the match failed, continue. if ($measure) { if ($RightToLeft) { $startAt - ($matches.Index - $matches.Length) } else { $matches.Index - $startAt } continue } $ei = # Determine the EndIndex if ($IncludeMatch) { # ( if we're including the match $matches.Index + $matches.Length # its the end of the match, } else { $matches.Index # otherwise, it's the start of the match). } if ($startAt, ($ei - $startAt) -lt 0) { continue } # Then get the substring and decorate it with the following properties: . $DecorateString ($m.Substring($startAt, $ei - $startAt)) ([Ordered]@{ StartIndex = $startAt # | StartIndex| The Start Index | EndIndex = $ei # | EndIndex| The End Index | Input = $matches.Result('$_') # | Input | The Match Input String | }) } elseif ($Split) { # If we're splitting, we get the matches. # (this lets us -IncludeMatch and sidestep a .NET bug when splitting -RightToLeft) $matches = @($regex.Matches($M,$StartAt) | & $filterMatches) $upTo = if ($Count) { $count } else {$matches.Count} $commonInfo = [Ordered]@{Input=$m;InputObject=$in} if ($RightToLeft) { $s = if ($startAt -ne $m.Length) { $startAt } else { $m.Length } for ($mc=0;$mc -lt $upTo;$mc++) { $me = $matches[$mc].Index + $matches[$mc].Length if ($me -lt $s) { . $decorateString $m.Substring($me, $s - $me) } if ($IncludeMatch) { . $decorateString $matches[$mc] ([Ordered]@{ StartIndex = $matches[$mc].Index EndIndex = $matches[$mc].Index + $matches[$mc].Length } + $commonInfo) } $s = $matches[$mc].Index } if ($s -gt 0) { . $decorateString $m.Substring(0, $s) } } else { $s = $startAt for ($mc=0;$mc -lt $upTo;$mc++) { if ($matches[$mc].Index - $s) { . $decorateString $m.Substring($s, $matches[$mc].Index - $s) } if ($IncludeMatch) { . $decorateString $matches[$mc] ([Ordered]@{ StartIndex = $matches[$mc].Index EndIndex = $matches[$mc].Index + $matches[$mc].Length } + $commonInfo) } $s = $matches[$mc].Index + $matches[$mc].Length } if ($s -ne $m.Length) { . $decorateString $m.Substring($s) } } } elseif ($Remove -or $Replace -or $ReplaceEvaluator -or $ReplaceIf.Count) { $$ = 'Replace' $methodArgs = @( $M if ($remove) { '' } elseif ($Replace) { $Replace } elseif ($ReplaceEvaluator) { $ReplaceEvaluator } elseif ($ReplaceIf) { { $tm = $($args[0]) $xm = $($tm | & $filterMatches | & $extractMatch ) foreach ($kv in $ReplaceIf.GetEnumerator()) { $_ = $xm $kvR = . $kv.Key $xm if ($kvR) { if ($kv.Value -is [ScriptBlock]) { return "$(. $kv.Value $xm)" } return $tm.Result("$($kv.Value)") } } return "$tm" } } if ($Count) { $Count } else { [int]::MaxValue } $StartAt ) } elseif ($IsMatch) { $$= 'IsMatch' $methodArgs = @($M;$StartAt) } elseif ($Count) { $$ =0 $methodArgs = @($M;$StartAt) $matches = $regex.Match.Invoke($methodArgs) if ($Measure) { $t = 0 } while ($matches.Success -and $$ -lt $Count) { if (-not $measure) { $matches | & $filterMatches } else { $t++ } $$++ $matches = $matches.NextMatch() } if ($measure) { $t } } else { $$ = 'Matches' $methodArgs = @($M;$StartAt) } if ($regex.$$ -and $methodArgs) { if ($measure) { @($regex.$$.Invoke($methodArgs)).Length } else { & { try { $regex.$$.Invoke($methodArgs) } catch { $PSCmdlet.WriteError([Management.Automation.ErrorRecord]::new($_.Exception, 'Regular.Expression.Error', 'NotSpecified', $inputObject)) } } | & $filterMatches } } } } } |