Functions/Test-IsHexString.ps1
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Function Test-IsHexString { <# .SYNOPSIS Tests to determine if a string is a valid hexadecimal number. Can optionally include a prefix of '0x' or '#' .DESCRIPTION Tests to determine if a string is a valid hexadecimal number. Can optionally include a prefix of '0x' or '#'. Can accept a string, an array of strings, or pipeline input. .EXAMPLE Test-IsHexString '123abc' True .EXAMPLE Test-IsHexString 'lmnop' False .EXAMPLE test-ishexstring @('0x1','#1abcdef','3c') -IncludeInput -AllowPrefix Input AllowPrefix Result ----- ----------- ------ 0x1 True True #1abcdef True True 3c True True .EXAMPLE Test-IsHexString '123abc' -Verbose VERBOSE: $h is [123abc] True #> [CmdletBinding(ConfirmImpact='None')] [OutputType('bool')] Param ( [parameter(ValueFromPipeLine,ValueFromPipeLineByPropertyName)] [Alias('Hex')] [string[]] $HexString, [switch] $IncludeInput, [switch] $AllowPrefix ) begin { Write-Verbose -Message "Starting $($MyInvocation.Mycommand)" $regexPrefix = '^(#|0x)?[0-9,a-f]*$' $regexNoPrefix = '^[0-9,a-f]*$' write-verbose -Message "`$regexPrefix is [$regexPrefix]" write-verbose -Message "`$regexNoPrefix is [$regexNoPrefix]" write-verbose -Message "`$AllowPrefix is $AllowPrefix" write-verbose -Message "`$IncludeInput is $IncludeInput" } Process { foreach ($h in $HexString) { $h = $h.Trim() write-verbose -Message "`$h is [$h]" if ($AllowPrefix) { if ($h -match $regexPrefix) { write-verbose -Message 'match' $n = [convert]::ToInt32(($h -replace '^(0x|#)', ''),16) write-verbose -Message "`$n is [$n]" if ($IncludeInput) { new-object -TypeName psobject -Property @{Input="$h"; AllowPrefix=$true; Result=$true; Decimal=$n} | select-object -Property Input, AllowPrefix, Result, Decimal } else { Write-Output -inputobject $true } } else { write-verbose -Message 'no match' if ($IncludeInput) { new-object -TypeName psobject -Property @{Input="$h"; AllowPrefix=$true; Result=$false; Decimal=$null} | select-object -Property Input, AllowPrefix, Result, Decimal } else { Write-Output -inputobject $false } } } else { if ($h -match $regexNoPrefix) { write-verbose -Message 'match' $n = [convert]::ToInt32(($h -replace '^(0x|#)', ''),16) write-verbose -Message "`$n is [$n]" if ($IncludeInput) { new-object -TypeName psobject -Property @{Input="$h"; AllowPrefix=$false; Result=$true; Decimal=$n} | select-object -Property Input, AllowPrefix, Result, Decimal } else { Write-Output -inputobject $true } } else { write-verbose -Message 'no match' if ($IncludeInput) { new-object -TypeName psobject -Property @{Input="$h"; AllowPrefix=$false; Result=$false; Decimal = $null} | select-object -Property Input, AllowPrefix, Result, Decimal } else { Write-Output -inputobject $false } } } } } End { Write-Verbose -Message "Ending $($MyInvocation.Mycommand)" } } |