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. .PARAMETER HexString A string or string array that you want tested to determine if is a valid hexadecimal string .PARAMETER IncludeInput Switch that will include the input parameters in the output .PARAMETER AllowPrefix Switch that accepts '#' or '0x' as valid characters that can begin the HexString .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 ($IncludeInput) { New-Object -TypeName psobject -Property ([ordered] @{Input="$h"; AllowPrefix=$true; Result=$true; Decimal=$n}) } 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)]" } } |