Test if a File is Binary

###############################################################################################################
# Language     :  PowerShell 4.0
# Filename     :  Test-IsFileBinary.ps1
# Autor        :  BornToBeRoot (https://github.com/BornToBeRoot)
# Description  :  Test if a file is binary
# Repository   :  https://github.com/BornToBeRoot/PowerShell
###############################################################################################################

<#
    .SYNOPSIS
        Test if a file is binary

    .DESCRIPTION
        Test if a file is binary like .exe or .zip.

	    I found this code snippet on Stackoverflow:
	    https://stackoverflow.com/questions/1077634/powershell-search-script-that-ignores-binary-files

    .EXAMPLE
        Test-IsFileBinary -FilePath "E:\Temp\Files\File_01.txt"
	    False

	.EXAMPLE
        Test-IsFileBinary -FilePath "E:\Temp\Files\File_04.zip"
        True

    .LINK
        https://github.com/BornToBeRoot/PowerShell/blob/master/Documentation/Function/Test-IsFileBinary.README.md
#>
function Test-IsFileBinary
{
    [CmdletBinding()]
    [OutputType('System.Boolean')]
    Param(
        [Parameter(
            Position = 0,
            Mandatory = $true,
            HelpMessage = 'Path to file which should be checked')]
        [ValidateScript({
                if (Test-Path -Path $_ -PathType Leaf)
                {
                    return $true
                }
                else
                {
                    throw 'Enter a valid file path!'
                }
            })]
        [String]$FilePath
    )
    process
    {
        # Encoding variable
        $Encoding = [String]::Empty

        # Get the first 1024 bytes from the file
        $ByteCount = 1024

        # $ByteArray = Get-Content -Path $FilePath -Encoding Byte -TotalCount $ByteCount
        $ByteArray = Get-Content -Path $FilePath -AsByteStream -TotalCount $ByteCount

        if ($ByteArray.Count -ge $ByteCount)
        {
            Write-Verbose -Message "Could only read $($ByteArray.Count)/$ByteCount Bytes. File "
        }

        if (($ByteArray.Count -ge 4) -and (('{0:X}{1:X}{2:X}{3:X}' -f $ByteArray) -eq 'FFFE0000'))
        {
            Write-Verbose -Message 'UTF-32 detected!'
            $Encoding = 'UTF-32'
        }
        elseif (($ByteArray.Count -ge 4) -and (('{0:X}{1:X}{2:X}{3:X}' -f $ByteArray) -eq '0000FEFF'))
        {
            Write-Verbose -Message 'UTF-32 BE detected!'
            $Encoding = 'UTF-32 BE'
        }
        elseif (($ByteArray.Count -ge 3) -and (('{0:X}{1:X}{2:X}' -f $ByteArray) -eq 'EFBBBF'))
        {
            Write-Verbose -Message 'UTF-8 detected!'
            $Encoding = 'UTF-8'
        }
        elseif (($ByteArray.Count -ge 2) -and (('{0:X}{1:X}' -f $ByteArray) -eq 'FFFE'))
        {
            Write-Verbose -Message 'UTF-16 detected!'
            $Encoding = 'UTF-16'
        }
        elseif (($ByteArray.Count -ge 2) -and (('{0:X}{1:X}' -f $ByteArray) -eq 'FEFF'))
        {
            Write-Verbose 'UTF-16 BE detected!'
            $Encoding = 'UTF-16 BE'
        }

        if (-not([String]::IsNullOrEmpty($Encoding)))
        {
            Write-Verbose -Message 'File is text encoded!'
            return $false
        }

        # So now we're done with Text encodings that commonly have '0's
        # in their byte steams.  ASCII may have the NUL or '0' code in
        # their streams but that's rare apparently.

        # Both GNU Grep and Diff use variations of this heuristic

        if ($byteArray -contains 0 )
        {
            Write-Verbose -Message 'File is a binary!'
            return $true
        }

        Write-Verbose -Message 'File should be ASCII encoded!'
        return $false
    }
}