MagicFile.psm1
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<# MagicFile Copyright (C) 2025 Vincent Anso This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. This program was inspired by the file(1) command. Copyright (c) Ian F. Darwin 1986-1995. Software written by Ian F. Darwin and others; maintained 1995-present by Christos Zoulas and others. https://www.darwinsys.com/file/ #> using namespace System.Net.Mime using namespace System.Collections using namespace System.Runtime.InteropServices # Magic flag definitions enum Flags { None = 0x0000000 # No flags Debug = 0x0000001 # Turn on debugging Symlink = 0x0000002 # Follow symlinks Compress = 0x0000004 # Check inside compressed files Devices = 0x0000008 # Look at the contents of devices MimeType = 0x0000010 # Return the MIME type Continue = 0x0000020 # Return all matches Check = 0x0000040 # Print warnings to stderr PreserveAtime = 0x0000080 # Restore access time on exit Raw = 0x0000100 # Don't convert unprintable chars Error = 0x0000200 # Handle ENOENT etc as real errors MimeEncoding = 0x0000400 # Return the MIME encoding Mime = 0x0000410 # Combined MIME type and encoding flags Apple = 0x0000800 # Return the Apple creator/type Extension = 0x1000000 # Return a /-separated list of extensions CompressTransp = 0x2000000 # Check inside compressed files but not report compression NoCompressFork = 0x4000000 # Don't allow decompression that needs to fork NoDesc = 0x1000410 # Combined Extension, MIME, and Apple flags } # Magic flags for disabling specific checks enum FlagsNoCheck { Compress = 0x0001000 # Don't check for compressed files Tar = 0x0002000 # Don't check for tar files Soft = 0x0004000 # Don't check magic entries AppType = 0x0008000 # Don't check application type ELF = 0x0010000 # Don't check for ELF details Text = 0x0020000 # Don't check for text files CDF = 0x0040000 # Don't check for cdf files CSV = 0x0080000 # Don't check for CSV files Tokens = 0x0100000 # Don't check tokens Encoding = 0x0200000 # Don't check text encodings JSON = 0x0400000 # Don't check for JSON files SIMH = 0x0800000 # Don't check for SIMH tape files Builtin = 0x0F7F000 # Combined flags for common disabled checks ASCII = 0x0020000 # Alias for NoCheck.Text Fortran = 0x0000000 # Don't check ASCII/Fortran (no-op) Troff = 0x0000000 # Don't check ASCII/Troff (no-op) } # Flags for disabling specific checks enum NoCheck { ASCII = [FlagsNoCheck]::Text # Alias for text checks Fortran = 0x000000 # Disable Fortran checks Troff = 0x000000 # Disable Troff checks } # Parameters for magic checks enum Params { IndirMax # "Max recursion for indirect magic" NameMax # "Max length for name checks" ELFPhNumMax # "Max ELF program headers" ELFShNumMax # "Max ELF section headers" ELFNotesMax # "Max ELF notes size" RegexMax # "Max regex patterns" BytesMax # "Max bytes to check" EncodingMax # "Max encoding checks" ELFShSizeMax # "Max ELF section size" MagWarnMax # "Max warnings for magic parsing" } enum MagicResult { Error = -1 Success = 0 } # Supported platforms # Darwin-arm64 # Darwin-x86_64 # Linux-aarch64 # Linux-armv7l # Linux-x86_64 # Windows-AMD64 # Windows-ARM64 # Windows-x86 enum OperatingSystem { Darwin Linux Windows } enum Architecture { arm64 x86_64 aarch64 armv7l amd64 x86 } # When $IsWindows doesn't exist on PowerShell 5.x if ($null -eq $PSVersionTable.Platform) { $IsWindows = $true } $platform = [Environment]::OSVersion.Platform if ($platform -eq [PlatformID]::Win32NT) { $currentOperatingSystem = [OperatingSystem]::Windows $currentArchitecture = $env:PROCESSOR_ARCHITECTURE } elseif ($platform -eq [PlatformID]::Unix) { $currentOperatingSystem = $(uname -s) $currentArchitecture = $(uname -m) if ( ($currentArchitecture -eq [Architecture]::aarch64) -and (-Not [Environment]::Is64BitOperatingSystem) ) { $currentArchitecture = [Architecture]::armv7l } } else { Write-Warning "Unsupported platform ($platform)." exit 0 } if ( ([OperatingSystem].GetEnumNames() -notcontains $currentOperatingSystem) -or ([Architecture].GetEnumNames() -notcontains $currentArchitecture) ) { Write-Warning "Unsupported operating system or hardware architecture ($currentOperatingSystem/$currentArchitecture)." exit 0 } $libraries = @{ [OperatingSystem]::Darwin = "libmagic.1.dylib" [OperatingSystem]::Linux = "libmagic.so.1.0.0" [OperatingSystem]::Windows = "libmagic-1.dll" } $libmagic = $libraries[[OperatingSystem]$currentOperatingSystem] $libraryPath = Join-Path -Path $PSScriptRoot -ChildPath "Platforms/$currentOperatingSystem-$currentArchitecture/$libmagic" Write-Debug "libmagic path : $libraryPath" Write-Verbose "Platform : $platform ($currentOperatingSystem/$currentArchitecture)" $sourceCode = @" using System; using System.Collections.Generic; using System.Runtime.InteropServices; public class LibMagic { [StructLayout(LayoutKind.Sequential)] public struct magic_t { public IntPtr Value; } public static List<string> magicFilePath = new List<string>(); public const string LIBRARY_NAME = @"$libraryPath"; // P/Invoke declarations with EntryPoint and simplified method names [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_open")] public static extern magic_t Open(int flags); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_close")] public static extern void Close(magic_t cookie); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_error")] public static extern IntPtr Error(magic_t cookie); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_errno")] public static extern int Errno(magic_t cookie); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_descriptor")] public static extern IntPtr Descriptor(magic_t cookie, int fd); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_file")] public static extern IntPtr File(magic_t cookie, string filename); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_buffer")] public static extern IntPtr Buffer(magic_t cookie, IntPtr buffer, IntPtr length); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_getflags")] public static extern int GetFlags(magic_t cookie); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_setflags")] public static extern int SetFlags(magic_t cookie, int flags); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_check")] public static extern int Check(magic_t cookie, string filename); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_compile")] public static extern int Compile(magic_t cookie, string filename); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_list")] public static extern int List(magic_t cookie, string filename); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_load")] public static extern int Load(magic_t cookie, string filename); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_load_buffers")] public static extern int LoadBuffers(magic_t cookie, IntPtr[] buffers, IntPtr[] sizes, IntPtr nbuffers); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_getparam")] public static extern int GetParam(magic_t cookie, int param, IntPtr value); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_setparam")] public static extern int SetParam(magic_t cookie, int param, IntPtr value); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_version")] public static extern int Version(); [DllImport(LIBRARY_NAME, CallingConvention = CallingConvention.Cdecl, EntryPoint = "magic_getpath")] public static extern IntPtr GetPath(string magicfile, int action); // Utility functions to convert returned IntPtr to string public static string PtrToString(IntPtr ptr) { return ptr == IntPtr.Zero ? null : Marshal.PtrToStringAnsi(ptr); } public static string GetError(magic_t cookie) { return PtrToString(Error(cookie)); } public static int GetErrorNumber(magic_t cookie) { return Errno(cookie); } } "@ class FInfo { [string]$Type [string]$Creator FInfo([string]$LibMagicApple) { $this.Type = $LibMagicApple.Substring(4,4) $this.Creator = $LibMagicApple.Substring(0,4) } [string] ToString() { return "$($this.Creator)$($this.Type)" } } $ExecutionContext.InvokeCommand.ExpandString($sourceCode) | Out-Null Add-Type -TypeDefinition $sourceCode -Language CSharp $contentTypePattern = '^[a-zA-Z0-9!#$%&''*+._-]+/[a-zA-Z0-9!#$%&''*+._-]+$' $magicFile = (Join-Path -Path ".magic"-ChildPath "magic.mgc") function Get-MagicFileVersion { <# .SYNOPSIS Retrieves the version of the libmagic library. #> $version = [LibMagic]::Version() $major = [math]::Floor($version / 100) $minor = $version % 100 [Version]::new($major, $minor) } Write-Verbose "libmagic version : $(Get-MagicFileVersion)" function Initialize-LibMagic { $magic = [LibMagic]::Open([Flags]::None) if ($magic -eq [IntPtr]::Zero) { Write-Error $( [InvalidOperationException]::new("Failed to initialize libmagic.") ) exit 0 } return $magic } function Get-MagicFileContent { <# .SYNOPSIS Shows a list of patterns and their strength sorted descending by magic(4) strength which is used for the matching. #> param( [Parameter(Position = 0, Mandatory = $true)] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string]$FilePath ) $magic = Initialize-LibMagic if ( [LibMagic]::List($magic, $FilePath) -eq [MagicResult]::Error ) { Write-Error $( [InvalidOperationException]::new() ) exit 0 } [LibMagic]::Close($magic) } function Debug-MagicFile { <# .SYNOPSIS Performs detailed debugging of the file type detection process, printing internal diagnostic information about the magic file and its checks. #> param( [Parameter(Position = 0, Mandatory = $true)] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string]$FilePath ) $magic = Initialize-LibMagic $result = $false $flags = [LibMagic]::GetFlags($magic) [LibMagic]::SetFlags($magic, $flags -bor [Flags]::Check -bor [Flags]::Debug ) if ( [LibMagic]::Check($magic, $FilePath) -eq [MagicResult]::Success ) { $result = $true } [LibMagic]::Close($magic) return $result } function Test-MagicFilePath { <# .SYNOPSIS Validates whether a file can be recognized as a valid magic file, based on the predefined magic patterns or user-customized magic files. #> param ( [string[]]$Path ) foreach ($filePath in $Path) { if (Test-Path -LiteralPath $filePath) { Write-Verbose $($filePath + "... yes") [LibMagic]::magicFilePath.Add($filePath) } else { Write-Verbose $($filePath + "... no") } } } function Get-MagicFilePathUnix { if ($IsLinux -or $IsMacOS) { $magicFilePath = @( $(Join-Path -Path $Env:HOME -ChildPath ".magic.mgc") $(Join-Path -Path $Env:HOME -ChildPath $magicFile) $(Join-Path -Path "/usr/local/share/misc/" -ChildPath "magic.mgc") $(Join-Path -Path "/usr/local/share/misc/" -ChildPath "magic") ) Test-MagicFilePath $magicFilePath } } function Get-MagicFilePathWindows { if ($IsWindows) { $magicFilePath = @( $(Join-Path -Path $Env:USERPROFILE -ChildPath "magic.mgc") $(Join-Path -Path $Env:USERPROFILE -ChildPath $magicFile) $(Join-Path -Path $Env:LOCALAPPDATA -ChildPath $magicFile) $(Join-Path -Path $Env:COMMONPROGRAMFILES -ChildPath $magicFile) ) Test-MagicFilePath $magicFilePath } } function Get-MagicFilePath { <# .SYNOPSIS Returns the full paths to the specified magic files, checking system directories or user-defined paths for the magic.mgc. #> [LibMagic]::magicFilePath.Clear() if ($Env:MAGIC) { Test-MagicFilePath $Env:MAGIC } else { Write-Verbose "`Env:MAGIC... no" } if ( $platform -eq [PlatformID]::Unix ) { Get-MagicFilePathUnix } elseif ( $platform -eq [PlatformID]::Win32NT ) { Get-MagicFilePathWindows } Test-MagicFilePath $(Join-Path -Path $PSScriptRoot -ChildPath "magic.mgc") return $([LibMagic]::magicFilePath) } function ConvertTo-MagicFile { <# .SYNOPSIS Converts a file containing a pre-parsed version of the magic file or directory into a compiled .mgc file. #> param( [Parameter(Position = 0, Mandatory = $true)] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string]$FilePath ) $magic = Initialize-LibMagic $result = $false if ( [LibMagic]::Compile($magic, $FilePath) -eq [MagicResult]::Success ) { $result = $true } [LibMagic]::Close($magic) return $result } function Test-MagicFile { <# .SYNOPSIS Validates whether a file can be recognized as a valid magic file. #> param( [Parameter(Position = 0, Mandatory = $true)] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string]$FilePath ) $magic = Initialize-LibMagic $result = $false if ( [LibMagic]::Check($magic, $FilePath) -eq [MagicResult]::Success ) { $result = $true } [LibMagic]::Close($magic) return $result } function Get-MagicFileType { <# .SYNOPSIS Determines the specific type of a file by analyzing its magic number. .INPUTS You can pipe a string that contains a path, but not a literal path, to this function. .PARAMETER Path Specifies a path to a file to be tested. Wildcard characters are permitted. .PARAMETER LiteralPath Specifies a path to be tested. Unlike Path, the value of the LiteralPath parameter is used exactly as it's typed. .PARAMETER IgnoreType Excludes certain tests from determining file type. .PARAMETER FollowSymlink Follow symlinks. .PARAMETER ExpandArchive Check inside compressed files. .PARAMETER InspectArchive Check inside compressed files but not report compression. .PARAMETER PreserveDate Attempt to preserve the access time of files analyzed. .PARAMETER All Finds all matches instead of stopping at the first. #> [CmdletBinding(DefaultParameterSetName = "Path")] param( [Parameter(ParameterSetName = 'Path')] [Parameter(Position = 0, Mandatory = $false, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string[]]$Path, [Parameter(ParameterSetName = 'LiteralPath')] [Parameter(Mandatory = $false)] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string[]]$LiteralPath, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [ValidateSet("Text", "Mime", "Extension", "Apple", IgnoreCase=$false)] [string[]]$FormatType = @("Text", "Mime", "Extension", "Apple"), [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [ValidateSet("AppType", "ASCII", "Tokens", "Encoding", "CDF", "Compress", "CSV", "ELF", "JSON", "Soft", "SIMH", "Tar", "Text", IgnoreCase=$false)] [string[]]$IgnoreType, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [switch]$FollowSymlink, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [switch]$InspectArchive, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [switch]$ExpandArchive, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [switch]$PreserveDate, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [switch]$All, [Parameter(ParameterSetName = 'Path')] [Parameter(ParameterSetName = 'LiteralPath')] [ValidateNotNullOrEmpty()] [ValidateScript({ Test-Path $_ })] [string[]]$MagicFilePath ) BEGIN { $items = [ArrayList]::new() if ($Path) { foreach ($item in $Path) { $paths = Get-Item -Path $item $items.AddRange([Object[]]$paths) } } if ($LiteralPath) { $items = Get-Item -LiteralPath $LiteralPath } if ( [string]::IsNullOrEmpty($MagicFilePath) ) { $MagicFilePath = Get-MagicFilePath } $MagicFilePathFromParts = $($MagicFilePath -join ":") Write-Verbose "magic file from : $MagicFilePathFromParts" $types = @{ Text = [Flags]::None Mime = [Flags]::Mime Extension = [Flags]::Extension Apple = [Flags]::Apple } $magic = Initialize-LibMagic $values = [ArrayList]::new() } PROCESS { foreach ($item in $items) { $entry = New-Object -TypeName PSObject Add-Member -InputObject $entry -MemberType NoteProperty -Name File -Value $item foreach ($type in $FormatType) { $flags = $types[$type] if ( $PSBoundParameters.ContainsKey("FollowSymlink") ) { $flags = $flags -bor [Flags]::Symlink } if ( $PSBoundParameters.ContainsKey("InspectArchive") ) { $flags = $flags -bor [Flags]::Compress -bor [Flags]::CompressTransp } if ( $PSBoundParameters.ContainsKey("ExpandArchive") ) { $flags = $flags -bor [Flags]::Compress } if ( $PSBoundParameters.ContainsKey("PreserveDate") ) { $flags = $flags -bor [Flags]::PreserveAtime } if ( $PSBoundParameters.ContainsKey("All") ) { $flags = $flags -bor [Flags]::Continue } if ($IgnoreType) { foreach($ignoredType in $IgnoreType) { $flags = $flags -bor [FlagsNoCheck]::$ignoredType } } if ( [LibMagic]::SetFlags($magic, $flags) -eq [MagicResult]::Success ) { if ( [LibMagic]::Load($magic, $MagicFilePathFromParts) -eq [MagicResult]::Error ) { $message = [LibMagic]::GetError($magic) Write-Error $( [InvalidOperationException]::new($message) ) [LibMagic]::Close($magic) exit 0 } } else { Write-Error $( [InvalidOperationException]::new("Unable to set flags : $flags") ) [LibMagic]::Close($magic) exit 0 } $fileType = [LibMagic]::File($magic, $($item).ToString() ) $managedString = [LibMagic]::PtrToString($fileType) if ($managedString) { Write-Debug $managedString $strings = $($managedString -split "\\012-") | ForEach-Object { $_.Trim() } } $values = [ArrayList]::new() $value = $null switch ($type) { "Text" { if ($strings) { $values = @($strings) } } "Apple" { if ($strings) { $typeCreators = $($strings -split "\\012-") foreach ($typeCreator in $typeCreators) { $values.Add( [FInfo]::new($typeCreator) ) | Out-Null } } } "Mime" { if ($managedString) { $mimes = $managedString -split ";" $mediaTypes = $(($mimes[0]) -split "\\012-") $charSet = $mimes[1] foreach($mediaItem in $mediaTypes) { $mediaItem = $mediaItem.Trim() if ($mediaItem -match $contentTypePattern) { try { $values.Add( [ContentType]::new($mediaItem + ";" + $charSet) ) | Out-Null } catch { $values.Add( [ContentType]::new($mediaItem) ) | Out-Null } } } } } "Extension" { if ($strings) { foreach($extension in $strings) { $values.Add( $($extension -split "/") ) | Out-Null } } } } if ( $PSBoundParameters.ContainsKey('All') ) { $value = $values } else { $value = $values[0] } Add-Member -InputObject $entry -MemberType NoteProperty -Name $type -Value $value $values = $null } Write-Output $entry } } END { [LibMagic]::Close($magic) } } Set-Alias -Name Get-FileType -Value Get-MagicFileType Set-Alias -Name Get-ItemType -Value Get-MagicFileType Export-ModuleMember -Alias @( 'Get-FileType', 'Get-ItemType' ) Export-ModuleMember -Function @( 'Get-MagicFileType', 'Get-MagicFileVersion', 'Get-MagicFileContent', 'Debug-MagicFile', 'Get-MagicFilePath', 'ConvertTo-MagicFile', 'Test-MagicFile' ) |