PowerShell · Armaan Mcleod (ArmaanMcleod) · Oct 23, 2023 · Oct 23, 2023 · Oct 27, 2023 · Oct 27, 2023
@@ -0,0 +1,71 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.IO;
+using System.Management.Automation;
+using System.Text;
+
+namespace Microsoft.PowerShell.Commands
+{
+    /// <summary>
+    /// This class implements the Get-FileEncoding command.
+    /// </summary>
+    [Cmdlet(VerbsCommon.Get, "FileEncoding", DefaultParameterSetName = PathParameterSet, HelpUri = "https://go.microsoft.com/fwlink/?LinkID=1234567")]
+    [OutputType(typeof(Encoding))]
+    public sealed class GetFileEncodingCommand : PSCmdlet
+    {
+        #region Parameter Sets
+
+        private const string PathParameterSet = "ByPath";
+        private const string LiteralPathParameterSet = "ByLiteralPath";
+
+        #endregion
+
+        #region Parameters
+
+        /// <summary>
+        /// Gets or sets path from from which to get encoding.
+        /// </summary>
+        [Parameter(Position = 0, Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true, ParameterSetName = PathParameterSet)]
+        public string Path { get; set; }
+
+        /// <summary>
+        /// Gets or sets literal path from which to get encoding.
+        /// </summary>
+        [Parameter(Position = 0, Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true, ParameterSetName = LiteralPathParameterSet)]
+        [Alias("PSPath", "LP")]
+        public string LiteralPath
+        {
+            get
+            {
+                return _isLiteralPath ? Path : null;
+            }
+
+            set
+            {
+                Path = value;
+                _isLiteralPath = true;
+            }
+        }
+
+        private bool _isLiteralPath;
+
+        #endregion
+
+        /// <summary>
+        /// Process paths to get file encoding.
+        /// </summary>
+        protected override void ProcessRecord()
+        {
+            string resolvedPath = PathUtils.ResolveFilePath(Path, this, _isLiteralPath);
+
+            if (!File.Exists(resolvedPath))
+            {
+                ItemNotFoundException exception = new(Path, "PathNotFound", SessionStateStrings.PathNotFound);
+                ThrowTerminatingError(exception.ErrorRecord);
+            }
+
+            WriteObject(PathUtils.GetPathEncoding(resolvedPath));
+        }
+    }
+}
@@ -25,7 +25,7 @@ CmdletsToExport = @(
   'Get-TraceSource', 'Set-TraceSource', 'Add-Type', 'Get-TypeData', 'Remove-TypeData', 'Update-TypeData',
   'Get-UICulture', 'Get-Unique', 'Get-Uptime', 'Clear-Variable', 'Get-Variable', 'New-Variable',
   'Remove-Variable', 'Set-Variable', 'Get-Verb', 'Write-Verbose', 'Write-Warning', 'Invoke-WebRequest',
-  'Format-Wide', 'ConvertTo-Xml', 'Select-Xml', 'Get-Error', 'Update-List', 'Unblock-File'
+  'Format-Wide', 'ConvertTo-Xml', 'Select-Xml', 'Get-Error', 'Update-List', 'Unblock-File', 'Get-FileEncoding'
 )
 FunctionsToExport = @()
 AliasesToExport = @('fhx')

@@ -24,7 +24,7 @@ CmdletsToExport = @(
   'Add-Type', 'Get-TypeData', 'Remove-TypeData', 'Update-TypeData', 'Get-UICulture', 'Get-Unique', 'Get-Uptime',
   'Clear-Variable', 'Get-Variable', 'New-Variable', 'Remove-Variable', 'Set-Variable', 'Get-Verb', 'Write-Verbose',
   'Write-Warning', 'Invoke-WebRequest', 'Format-Wide', 'ConvertTo-Xml', 'Select-Xml', 'Get-Error', 'Update-List',
-  'Out-GridView', 'Show-Command', 'Out-Printer'
+  'Out-GridView', 'Show-Command', 'Out-Printer', 'Get-FileEncoding'
 )
 FunctionsToExport = @()
 AliasesToExport = @('fhx')

@@ -1241,13 +1241,6 @@ internal TranscriptionOption()
         /// </summary>
         internal void FlushContentToDisk()
         {
-            static Encoding GetPathEncoding(string path)
-            {
-                using StreamReader reader = new StreamReader(path, Encoding.Default, detectEncodingFromByteOrderMarks: true);
-                _ = reader.Read();
-                return reader.CurrentEncoding;
-            }
-
             lock (OutputBeingLogged)
             {
                 if (!_disposed)
@@ -1256,7 +1249,7 @@ static Encoding GetPathEncoding(string path)
                     {
                         try
                         {
-                            var currentEncoding = GetPathEncoding(this.Path);
+                            var currentEncoding = PathUtils.GetPathEncoding(this.Path);
 
                             // Try to first open the file with permissions that will allow us to read from it
                             // later.

@@ -869,6 +869,13 @@ private static bool IsDirectorySeparator(char c)
             return c == Path.DirectorySeparatorChar || c == Path.AltDirectorySeparatorChar;
         }
 
+        internal static Encoding GetPathEncoding(string path)
+        {
+            using StreamReader reader = new(path, Encoding.Default, detectEncodingFromByteOrderMarks: true);
+            _ = reader.Read();
+            return reader.CurrentEncoding;
+        }
+
         #endregion
     }
 }
@@ -0,0 +1,45 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+Describe "Get-FileEncoding" -Tags "CI" {
+    BeforeAll {
+        $testFilePath = Join-Path -Path $TestDrive -ChildPath test.txt
+        $testFileLiteralPath = Join-Path -Path $TestDrive -ChildPath "[test].txt"
+        $content = 'abc'
+
+        $testCases = @(
+            @{ EncodingName = 'ansi'; ExpectedEncoding = 'utf-8' }
+            @{ EncodingName = 'ascii'; ExpectedEncoding = 'utf-8' }
+            @{ EncodingName = 'bigendianunicode'; ExpectedEncoding = 'utf-16BE' }
+            @{ EncodingName = 'bigendianutf32'; ExpectedEncoding = 'utf-32BE' }
+            @{ EncodingName = 'oem'; ExpectedEncoding = 'utf-8' }
+            @{ EncodingName = 'unicode'; ExpectedEncoding = 'utf-16' }
+            @{ EncodingName = 'utf8'; ExpectedEncoding = 'utf-8' }
+            @{ EncodingName = 'utf8BOM'; ExpectedEncoding = 'utf-8' }
+            @{ EncodingName = 'utf8NoBOM'; ExpectedEncoding = 'utf-8' }
+            @{ EncodingName = 'utf32'; ExpectedEncoding = 'utf-32' }
+        )
+    }
+
+    It "Validate Get-FileEncoding using -Path returns file encoding for '<EncodingName>'" -TestCases $testCases {
+        param($EncodingName, $ExpectedEncoding)
+        Set-Content -Path $testFilePath -Encoding $EncodingName -Value $content -Force
+        (Get-FileEncoding -Path $testFilePath).BodyName | Should -Be $ExpectedEncoding
+        (Get-ChildItem -Path $testFilePath | Get-FileEncoding).BodyName | Should -Be $ExpectedEncoding
+    }
+
+    It "Validate Get-FileEncoding using -LiteralPath returns file encoding for '<EncodingName>'" -TestCases $testCases {
+        param($EncodingName, $ExpectedEncoding)
+        Set-Content -LiteralPath $testFileLiteralPath -Encoding $EncodingName -Value $content -Force
+        (Get-FileEncoding -LiteralPath $testFileLiteralPath).BodyName | Should -Be $ExpectedEncoding
+        (Get-ChildItem -LiteralPath $testFileLiteralPath | Get-FileEncoding).BodyName | Should -Be $ExpectedEncoding
+    }
+
+    It "Should throw exception if path is not found using -Path" {
+        { Get-FileEncoding -Path nonexistentpath } | Should -Throw -ErrorId 'PathNotFound,Microsoft.PowerShell.Commands.GetFileEncodingCommand'
+    }
+
+    It "Should throw exception if path is not found using -LiteralPath" {
+        { Get-FileEncoding -LiteralPath nonexistentpath } | Should -Throw -ErrorId 'PathNotFound,Microsoft.PowerShell.Commands.GetFileEncodingCommand'
+    }
+}
@@ -310,6 +310,7 @@ Describe "Verify aliases and cmdlets" -Tags "CI" {
 "Cmdlet",       "Get-EventSubscriber",              "",                                 $($FullCLR -or $CoreWindows -or $CoreUnix),     "",                     "",                     "None"
 "Cmdlet",       "Get-ExecutionPolicy",              "",                                 $($FullCLR -or $CoreWindows -or $CoreUnix),     "",                     "",                     "None"
 "Cmdlet",       "Get-ExperimentalFeature",          "",                                 $(             $CoreWindows -or $CoreUnix),     "",                     "",                     "None"
+"Cmdlet",       "Get-FileEncoding",                 "",                                 $(             $CoreWindows -or $CoreUnix),     "",                     "",                     "None",
 "Cmdlet",       "Get-FileHash",                     "",                                 $(             $CoreWindows -or $CoreUnix),     "",                     "",                     "None"
 "Cmdlet",       "Get-FormatData",                   "",                                 $($FullCLR -or $CoreWindows -or $CoreUnix),     "",                     "",                     "None"
 "Cmdlet",       "Get-Help",                         "",                                 $($FullCLR -or $CoreWindows -or $CoreUnix),     "",                     "",                     "None"