Add Install-IronPython.ps1 (#1433)

* Add Install-IronPython.ps1

* Update to work on macOS

* Update to work on Linux

* Update after review

Author: BCSharp

Src/Scripts/Install-IronPython.ps1

@@ -0,0 +1,101 @@
+#!/usr/bin/env pwsh
+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the Apache 2.0 License.
+# See the LICENSE file in the project root for more information.
+
+<#
+.SYNOPSIS
+    Install IronPython 3 for .NET 6 from an official zip file distributable.
+
+.DESCRIPTION
+    This script facilitates installation of IronPython on .NET 6 binaries from a zip file. The zip file is assumed to have content as published on the IronPython's download page. The zip file is produced by IronPython's "package" build target.
+
+.EXAMPLE
+    PS>./make
+    PS>./make package
+    PS>./Src/Scripts/Install-IronPython.ps1 env
+
+    These commands should be issued on a Powershell prompt with the current directory set to the project root.
+    The project is first built, then packaged, and finally the script uses the zipfile produced during packaging to install IronPython in directory "env"
+
+.EXAMPLE
+
+    PS>Invoke-WebRequest -Uri https://github.com/IronLanguages/ironpython3/releases/download/v3.4.0-beta1/IronPython.3.4.0-beta1.zip -OutFile IronPython.3.4.0-beta1.zip
+    PS>Install-IronPython -Path ~/ipyenv/v3.4.0-beta1 -ZipFile IronPython.3.4.0-beta1.zip -Force
+
+    The official binaries are downloaded from GitHub to the current directory and then the installation proceeds using the downloaded zip file. IronPython is installed into ~/ipyenv/v3.4.0-beta1, overwriting any previous installation in that location.
+    This example assumes that the installation script is in a directory on the search path ($env:PATH).
+#>
+[CmdletBinding()]
+Param(
+    # Target directory to which IronPython is to be installed.
+    [Parameter(Position=0, Mandatory)]
+    [SupportsWildcards()]
+    [string] $Path,
+
+    # The path to the downloaded zip file with IronPython binaries. If empty, the script will try to grab the package directly produced by the local build.
+    [string] $ZipFile,
+
+    # If the target path exists, it will be wiped clean beforehand.
+    [switch] $Force
+)
+
+$ErrorActionPreference = "Stop"
+
+$defaultVersion = "3.4.0-beta1"
+
+if (-not $ZipFile) {
+    # If zipfile path not given, assume that the script is in the standard location within the source tree
+    # and locate the zip archive in the standard location of the package target.
+    $projectRoot = $PSScriptRoot | Split-Path | Split-Path
+    $ZipFile = Join-Path $projectRoot "Package/Release/Packages/IronPython-$defaultVersion/IronPython.$defaultVersion.zip"
+}
+
+if (Test-Path $Path) {
+    if ($Force) {
+        if ((Resolve-Path $Path).Count -gt 1) {
+            Write-Error "Overwriting of multiple destinations not allowed: $Path"
+        }
+        Remove-Item -Path $Path -Force -Recurse
+    } else {
+        Write-Error "Path already exists: $Path"
+    }
+}
+
+# Unzip archive and move files into place
+$unzipDir = Join-Path $Path "zip"
+
+Expand-Archive -Path $ZipFile -DestinationPath $unzipDir
+Move-Item -Path (Join-Path $unzipDir "Lib") -Destination $Path
+Move-Item -Path (Join-Path $unzipDir "net6.0/*") -Destination $Path -Exclude "*.xml","*.dll.config"
+Remove-Item -Path $unzipDir -Recurse
+
+# Create a startup script
+$ipyPath = Join-Path $Path "ipy.ps1"
+Set-Content -Path $ipyPath -Value @'
+#!/usr/bin/env pwsh
+dotnet (Join-Path $PSScriptRoot ipy.dll) @args
+'@
+if ($IsMacOS -or $IsLinux) {
+    chmod +x $ipyPath
+}
+
+# Add items that are missing in the zip file, directly from the bin directory
+if ($projectRoot) {
+    $binPath = Join-Path $projectRoot "bin/Release/net6.0"
+    Copy-Item (Join-Path $binPath "ipy") $Path
+    if ($IsMacOS -or $IsLinux) {
+        Copy-Item (Join-Path $binPath "Mono.Unix.dll") $Path
+        $arch = uname -m
+        switch ($arch) {
+            "x86_64" { $arch = "x64" }
+        }
+        if ($IsMacOS) {
+            $os = "osx"
+        } else {
+            $os = "linux"
+        }
+        $libs = Join-Path $binPath "runtimes" "$os-$arch" "native/*" -Resolve
+        Copy-Item $libs $Path
+    }
+}