JAL-3830 Improved jalview.bat to find either pwsh.exe or powershell.exe, and give...

diff --git a/utils/getdown/bin/jalview.bat b/utils/getdown/bin/jalview.bat
index 428019b..0eca4e4 100755 (executable)
--- a/utils/getdown/bin/jalview.bat
+++ b/utils/getdown/bin/jalview.bat
@@ -1,4 +1,50 @@
 @ECHO OFF
-SET ThisScriptsDirectory=%~dp0
-SET PowerShellScriptPath=%ThisScriptsDirectory%jalview.ps1
-PowerShell -NoProfile -ExecutionPolicy Bypass -Command "& '%PowerShellScriptPath%' %*";
+
+REM This is the Jalview batch script wrapper to run the powershell script of the same name.
+REM There is nothing specific to Jalview.
+
+REM ******************************************************************************
+REM If you need to set a full path to the PowerShell executable please do so here:
+SET PWSHPATH=
+REM ******************************************************************************
+
+REM This is some DOS magic to substitute the extension in the full path of this batch script with .ps1
+SET SCRIPTPATH=%~dpn0.ps1
+
+REM PowerShell script isn't where it should be!
+IF NOT EXIST %SCRIPTPATH% (
+  ECHO Could not find PowerShell script %SCRIPTPATH%.  Is %~nx0 in the right folder?
+  EXIT /B 1
+)
+
+REM Look for either pwsh.exe or powershell.exe if not set in PWSHPATH above.
+REM pwsh.exe is preferred as it is likely to be a newer version.
+SET PWSH=
+IF DEFINED PWSHPATH (
+  SET PWSH=%PWSHPATH%
+)
+FOR %%X IN (pwsh.exe powershell.exe) DO (
+  IF NOT DEFINED PWSH ( 
+    IF NOT "%%~$PATH:X" == "" (
+      REM Found a PowerShell executable in the PATH
+      SET PWSH=%%X
+      GOTO end_looking
+    )
+  )
+)
+:end_looking
+
+IF NOT DEFINED PWSH (
+  REM No PowerShell executable found -- tell the user what to do.
+  ECHO No PowerShell found in %%PATH%%. If PowerShell is installed either
+  ECHO 1. add it to your PATH, or
+  ECHO 2. edit the PWSHPATH value at the top of this file:
+  ECHO    "%~dpnx0"
+  ECHO.
+  ECHO %~n0 on the command line requires PowerShell. To install PowerShell see
+  ECHO https://docs.microsoft.com/en-us/powershell/scripting/install/installing-powershell
+  EXIT /B 2
+)
+
+REM Run the PowerShell script
+%PWSH% -NoProfile -ExecutionPolicy Bypass -Command "& '%SCRIPTPATH%' %*";