[NTG-context] Update setpath to set the path

9 May 2021

      Thoughts on updating the setpath.bat file to persist setting the path?

Here's an updated version that sets the system environment variable while
preserving the existing unexpanded PATH value:

rem SOF
echo off
set OWNPATH=%~dp0
set PLATFORM=mswin

if defined ProgramFiles(x86)                        set PLATFORM=win64
if "%PROCESSOR_ARCHITECTURE%"=="AMD64"              set PLATFORM=win64
if exist "%OWNPATH%tex\texmf-mswin\bin\context.exe" set PLATFORM=mswin
if exist "%OWNPATH%tex\texmf-win64\bin\context.exe" set PLATFORM=win64

echo %PATH% | findstr "texmf-%PLATFORM%" > nul

rem Only update the PATH if not previously updated
if ERRORLEVEL 1 (
  set Key="HKLM\SYSTEM\CurrentControlSet\Control\Session
Manager\Environment"
  set "CurrPath="
  for /F "USEBACKQ tokens=2*" %%A in (`reg query %%Key%% /v PATH`) do (
    if not "%%~B" == "" (
      rem Preserve the existing PATH
      echo %%B > currpath.txt

      rem Update the current session
      set PATH=%PATH%;%OWNPATH%tex\texmf-%PLATFORM%\bin

      rem Change the PATH environment variable
      setx PATH "%%B;%OWNPATH%tex\texmf-%PLATFORM%\bin" /M
    )
  )
)
rem EOF

Another possibility would be to define CONTEXT_HOME as an unexpanded value
added to both the system environment variables and  the PATH variable. For
example (haven't tried it):

setx CONTEXT_HOME "%OWNPATH%tex\texmf-%PLATFORM%\bin"
setx PATH "%%B;%%CONTEXT_HOME%%"

The advantage with this pattern is that subsequent updates need only check
for CONTEXT_HOME and change its value without having to worry about PATH
parsing, which can be hairy.

Yet another option to consider is changing the value for only the existing
user, rather than system-wide. Perhaps two different batch files?

The reason for this change is because the Windows installation instructions
(on the wiki) are incomplete: technically, the user must run setpath.bat
for each new session. This implies that any third-party program that wants
to make use of ConTeXt on Windows would have to communicate said fact to
the user, or let the user set the full path to ConTeXt within the
third-party program. Both of these can be avoided by persisting the PATH
setting across sessions.

Thank you!

P.S.
Pasted: https://pastebin.com/qpsqXZNB

[NTG-context] Update setpath to set the path

Thangalin