I open a command line window, and run the following 6 line program

void main()
{
   string envPath = environment["PATH"];

   writeln("PATH is: ", envPath);

   envPath ~= r";F:\dmd2\windows\bin";

   environment["PATH"] = envPath;

   envPath = environment["PATH"];

   writeln("PATH is: ", envPath);

}

It prints out the following

PATH is: C:\Windows\system32;C:\Windows...
PATH is: C:\Windows\system32;C:\Windows...F:\dmd2\windows\bin

when the program exits, I'm back at the command line and I do a

echo %PATH%

which just shows C:\Windows\system32;C:\Windows...

Anybody know of a way to make the change stick for the lifetime of the
command window?

On 2014-06-25 03:53, WhatMeWorry wrote:
> I open a command line window, and run the following 6 line program
>
> void main()
> {
>     string envPath = environment["PATH"];
>
>     writeln("PATH is: ", envPath);
>
>     envPath ~= r";F:\dmd2\windows\bin";
>
>     environment["PATH"] = envPath;
>
>     envPath = environment["PATH"];
>
>     writeln("PATH is: ", envPath);
>
> }
>
> It prints out the following
>
> PATH is: C:\Windows\system32;C:\Windows...
> PATH is: C:\Windows\system32;C:\Windows...F:\dmd2\windows\bin
>
> when the program exits, I'm back at the command line and I do a
>
> echo %PATH%
>
> which just shows C:\Windows\system32;C:\Windows...
>
> Anybody know of a way to make the change stick for the lifetime of the
> command window?

That's not possible. There is a workaround, DVM does something similar. Although, I don't remember how the code works for Windows but you can have a look at the code [1], or perhaps Nick can explain it.

[1] https://github.com/jacob-carlborg/dvm/blob/master/dvm/commands/Use.d#L34

-- 
/Jacob Carlborg

On Tue, 24 Jun 2014 21:53:51 -0400, WhatMeWorry <kc_heaser@yahoo.com> wrote:

> I open a command line window, and run the following 6 line program
>
> void main()
> {
>     string envPath = environment["PATH"];
>
>     writeln("PATH is: ", envPath);
>
>     envPath ~= r";F:\dmd2\windows\bin";
>
>     environment["PATH"] = envPath;
>
>     envPath = environment["PATH"];
>
>     writeln("PATH is: ", envPath);
>
> }
>
> It prints out the following
>
> PATH is: C:\Windows\system32;C:\Windows...
> PATH is: C:\Windows\system32;C:\Windows...F:\dmd2\windows\bin
>
> when the program exits, I'm back at the command line and I do a
>
> echo %PATH%
>
> which just shows C:\Windows\system32;C:\Windows...
>
> Anybody know of a way to make the change stick for the lifetime of the
> command window?

Only the command shell can change it's own environment. When you execute commands that set an environment variable, those are shell builtins, not external programs.

You can run a batch file (which is not run in a separate process) which sets environment variables. This may be the only way to affect the environment. Basically, have a program run that dictates what to set, builds a batch file, then run that batch file from the command line. This could be done in another batch file.

-Steve