How to set windows environment variable In tcl script

Question

I am working on a Tcl script in which I have a variable and I just want to keep its value alive after the completion of its execution, so I am trying to define a windows environment variable by executing the set windows command within the script using the exec function.

I have also tried to find the solution through google but that too didn't work. Here is the line of code which I have tried

exec set verName=$xVar

It would be great if you can help me. Thanks in advance.

`set env(YOUR_VARIABLE) value` will set the environmental variable and it is available only during the execution. i.e. It is temporary, not a permanent. — Dinesh, Jun 03 '16 at 12:07

score 2 · Answer 1 · edited May 23 '17 at 11:55

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First, read this question and its accepted answer: Set a persistent environment variable from cmd.exe

How do you do that from Tcl? Well, the standard registry package gives you the tools:

package require registry

set root {HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment}
set theVariable "ABCDE"
set theValue "12345XYZ"

registry set $root\\$theVariable $theValue
registry broadcast "Environment"

The manual page for the registry package has a specific example for using this with the PATH. Updating to other variables is trivial. The script will need to be run in a session with Administrator privileges in order to update that part of the registry.

edited May 23 '17 at 11:55

Community

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answered Jun 03 '16 at 12:43

Donal Fellows

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This won't affect the calling process, though. Unless it is Explorer. – Joey Jun 03 '16 at 13:03
@Joey That depends on whether the process listens for the `WM_SETTINGSCHANGED` event and acts on it right. – Donal Fellows Jun 03 '16 at 14:21
indeed, but to a first approximation Explorer is about the only process that does that. – Joey Jun 03 '16 at 14:24

score 0 · Answer 2 · answered Jun 06 '16 at 16:47

0

catch {exec cmd /C "setX $variable_name $valueToSet"}

answered Jun 06 '16 at 16:47

Ulysses

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How to set windows environment variable In tcl script

2 Answers2