Env variable change

Hello
How to set the environment variable through tcl.

setenv <name> <value>

if i execute the same it not working.Is there any specific way in tcl
where in we can set the variable.

Thanks
chendu

Chendu schrieb:
> Hello
> How to set the environment variable through tcl.
>
> setenv <name> <value>
>
> if i execute the same it not working.Is there any specific way in tcl
> where in we can set the variable.
>
set ::env(name) value

e.g.

set ::env(PATH) /usr/local/bin


Michael

Michael Schlenker wrote:
> Chendu schrieb: 
>
> set ::env(name) value

For those that like setenv...

proc setenv {name value} {
set ::env($name) $value
}

Donal.

In article <fae9o7$594$1@godfrey.mcc.ac.uk>,
Donal K. Fellows <donal.k.fellows@manchester.ac.uk> wrote:
>Michael Schlenker wrote: 
>
>For those that like setenv...
>
>   proc setenv {name value} {
>      set ::env($name) $value
>   }
>
>Donal.

Understand, this does NOT set the environment of the process which
*invokes* a Tcl application; the latter is often what questioners
think they want <URL: http://wiki.tcl.tk/4282 >.

Cameron Laird wrote:
> Understand, this does NOT set the environment of the process which
> *invokes* a Tcl application; the latter is often what questioners
> think they want <URL: http://wiki.tcl.tk/4282 >.

Mind you, nothing does except editing a file/registry entry[*] and
restarting the shell or reloading its configuration. This is by
deliberate design, and applies to thing other than Tcl.

Donal.
[* Depending on platform. ]

In article <faemmk$8r8$1@godfrey.mcc.ac.uk>,
Donal K. Fellows <donal.k.fellows@manchester.ac.uk> wrote:
>Cameron Laird wrote: 
>
>Mind you, nothing does except editing a file/registry entry[*] and
>restarting the shell or reloading its configuration. This is by
>deliberate design, and applies to thing other than Tcl.

"Donal K. Fellows" <donal.k.fellows@manchester.ac.uk> wrote:

> Cameron Laird wrote: 
>
> Mind you, nothing does except editing a file/registry entry[*] and
> restarting the shell or reloading its configuration. This is by
> deliberate design, and applies to thing other than Tcl.
>
> Donal.
> [* Depending on platform. ]

Sufficient knowledge of the internal data structures of the platform
lets you do theoretically impossible things.  In my early career as a
software developer, I wrote a large collection of DOS programs that
communicated with each other by manipulating the "root" environment.

(There was much about that project I should have done differently, or
not done at all.  Basing the entire architecture of the user interface
and network communication around the capabilities of a Hercules Network
Card Plus made for a fast and reasonably pretty system, but when the
supply of monochrome monitors started to dry up...)

Alan Anderson wrote:
> Sufficient knowledge of the internal data structures of the platform
> lets you do theoretically impossible things.  In my early career as a
> software developer, I wrote a large collection of DOS programs that
> communicated with each other by manipulating the "root" environment.

You can't do that on "modern" systems, i.e. anything with virtual memory
or real memory protection! You either can't see the root environment at
all, or can't recognize it, or can't write it (the most common case.)

Donal.

Donal K. Fellows wrote:
> Alan Anderson wrote: 
>
> You can't do that on "modern" systems, i.e. anything with virtual memory
> or real memory protection! You either can't see the root environment at
> all, or can't recognize it, or can't write it (the most common case.)

You can, if you have enough privileges -- or at least the right ones.

After all that is how ACPs work.

--
+--------------------------------+---------------------------------------+
| Gerald W. Lester                                                       |
|"The man who fights for his ideals is the man who is alive." - Cervantes|
+------------------------------------------------------------------------+

On Aug 22, 6:43 am, "Gerald W. Lester" <Gerald.Les...@cox.net> wrote:
> Donal K. Fellows wrote: 
> 
>
> You can, if you have enough privileges -- or at least the right ones.
>
> After all that is how ACPs work.
>
> --
> +--------------------------------+---------------------------------------+
> | Gerald W. Lester                                                       |
> |"The man who fights for his ideals is the man who is alive." - Cervantes|
> +------------------------------------------------------------------------+

i am able to set env variable and able to get it with in the same tcl
script .

But if i want to access in the value in other tcl script with out
editing the shell rc file.

Is there any way
Process:
1.I would open a shell.
2.run a tcl script to set a env variable
3.run a second tcl script to accss the env  variable set by 1st
script.

i tried using as in wiki
source export myvar=<value>
but i am not able to get it. basically i am not able to get what
export does.

Thanks
chendu