[delphi-en] Re: Set Environment Variable from Delphi Console App

[tim11g]

Branko,

Thanks for the reply. A call to the SetEnvirontVariable function is
part of the SetGlobalEnvironment function I got from the link to
swissdelphicenter. Just to be sure, I made the simplest program using
only your function:

{$APPTYPE CONSOLE}
program Date2Env;   {Set todays date as a string into environment}
uses
  windows,messages,sysutils,registry;
var
   env_var    :  string[40];
   datestr           : string[10];


procedure SetEnvVariable(const AName, AValue: string);
 begin
 if Trim(AValue) = '' then
 SetEnvironmentVariable(PChar(AName), nil)
 else
 SetEnvironmentVariable(PChar(AName), PChar(AValue));
 end;

begin

   env_var := Paramstr(1);
   if (paramcount < 1 ) then begin
      writeln('Usage: Date2Env EnvVar');
      halt(1);
      end;

   DateStr := FormatDateTime('yymmdd',Date);
   writeln('Writing ',DateStr,'  to env variable: "', env_var,'"');
   SetEnvVariable(env_var,DateStr);

end.

Then I created a simple batch file to test it:

set f
set foobar=abcdef
set f
set foobar=
set f
Date2Env foobar
set f


Here are the results:

C:\Data\DELPHI\ConsUtil>testdate2env.bat

C:\Data\DELPHI\ConsUtil>set f
FP_NO_HOST_CHECK=NO

C:\Data\DELPHI\ConsUtil>set foobar=abcdef

C:\Data\DELPHI\ConsUtil>set f
foobar=abcdef
FP_NO_HOST_CHECK=NO

C:\Data\DELPHI\ConsUtil>set foobar=

C:\Data\DELPHI\ConsUtil>set f
FP_NO_HOST_CHECK=NO

C:\Data\DELPHI\ConsUtil>Date2Env foobar
Writing 080816  to env variable: "foobar"

C:\Data\DELPHI\ConsUtil>set f
FP_NO_HOST_CHECK=NO


The set foobar=abcdef command in the batch file does set the variable. 
My program does not set the environment variable. The SET f displays
all environment variables starting with "f".

I think the problem is that Date2Env gets a private set of environment
variables when it runs. That is where the function
SetEnvironmentVariable writes to. When Date2Env ends, that private
environment is eliminated. That is why I was trying to write to the
Global Environment, which persists after a program runs. But even with
the SendMessage, which is supposed to update the Windows environment
so running processes are aware of the change, it still doesn't work
for a batch file for some reason. 

Thanks,
Tim.





--- In delphi-en@yahoogroups.com, "Branko BURDIAN" <[EMAIL PROTECTED]>
wrote:
>
> Uses
>     Windows, ...;
> 
> ...
> 
> procedure SetEnvVariable(const AName, AValue: string);
> begin
>   if Trim(AValue) = '' then
>     SetEnvironmentVariable(PChar(AName), nil)
>   else
>     SetEnvironmentVariable(PChar(AName), PChar(AValue));
> end;
> ...
> 
> Best regards
> Branko
>