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

[Branko BURDIAN]

Simple example;

program SetEnv;
{$APPTYPE CONSOLE}
uses
  Windows;
procedure SetEnvVariable(const AName, AValue: string);
begin
  if Trim(AValue) = '' then
    SetEnvironmentVariable(PChar(AName), nil)
  else
  SetEnvironmentVariable(PChar(AName), PChar(AValue));
end;
begin
  SetEnvVariable('foobar', 'abcdef');
end;

Compile and run program:

C:\>SetEnv <Enter>
C:\>set foobar <Enter>
foobar=abcdes   <= This is the result of "set foobar" command

Result of runing program SetEnv is same as if you execute
"set foobar=abcdef" (without ") on command prompt!!

Best regards 
Branko


  ----- Original Message ----- 
  From: tim11g 
  To: delphi-en@yahoogroups.com 
  Sent: Saturday, August 16, 2008 7:16 PM
  Subject: [delphi-en] Re: Set Environment Variable from Delphi Console App


  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
  > 



   

  __________ NOD32 3360 (20080815) Informacija __________

  To sporoèilo je preveril protivirusni sistem NOD32.
  http://www.nod32.com


[Non-text portions of this message have been removed]