Using Environment Variables (preferably Windows)

[WickedDum]

Greetings!

Being told to use the directories that Windows dictates, sent me on a journey.  (Due credit to Leonard Nimoy) I went In Search of... how to use the variables and realized I should know what all of the variables are to avail myself of them in the future.  I have compiled a list of Environment Variables for Windows and flavors of UNIX.  I would like to get it checked for accuracy/completeness.  How might I accomplish that?

I believe the list is fairly complete, BUT:  I still don't know how to use them!!

I have found multiple discussions/examples if I were using the command line, but I have resigned myself to using the GUI.

Any and all assistance would be GREATLY appreciated!!!

Thank you!

[Phil]

To see what environment variables are defined on any system, open a command prompt window (Windows) or terminal window (OS X, Linux) and enter set. That will display PATH, etc. settings.

For example, to get the PATH in order to do something with it in your program, use GetEnvironmentVariable('PATH') .

[howardpc]

How long is a piece of string?
Any user anywhere can define his/her own environment variable.

To see the environment on your machine, Lazarus provides a simple listing.
View -> IDE Internals -> About IDE, the General tab has a section headed
  Environment variables:

[Remy Lebeau]

Being told to use the directories that Windows dictates, sent me on a journey.

When dealing with Microsoft-dictated folders, you should be using Win32 APIs that are specialized to return those specific paths directly (SHGetFolderPath(), SHGetKnownFolderPath(), etc).  Don't use environment variables for them.

[WickedDum]

Thank you!

@Phil - I didn't realize that all of the environment variables were set by default.

@howardpc - About this long:
GetEnvironmentVariable('PATH') is what I was looking for!!  Thanks!

@Remy Lebeau - Win32 APIs...even on a 64bit system?  How do you use them (SHGetFolderPath(), SHGetKnownFolderPath(), etc)?

Thank you for your input!!!

[Remy Lebeau]

@Remy Lebeau - Win32 APIs...even on a 64bit system?

Yes. It it is same API on 32bit and 64bit systems.

How do you use them (SHGetFolderPath(), SHGetKnownFolderPath(), etc)?

Did you read their documentation yet?

https://msdn.microsoft.com/en-us/library/windows/desktop/bb762181.aspx

https://msdn.microsoft.com/en-us/library/windows/desktop/bb762188.aspx

https://msdn.microsoft.com/en-us/library/windows/desktop/bb776911.aspx

Also, FreePascal has a GetWindowsSpecialDir() function:

http://www.freepascal.org/docs-html-3.0.0/rtl/windirs/getwindowsspecialdir.html

[WickedDum]

Good morning!

I read some of the documentation.  (There are a couple of links you missed... ).  Because the examples are in C++, I asked, "How do you use them..."  I probably should have said, "How are they translated into FPC?"  I just figured I would stick with Pascal...one language at a time. 

Besides, if I try to use generic terms to assist in cross-compiling, those Windows functions wouldn't work, would they?

I thought FPC would have the capability.  And...it does! GetWindowsSpecialDir().  Except...I still have to resort to Windows-specific input for that function.

Thanks!

[Thaddy]

The languages are so similar that the msdn documentation (very basic) should be enough. We all - well, all reasonably experienced programmers, do that. Both ways

[howardpc]

The RTL has several cross-platform functions related to environment variables including these:

• GetEnvironmentVariableCount
• GetTempDir
• GetTempFileName
• GetAppConfigDir
• GetUserDir

[WickedDum]

Thanks Guys!

During my readings, I ran across an MSDN page that showed hex values for the CSLID calls.  Now, when I need it, I can't find it...    Anyone have that info?  It would tell me what works and what doesn't.   

@howardpc - Just what I needed.  I am playing around with GetWindowsSpecialDir() and GetEnvironmentVariable() right now - trying to learn which does what.

@Thaddy - Well...  if I was a "reasonably experienced programmer", I wouldn't be posting in a Beginners forum...   

On a personal note:  I've never know MS to do anything basic.  Not even with DOS1.1!!

It's so nice that Microsoft keeps changing everything, isn't it?   

Thanks, again!!

[Phil]

It's so nice that Microsoft keeps changing everything, isn't it?   

You mean the changes they made 20 years ago, right?

[WickedDum]

 

They are still changing things:  Look and feel of their OS's and apps, such as Office, Visual Studio, Serverware, etc., etc.   

[Thaddy]

@Thaddy - Well...  if I was a "reasonably experienced programmer", I wouldn't be posting in a Beginners forum... 

My comment is meant to encourage you to try to gain the needed experience....
msdn C examples are really easy to follow.

[Remy Lebeau]

My comment is meant to encourage you to try to gain the needed experience....
msdn C examples are really easy to follow.

And C is very easy to translate to Pascal.

[WickedDum]

This post should probably change from ENVIRONMENT variables to CSIDL constants...  But they both fall under locating 'system independent' values. 

If it is recommended not to use the CSIDL constants, then why are they required as an input to GetKnownFolderPath or SHGetSpecialFolderPath or some of the other API routines? 

What am I missing here:?

Code: Pascal  [Select][+][-]

1. uses
2.   ..., SHFolder, ShlObj, Windows,  ...;
3.  
4. function GetKnownFolderPath(const folder : KNOWNFOLDERID) : string;
5.  
6. var
7.   path: array [0..MAX_PATH] of char;
8.  
9. begin
10.   if SUCCEEDED(SHGetKnownFolderPath(folder, 0, 0, path)) then
11.   begin
12.     try
13.       Result := path;
14.     finally
15.       CoTaskMemFree(path);
16.     end;
17.   end else
18.     Result := '';
19. end;
20.  
21. dir_programdata:= GetKnownFolderPath(FOLDERID_RoamingAppData);

I try to correct something that won't compile and something else jumps up...

Thanks!