share/WinGit/environment.inc.iss

   1 // Returns the value(s) of the environment variable "VarName", which is tokenized
   2 // by ";" into an array of strings. This makes it easy query PATH-like variables
   3 // in addition to normal variables. If "AllUsers" is true, the common variables
   4 // are searched, else the user-specific ones.
   5 function GetEnvStrings(VarName:string;AllUsers:Boolean):TArrayOfString;
   6 var
   7     Path:string;
   8     i:Longint;
   9     p:Integer;
  10 begin
  11     Path:='';
  12
  13     // See http://www.jrsoftware.org/isfaq.php#env
  14     if AllUsers then begin
  15         // We ignore errors here. The resulting array of strings will be empty.
  16         RegQueryStringValue(HKEY_LOCAL_MACHINE,'SYSTEM\CurrentControlSet\Control\Session Manager\Environment',VarName,Path);
  17     end else begin
  18         // We ignore errors here. The resulting array of strings will be empty.
  19         RegQueryStringValue(HKEY_CURRENT_USER,'Environment',VarName,Path);
  20     end;
  21
  22     // Fallback for built-in variables which are not stored in the Registry.
  23     if Length(Path)=0 then begin
  24         Path:=ExpandConstant('{%'+VarName+'}');
  25     end;
  26
  27     // Make sure we have at least one semicolon.
  28     Path:=Path+';';
  29
  30     // Split the directories in PATH into an array of strings.
  31     i:=0;
  32     SetArrayLength(Result,0);
  33
  34     p:=Pos(';',Path);
  35     while p>0 do begin
  36         SetArrayLength(Result,i+1);
  37         if p>1 then begin
  38             Result[i]:=Copy(Path,1,p-1);
  39             i:=i+1;
  40         end;
  41         Path:=Copy(Path,p+1,Length(Path));
  42         p:=Pos(';',Path);
  43     end;
  44 end;
  45
  46 // Sets the contents of the specified environment variable for the current process.
  47 function SetEnvironmentVariable(lpName,lpValue:String):Boolean;
  48 #ifdef UNICODE
  49 external 'SetEnvironmentVariableW@Kernel32.dll stdcall delayload';
  50 #else
  51 external 'SetEnvironmentVariableA@Kernel32.dll stdcall delayload';
  52 #endif
  53
  54 // Sets the environment variable "VarName" to the concatenation of "DirStrings"
  55 // using ";" as the delimiter. If "AllUsers" is true, a common variable is set,
  56 // else a user-specific one. If "DeleteIfEmpty" is true and "DirStrings" is
  57 // empty, "VarName" is deleted instead of set if it exists.
  58 function SetEnvStrings(VarName:string;AllUsers,DeleteIfEmpty:Boolean;DirStrings:TArrayOfString):Boolean;
  59 var
  60     Path,KeyName:string;
  61     i:Longint;
  62 begin
  63     // Merge all non-empty directory strings into a PATH variable.
  64     Path:='';
  65     for i:=0 to GetArrayLength(DirStrings)-1 do begin
  66         if Length(DirStrings[i])>0 then begin
  67             if Length(Path)>0 then begin
  68                 Path:=Path+';'+DirStrings[i];
  69             end else begin
  70                 Path:=DirStrings[i];
  71             end;
  72         end;
  73     end;
  74
  75     // See http://www.jrsoftware.org/isfaq.php#env
  76     if AllUsers then begin
  77         KeyName:='SYSTEM\CurrentControlSet\Control\Session Manager\Environment';
  78         if DeleteIfEmpty and (Length(Path)=0) then begin
  79             Result:=(not RegValueExists(HKEY_LOCAL_MACHINE,KeyName,VarName)) or
  80                          RegDeleteValue(HKEY_LOCAL_MACHINE,KeyName,VarName);
  81         end else begin
  82             Result:=RegWriteStringValue(HKEY_LOCAL_MACHINE,KeyName,VarName,Path);
  83         end;
  84     end else begin
  85         KeyName:='Environment';
  86         if DeleteIfEmpty and (Length(Path)=0) then begin
  87             Result:=(not RegValueExists(HKEY_CURRENT_USER,KeyName,VarName)) or
  88                          RegDeleteValue(HKEY_CURRENT_USER,KeyName,VarName);
  89         end else begin
  90             Result:=RegWriteStringValue(HKEY_CURRENT_USER,KeyName,VarName,Path);
  91         end;
  92     end;
  93
  94     // Also update the environment of the current process.
  95     SetEnvironmentVariable(VarName,Path);
  96 end;