Change the attributes of all files in a drive partition - delphi

Question

To change the attribute of a file is easy with FileSetAttr.
I want to change the attributes of all files located on any partition ("D:" for example).
For the search function I tried:
procedure FileSearch(const PathName, FileName : string) ;
var
Rec : TSearchRec;
Path : string;
begin
Path := IncludeTrailingPathDelimiter(PathName) ;
if FindFirst (Path + FileName, faAnyFile - faDirectory, Rec) = 0 then
try
repeat
ListBox1.Items.Add(Path + Rec.Name) ;
until FindNext(Rec) <> 0;
finally
FindClose(Rec) ;
end;
But how can I use this to traverse the entire drive?

Answer 1

You will indeed need to iterate across the entire drive setting attributes file by file. You will need to modify the code to recurse into sub-directories. And obviously you will actually need to call the function that sets attributes.
The basic approach looks like this:
type
TFileAction = reference to procedure(const FileName: string);
procedure WalkDirectory(const Name: string; const Action: TFileAction);
var
F: TSearchRec;
begin
if FindFirst(Name + '\*', faAnyFile, F) = 0 then begin
try
repeat
if (F.Attr and faDirectory <> 0) then begin
if (F.Name <> '.') and (F.Name <> '..') then begin
WalkDirectory(Name + '\' + F.Name, Action);
end;
end else begin
Action(Name + '\' + F.Name);
end;
until FindNext(F) <> 0;
finally
FindClose(F);
end;
end;
end;
I've written this in a generic way to allow you to use the same walking code with different actions. If you were to use this code you'd need to wrap up the attribute setting code into a procedure which you pass as Action. If you don't need the generality, then remove all mention of TFileAction and replace the call to Action with your attribute setting code. Like this:
procedure WalkDirectory(const Name: string);
var
F: TSearchRec;
begin
if FindFirst(Name + '\*', faAnyFile, F) = 0 then begin
try
repeat
if (F.Attr and faDirectory <> 0) then begin
if (F.Name <> '.') and (F.Name <> '..') then begin
WalkDirectory(Name + '\' + F.Name);
end;
end else begin
DoSetAttributes(Name + '\' + F.Name);
end;
until FindNext(F) <> 0;
finally
FindClose(F);
end;
end;
end;
Expect this to take quite a while when you try to run it on an entire volume. You'll want to do your testing on a directory containing only a few files and a couple of sub-directory levels.
Also, be prepared for your code that modifies attributes to fail for some files. You cannot expect to perform volume wide operations without sometimes encountering failures due to, for instance, security. Make your code robust to such scenarios.