//删除文件 DeleteFile; Windows.DeleteFile
var
f: string;
begin
f := 'c:\temp\test.txt';
//DeleteFile(f); //返回 Boolean

//或者用系统API:
Windows.DeleteFile(PChar(f)); //返回 Boolean
end;

======================

function DeleteFile(const FileName: string): Boolean;
begin
{$IFDEF MSWINDOWS}
Result := Windows.DeleteFile(PChar(FileName));
{$ENDIF}
{$IFDEF LINUX}
Result := unlink(PChar(FileName)) <> -1;
{$ENDIF}
end;