So i have a 'downloads' folder where i put everything i download in my day by day work. You know we always automate everything, so I'm trying to build a simply app to run everyday to delete files older than 30 days, as i have to do this manually from time to time to avoid the folder become too big.
Here is my code :
function TForm1.deleteOldDownloads: boolean;
var
f: string;
i, d: Integer;
var
sl: tstringlist;
begin
try
FileListBox1.Directory := '\\psf\home\downloads';
FileListBox1.refresh;
sl := tstringlist.create;
for i := 0 to FileListBox1.items.count - 1 do
begin
f := FileListBox1.Directory + '\' + FileListBox1.items[i];
if fileexists(f) then
d := daysbetween(FileAge(f), now)
else
d := 0;
if d > 30 then // problem is here, d is always a big number, not the actually age of file
sl.Add(f);
end;
if sl.count > 0 then
begin
for i := 0 to sl.count do
begin
f := sl[i];
deletefile(f);
end;
end;
sl.Free;
except
on e: Exception do
begin
end;
end;
Problem is "d" variable is returning very big numbers like 1397401677, even if the file has only 1 day.
The only detail here is i run Windows in a Parallels virtual machine and the "\psf\home\downloads" folder is on Mac, but i can access this folderl normally using Windows Explorer, so for Delphi is like a regular local folder.
What am i missing ?
Did you read the documentation for FileAge
? The first day in programming school, you are taught "When you start using a new function or API, you begin by reading its documentation." In this case, the function's documentation says
The [one-argument] overloaded version of
FileAge
is deprecated.
So you are using a function you shouldn't be using.
Still, this function should probably still work.
But what do you expect it to return? Well, obviously the thing that the docs say it should return:
The first overload returns an integer that represents the OS time stamp of the file. The result can be later converted to a
TDateTime
using theFileDateToDateTime
function.
But when you use this in DaysBetween
, you assume it already is a TDateTime
!
Why is FileAge returning unexpected values?
It isn't. It is probably returning exactly the thing its documentation says it should return.