Subj : Directory Listing
To : Robert Wolfe
From : mark lewis
Date : Thu Nov 27 2014 05:46 pm
On Thu, 27 Nov 2014, Robert Wolfe wrote to All:
RW> I am trying to get a listing of files in the currently logged
RW> directory and output those to a text file.
ok, that's simple enough...
RW> However, I cannot seem to figure out how to do this with the
RW> FindFirst() and FindNext() functions in FreePascal. The example I
RW> tried to base my own code on is as follows:
[chomp]
RW> Unfortunately, I was not able to get my example (which follows) to
RW> work:
RW> Procedure GenDirFile ;
RW> Var SR: TSearchRec ;
RW> DirList: TStrings;
RW> Path: String;
RW> DirFile: Text;
RW> Begin ;
RW> Assign(DirFile, 'directory.lst') ;
RW> Rewrite(DirFile) ;
RW> DirList := TStringsList.Create;
RW> if FindFirst('*.zip', faArchive, SR) = 0 then
RW> begin
RW> repeat
RW> WriteLn(DirFile, SR.Name);
RW> until FindNext(SR) <> 0;
RW> FindClose(SR);
RW> end;
RW> Close(DirFile);
RW> End ;
RW> Is there something I am doing wrong here?
ok, there's several things going on here... i won't step through all of them
but since you are attempting to use tstrings, let's go a little further and use
a tstringlist instead... mainly because tstrings is designed to be inherited by
other objects whch perform specialized tasks... tstringlist is one such
object...
the second thing is that you're not doing anything with the DirList that you've
created... you are, however, attempting to write the filenames directly to your
output file... that's ok but since we're using the tstringlist, all that stuff
is done for you...
there's a few other things but for now, let's look at this...
1. create our tstringlist object
2. fill our object with the files returned by findfirst/findnext
3. when all files are found, write our stringlist to a file
nice and easy... especially since the stringlist object already does a huge
amount of heavy lifting for us ;)
so here's the full code (!) of a working program... this was done on a vista
machine using FPC's trunk code (FPC 2.7.1) from their repository... i also
tested it on OS/2 eCS with FPC 2.6.4 and on a Linux with FPC 2.6.5 (the fixes
branch of FPC 2.6)...
===== snip =====
program DirectoryList;
// we need the following unit libraries
uses Sysutils, Classes;
// Sysutils for findfirst and friends
// Classes for TStringList and friends
Procedure GenDirFile;
Var SR: TSearchRec;
DirList: TStringList;
Begin;
// create the class to hold the returned filenames
DirList := TStringList.Create;
// let's sort the list
DirList.Sorted := True;
if FindFirst('*.*', faArchive, SR) = 0 then
begin
repeat
// add the returned filename to the list
DirList.Add(SR.Name);
until FindNext(SR) <> 0;
// all done, close the find handle
FindClose(SR);
end;
// now let's write our list of filenames to a text file.
DirList.SaveToFile('directory.lst');
End ;
begin
GenDirFile;
end.
===== snip =====
RW> Any help anyone can give would be greatly appreciated.
how's that? ;)
(!) please try to reduce the problem to the minimal code needed for a working
program that shows the failure or problem. partial code is ok in some cases but
that'll come later ;)
)\/(ark
If you think it's expensive to hire a professional to do the job, wait until
you hire an amateur.
