ICS FTP - Function to check if folder exists on the ftp server - delphi

Question

I'm trying to create a function to check if a folder exists using Overbyte ICS FTP component.Using the DIR command from the icsftp does not display anything in my memo log.
I'm interested in parsing the result of the dir command into a stringlist in order to search for a specific folder.
For the moment I use an indy function like this. How can I make the same thing with ICS?
function exista_textul_in_stringlist(const stringul_pe_care_il_caut:string; stringlistul_in_care_efectuez_cautarea:Tstringlist):boolean;
begin
if stringlistul_in_care_efectuez_cautarea.IndexOf(stringul_pe_care_il_caut) = -1 then
begin
result:=false;
//showmessage('Textul "'+text+'" nu exista!' );
end
else
begin
result:=true;
//showmessage('Textul "'+text+'" exista la pozitia '+ inttostr(ListBox.Items.IndexOf(text)));
end;
end;
function folder_exists_in_ftp(folder_name_to_search_for,ftp_hostname,ftp_port,ftp_username,ftp_password,ftp_root_folder:string;memo_loguri:Tmemo):boolean;
Var
DirList : TStringList;
ftp:Tidftp;
antifreeze:TidAntifreeze;
var i,k:integer;
begin
dateseparator:='-';
Result := False;
DirList := TStringList.Create;
ftp:=tidftp.Create;
antifreeze:=TidAntifreeze.Create;
try
antifreeze.Active:=true;
ftp.Host:=ftp_hostname;
ftp.Port:=strtoint(ftp_port);
ftp.username:=ftp_username;
ftp.password:=ftp_password;
ftp.Passive:=true;
ftp.Connect;
ftp.ChangeDir(ftp_root_folder);
ftp.List(DirList, folder_name_to_search_for, True);
if DirList.Count > 0 then begin
k := DirList.Count;
DirList.Clear; // DIRLIST will hold folders only
for i := 0 to k - 1 do begin
if (ftp.DirectoryListing.Items[i].FileName <> '.') and (ftp.DirectoryListing.Items[i].FileName <> '..') then begin
if ftp.DirectoryListing.Items[i].ItemType = ditDirectory then begin
DirList.Add(ftp.DirectoryListing.Items[i].FileName);
end;
end;
end;
end;
if exista_textul_in_stringlist(folder_name_to_search_for,DIRLIST) then
begin
Result := True;
memo_loguri.Lines.Add(datetimetostr(now)+' - caut folderul "'+folder_name_to_search_for+'" in directorul ftp "'+ftp_root_folder+'" => EXISTS!');
end
ELSE
begin
result:=false;
memo_loguri.Lines.Add(datetimetostr(now)+' - caut folderul "'+folder_name_to_search_for+'" in directorul ftp "'+ftp_root_folder+'" => NOT exists!');
end;
finally
ftp.Free;
antifreeze.Free;
DirList.Free;
end;
end;

Answer 1

I assume you are using the latest released version of OverbyteIcs (ICS-V8.16 (Apr, 2015)).
If you just need to check if a remote directory exists its a good recommendation mentioned in the other answer to avoid a list (it could be a time consuming operation if a lot of files and folders are returned).
I suggest you just try to be "optimistic" and change to the remote dir you wish to investigate using FTP.Cwd. If this call return true the folder of course exists, and if you plan to continue with the same client you have to change back to the original dir. On the other hand, if the call fails, the directory does not exist if the ftp server reponds with code 550.
I have included a simple sample doing the above (however, it does not provide the "change-back-to-original-dir-on-success" feature):
uses
...
OverbyteIcsFtpCli;
function FtpRemoteDirExists(
HostName: String;
UserName: String;
Password: String;
HostDirToCheck : String ) : Boolean;
const
cFtpCode_FileOrDirNotExists = 550;
var
FTP: TFtpClient;
begin
FTP := TFtpClient.Create(nil);
try
FTP.HostName := HostName;
FTP.Passive := True;
FTP.Binary := True;
FTP.Username := UserName;
FTP.Password := Password;
FTP.Port := '21';
if not FTP.Open then
raise Exception.Create('Failed to connect: ' + FTP.ErrorMessage);
if (not FTP.User) or (not FTP.Pass) then
raise Exception.Create('Failed to login: ' + FTP.ErrorMessage);
FTP.HostDirName := HostDirToCheck;
if FTP.Cwd then
Result := True
else
begin
if FTP.StatusCode = cFtpCode_FileOrDirNotExists then
Result := False
else
raise Exception.Create('Failed to change dir: ' + FTP.ErrorMessage);
end;
finally
FTP.Free;
end;
end;

Answer 2

You better use a command like SIZE (TFtpClient.Size) or MLST (TFtpClient.Mlst) to check for file existence.
Using LIST is quite an overkill.