Archived Forum Post

Index of archived forum posts

Question:

PRET support for FTP?

Jul 17 '15 at 11:28

A client of mine receives this error message:

ChilkatLog:
 NumFilesAndDirs:
   DllDate: Jan 21 2015
   ChilkatVersion: 9.5.0.47
   UnlockPrefix: ....
   Username: xxx:xxx
   Architecture: Little Endian; 32-bit
   Language: Visual C++ 9.0 (32-bit)
   VerboseLogging: 0
   fetchDirListing:
     supportsMLSD: 1
     fetchDirListing2:
       setupDataConnection:
         passive transfer mode
         setupPassiveDataSocket:
           sendCommand:
             sendingCommand: PASV
           --sendCommand
           readCommandResponse:
             replyLineQP: 500 You need to use a client supporting PRET (PRE Transfer) to use PASV
             commandResponse: 500 You need to use a client supporting PRET (PRE Transfer) to use PASV
             statusCode: 500
           --readCommandResponse
         --setupPassiveDataSocket
         Failed to setup passive data socket for upload
       --setupDataConnection
     --fetchDirListing2
   --fetchDirListing
   N: -1
   Failed.
 --NumFilesAndDirs
--ChilkatLog

I found little info on google about PRET, not sure what its purpose is. Does CkFTP2 support PRET or can you add this feature?

Thanks, Gert

---

Answer

From some research it appears that PRET is a non-standard vendor specific proprietary extension to FTP, without a proper spec and no RFC. The Filezilla dev refuses to touch it for that reason, and I'm not sure if Chilkat would have any interest for the same reasons (but only Chilkat can answer that).

A workaround seems to be using Active mode instead of Passive (if that's possible in your scenario).

---

Answer

Yes, I understand.

I will see if he can use active.

---

Answer

Gert, I'll do some research too... :)