Advanced FTP using Probe

• Through the FTP (File Transfer Protocol) concept, files may be transfered between two computers connected by the Internet or an intranet. The computers may be two PC:s, or one of them may, for example, be a public UNIX file server.

• For files to be transfered, the remote machine must run a FTP server program, and the local machine runs a FTP client.

• Probe comes with a builtin FTP client, which presents the storage of the remote machine as a subfolder structure, available under a Probe FTP sub-folder.

• The probe FTP client exploits advanced aspects of the FTP protocol. It is a fully multithreaded implementation, resulting in a powerful client, at all times maintaining the Probe user interface responsive.

Figure 1 : Browsing a remote FTP-site in the Tree Browser.

• Accessing the files within a remote FTP folder is easy. One just invokes file popup menu items for the selected files or double-clicks them.

• Since Probe is fully multi-threaded, Probe allows for having multiple FTP-connections active simultaneously. So files may be downloaded, while at the same time, some other directory of the same site is beeing browsed. And several downloads, from one or several different FTP servers, may be in progress at any one time.

• New FTP-connections are created using the New Folder functionality of Probe (in the toolbar, from a pulldown menu, or keyboard accelerator F7). After selecting a FTP type subfolder, and providing a nickname to the connection, the FTP-Settings Dialog is invoked, providing full control over the details of the connection.

Figure 2 : The FTP-Settings Dialog in Probe.

• Since the contents of remote FTP folders are browsed just as ordinary sub-folders, the powerful sorting, navigation, selection and search tools of Probe are available. This makes it easy, for example, to find all image files whose filename contains the word 'NASA', and whose size is less than 200 kb in a certain FTP site. Just do a search from within Probe with the criterion:
  • Filename wildcard :
    • *NASA*.jpg
    • *NASA*.gif
  • Size criterion: <200kb

• When doing FTP file-transfers over a low bandwidth connection, it is annoying if the transfer is aborted by some network problem. To help in these situations, Probe implements resumed uploads and downloads. Through this concept, one can resume a previous upload or download attempt that was aborted, given that the remote server allows for this.

Figure 3 : Resuming an aborted upload attempt with Probe.

• Probe implements the 'Server to Server' aspect of the FTP protocol. This means that Probe can be used to initiate a file-transfer between two different FTP servers, without the file-contents having to be transfered through the machine running the Probe FTP client. The file-contents rather travels the most efficient path on the Internet between the two servers.

As a result, one can achieve transfer rates at multiples of 100 kb/sec, even if the transfer is initiated by a telephone quality connection.

A server to server connection is automatically initiated by Probe when files are copied/moved between two FTP-sites within Probe.

• A special case of 'Server to Server' transfers is to transfer files within a single server. Through this, Probe can be used to effectively copy and move files within a remote computer, with no file-contents having to be transfered over the Internet.