Volume Number: 23 (2007)
Issue Number: 09
Column Tag: Networking

FTP Clients for Mac OS X

Roundup of some popular FTP client apps

By Mary Norbury

This article will cover a few of the most popular FTP clients for Mac OS X. We'll look at a mix of open source, and shareware/commercial software available. The personal choice of an FTP client is based on how stable the app is, how securely it handles data transfers, and how well the features of the app meet your current needs.

As a brief overview, let's cover some FTP basics to bring ourselves up to speed. FTP is an interactive protocol used for file transfer over any TCP supported network. Networked hosts create connections to each other in order to transfer data between a client machine and a server. The FTP server uses port 21 (also called the command port) to listen for a connection from an FTP client and port 20 to send data from (also called the data port) but we'll see that the data port can be redirected to a different/random port. The initial greeting consists of the FTP client sending a request via a command to the server and the server sending back a response to either accept or reject the connection. This two-way communication where commands are passed is called the control stream and occurs in plain text. The next step in the process is the actual file transfer, which requires a different socket connection called the data stream. Three different transfer modes dictate how the data stream is set up:

Active mode: The FTP client opens a random port (port # > 1023) and sends the random port number over the control stream using the PORT command with the IP and port number as argument. The server connects back to the client in this scenario.

Passive mode: The FTP server opens a random port (port # > 1023) and sends the server's IP address and the port number to the FTP client and then the server listens. The FTP client would respond with the PASV command. The client connects to the server in this scenario.

Extensive passive mode: The FTP server acts as in the passive transfer mode but, in this case, only sends the port number and assumes the client will use the same IP it initially connected to. Again, the client connects out to the server.

Data is commonly sent in either ASCII or binary formats, although most FTP clients use ASCII by default as their data transfer mode.

An obvious problem with FTP is one of security: commands, passwords, and directories are sent in clear text and are not encrypted in any fashion. As we'll see with our choices for FTP clients in this article, this can be made more secure by using FTPS (FTP over SSL) or SFTP (SSH File Transfer Protocol).

Captain FTP

Figure 1. Captain FTP

Captain FTP version 5.0 is a shareware product available for $25 from http://captainftp.xdsnet.de/. You can try out the application for a 14-day evaluation period before purchasing a license. Captain FTP bills itself as "the very first cooperative FTP client" by allowing local network file sharing via FTP. This facilitates project collaboration among co-workers. The application sports a tabbed interface with the tabs representing separate FTP sessions. Drag and drop between tabs is supported. The main application window has a two-pane browser format with two sets of navigation controls. By default, your computer view is shown in both panes when you're not connected. These browser panes are multi-purpose: they can show remote or local files, or two remote FTP servers. Connections are set up via the Remote item in the menu bar.

Figure 2. Captain FTP Connection Settings.

The menu bar can be customized to show more actions or the server connections that exist in your Captain FTP address book.

Figure 3. Captain FTP Toolbar Customization.

Captain FTP also has a preview drawer on the right side of the main window and a tasks drawer below the main window that are collapsible.

Figure 4. Captain FTP Preview and Tasks Drawers.

The transfer manager is a separate window that manages individual transfers (pause, halt, resume) and allows for scheduling file transfers. Transfer status is easily viewed and prioritized through this window.

Captain FTP supports AppleScript and the help documentation comes with sample scripts for browsing and uploading.

The Captain FTP dashboard widget can be downloaded at the developer's download site (http://captainftp.xdsnet.de/cftp/download.html). The Widget does auto-populate the connection settings when the FTP server is selected from the pop down list (Captain FTP address book). Uploads worked very well and without any issues.

Figure 5. Captain FTP Widget.

A few other items of note: Captain FTP supports FTP/SSL-FTP/SFTP encryption protocols, file sharing transfers are restricted to authorized users by user authentication and IP access,

Figure 6. Captain FTP Sharing Preference Pane.

Captain FTP also includes WebDAV transfer capabilities, Growl notification, and external text editors are also supported.

Cyberduck

Figure 7. Cyberduck

Cyberduck (http://cyberduck.ch/) is an open source browser that supports FTP, FTP/TLS (FTP secured over SSL/TLS), and SFTP (SSH File Transfer Protocol). The download consists of the Cyberduck app, a Widget for rapid uploads, an AppleScript samples directory, and links to the developer home and donation pages. The current stable release version is 2.7.3 (build 2930) and a beta release of version 2.8b1 (build 3161).

Cyberduck is a Cocoa app with multiple localizations, support for external editors (SubEthaEdit, BBEdit, TextWrangler, TextMate, and others), full AppleScript integration, and support for Bonjour, Keychain, Spotlight, and iDisk bookmark synchronization. There is also support for Growl and recursive permissions modifications.

Cyberduck has a lean interface, with a bookmarks drawer, fully customizable toolbar accessed through the View menu item, and sortable columns.

Figure 8. Cyberduck GUI

Connections are easily configured and bookmarked via the Open Connection sheet.

Figure 9. Cyberduck Connection Sheet.

Once the connection is established, Cyberduck uses the Finder for local directory access via drag and drop, which is a bit of an annoyance. It would be nice to see the local directories show up in a pane next to the bookmarked FTP server directories. It would be helpful for file modification date comparison and just file directory matching.

Figure 10. Cyberduck FTP server directory listing.

Cyberduck comes with a suite of sample AppleScripts including recursive listing of server folder contents, remote and local directory synchronization, a folder action script for uploading files, and others. Since it's a simple matter of

   
   tell application "Cyberduck"
...
end tell

you can script pretty much any routine use of the application.

The Cyberduck widget requires configuration even though the bookmarks appear in a pop down list at the top of the Widget. Selecting a bookmark doesn't auto-populate the FTP connection settings. I also had problems with the Cyberduck app quitting unexpectedly when dropping files on the Widget and not completing the upload.

Figure 11. Cyberduck FTP Widget Settings

Although a freeware app, donations are accepted for ongoing development of Cyberduck via a link on the website.

Fetch

Figure 12. Fetch.

Fetch is a venerable FTP client and now a Universal app at version 5.2.1, available from the developer's website (http://www.fetchsoftworks.com/) for a 14-day trial version or $25 for a licensed copy. Fetch supports SFTP, FTPS, and FTP with Kerberos connections, external editors including GraphicConverter for graphics editing on the remote server, automatic passive transfer mode, support for Bonjour, folder synchronization using a GUI version of the mirror command, droplet shortcuts, AppleScript recording, and Automator actions.

After installation, Fetch opens a new connection sheet at launch and automatically populates a separate shortcut window with FTP servers detected through Bonjour.

Figure 13. Fetch Connection Settings.

Fetch contains a single main window showing the remote FTP Server directory listing. Files are transferred using the Get or Put button in the toolbar or by dragging and dropping local files from the Finder.

Figure 14. Fetch File Transfer.

Fetch also recently added a new feature in version 5.2 called WebView which allows you to view files in a web browser and copy web addresses while in Fetch. So, you can use WebView to see your corresponding Fetch files in your Web browser and then copy the URLs using the Copy Web Address function.

Fetch fully supports AppleScript and Automator actions. Ben Waldie wrote a complete article on AppleScripting Fetch in MachTech Vol. 22, Issue 5. The current version of Fetch includes an updated AppleScript dictionary (for a complete summary, see http://www.fetchsoftworks.com/FetchWebHelp/Contents/WhatsNew/AppleScriptChanges.html). A very good selection of sample AppleScripts can be downloaded at the Fetch downloads page (http://fetchsoftworks.com/downloads.html) and you can also take advantage of Fetch's ability to record through Script Editor and create your own custom scripts.

Fetch also includes a number of Automator actions to create workflows. Automator workflows can be saved as application droplets; for example, you can drag files onto the droplet to complete tasks like uploading and then changing file permissions.

Figure 15. Fetch and Automator.

The Fetch Widget is very slick and uploads files very quickly. It gets the job done without too much fanfare and complication.

Figure 16. Fetch Widget.

Fugu

Figure 17. Fugu.

Created at the Research Systems UNIX Group at the University of Michigan, Fugu 1.2.0 is an open source, graphical front end to OpenSSH's command line SFTP and SCP (secure copy) applications [Ed. note: unlike other apps in this article, Fugu does not work with traditional ftp servers]. Fugu is a Universal binary app available as source tarballs or disk image on the RSUG Web site (http://rsug.itd.umich.edu/software/fugu/download.html). Winner of the 2003 Apple Design Award for Best OS X Use of Open Source, licensing is BSD style. Full source code is available with revision history documentation via anonymous CVS or through http://rsug.itd.umich.edu/cgi-bin/cvsweb.cgi/fugu/. Several localizations are also supported.

Launching Fugu gives you a two pane main window. The left pane contains your local files and the right pane is initially used to set your FTP connection.

Fugu supports Bonjour and you can save your server connections as favorites.

Figure 18. Fugu FTP Connection Settings.

After connecting to your remote FTP server, the right pane contains the remote file directory. You can drag and drop files between panes or drag files from the remote directory to the desktop or open Finder window. Since the SFTP client that Fugu wraps doesn't support folder downloads, Fugu uses SCP to complete the folder download.

Fugu also supports tunneling over SSH. An SSH tunnel creates a secure communication tunnel from your computer to the remote FTP server. The SSH tunnel encrypts your login credentials and forwards them to the remote FTP server for authentication. Using the SSH menu item, select New SSH Tunnel. After the tunnel has been started, you can securely transfer files.

Figure 19. Fugu SSH Tunnel.

Fugu includes a basic AppleScript dictionary that can be accessed through Script Editor.

Interarchy

Figure 20. Interarchy.

Nolobe Software (http://nolobe.com/interarchy/) acquired Interarchy from Stairways Software in early 2007 as a developer buyout; the lead developer of Interarchy (previously known as Anarchie) spun off his own company in order to acquire the application. A single user license of Interarchy costs $59.95, with multi-seat, upgrade, and educational pricing available.

Interarchy 8.5.3 transfers files via FTP, SFTP, FTP/SSH, FTP/SSL-TLS, WebDAV, and WebDAV over HTTPS. It also supports mirroring between local and remote directories, scheduling for task automation, allows for HTTP listing with Web links, and iDisk access. Interarchy goes beyond the definition of a "basic" FTP client by providing a full suite of network analysis tools like packet sniffing, host information (IP, DNS name, MX records), trace route, ping, and port scan.

At launch, Interarchy opens a Bookmarks main window pre-populated with Interarchy and Nolobe favorites in the right pane and collections of bookmarks in the left pane.

Figure 21. Interarchy Bookmarks.

Using the Connect to Server bookmark (or File – Connect to Server from the menu bar), connection settings can be entered into a new List window.

Figure 22. Interarchy Connection Settings.

After a connection to the FTP server is established, the List window shows the requested directory on the remote server. Files are transfers by drag and drop from the Finder.

Figure 23. Interarchy Remote Server Listing.

Interarchy supports Automator actions and is AppleScriptable and recordable. The AppleScript dictionary for Interarchy includes an FTP Suite, Standard Suite, Standard URL Suite, and the Interarchy Suite. HTTP actions (weblist, webview, getwebsite, etc.), local actions (filelist, fileremove, filesetpermissions, etc.), perform mirrors, and create and control virtual Net Disks. Interarchy includes three Automator actions: List URLS, Download URLs, and Upload Files.

You can also script Interarchy from the Terminal by installing the Interarchy Command Line Tool from the Preferences window of the GUI app.

The network tools suite included in Interarchy is accessed through the File item in the menu bar and selecting Net from the menu list.

Figure 24. Interarchy Network Tools Menu.

Interarchy will prompt you to install by providing your local admin credentials. You can use a number of network tools from within Interarchy.

Figure 25. Interarchy Network Interface Tool.

A Widget is available to allow for quick uploads and a separate Interarchy Network Status Widget that monitor individual network interfaces.

Figure 26. Interarchy Network Status Widget.

The Nolobe website is a bit difficult to maneuver and locating specific information is difficult. However, the Help file built into Interarchy has extensive documentation.

While Interarchy appears to be a bit pricey at first glance, it's an extremely full-featured application. If all you want is a basic FTP client, then look elsewhere. Interarchy is for more experienced administrators who are looking for a complete FTP and network analysis package.

RBrowser

Figure 27. RBrowser.

RBrowser 4.4.1 is a Universal Binary and is available from http://www.rbrowser.com/. RBrowser comes as a free, unlicensed version that includes remote editing (called SaveBack) and SFTP with SSL. The single user license costs $35 and includes unrestricted access to all protocols (FTP/SSL/TLS, SFTP-SSH) and Folder Sync which preserves HFS Metadata (retains fork data, type/creator, and attributes on Mac-to-Mac transfers, both local-local and local-remote). Auto detection allows RBrowser to decide which protocol to use without need for user configuration.

Launching RBrowser brings up a File Viewer for the local host. Select a new connection through Go item in the menu bar and choosing New Site....

Figure 28. RBrowser Connection Settings.

After the auto-detection process for selecting the correct protocol, a directory listing for the remote FTP server will appear in the remote File Viewer window. A status drawer is located under the main window to provide connection and transfer status.

Figure 29. RBrowser Remote File Viewer.

Folder Sync (licensed version only) is a feature that allows synchronizing via several scenarios: local to local (ex. Mac – external drive), local to remote (Mac – remote host like an FTP or backup server), and remote to local (remote host like a back up server - Mac).

RBrowser is AppleScriptable but does not come with dedicated Automator action files.

I experienced several annoyances with RBrowser: slow connections to remote servers/directory listings and a single click on the file name will make it immediately editable. Since I tend to click on the name rather than the smaller icon, I found myself repeatedly having to re-click on another column to get out of the file name edit before I deleted the entire file name.

Transmit

Figure 30. Transmit.

Transmit 3.5.6, available from Panic (http://www.panic.com/transmit/) is $29.95 for a single copy license. Multi-user, upgrade, and educational pricing is available.

Transmit is a Universal app with a clean, elegant interface. It supports external editing (including graphics), Growl notifications, folder size calculations, droplets, zooming previews, FTP, SFTP, TLS/SSL, server to server transfers, iDisk/WebDAV, DockSend, .Mac synchronization, AppleScript, and Automator actions.

Launching Transmit opens the main window with dual panes: the left pane lists your local files and the right pane initially shows the remote FTP server connection settings. You can optionally view the sidebar to right of the main window (where you can add folders for easy access) or the transcript drawer below the main window (which shows the progress of FTP connection communication).

Figure 31. Transmit Connection Settings.

Once connected to the remote server, the right pane contains your remote directory listing. You can change the sidebar to a preview pane to view and zoom in (using the magnifying glass icon) on files in either local or remote directories.

Figure 32. Transmit Remote Server Listing.

Transmit's Widget worked without a hitch once configured.

Figure 33. Transmit Widget.

Transmit has an extensive AppleScript dictionary. You can download a Sample AppleScripts folder from http://www.panic.com/transmit/d/Transmit%20Sample%20AppleScripts.zip that contains a number of example scripts for creating droplets, listing, and synchronizing files.

Transmit also has Automator support for uploading, downloading, and synchronizing files.

Yummy FTP

Figure 34. Yummy FTP.

Yummy FTP 1.6.1b3 (http://www.yummysoftware.com/) has a 30 day demo version or a single user license for $25. Multi-user, site, educational, and non-profit licensing are also available.

Yummy FTP has full SFTP support, supports local and remote directory synchronization including scheduling, remote editing, preview, FTP aliases on the desktop, is AppleScriptable, enhanced Growl support, and color labels.

Figure 35. Yummy FTP Connection Settings.

Yummy FTP opens in the default Mac Browser mode, with local files listed in the left pane and remote server files in the right pane.

Figure 36. Yummy FTP Default Mac Browser.

Alternatively, you can open the transcript window under the main browser, the queue drawer under the transcript window, and the preview drawer, which appears to the right of the main browser window.

Figure 37. Yummy FTP Optional Views.

A nice feature in Yummy FTP is called DualBrowse: both local and remote sites are synchronized and folder linked so you can browse both local and remote directories simultaneously. DualBrowse can be toggled on or off in the toolbar.

Figure 38. Yummy FTP DualBrowse.

Yummy FTP does not have a Widget but it does have both desktop aliases and AutoRoute, which is a functionality that allows for dropping files onto the Yummy FTP dock icon for automatic uploading to a preconfigured server (similar to Transmit's DockSend). I find the FTP aliases and AutoRoute much more useful than a Widget which requires more keystrokes and manual dexterity.

Yummy FTP does not have included Automator actions but since it is AppleScriptable and recordable, you can create workflows. Under the Help menu item, you can select Yummy FTP Extras to download a set of AppleScripts for multi-site uploads, save and upload, mirror on demand, update Mac on demand, and update server on demand.

The clients covered in this article are a cross section of many of the top downloaded apps. There are many more FTP clients that I didn't have time or space to cover and many are favorites for specific features or have special functionality that other clients don't sport. If you have one you love, drop me an email and let me know why.

The AppleScripting Fetch article referenced is MacTech Issue Vol. 22, Issue 5 and was written by Ben Waldie.

Mary Norbury is IT Director at the Barbara Davis Center for Childhood Diabetes, an affiliate center at the University of Colorado at Denver and Health Sciences Center in Aurora, Colorado. She has extensive experience in cross-platform systems implementation and administration in the education sector. You can reach her at norburym@mac.com.