The Darxite FAQ
                                      
  What is it?
  
   "Darxite" is the name given to a system consisting of a daemon running
   in the background whose job is to retrieve or upload files via FTP or
   HTTP and execute other FTP commands, and a number of "client" programs
   whose jobs are to control the daemon and to provide a user interface.
   Darxite is the ideal program to use when you need to get some files
   over an unreliable network connection.
     _________________________________________________________________
   
  What are the requirements to use it?
  
   Darxite has only been tested on Linux kernels 2.0 and above, and with
   glibc2. It may work on other Unices and with libc5 - try it, and tell
   me if it does or doesn't. The daemon does not require any other
   libraries, but libpthread is optional and improves performance.
   
   Unsurprisingly, the GTK client programs require GTK (1.0+ should do)
   and the GNOME clients require GNOME 1.0. The command-line FTP client
   requires a reasonably recent version of GNU readline.
     _________________________________________________________________
   
  Why was it written?
  
   Darxite was born from the concept of having a process sit in the
   background and get files for you quietly. As a dialup user in Britain,
   with its overly high phone charges during the week, if you want to get
   a large file, it's not really worth loading up an FTP client and going
   through all the hassle of finding the file when you'll only have time
   to download a tiny bit of it. With Darxite, you can make progress in
   downloading it even when you're only connected for a short time.
   
   Plus, Netscape crashed one time too many. If the server supports file
   resume, Darxite will never delete partially-complete files - unless
   you tell it to.
     _________________________________________________________________
   
  What nice features does it have?
  
     * Control/monitoring via "client" programs, which are easy to write
       and can be written for any medium - ncurses, GTK, QT, or simply
       command-line
     * A GNOME Panel client has been written, so URLs can be dragged and
       dropped from Netscape
     * There are also nice GTK and command-line FTP clients
     * Transfers are auto-resumed if possible
     * If a transfer gets too slow, the system can switch to a mirror
       site automagically
     * Transfers can be spooled, so you know from looking at the file
       when they have completed
     * The daemon can be controlled remotely, thus enabling a faster
       computer to be used as a sort-of FTP proxy or file server, etc.
     * Connecting and de-spooling are multi-threaded via pthreads (can be
       set to single-threaded at compile time)
     * Programs can be set to automatically execute when transfer is
       complete
     * Support for FTP and HTTP download and FTP upload, and HTTP proxies
     * Recursive FTP download and upload
     * And many more...
     _________________________________________________________________
   
  What are the differences between Darxite and GetRight?
  
   Firstly, [1]GetRight only works under Windows 95/NT, and it's not open
   source. But apart from this, it's based around a different model: it
   is simply intended to help the user download files using Netscape,
   Internet Explorer, and so on, and does not have a "client-server"
   system where applications can control it. This makes it more
   inflexible; for example, you are forced to use the provided GUI.
   Darxite also has some features that GetRight does not; for example,
   remote control. As of version 0.4, Darxite includes a script for
   converting your GetRight bookmarks.
     _________________________________________________________________
   
  Why not use another Unix utility, eg. ncftp, sftp...
  
   Darxite has a number of nice features, such as the ability to switch
   to a mirror site if transfer rates get too low. It was designed from
   the outset for multiple simultaneous transfers and for batch
   operation, and can be easily scripted by use of the various helper
   utilities such as "darxget" and "darxcmd". You can use a command-line
   or X-based GUI, and switch between them at will without losing data -
   eg. if X crashes, you'll still be OK. The spooling system means that
   you know when a file transfer has completed. And finally, its name
   isn't an acronym involving the letters "ftp" :)
     _________________________________________________________________
   
  Why didn't you base it on an FTP library or something?
  
   None of them seemed to support features I needed, like multithreading.
   Also, I wanted to really understand our FTP/HTTP backend and to get
   the best performance out of it we could. We didn't just script an FTP
   client (such as curl) because that would have been very limiting.
     _________________________________________________________________
   
  Why is it called "Darxite"?
  
   For the following reasons and many more:
     * It is a hilarious pun on the well-known FTP site "Sunsite"
     * It sounds like the bot on IRCnet #Amiga, Darxide
     * It processes a batch of files and, as every A-Level Computing
       student knows, batch processing is carried out at night, in the
       dark
     * According to Lycos and Altavista, no site on the Internet has used
       the name
     * It sounds good
     * It doesn't have the letters "ftp" in it.
     _________________________________________________________________
   
  Why the odd release names?
  
   If Microsoft can name their releases after American towns, and Debian
   can name theirs after characters from Toy Story, why can't we name
   ours after characters from an amazing set of books? To be specific,
   the Hitch-Hiker's Guide to the Galaxy quintet. But if you've never
   heard of them, maybe you aren't the sort of person we want using our
   system anyway :)
     _________________________________________________________________
   
  So how do I simply download a file from the command line?
  
   Use the provided client program "darxget". For example, you might
   type:
darxget ftp://ftp.microsoft.com/windows/98/full-source.tgz

   ...if it existed. There are many command-line options to select things
   like the output filename: type "darxget -h" to see them. An especially
   useful one is -b for blocking mode; ie. the utility will wait for the
   file to complete its transfer before continuing.
     _________________________________________________________________
   
  Is there any snazzier way to transfer files?
  
   Lots. Try the command-line FTP client dxftp or the GUI client NoctFTP.
   Or the GNOME Panel applet. But you should really read the USAGE file;
   it should tell you everything you need to know.
     _________________________________________________________________
   
  What clients are included as standard?
  
   The following clients are included in the standard Darxite tree:
     * DarxGet - get a URL from the command line
     * DarxPut - upload a URL from the command line
     * NoctFTP - a very nice GTK FTP client
     * DarxStat - display the current transfer status in text form
     * DarxStat-GTK - display the transfer status in a GTK window
     * Darxite Monitor - GNOME Panel applet
     * Darxite-Control - GNOME batch control program
     * dxFTP - a command-line FTP client a la ncftp.
     * dxclip - a GTK-based clipboard monitor
     * dxpref - GTK utility allowing preference editing
     * pdarxget - a very simple Perl script to get a URL
     * DarxCmd - a low-level utility to send commands to the daemon
     _________________________________________________________________
   
  How do I pause or cancel files from the command line?
  
   Type 'darxcmd "pause [url]"' to pause the file with [url], and
   'darxcmd "continue [url]"' to resume transfer. To cancel a file, type
   'darxcmd "cancel [url]"'. If you want to pause, cancel or resume all
   the files in the batch, simply type 'darxcmd "pause all"', etc. You
   may like to alias these commands, eg. to "dxpause", "dxresume" and
   "dxcancel", if you use them a lot. Note that the quotes are required!
     _________________________________________________________________
   
  What's all this about controlling the daemon remotely?
  
   You can run the Darxite daemon on a remote computer and control it via
   the network. You can even use clients like NoctFTP, which can be
   really handy if the remote computer is slow or doesn't have X, or
   whatever. Read the USAGE file to find out more.
     _________________________________________________________________
   
  Is there a Windows client I can use?
  
   Not yet. But what you can do is use telnet, which works almost the
   same as darxcmd does. See the USAGE file, under the section
   "Telnetting to Darxite", to find out more. This is kind of clunky and
   user-unfriendly, but it works.
     _________________________________________________________________
   
  Does Darxite support FXP?
  
   No. Transfer from one FTP server directly to another (so-called FXP)
   is not supported, and probably never will be, for the following
   reasons. Many modern servers do not allow it because it is a security
   risk, and Darxite is intended to be a utility for transferring files
   to a local computer, thus enabling many features. Also, if you have
   login access to one of the servers, you can achieve much the same
   thing with Darxite by running the daemon remotely on either server.
     _________________________________________________________________
   
  Can I tell Darxite to download a file at a certain time?
  
   Not directly, but you can use the "at" command to do so, eg: "at
   9.00am darxget ftp://some.server/some.file". And you can even get
   Darxite to e-mail you when it's finished, or to automatically
   disconnect from the Internet. If you want it to be downloaded at the
   same time every day, you can use "crond" to do it. If you set up your
   computer nicely, it should even be possible to tell it to dial up,
   download the file and then disconnect...
     _________________________________________________________________
   
  Darxite uses a huge amount of CPU time. This is evil!
  
   If there is a very large data transfer rate (eg. when using FTP
   locally), Darxite will use a large amount of CPU time. If you don't
   like this, run it via nice, eg. "nice -n 19 darxite" would give the
   program a very low priority and make it use less CPU time.
     _________________________________________________________________
   
  I've downloaded a file but I can't find it. Huh?
  
   By default, all files are downloaded to your home directory, and
   transfers are spooled - ie. files are saved in the directory
   "$HOME/.darxite/spool/" and are only copied when they are complete. If
   the transfer is canceled, Darxite will not delete the
   partially-complete file, so it'll stay in the spool directory. You can
   change all this behaviour via your ".darxiterc" file. For example, to
   download all files to the current directory, add the line "OutputDir
   ." to the file.
     _________________________________________________________________
   
  ps shows I've got two copies of Darxite running. Why?
  
   The way that threads work in Linux means that you'll see an extra line
   "darxite" in ps' display for every thread running - plus one for the
   thread scheduler. It shouldn't actually be possible to run Darxite
   twice as the same user, unless things have gone very wrong.
     _________________________________________________________________
   
  I want to write a Darxite client. How easy is it?
  
   Very easy, especially if you use the Darxite library, which
   essentially makes it a matter of calling one function to connect to
   the daemon, one to send commands, and one to disconnect. If you don't
   want to use the library or aren't using C, it's still easy and
   requires very few lines of code. Take a look at the file "develop.txt"
   and e-mail Ashley for more information.
     _________________________________________________________________
   
  Are there any clients that you'd really like to be written?
  
   Yes. A few of the ideas we've had are: an ncurses client, a QT client,
   a KDE Panel or Afterstep dock applet, a Perl client (especially useful
   for Web sites), a TCL client (erm...), an Xlib client (even more
   erm...) and so on. E-mail me if you come up with any ideas.
     _________________________________________________________________
   
  Are there any performance issues with running loads of clients at once?
  
   Clients talk to the daemon using multiple sockets and asynchronous I/O
   and only when they need to, so there is no performance impact entailed
   simply in running lots of clients at once (except that a small amount
   of extra memory is allocated for each client), but running many
   clients that poll the daemon repeatedly - such as darxstat-GTK - will
   cause a performance hit, though it won't really be noticeable with
   most transfers from remote sites.
     _________________________________________________________________
   
  I use KDE. Is there a panel applet like the one for GNOME?
  
   No, there isn't (yet). But there is a simple way you can get some of
   the functionality of the GNOME applet. Just create an "Application"
   link on the panel (or even on your desktop) and set the command to
   execute to be "darxget %u". Then, if you drop a URL on the icon from
   KFM or any other KDE client, it will silently be retrieved in the
   background. This won't work with Netscape links, but maybe in KDE 2.0
   it will.
     _________________________________________________________________
   
  I found a bug in Darxite...
  
   Doh! Make sure you tell me about it, if it's repeatable. If it's in
   the daemon, enable error logging (via dxpref or editing your
   .darxiterc), and e-mail me the "log-errors.txt" file produced. If not,
   just tell me the problem and I'll try to fix it. I'm also very happy
   to receive feature requests, no matter how insane.
     _________________________________________________________________
   
  I don't like Darxite. Does it have any competitors?
  
   If you want a utility to get URLs from the command-line, I recommend
   curl, wget and got_it. If you want a command-line FTP client, why not
   look at ncFTP, sftp or lftp. As GTK FTP clients go, gftp and IglooFTP
   are worth trying. Many ideas have been liberally stolen from all of
   these. If you would like a client you can drag and drop a URL on,
   GTransferManager (for GNOME apps and Netscape) and Caitoo (for KDE
   apps) might be worth looking at. And if you have to use Windows,
   there's GetRight and Go!Zilla, which are unfortunately non-free.
     _________________________________________________________________
   
  What sort of features are you planning to add in the future?
  
   Lots.
     _________________________________________________________________
   
   
    [2]Ashley Montanaro
    
   Last modified: Wed Nov 9 12:30:41 GMT 1999

References

   1. http://www.getright.com/
   2. mailto:hell@ukgateway.net