Applications for the Sharp Zaurus
Now that you can walk around with the Zaurus in the palm of your hand, while being connected to the Internet, there are some applications you need to install.
First is tkcjabber, a commercial, closed-source application from www.thekompany.com that is worth every cent. Basically, it will turn your 802.11b Zaurus into an instant messenger that is always on if you run it in the background. Using ICQ, AIM, MSN, YM and IRC will now be just like using a cell phone.
When you receive a message, the Zaurus “incoming message” LED blinks, and a cell phone-like sound is played. Then you can chat in a window.
There are only two drawbacks. First, the interface is icon-only. The first time you use it will be the worst: no tooltips, no text, no nothing. Fortunately, the user interface is very intuitive, and you will not be lost for long, except for the contacts. I have yet to find how to add contacts by ICQ number or nickname.
The second big problem is AIM connectivity. With the tkcjabber test version I used, I got disconnected from AIM every minute for the famous “unauthorized software access” reason—a very strange reason, considering Jabber got a license to use AIM. These bugs are very minor and did not interfere with the daily use of this great application. It is a recommended purchase. In fact, like Opera, it should come bundled with the Zaurus because you will always run it if you do instant messaging.
Zic is a free application that only does IRC. We can only hope it will compete with tkcjabber soon because competition would increase the quality of both products.
Now what about sniffing wireless traffic? There is an excellent application running on the Zaurus to sniff 802.11b traffic. If you are using a prism2-based wireless card, like the Linksys WCF11, you should not have any problem installing and using it.
Go to kismetwireless.net and download the binary archive for the Zaurus. Uncompress it with tar zxvf. It will give you the ipkg file you can install with ipkg install. If you installed zlib before as suggested, you are ready to run it. However, there is one fault: you cannot sniff traffic and use the wireless connection at the same time.
Therefore, you should use the following script to start Kismet. Store the script (see Listing 1) in /usr/local/bin/sniff.
Now try to do a ping to the Zaurus from your computer, and launch this script. You will see that it will not only find your access point but also the channel being used, and then capture the traffic. As suggested on the Kismet web site, you should use ethereal to process the dump file. The next versions of Kismet will let you plug in a GPS on the audio port of the Zaurus (to read the wireless network position) and may decrypt WEP.
Now that you can sniff traffic, scanning the machines on the wireless is the next logical step. This is where Nmap comes in. Get it from prdownloads.sourceforge.net/zaurus/zutilsnmap-extra.zip, and port scan the machines on the wireless network using nmap IPaddress.
You can get OpenSSH for the Zaurus from the Sharp web site.
It is not a standard ipkg file but a .tar.gz archive with an install script within. To install OpenSSH, type
tar zxvf openssh*.tar.gz cd openssh ./install.sh m
This will install OpenSSH in the main memory. If you have an SDRAM card, replace ./install.sh m with install.sh s. Do not install OpenSSH on the CompactFlash port, since the wireless card will use it, and you will not be able to use OpenSSH and the network connection at the same time.
Note: you cannot untar the archive and install it. The /root directory is the home directory for the root user on many UNIX platforms and the Zaurus. However, it is mounted read-only at boot time, while many applications, including OpenSSH, expect to write to this directory. The Zaurus actually uses /home/root as the root home directory, but through some .profile hack. You need to fix that directly in /etc/passwd where /root is mentioned.
Editing /etc/passwd by setting /home/root as the home directory instead of /root solves the problem. This should be considered one of the many bugs that Sharp needs to fix by default.
If you have not installed an editor, or if you do not know how to use one, type the following command to fix /etc/password:
sed -e ':/root:/home/root:' /etc/passwd > /tmp/passwd cp -p /etc/passwd /etc/passwd.BAK mv /tmp/passwd /etc
Once this is done, you can complete the installation. Now that you have OpenSSH installed, not only can you administer a remote machine, but you can also remotely log in on the Zaurus with SSH. Type killall -HUP inetd to restart the inetd dæmon and allow for incoming SSH connections.
An FTP dæmon running on the nonstandard port 4242 completes the SSH. You can use it to get the files you handle with an SSH connection. But did you know there is no root password on the Zaurus by default? This means you are walking around with an open FTP server in your pocket, accessible with 802.11b. You may run passwd to set up a root password, but it does nothing to the FTP server, as if it was not using /etc/password. At least, the latest version of the ROM makes the FTP server open only on the USB network interface.
Anyway, a mobile FTP server would be great if only you could put a password on it. Now, what about an HTTP server to complete it? Get boa from sourceforge.net, and you can tell your friends you are walking with your internet server and that they can open an SSH version to administer it if they want—just make sure not to mention the FTP dæmon.
If they do not have SSH, or if they would prefer a graphical remote administration, what about using VNC? Grab a VNC server for the Zaurus from opensource.lineo.com/fbvncserver (opensource.lineo.com/fbvncserver/zaurus-fbvncserver_0.1.1_arm.ipk currently) and install it. Then somewhere on your network, start a VNC client; the Zaurus display is exported as if it was running X.
After you are done, you really deserve some time off. So, go get the demo version of zradio, a radio streamer. For only $10, you can use it to listen to on-line radio stations from your Zaurus. If you do not like the earphones, you may try the speaker hack from www.zymurgy.net/zaurus.html. Maybe the next version of this hack will include a microphone, which would let you use your Zaurus as a memo with the default “Recorder” application.
I hope you had some fun and found a lot of ideas for possible uses of the Zaurus with this software review.
- March 2015 Issue of Linux Journal: System Administration
- High-Availability Storage with HA-LVM
- DNSMasq, the Pint-Sized Super Dæmon!
- Localhost DNS Cache
- Real-Time Rogue Wireless Access Point Detection with the Raspberry Pi
- Days Between Dates: the Counting
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- The Usability of GNOME
- Multitenant Sites
- Linux for Astronomers