Category: Portable Code

Scripting on the Java Virtual Machine

Now that OpenVMS has Java, and that HP-UX has Java, I started wondering about the possibility of running a scripting language on the Java Virtual Machine (JVM) as a way of supporting all these diverse environments with the same code and tools.

Choosing a language can be difficult, especially when there are so many good ones to choose from. I’ll assume for purposes of discussion that one is already familiar with at least one or more computer languages already (you should be!).

So what are the criteria a system administrator should use to choose a language on the JVM?

  • Does the language have a strong and vibrant community around it? The language might be nice, but if no new development is being done on it, it will eventually fail and stop working on the newer JVM. Bugs will not be fixed if development has halted. It also helps to have a large variety of people to call on when trouble arises, or when your code has to be maintained in the future.
  • Does the language support your favored method of programming? If you have no desire to learn functional programming, then don’t choose a language that is a functional language. Find a language that thinks the way you do (unless you are specifically trying to stretch your mind…).
  • Is your preferred langauge already available for the JVM? There are implementations of Ruby (JRuby), Python (Jython), LISP (Armed Bear Common Lisp), Tcl (Jacl) and many others. A language that you already know will reduce your learning time to near zero on the Java Virtual Machine.
  • What are the requirements? For example, JRuby requires a dozen libraries; Clojure and Armed Bear Common Lisp have no outside requirements. Which is simpler to install onto a new machine?

So what languages am I looking at? I am looking at these:

  • Clojure – a LISP-like functional programming language which seems to be taking off handsomely.
  • JRuby – Ruby is my all-time favorite scripting language, and having it available whereever the Java VM is is a very tintillating prospect. It’s also directly supported by Sun, the makers of Java.
  • Groovy – this is a new language that takes after Ruby and Smalltalk, and it is growing in popularity at a dramatic pace.
  • Scala – this is a language with a strong developer base and an object-oriented and functional design. Don’t know much more about it yet.
  • Armed Bear Common Lisp – ABCL is a full Common LISP implementation for the Java VM, and is used as part of the J editor. Unlike ABCL, development on J seems to have stopped; development on ABCL has gone through a resurgence after not quite dying for several years. ABCL is the closest thing to LISP on the JVM, and is usually the first mentioned – even though its development community is not nearly as strong as Scala or JRuby.

These are only the ones I’ve chosen to focus on; there are many, many more.

Getting Passwords from Random Data (portably!)

Over at Mark Kolich’s blog, he wrote several months ago about using a source of randomness (/dev/urandom) to generate passwords. The idea is simple enough: take the random data, strip out only the printable characters, and then print the desired length of characters for a password.

Shortly thereafter, he described how to use a simple shell script to generate many passwords – such as for setting up many different accounts.

Working with HP-UX and OpenVMS as I do, I immediately thought: how could I do this in Perl, making the idea portable and making a program that will work on both UNIX and OpenVMS? It was easy – and easy to make it flexible as well. Here is the program that I came up with:

#!/usr/bin/perl

# code released by David Douthitt into the public domain

use Getopt::Long;

Getopt::Long::Configure('bundling');
GetOptions( 'l=i' => \$opt_l,
            'p=s' => \$opt_p,
            'm=i' => \$opt_m );

$pat{"ext"} = "[[:alnum:][:punct:]]";
$pat{"alnum"} = "[[:alnum:]]";
$pat{"alpha"} = "[[:alpha:]]";
$pat{"simple"} = "[a-km-z2-9]";
$pat{"normal"} = "[a-km-z2-9A-HJ-NPR-Z]";

if (defined($opt_p)) {
   if (defined($pat{$opt_p})) {
      $pat = $pat{$opt_p};
   } else {
      print "undefined pattern!\n";
      exit(1);
   }
} else {
   $pat = $pat{"normal"};
}

$max = (defined($opt_m) ? $opt_m : 1000);
$len = (defined($opt_l) ? $opt_l : 6);

$x = $len;

for $i (0..$max) {
   $c = chr(int(rand(255)));
   if ($c =~ /$pat/o) {
      $s .= $c;
      if (--$x == 0) {
         print "$s\n";
         $x = $len;
         $s = "";
      }
   }
}

Note that since OpenVMS does not use the “#!” notation, that this line will be ignored as a comment and the program needs to be invoked via direct invocation of perl itself.

As an aside, Mark says how he prefers random passwords. Me, I prefer “pronouncable” passwords – still random, but using phoenemes which makes the generation process just that more complicated – and complicates internationalization. Apple’s MacOS X comes with a password generator that can generate random and pronouncable passwords.

However, with the proper password storage system a fully randomized password is good – or is it? A completely random password of eight characters could be zzzzzzzz as much as anything else. Perhaps a password with a random distribution of characters (rather than a random selection of characters) would be better. I’m not aware of any password generators that guarantee a random distribution instead of a random collection.

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Overview: how to install UNIX/Linux to a machine with no bootable disk

Installing operating systems to the HP nc4010 ultralight notebook has been an excercise in how to accomplish the seemingly impossible: installing an operating system to a laptop with no removable disk and no bootable disk.

Generally, there are three different ways to do this:

  • Boot from the network using PXE.
  • Boot from an external add-on device such as USB CDROM or USB memory device.
  • Create a bootable disk in another system and install the disk afterwards.

Booting from the network requires several servers to be set up, including a TFTP server, a NFS server, and a DHCP server. Though they could all be on the same machine, it does represent a significant amount of set up and configuration in order to install, including the need to copy all installation parts to the NFS server to be served up to clients. In addition, there are special configurations needed for DHCP to get this started.

Booting from an external device is much easier, and can be done on the nc4010 and probably can be done on most laptops from the last 10 years or so. This method is probably the easiest to accomplish and without any fuss.

Alternately, it is possible to install the operating system normally in another system and then transfer the disk over to the new system. The biggest problem – the major problem – is that the disk locations all change. What had been /dev/hd1 is now /dev/hd0; all of this will need to be changed in order to have the new system boot properly.

The boot loader may also need to be changed to recognize the new location of the disk.

Linux has a parameter “root=/dev/zzzz” which allows the boot process to specify where the system root disk is. After this, then /etc/fstab will have to be changed (which is standard everywhere).

Solaris has UFS and ZFS, and UFS can be modified to reflect a new source disk location. ZFS is more troublesome and hard to do, as the filesystem is newer and has not been used as a boot drive for hardly any time at all. I still do not have an understanding of how to convert ZFS from using one boot disk to another (in name only) – once that happens, I’ll have OpenSolaris on an nc4010.

Living in the Internet Cloud

When we are on-the-go professionals, and are potentially required to work from home or from other locations on the road, isn’t it good to be able to reach your data no matter where you are?

Thus is the interest in being able to “live in the cloud”, keeping data and information on Internet computers out there somewhere.  Unfortunately, it also means that instead of making our own backups, we must rely on someone else’s backups.  Suppose the company goes out of business?  This has already happened for several photo sites – and in one case, it took the customer’s photos with them.

There are many sites that can provide a safe harbour for data or for information of various kinds.  My favorites are these:

The online desktops Goowy and eyeOS deserve special mention.  Not only do they provide a desktop, but also all the standard applications you might need.  It is possible to run within one of these desktops and save your data entirely with one of these setups.  This makes for a fantastic central location for everything – and a larger-than-normal risk.

EyeOS has one more feature that most of these do not: it is open source.  If you want to run your own version of EyeOS, there’s no problem doing so.  This is incredibly useful if you have your own server to run this on.  Then you can centralize your information and retain control at the same time.

I also find the mail clients in Goowy and eyeOS to be quite useful for sending mail from anywhere with a browser.

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FreeBSD on the fitPC and on the EeePC

FreeBSD is a nice environment, and I tend to gravitate to it (though I love Linux and Solaris as well). It does tend to work better in smaller environments than either Linux or Solaris.

There was recently a discussion of FreeBSD on the EeePC; it appears that while some items do not work (to be expected) it runs nicely and works nicely (including wireless). There was recently posted a simple introductory article which also refers to a comprehensive article on FreeBSD on the EeePC.

There was also an article (with followup) about running FreeBSD on the fitPC; in contrast to the EeePC, this sounds like it is not as good. However, the fitPC has less memory and a slower processor; it is unclear as to whether the processor is “fast enough” (I still use Pentium IIIs for my use!) or if it really is slow. It is, however, very surprising that the default Ubuntu install would be a graphical installation that swaps badly and comes without SSH.

The fitPC forums have a nice Linux on fitPC section, which also includes the BSDs as well. The biggest problem with FreeBSD seems to be its lack of a USB CDROM driver in the base kernel; however, apparently OpenBSD loads fine. Since the system has only 256M of memory, it perhaps should not be swamped with heavy desktop applications.

FreeBSD 6.3 is OUT! (Armada E500 installation)

Just after installing 6.3-RC2, I discovered that 6.3 was officially released!

This didn’t take much work to update to. The basic steps were:

freebsd-update upgrade
freebsd-update install

Then – after a reboot (for kernel updates, I presume) another:

freebsd-update install

Relatively painless, throughout.

Then, continuing my install over the weekend, there were a few niggling things to fix. First off, the buttons up on the top of the keyboard didn’t work (no surprise there). Using the xev utility helps to pin down the actual keycodes for these keys, then use the xmodmap tool to add the appropriate actions to the keys. In my case, xev reported that the keys left to right were:

  • 163 (info key)
  • 142 (home key)
  • 154 (search key)
  • 143 (mail key)

These can be configured using xmodmap and a .Xmodmap file configured this way:

keycode 163 = Help
keycode 142 = XF86HomePage
keycode 154 = XF86Search
keycode 143 = XF86Mail

The values on the right (Help, XF86HomePage, XF86Search, XF86Mail) show their XFree86 heritage, but apparently do not change for X.org. These are activated by using the command:

xmodmap .Xmodmap

A good place for this line would be in the .xinitrc. However, once this is set, it is still necessary to tie applications to the shortcuts listed. In KDE, this is done in the Keyboard Shortcuts section of the Regional and Accessibility pane in Settings. In this dialog, select the “Command Shortcuts” tab, then the application you desire to use. For example, “Find Files/Folders” could be attached to the shortcut XF86Search. Once the xmodmap has been modified using the command above, then click on the Custom radio button, and click the shortcut button. Press the actual shortcut button to define the shortcut for the application.

Do this for all four buttons, and all will be well.

Then there was the problem of the mouse not being operational when waking up from a suspend. Turns out that the moused(8) daemon is the culprit. Sending a HUP signal to the daemon fixes it, but having to do this all the time is not a desirable outcome. The utility acpiconf(8) describes how it uses /etc/rc.suspend and /etc/rc.resume before and after suspending the system. I placed the command:

pkill -HUP moused

into this script, but I don’t yet know if it is truly having the desired effect or if other things are causing failures.

Another thing: the CD player would not play CDs in Amarok. Apparently, this is due to HAL and DBUS not being available. HAL depends on DBUS, so both are necessary. The following packages were needed:

hal-0.5.8.20070909
dbus-1.0.2_2
dbus-glib-0.74
dbus-qt3-0.70_1

I don’t know that all the dbus packages are necessary, but I decided not to chance it. Of course, dbus is part of GNOME, but whatever. Once these packages are installed, add the following to the startup configuration in /etc/rc.conf:

hald_enable="YES"
dbus_enable="YES"

Next time the system boots, these daemons will start.

Also, up until this point X.org had to be started using startx as a normal user. However, adding the login screen isn’t difficult. Edit the /etc/ttys file. In this file, there will be a line that specifies the command xdm.

Since kdm (the KDE display manager, the login screen) is actually a reworked xdm, switching one for the other is smooth and clean. Replace the xdm setting with /usr/local/bin/kdm (keeping the -nodaemon option) and set the tty to “on” (instead of “off”). Then the next time the system starts (or the ttys file is read) a login screen will activate on ttyv8 (if your file is like mine).

FreeBSD 6.3 RC-2 on a Compaq Armada E500

FreeBSD 6.2 has been on this machine for a while, but then I tried to upgrade all of the applications using the ports tree. This almost worked, except upgrading to Xorg turned out to be a massive headache and nothing worked.

It was then that FreeBSD 6.3 RC-2 was announced. I thought, why not? So off I went.

It installed well – if you don’t count my not providing enough room for /usr/local. With my “full-featured” (ha!) list of software, I wound up needing more than the original 2 Gb I originally alloted for /usr/local; with 4 Gb it worked. I also had to change the boot options, as it was still set to use 6.3-RC1 instead of 6.3-RC2. Changing the name in the options screen worked just fine.

Then after loading, I had to load the proper kernel – it couldn’t find the kernel. I selected /boot/GENERIC/kernel and all was well. At the boot loader prompt:

load /boot/GENERIC/kernel
boot

I had to configure Xorg. This was another headache. There was an excellent article from Julien Valroff about instaling Debian GNU/Linux on this machine. Despite the difference in operating systems, the fundamentals were similar. Another fantastic resource was this old page by Frank Steiner. Despite the age, the descriptions are relevant and useful (though, again, it is about Linux). There is a page on the Gentoo Wiki that describes the machine as well, though the other pages are more descriptive.

The screen display descriptions turned out to be the easiest; the problem was the mouse. Some descriptions suggest that the synaptics driver should work. However, this never did work for me. Using the standard PS/2 mouse driver and protocol worked just fine.

I also had to up the maximum files available, though for what reason I forget. Add this line to /etc/sysctl.conf to fix this problem:

kern.maxfiles=10000

Sound was another matter. It took a bit to figure out. First off, all the Linux directions suggested using lspci to see if it was there; this is Linux-specific. The FreeBSD counterpart is pciconf. Running pciconf -lv presents this:

pcm0@pci0:8:0:   class=0x040100 card=0xb1120e11 chip=0x1978125d rev=0x10 hdr=0x00
    vendor     = 'ESS Technology'
    device     = 'ES1978 Maestro-2E Audiodrive, ES1970 Canyon3D'
    class      = multimedia
    subclass   = audio

Thus, I knew that the sound was recognized. I just had to figure out how to get things to work with it. This means kernel support, da?

First attempts to load a driver turned up short; nothing is found in /boot/modules (!). The search path had to be changed to /boot/GENERIC:

kldconfig -i /boot/GENERIC

After this, load the snd_maestro driver:

kldload snd_maestro

After this, sound will work! Amarok is great…… and sound on this machine is excellent too!

Seeing as a I was trying to load KDE on here, the next step (once Xorg is working) is to add a startkde command to the .xinitrc file (in one’s home directory).

To make the system boot properly (and so you don’t have to load kernel modules manually all the time), the /boot/loader.conf file had to be created with this:

# Directory (in /boot) containing kernel and modules
kernel="GENERIC"
 
# Load maestro driver
snd_maestro_load="YES"

This then worked well.

I’m enjoying this machine again – though I am attempting to make it more of a usable desktop, which means more memory and all of the niggling setup work – like bootup splash screens, configuring kdm, and more – but hey, we’re system admins here, right?

The fitPC: Is it a good fit?

I’ve been seriously considering the fitPC for my own purposes. Currently, the DHCP server (ISC) and the web proxy (Squid) in my home network are two separate servers running versions of Red Hat or CentOS. Both are slimline computers, but otherwise are standard in their configuration: standard hard drives, standard motherboards, etc. I think it might be safe to assume that this also means standard power consumption (200-250 watts, I’m guessing).

Along with the wattage is the noise as well. With the two servers and two desktops running (and a rackmountable switch), that is a lot of fans and a lot of noise (more than non-techies would realize!).  That’s four computers with 200-250 watts each (high estimate) – for 800-1000 watts of power consumption.

This doesn’t even take into account what it would be like with the Sun SparcStation 20 or the UltraEnterprise 1 started up – I shudder to think how much power they take up (and I know how noisy they are….).

A 5-watt computer with no fan (silence!) would be very nice. The things that are most appealing about the 5-watt fitPC are the silence, the minimal power drain, and the standard configuration. Many computers that fall into this category are in fact, embedded systems – small memory, small flash drives, and so on – often with specialized software (even if it is open source).

The fitPC is a standard system, so it will run anything that will run on an Intel 586-based system.

The company is in Israel, and until recently was the only source for their product. They appear to have been overwhelmed with orders sometime in November, but are going as fast as they can.  I’ve no idea if they are backed up now or not. They’ve also introduced resellers apparently: System Industrie Electronic AG in Austria, Anders Electronics in the United Kingdom, and CompuLab Embedded Systems in the United States.  None of the resellers has the fitPC listed as available, but presumably if you contact the right people from their list, everything will be just fine.

They have a set of forums that are excellent, and serve as an excellent resource for purchasers and owners of fitPC systems.

One of the questions that comes up on the forums is: Does the fitPC work well with X where X is:

It comes with either Windows XP or Ubuntu (an optimized Gentoo is also available). The listed cost is $285 US.

Modding the Asus Eee PC

It seems that people are already busy at work modifying the Asus Eee PC. Over at tnkgrl there are extensive pictures of the internals, and now a new post with detailed instructions on adding a USB Bluetooth adapter to it without losing the USB port.

The Eee PC community is already flourishing, with forums and more at eeeuser.com.

OpenSolaris on a MacBook

OpenSolaris is very interesting, and since the introduction of dtrace and ZFS has enthralled many. I tried to install it onto my HP Compaq E300 laptop (which it was unsuitable for), and tried to install it onto an HP Compaq 6910p laptop. In this case, the networking was unsupported: both the ethernet and the wireless drivers were not included with OpenSolaris Express (Developer Edition).

In any case, I expect I might just be shopping for a laptop in the next year – and it’s nice to see that OpenSolaris does run on the Apple MacBook.  This article goes into detail about how the writer got it to work, and each of the steps that were taken to make it happen.  Paul Mitchell from Sun discusses dual-partitioning a MacBook in this context as well.  Alan Perry (also from Sun) had done the same thing with a Mac Mini, and Paul extended it to the MacBook.  Both entries are detailed and have to do with MacOS X and Solaris dual-booting.

An a different note, check out the graph of library calls from dtrace in this article.  From what I’ve heard of dtrace, it’s the ultimate when it comes to debugging…