Returning to Pre-Framebuffer console fonts

At some point in time, the various Linuxes out there decided that the large, blocky, easy-to-read console (as in Virtual Console, not Terminal Emulator) fonts should be replaced with tiny, hard-to-read fonts that make it a chore to edit standard 80-column scripts/source/config files in vim.

Experimenting with various grub and kernel options to change the resolution, fix i915.modeset, and so forth make for a lot of rebooting to get things just right.

Enter the Debian console-setup package. This provides a wizard that ultimately calls setfont and stty to configure the Linux Virtual Consoles.

The dialog-based wizard is invoked via sudo dpkg-reconfigure console-setup .  Each screen is simple enough to navigate on its own; however, the following selections will configure the consoles to display an old, 90s-to-early-oughts style of font:

1. UTF-8 [default, just press ENTER]
2. Combined - Latin; Slavic Cyrillic; Greek [default]
3. VGA
4. 28x16

The result should produce a nice 80 column x 25 row vim display that is visible from halfway across the room (and to old geezers a few inches away). Chuck it on a Macbook air to really get some double-takes from passers by.

Determining installed version of Ubuntu

Neither uname nor motd are of much use in determining the version of Ubuntu installed on a third-party system, and searching launchpad.net for version details of key packages in dpkg is annoying.

Fortunately there is a utility called lsb_release that provides this information:


bash$ lsb_release -si
Ubuntu
bash$ lsb_release -sr
11.04
bash$ lsb_release -sc
natty

Complete all the way down to the silly nickname for each release.

Since this is an LSB utility, it's probably been in place for some time, silently waiting to provide more detail than uname. Seriously, would a mention in the SEE ALSO section of the uname manpage be *so* hard to add?

knotify4 uses 100% CPU

This is true, and has been for awhile. It tends to occur when a laptop is suspended while online, then resumed while offline. A nice side effect is that battery life gets reduced by about 75% while offline, which is generally when one wants the longest battery life.

There are plenty of bug reports open on this, but it's pretty clear that the KDE/Kubuntu guys either have no clue how to fix this, or cannot be bothered.

Since knotify4 isn't really all that useful (especially when using E17 for a WM), there is a brutal hack that will effectively silence it:



sudo mv /usr/bin/knotify4  /usr/bin/knotify4.orig

sudo cp /bin/true /usr/bin/knotify4

Needless to say, the original file should be restored before doing an upgrade.

Disabling startup (init.d) services in Ubuntu

Ubuntu never has made obvious what the "Ubuntu way" of removing services from System-V run levels is. The GUI tools in GNOME and KDE are incomplete, and a quick investigation of the run level directories shows that they are filled automatically -- so that symlinks added and removed manually might, in the future, get ignored.

Fortunately, the README in /etc/init.d ends with the following advice:

Use the update-rc.d command to create symbolic links in the /etc/rc?.d
as appropriate. See that man page for more details.

The man page lists the following forms for invoking upgrade-rc.d:                                                        


      update-rc.d [-n] [-f] B name  remove


       update-rc.d [-n] B name  defaults [NN | SS KK]


       update-rc.d  [-n]  name  start|stop  R  NN runlevel  [ runlevel ]... 


       update-rc.d [-n] B name  disable|enable [ S|2|3|4|5 ]

The following command will remove the service collectd from all run levels:


bash$ sudo update-rc.d collectd disable
update-rc.d: warning: collectd start runlevel arguments (none) do not match LSB Default-Start values (2 3 4 5)
update-rc.d: warning: collectd stop runlevel arguments (none) do not match LSB Default-Stop values (0 1 6)
 Disabling system startup links for /etc/init.d/collectd ...
 Removing any system startup links for /etc/init.d/collectd ...
   /etc/rc0.d/K95collectd
   /etc/rc1.d/K95collectd
   /etc/rc2.d/S95collectd
   /etc/rc3.d/S95collectd
   /etc/rc4.d/S95collectd
   /etc/rc5.d/S95collectd
   /etc/rc6.d/K95collectd
 Adding system startup for /etc/init.d/collectd ...
   /etc/rc0.d/K95collectd -> ../init.d/collectd
   /etc/rc1.d/K95collectd -> ../init.d/collectd
   /etc/rc6.d/K95collectd -> ../init.d/collectd
   /etc/rc2.d/K05collectd -> ../init.d/collectd
   /etc/rc3.d/K05collectd -> ../init.d/collectd
   /etc/rc4.d/K05collectd -> ../init.d/collectd
   /etc/rc5.d/K05collectd -> ../init.d/collectd

The command to remove a service from a specific runlevel should be the following:


sudo update-rc.d BASENAME disable `runlevel | cut -d ' ' -f 2`

...however a quick experiment shows that the runlevel argument is ignored:

bash$ sudo update-rc.d collectd disable 2

sudo update-rc.d collectd disable 2
update-rc.d: warning: collectd start runlevel arguments (none) do not match LSB Default-Start values (2 3 4 5)
update-rc.d: warning: collectd stop runlevel arguments (none) do not match LSB Default-Stop values (0 1 6)
 Disabling system startup links for /etc/init.d/collectd ...
 Removing any system startup links for /etc/init.d/collectd ...
   /etc/rc0.d/K95collectd
   /etc/rc1.d/K95collectd
   /etc/rc2.d/S95collectd
   /etc/rc3.d/S95collectd
   /etc/rc4.d/S95collectd
   /etc/rc5.d/S95collectd
   /etc/rc6.d/K95collectd
 Adding system startup for /etc/init.d/collectd ...
   /etc/rc0.d/K95collectd -> ../init.d/collectd
   /etc/rc1.d/K95collectd -> ../init.d/collectd
   /etc/rc6.d/K95collectd -> ../init.d/collectd
   /etc/rc2.d/K05collectd -> ../init.d/collectd
   /etc/rc3.d/K05collectd -> ../init.d/collectd
   /etc/rc4.d/K05collectd -> ../init.d/collectd

perf-backed disassembly

Since 2.6.31 or thereabouts, the Linux kernel has come with a built-in performance counter known as perf.

The common form of perf is well-known to be useful in gathering performance statistics on a running program:


bash$ perf stat -cv ./a.out 


cache-misses: 11313 2020574449 2020574449
cache-references: 62031796 2020574449 2020574449
branch-misses: 17909 2020574449 2020574449
branches: 606684832 2020574449 2020574449
instructions: 6324531571 2020574449 2020574449
cycles: 6408533747 2020574449 2020574449
page-faults: 304 2019963367 2019963367
CPU-migrations: 7 2019963367 2019963367
context-switches: 205 2019963367 2019963367
task-clock-msecs: 2019963367 2019963367 2019963367


 Performance counter stats for './a.out':

             11313 cache-misses             #      0.006 M/sec
          62031796 cache-references         #     30.709 M/sec
             17909 branch-misses            #      0.003 %    
         606684832 branches                 #    300.344 M/sec
        6324531571 instructions             #      0.987 IPC  
        6408533747 cycles                   #   3172.599 M/sec
               304 page-faults              #      0.000 M/sec
                 7 CPU-migrations           #      0.000 M/sec
               205 context-switches         #      0.000 M/sec
       2019.963367 task-clock-msecs         #      0.996 CPUs 


        2.027948307  seconds time elapsed

The  events to be recorded can be specified with the -e option in order to refine the output:

bash$ perf stat -e cpu-clock -e instructi

ons  

 Performance counter stats for './a.out':

       2026.748812 cpu-clock-msecs         

        6324293589 instructions             #      0.000 IPC  

        2.032519896  seconds time elapsed

A list of available events can be obtained via perf list:

bash$ perf list | head

List of pre-defined events (to be used in -e):

  cpu-cycles OR cycles                       [Hardware event]

  instructions                               [Hardware event]

  cache-references                           [Hardware event]

  cache-misses                               [Hardware event]

  branch-instructions OR branches            [Hardware event]

  branch-misses                              [Hardware event]

  bus-cycles                                 [Hardware event]

The perf toolchain also includes the utility perf top, which can be used to monitor a single process, or which can be used to monitor the kernel:

bash$ sudo perf top 2>/dev/null

-------------------------------------------------------------------------------

   PerfTop:       0 irqs/sec  kernel:-nan%  exact: -nan% [1000Hz cycles],  (all, 4 CPUs)

-------------------------------------------------------------------------------

             samples  pcnt function               DSO

             _______ _____ ______________________ __________________

               77.00 39.3% intel_idle             [kernel.kallsyms] 

               13.00  6.6% __pthread_mutex_unlock libpthread-2.13.so

               13.00  6.6% pthread_mutex_lock     libpthread-2.13.so

               12.00  6.1% __ticket_spin_lock     [kernel.kallsyms] 

                7.00  3.6% schedule               [kernel.kallsyms] 

                6.00  3.1% menu_select            [kernel.kallsyms] 

                6.00  3.1% fget_light             [kernel.kallsyms] 

                6.00  3.1% clear_page_c           [kernel.kallsyms] 

Where things start to get interesting, however, is with perf record. This utility is generally used along with perf report to record the performance counters of a process, and review them later.

This can be used, for example, to generate a call graph:

bash$  perf record -g -o /tmp/a.out.perf ./a.out

[ perf record: Woken up 1 times to write data ]

[ perf record: Captured and wrote 0.148 MB /tmp/a.out.perf (~6461 samples) ]

bash$ perf report -g -i /tmp/a.out.perf

# Events: 1K cycles

#

# Overhead        Command  Shared Object  Symbol

# ........  .............  .............  ......

#

    99.90%          a.out  a.out          [.] main

            |

            --- main

                __libc_start_main

     0.10%          a.out  [l2cap]        [k] 0xffffffff8103804a

            |

            --- 0xffffffff8105f438

                0xffffffff8105f675

...

Once perf data has been recorded, the perf annotate utility can be used to display a disassembly of the instructions that were executed:

bash$  perf annotate -i /tmp/a.out.perf |more

------------------------------------------------

 Percent |      Source code & Disassembly of a.out

------------------------------------------------

         :

         :

         :

         :      Disassembly of section .text:

         :

         :      0000000000400554

:

    0.00 :  400554:       55                      push   %rbp
    0.00 :  400555:       48 89 e5                mov    %rsp,%rbp
    0.00 :  400558:       48 81 ec 30 00 0c 00    sub    $0xc0030,%rsp
    0.00 :  40055f:       48 8d 85 d0 ff fb ff    lea    -0x40030(%rbp),%rax
    0.00 :  400566:       ba 00 00 04 00          mov    $0x40000,%edx
    0.00 :  40056b:       be 00 00 00 00          mov    $0x0,%esi
    0.00 :  400570:       48 89 c7                mov    %rax,%rdi
    0.00 :  400573:       e8 b0 fe ff ff          callq  400428 <memset@plt>
    0.00 :  400578:       c7 45 fc 00 00 00 04    movl   $0x4000000,-0x4(%rbp)

    ...

    4.21 :  4006a5:       8b 45 d0                mov    -0x30(%rbp),%eax
   15.54 :  4006a8:       83 c0 01                add    $0x1,%eax
    4.97 :  4006ab:       89 45 d0                mov    %eax,-0x30(%rbp)
    4.87 :  4006ae:       8b 45 d0                mov    -0x30(%rbp),%eax
   17.79 :  4006b1:       83 c0 01                add    $0x1,%eax
    4.36 :  4006b4:       89 45 d0                mov    %eax,-0x30(%rbp)
    4.72 :  4006b7:       48 83 45 f0 01          addq   $0x1,-0x10(%rbp)
    0.00 :  4006bc:       48 8b 45 f0             mov    -0x10(%rbp),%rax

    ...

As to be expected from Torvalds and company, the utilities include a number of options for generating parser-friendly output, limiting reporting to specified events and symbols, and so forth. Check the man pages for details.

Easy E(17)

Ubuntu finally ships with a working E17, but there is a lingering problem: most of the modules are gone!

To get a full-featured install of E17, replete with modules and UI enhancements (finally! the settings panel entries re available from the main menu!), it is best to install from SVN.

Building E17 has always been an ordeal. Fortunately, the script easy_e17.sh makes downloading, building, and installing E17 from SVN to be quite a simple affair, once all of the dependencies are met.


To begin with, download the easy_e17 script from http://omicron.homeip.net.

There is a bug in the script which must be fixed if packages are going to be built. According to this bug report, the line (around 36 or 37)

  packages_full="$efl_basic $bin_basic $e_modules_bin $e_modules_extra $efl_extra
$bin_extra"


should be

  packages_full="$efl_basic $bin_basic $e_modules_bin $efl_extra $bin_extra $e_modules_extra"


... in order to get all the internal dependencies straight. Failure to do this results in the following error:
e_mod_main.c:1527:32: error: ‘ethumb_client’ undeclared (first use in this function)


Next, install all necessary dependencies to build E17 and the modules:

bash$ sudo apt-get install autopoint libudev-dev libgcrypt11 libgcrypt11-dev
bash$ sudo apt-get install libasound2-dev libasound2 libxine-dev 
bash$ sudo apt-get install paman padevchooser paprefs pavucontrol pavumeter 
bash$ sudo apt-get install libiptcdata-dev libmpd-dev cython libxcb-shape0-dev

According to this guide, the full list of dependencies is as follows:

bash$ sudo apt-get install xterm make gcc bison flex subversion cvs automake1.10 autoconf autotools-dev autoconf-archive libtool gettext libpam0g-dev libfreetype6-dev libpng12-dev zlib1g-dev libjpeg62-dev libtiff4-dev libungif4-dev librsvg2-dev libx11-dev libxcursor-dev libxrender-dev libxrandr-dev libxfixes-dev libxdamage-dev libxcomposite-dev libxss-dev libxp-dev libxext-dev libxinerama-dev libxft-dev libxfont-dev libxi-dev libxv-dev libxkbfile-dev libxres-dev libxtst-dev libltdl7-dev libglu1-xorg-dev libglut3-dev xserver-xephyr libdbus-1-dev liblua5.1-0-dev libasound2-dev libudev-dev autopoint  libxml2-dev

Chances are, however, that most of these are already installed.


The E17 build makes some assumptions about the location of the gcrypt libraries, so they must be symlinked:

bash$ sudo ln -s /usr/lib/x86_64-linux-gnu/libgcrypt.a /lib/x86_64-linux-gnu
bash$ sudo ln -s /usr/lib/x86_64-linux-gnu/libgcrypt.la /lib/x86_64-linux-gnu
bash$ sudo ln -s /usr/lib/x86_64-linux-gnu/libgcrypt.so /lib/x86_64-linux-gnu

...other wise linker errors such as the following will appear:
../../src/lib/.libs/libeet.so: undefined reference to `gcry_cipher_setiv'
../../src/lib/.libs/libeet.so: undefined reference to `gcry_cipher_setkey'

The Xine development headers (libxine-dev) must be installed in order for emotion to compile; otherwise an error like this will appear:
configure: error: Xine, Gstreamer or VLC backends must be selected to build Emotion
Naturally, Gstreamer or VLC headers could be installed instead.


The asound2-dev and the pulseaudio tools are required to get the mixer module working. Without them, the error
No ALSA mixer found!

will appear in the mixer module settings. Note that pulseaudio requires that the current user be added to the audio group; this can be done with the following command:

  sudo adduser $USERNAME audio

Once all this is done, it is a simple matter to install E17 with the following command:

./easy_e17.sh --instpath=/usr/local/e17 --srcpath=/home/$USER/src/e17 -i

This downloads the E17 source code to ~/src/e17, and sets the install directory to /usr/local/e17. There should be a nice success message if everything goes well.

Next, build all of the modules:

./easy_e17.sh --instpath=/usr/local/e17 --srcpath=/home/$USER/src/e17 --packagelist=full -i


Upgrading is just as straightforward:

./easy_e17.sh --instpath=/usr/local/e17 --srcpath=/home/$USER/src/e17 --packagelist=full -u


Final notes:

  * The composite module causes problems: when using the Software engine, it causes typing delays that make terminals near unusable; when using the OpenGL engine, windows do not update until there is a focus change (BIG problem). It should be disabled.

  * The shelf containing the systray module must be given the stacking order Above Everything; otherwise, the applications in the E17 systray will not receive mouse clicks (VERY BAD).

  * Determining the fonts used by various modules is easier when the source is available. The font classes used in the tclock module, for example, are in E-MODULES-EXTRA/tclock/tclock.edc. The time is displayed in text_class: "module_large", and the date is displayed in text_class: "module_small". The Settings->Look->Fonts dialog can be used to determine the font used for these classes by enabling (via the checkbox at bottom-right) the font class Modules::Small or Modules::Large, and setting the font (e.g. Sans/Regular/12 pixels) to be used for each.

UPDATE : Recent builds now fail when using --packagelist=full. Best stick with --packagelist=half if the full build fails.

Static DNS servers in /etc/resolv.conf

It's an old problem: NetworkManager overwrites /etc/resolv.conf with each connection, forcing one to use the local ISP's crappy DNS servers instead of one's tried-and-true public DNS servers.

The fixes for this are legion: chattr resolv.conf, disable dhclient, replace NetworkManager.

It turns out that dhclient can be configured to include specified DNS servers (up to twp before a warning is displayed) in the resolv.conf.

Simply add the following line to /etc/dhcp/dhclient.conf :

prepend domain-name-servers 4.2.2.1, 4.2.2.4;                

Obviously, replace 4.2.2.1 and 4.2.2.4 with whatever name servers are desired. The semicolon, by the way, is extremely important -- don't leave it out.

Ubuntu, you're fired.

Attempted to upgrade a workstation (dual-xeon, sata3 ssd for /; sata 3 hdd for /usr, /var, /opt, /usr/local; sata2 mirrored raid (via dmraid) for /home) from 10.04 to 11.04 via do-release-upgrade (in update-manager-core) last night. Why do that? Because Ubuntu only updates software packages for its newest release, so if you need, say, Python 2.7 in order to work on a project, you're SOL unless you upgrade.

Everything went well until the final reboot, which left the machine at:


error: the symbol 'grub_xputs' not found.

Verified that the grub software is all present:

grub rescue> ls (hd0,1)/boot
... lots of modules and such...

Everything seemed to be there, so attempted to boot manually, under the assumption it was all due to misconfiguration:

grub rescue> set root=(hd0,1)
grub rescue> set kernel=/boot/vmlinuz-2.6.32-33-generic
grub rescue> set initrd=/boot/initrd.img-2.6.32-33-generic
grub rescue> boot
error: no loaded kernel

Second attempt, loading the grub modules manually (per Ubuntu Grub2 Docs and this thread):

grub rescue> set prefix=(hd0,1)/boot/grub
grub rescue> insmod normal
error: the symbol 'grub_xputs' not found.
grub rescue> insmod linuxgrub
error: the symbol 'grub_xputs' not found.

For some reason, the symbols in the grub2 bootstrap code do not match the ones expected by the modules. One of them is the wrong version. Looks to be a reported bug.

The solution, per Ubuntu Grub2 Docs and this fix, is to boot a LiveCD (which must be the same version as the newly-installed-but-broken Ubuntu) and run grub-install. This turns out to be a huge delay, as the upgrade took place without a LiveCD, so an ISO must be downloaded. It is also a huge pain when one is out of blank CDs, and has to press a usbstick into service (accomplished per Ubuntu Install Docs).

It also doesn't work. The new error on reboot is

error: file not found

grub rescue> insmod linux

ELF header smaller than expected

It turns out that 10.04 upgrades to 10.10, NOT 11.04, so the LiveCD contained the wrong version of grub!

Fortunately, there is a guide to purging and reinstalling grub once booted from any LiveCD.

The steps are (details such as hdd devices and mount points are specific to this workstation):

bash$ sudo bash

bash# mount /dev/sdk1 /mnt

bash# mount /dev/sdf3 /usr

bash# mount /dev/sdf4 /var

bash# mount --bind /dev /mnt/dev

bash# mount --bind /dev/pts /mnt/dev/pts

bash# mount --bind /proc /mnt/proc

bash# mount --bind /sys /mnt/sys

bash# chroot /mnt

bash-chroot# apt-get update

bash-chroot# apt-get purge grub grub-common grub-pc

bash-chroot# apt-get install grub-common grub-pc

bash-chroot# #NOTE: Be sure to select /dev/sdk for Grub2 install location

bash-chroot# exit

bash# umount /mnt/dev/pts

bash# umount /mnt/dev 

bash# umount /dev/sys

bash# umount /mnt/proc

bash# umount /mnt/var

bash# umount /mnt/usr

bash# umount /mnt

bash# reboot

That does the trick.

But you know what would really be nice? A way to upgrade the OS, including the kernel and all packages, WITHOUT TOUCHING THE GODDAMN BOOT-LOADER. Seriously, it's an upgrade, the bootloader already works -- don't mess with it!

Installing Google Go system-wide on Ubuntu

Just some quick notes. This assumes all necessary packages for C dev are installed (sudo apt-get install bison ed gawk gcc libc6-dev make).

As root (sudo bash):

bash# apt-get install mercurial mercurial-common mercurial-git

bash# cd /usr/local

bash# hg clone -u release https://go.googlecode.com/hg/ go
bash# cd go/src

bash# export GOBIN=/usr/local/bin

bash# ./all.bash

After this, the Go toolchain will be installed in /usr/local/bin, with all supporting files in /usr/local/go. Ubuntu should already have /usr/local/bin in the path for all users.

To test (as a normal user):

bash$ cd /tmp
bash$ cat >hello.go <
> package main
>
> import "fmt"
>
> func main() {
> fmt.Printf("hello, world\n")
> }
> EOF
bash$ 6g hello.go
bash$ 6l hello.6
bash$ ./6.out
hello, world
bash$ rm hello.go hello.6 6.out

Ubuntu getting crappier and crappier

Stupidly made the decision to upgrade to 10.10 (for a single package!) on the main laptop (mbpro 5,5) and poof! No wireless!

Seriously, it's been three releases since an ethernet cable was required to do an upgrade.

Piece.
Of.
Shit.

Only question now is how many hours of productivity are going to be lost fixing what *was* a perfectly working system before the upgrade.

The sad fact is that os x and windows are just as unreliable for upgrades (while being less usable), and FreeBSD refuses to even glance at this hardware.

A decade ago, this shit used to *work*!

Running log of the fixes:

* apt-get install gnome-icon-theme to get NetworkManager running again. There is no fix for Wicd; it has apparently "stopped working".

* apt-get install gnome-alsa-mixer to un-mute the sound. Kmixer has been reduced from 7 or so channels to 1 (without a mute option).

* uninstall ruby 1.9 via apt-get. Download and install rvm (system-wide as this is a workstation), then do 'sudo rvm --default use 1.9.2' to make 1.9 the system-wide default (might roll that back later).

* reinstall all 1.9 gems.

* rebuild the passenger apache module ('sudo passenger-install-apache2-module') and update the config files to point to the new location.

* fix all rack-based webapps to include the line
    $: << File.dirname(__FILE__)
in config.ru and in each Sinatra::Base application file, as something got screwed in the ruby-passenger-rack environment, and PassengerRoot is no longer in the Ruby module path.

See? A smooth, seamless upgrade! You almost don't even notice that it happened!

Apache + Passenger + Sinatra

OK, this seems like a pretty normal situation, and like most normal situations it apparently never occurs in nature (judging by the available docs).

An existing Apache webserver is to have a new webapp added to it, in a subdirectory of the DocumentRoot. Sinatra is the framework to be used, and Passenger is going to route requests from Apache to Sinatra without going through any mod_proxy or mod_rewrite business.

Assume the following: Apache2, an Ubuntu system, and all of the relevant gems have been apt-get installed. The web server root directory is /var/www, and the webapp will be in /var/www/timon.

First, update the Apache config file (/etc/apache2/apache2/conf):

<VirtualHost *:80>
  ServerName Apemantus
  DocumentRoot /var/www

  <Directory />
    Options -Indexes
    AllowOverride None
  </Directory>

  <Directory /var/www/>
    AllowOverride AuthConfig
    Order allow,deny
  </Directory>

  SetEnv RUBYLIB '/var/www/timon'
  PassengerEnabled on
  PassengerAppRoot /var/www/timon
  RackBaseURI /timon
</VirtualHost>

The bold lines indicate what must be added.

• SetEnv : This just allows the code in subdirectories of the webapp to be easily required.
• PassengerEnabled : Seems fairly obvious.
• PassengerAppRoot : The full filesystem path to the webapp directory.
• RackBaseURI : The relative (to DocumentRoot) path to the webapp directory.

Next, verify that the Passenger options (/etc/apache2/mods-enabled/passenger.conf) are correct:


<IfModule mod_passenger.c>

  PassengerRoot /usr
  PassengerRuby /usr/bin/ruby
  PassengerMaxPoolSize 10
  PassengerDefaultUser www-data

</IfModule mod_passenger.c>

These options are pretty straightforward. The only thing to note is that PassengerRuby can be set to a specific version of Ruby, e.g. jruby or ruby1.9.

Now, create an empty Rack-friendly directory structure for the webapp:

bash# cd /var/www

bash# mkdir timon

bash# mkdir timon/public

bash# mkdir timon/tmp

The use of public for static pages and tmp for restart.txt is well-documented.

Next, a Rack config file must be provided. This will be named config.ru (/var/www/timon/config.ru) and will have the following contents:

#!/usr/bin/env ruby

require 'rubygems'

require 'sinatra'

# Disable Sinatra's default Webrick instance

set :run, false

# Include timon.rb, the main webapp script

require 'timon'

run Sinatra::Application

Finally, the app itself must be provided. This will be named timon.rb (/var/www/timon/timon.rb) and will have the following contents:

#!/usr/bin/env ruby

require 'rubygems'

require 'sinatra'

get '/' do

  "<b>TIMON!</b>"

end

# Local 404 handler

not_found do

  "Timon NotFound exception"

end

# Local error handler

error do

  "Timon Error: " + env['sinatra_error'].name

end

Debugging can be made a bit more straightforward by adding some basic logging code to config.ru:

#!/usr/bin/env ruby

require 'rubygems'

require 'sinatra'

# Disable Sinatra's default Webrick instance

set :run, false

# Local logging

FileUtils.mkdir_p 'log' unless File.exists?('log')

log = File.new('log/sinatra.log', 'a')

$stdout.reopen(log)

$stderr.reopen(log)

# Include timon.rb, the main webapp script

require 'timon'

run Sinatra::Application

That's it.

Nothing much to it, really, but the lack of RackBaseURI in the relevant examples really makes debugging this kind of thing difficult.

Ubuntu, bluetooth, and the E70

A few quick notes on connecting a phone (in this case the venerable Nokia E70, the last with the excellent gull-wing keyboard design) to ubuntu via bluetooth.

Assuming the kernel modules and all necessary utilities (bluetooth, bluez, obexftp, obexfs, obecpushd, obex-data-server, irda-utils, cobex, gammi, kbluetooth) are installed, the first step is to create an rfcomm device:

mknod /dev/rfcomm0 c 216 0

Next, bind the device to the phone's bluetooth MAC address:

sudo rfcomm bind 0 00:12:D1:AD:FD:5E

The MAC address can be obtained using

hcitool scan

Note that the link and the bind have to be performed at boot; the file /etc/bluetooth/rfcomm.conf can be modified to perform this (it contains a sufficiently clear example).

Once these steps are performed, utilities like cobex and kbluetooth should just work.

With the E70, though, they don't, so it's necessary to use Obex to get data to and from the device.

The standard, longhand way to do this is with obex-ftp:

obexftp -b $MAC_ADDR -B 11 -l

The -b option is the bluetooth MAC address; the -B option is the channel (usually 10 or 11), and the -l option is the command to execute (ls). The man page lists commands.

Better that obexftp is obexfs, which mounts the phone as a filesystem:

mkdir ~/e70
obexfs -b $MAC_ADDR -B 11 ~/e70

This mounts the phone at the mount point ~/e70, where its phone and MMC memory can be accessed directly.

Toshiba R500 Backlight Button

Keep forgetting to u/l this script for toggling the r500 backlight using toshset:

#!/bin/sh

TOSHSET=/usr/local/bin/toshset

STATE=`sudo $TOSHSET -trmode 2>/dev/null | grep -a transreflective | \
cut -f 3 -d ' '`

if [ $STATE = "on" ]
then
NEW_STATE="off"
else
NEW_STATE="on"
fi

sudo $TOSHSET -trmode $NEW_STATE

Xev shows the keycode for the backlight (and the 'i' internet/information/idiot key, so they'll both do the same thing) to be 180, which is already taken by XF86HomePage in Ubuntu. If for some reason this key is undefined (i.e. nothing shows up on `xmodmap -pke | grep '^keycode 180'`), add the following line to ~/.Xmodmap (which might need to be symlinked to ~/.xmodmaprc on non-Ubuntu Linuxes):

keycode 180 = XF86HomePage

In E17, edit the keyboard bindings using Settings-> Settings Panel -> Input -> Key Bindings. For XF86HomePage, select the Launch : Defined Command option, and point it to the above shell script (e.g. in ~/bin).

Note that the script uses sudo to launch toshset, so you will either need to change this to invoke an GUI sudo program like gtksu, or add a line like the following to /etc/sudoers:

$USER ALL=(root) NOPASSWD: /usr/local/bin/toshset

where $USER is your username. Note that this allows any toshset command to be run as root without a password from this user's session, which could be exploited if someone were sufficiently motivated.

Insipid Ibex

Finally upgraded (K)Ubuntu to 8.10. Thanks for breaking my xorg config, guys, by assuming that HAL could actually do a better job that my hand-picked settings. This is easily fixed by uncommenting all of the lines commented out by HAL, but it's amazing that it had to be done at all, since the HAL change made X flat-out stop working. Also, for some reason, ~/.xsession no longer works -- one has to use ~/.xsessionrc instead. Those wacky Ubuntites.

Upgraded E17 shortly afterwards, using the packages at

deb http://greenie.sk/ubuntu intrepid e17

The new version of E has compiz support (which has to almost entirely be disabled for it to run at E17's proper speed) and looks nice. The modules all seem to work, for once.

But it crashes!

The first one came immediately, and was fixed by wiping ~/.e, which contained all of my old config settings. Apparently E17 can't reliably be upgraded with an existing config. Thanks for moving to a binary config file, guys, so that this is actually a far larger problem than it should be. Really, how hard is it to use the binary config only at runtime, and compile from text to binary whenever a config change is made?

Some of the other crashes appear to be from the OpenGeu inclusion of compiz. After removing the calls to emerald and ecomorph from enlightenment_startup.sh, and stripping out the -evil command line option (which, along with -good and -psychotic, did not seem to make things stable), it's become pretty stable, if a little buggy. Dialog boxes occasionally do not disappear when closed, requiring a restart of E17.

Also, some E17 idiocies remain -- things that seemed to be oversights before, but now (having been a pretty stable WM for the past three years) appear to be truly asinine design decisions.

Specifically:

* There is no way to modify the properties of an application (short of adding it to iBar, or modifying the desktop file directly). A dialog exists for this (it's used by ibar and when creating a new application), so it can't be much extra work.

* One cannot cut/copy/paste between E17 widgets and X. This is nice to be able to do when, say, setting an icon file path (since the desktop files for KDE applications do not seem to be handled correctly by E17, and therefore have no icon files). Hope you like typing.

* The binary only config, mentioned above. Really, there is no excuse for this -- the rest of the industry learned that lesson in the 90s. Even Windows allows its abhorred registry to be read from and written to text files.

Aside from that, Ibex works well, and the upgrade was generally painless. The only sticky points were the Xorg conf file (their mistake), E17 (my fault for running it), and the patch I needed to add to get toshset supported by the latest kernel (the maintainer's fault, for not getting it merged after 2 years of reliable performance).

DNS

DNS timeouts have been pretty bad lately; decided to take action and make resolve.conf actually be usable. Of course, it gets overwritten every time DHCP is used to configure an interface, so the name servers have to be added to dhclient.conf .

There are quite a lot of reliable servers to choose from:

OpenDNS
TechFAQ public dns server list
dnsserverlist.org
dnsserverlist.org organized by round trip time

The last two are particularly useful: dnsserverlist.org recommends three DNS servers based on your current IP, and provides an option for sorting their list by round-trip-time.

"Permanent" DNS servers can be added by editing /etc/dhcp3/dhclient.conf and adding 'prepend domain-name-servers' lines:

prepend domain-name-servers 216.224.112.14;
prepend domain-name-servers 67.198.198.213;
prepend domain-name-servers 69.111.95.106 ;
prepend domain-name-servers 208.67.222.222;
prepend domain-name-servers 208.67.220.220;
prepend domain-name-servers 4.2.2.1;
prepend domain-name-servers 4.2.2.2;
prepend domain-name-servers 151.197.0.38;
prepend domain-name-servers 151.202.0.84;
prepend domain-name-servers 151.203.0.84;

Remember to list these in reverse-order: the last server prepended will be the first line in resolv.conf.

The ultimate solution, of course, is to set up a local caching DNS server.

Nightly Tester Tools

Got sick of the Intel driver crashing X11, and Ubuntu releasing their upgraded packages only on the recent version (Horny Heron or something). Bit the bullet, did the upgrade, and...

...Firefox 3beta got installed! What the hell?!? Poof go all (well, most) of my extensions, you know those handy things I use for, oh, locking down Firefox, anonymous browsing, other small conveniences that make using such a poorly-performing browser worthwhile.

Included in these was Zotero, in which I have quite a number of documents stored for offline viewing, and which *still* has no independent UI for accessing them (even the Open Office plugin requires a running instance of Firefox). Suckfest à la mode, just what I ordered!

A search of the Zotero forums, though, turns up a link to the Nightly Tester Tools plugin, which can be used to run an extension for a previous version of Firefox. Zotero is now up and running on Firefox 3beta.

Version 3 does seem to be a bit faster than 2, and hasn't been too crashy. The theme/extension writers should really get their act together and update/port their stuff before this puppy hits the street.

Pulseaudio, Firefox, Flash 9

Upgrading to the latest flash plugin (9) kills audio in Firefox. Awesome!

Based on the PulseAudio information on http://www.pulseaudio.org/wiki/PerfectSetup
and the library provided by revolutionlinux, it took only a couple of steps to get things working:

cd /usr/src
git-clone http://git.0pointer.de/repos/libflashsupport.git
cd libflashsupport
sudo ./bootstrap.sh
sudo ./configure --prefix=/usr
sudo make
sudo make install

Then restart firefox.

It probably helps to have /etc/firefox/firefoxrc contain the line

FIREFOX_DSP="padsp"

...and to have /etc/asound.conf contain the lines

pcm.!default {
type pulse
}

ctl.!default {
type pulse
}

pcm.pulse {
type pulse
}

ctl.pulse {
type pulse
}

...but libflashsupport is the magic bit.

Git as a backup tool

Recently migrated from CVS to GIT at work, and started to look at other uses of local GIT repositories. Backing up config files in home directories seemed a natural application, and as usual someone else has thought of it, implemented it, and abandoned it:

git-home-history

Getting this built is pretty straightforward:
cd /usr/src
git clone http://jean-francois.richard.name/ghh.git
cd ghh
./autogen.sh
make
make install
cd ~
git-home-history init
vi .gitignore
git commit -a
crontab -e
* */4 * * * /usr/local/bin/git-home-history commit >/dev/null 2>&1

The last line is what should be added to crontab to run this every 4 hours.

There are similar projects for /etc and for general backup:
etckeeper
gibak

Other useful GITisms:
* install tgit
* install qgit
* get vim syntax and filetype plugins from vim-mode-for-git-commits; also check out the GitDiff plugin
* add the following to ~/.bashrc or equivalent:
GIT_PAGER=`which tig`
export GIT_PAGER
* add the following to ~/.vimrc or equivalent:
let git_diff_spawn_mode=1
autocmd BufNewFile,BufRead COMMIT_EDITMSG set filetype=git

e17 profile backup script

Given that E17 uses binary config files, and these may get hosed without warning, it is useful to back them up after making changes.

The following shell script will do just that, via tar:

#!/bin/sh

[ -d ~/.e/backup ] || mkdir -p ~/.e/backup

tar -zcf ~/.e/backup/e17-config-$(date +%F-%T).tgz ~/.e/e

Also worth noting is an improved way of using the E17 profile switching for extending battery life: put a shell script for switching to the battery profile in /etc/acpi/battery.d, and one for switching to the A/C profile in /etc/acpi/ac.d . Note that this occasionally causes E17 to crash (and take X with it), so be conservative.

Current configuration:

• Smoke theme, Darkness startup, Slick icons
• 10 1x1 virtual desktops
• XRENDER engine with Composite disabled
• 3 profiles (AC, battery, and default)
• Run command: uxterm -bg black -fg orange -fa 'xft:Courier New' -fs 11 -hold -e
  
• Shelf (invisible, below windows, shrink:48, all desktops) on upper right-top (Contents: cpufreq, mixer, winselector, battery, deskshow, tclock, temperature, exalt)
• Shelf (invisible, below windows, shrink:60, all desktops) on lower left-left (Contents: Pager)
• Shelf (default, below everything, shrink:40, all desktops, auto-hide) on upper left-top (Contents: Start, IBar, Taskbar)
• Shelf (invisible, above everything, shrink:40, all desktops, auto-hide) on lower right-bottom (C0ntents: IBox)
• Shelf( default, above everything, shrink:48, desktop 0:0, auto-hide) on lower-right-right (Contents: News, Forecasts)

I should note that Forecasts doesn't seem to work at all. I also disabled the screen savers, lock, and power management as they are all a bit crashy.

The screenshot isn't much to look at.

Powertop && Latencytop

Now that most everything is working (sans the crappy TI SD reader) on a good solid kernel, it's time to break stuff by adding powertop and latencytop. Laptop users should play with powertop a bit to find out how to lower their power consumption; latencytop can be useful in debugging lagged or unresponsive applications.

sudo apt-get install powertop

http://www.latencytop.org/

The latencytop patch applies cleanly to 2.6.24.2, and requires CONFIG_SCHEDSTATS be set. Powertop requires CONFIG_TIMER_STATS and suggests many more adjustments while it is running ( though apparently the usbcore.autosuspend advice is deprecated).

On an unrelated topic, now that inttab is gone the settings for terminals (you know, respawn getty and all that) is in tty-specific files in /etc/event.d . Why? Who knows! Maybe they're trying to reduce the AT&Tness of their *nix.