Sunday, July 31, 2011

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 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

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

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/ /lib/x86_64-linux-gnu
bash$ sudo ln -s /usr/lib/x86_64-linux-gnu/ /lib/x86_64-linux-gnu

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

./ --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:

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

Upgrading is just as straightforward:

./ --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,;                

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

Friday, July 29, 2011

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!

Monday, July 18, 2011

Pre-defined preprocessor definitions (GCC)

The predef project is extremely convenient for looking up architecture-dependent, os-dependent, compiler-dependent, or standard C/C++ compiler macros, but it is not available when working offline.

To get around this, the preprocessor definitions defined automatically by GCC can be viewed with this command line:

bash$ gcc -dM < /dev/null

#define __DBL_MIN_EXP__ (-1021)
#define __UINT_LEAST16_MAX__ 65535
#define __FLT_MIN__ 1.17549435082228750797

This will output the #define commands as they would be executed by the preprocessor. To get a list of the non-expanded macros, use -dN :

bash$ gcc -dN < /dev/null
# 1 ""
# 1 ""
#define __STDC__
#define __STDC_HOSTED__
#define __GNUC__
#define __GNUC_MINOR__

This is a bit more noisy, as undefined macros (e.g. "# 1") are included, but may be more suitable for parsing.

Sunday, July 17, 2011

/usr/bin/say linux

Anyone who has spent any time fiddling with OS X on the command line will have discovered /usr/bin/say, and incorporated it into a few shell scripts to provide background notifications ("build complete", etc).

While Linux doe snot provide this command out of the box, there is a package called festival which provides text-to-speech capability:

apt-get install festival festival-freebsoft-utils

The usage is quite straightforward:

echo "this is only a test" | festival --tts

A simple alias can be used to replace /usr/bin/say on the command line:

alias say='festival -tts'

A more script-friendly solution would be to create a small wrapper script that passes /usr/bin/say arguments (filenames or STDIN) to festival:

#!/usr/bin/env ruby                                                             

def say(str)
  `echo '#{str}' | festival --tts`

if __FILE__ == $0

Friday, July 8, 2011


Rattle is a useful data analysis UI for R.

Unfortunately, it's a bit hard to get started from a shortcut such as an XDG .desktop file. The usual method (ala Rkward and RCommander), `R_DEFAULT_PACKAGES="$R_DEFAULT_PACKAGES rattle" R`, doesn't work. Instead, one is left doing the `library(rattle); rattle()` commands in an R terminal.

A first stab with Rscript fails:

#!/usr/bin/env Rscript

This starts Rattle, then exits both Rattle and R. Obviously, rattle() is spawning a thread and returning immediately, causing RScript to reach EOF and exit. The same happens when the commands are sent to R, r, or Rscript via STDIN.

Adding a line to wait for an enter keypress seems a likely workaround:

#!/usr/bin/env Rscript

system('bash -c read')

This starts Rattle, and pauses R waiting for an enter key as expected, but Rattle does not receive input. Whatever it's doing for its UI, it is not properly threaded as locking up the parent also locks up the child --- probably some sort of "greenthreads" ala Ruby or Python.

It turns out, however, that this is not an unknown problem. A query of "R_DEFAULT_PACKAGES rattle" turns up pages that provide a fix for the original method: specifying Rattle's dependencies.

The correct command is therefore

 R_DEFAULT_PACKAGES="datasets,utils,grDevices,graphics,stats,rattle" R -q --save

Note the -q, to suppress the startup text, and --save (or, alternately, --no-save) to suppress the confirm-quit message. This should be launched in a .desktop file with Terminal=true. R will still wait around for a q() or Ctrl-D, but that is a small price to pay.