Productivity: De-activate social networking on a schedule with cron

Sometimes you need to block out distractions for a set amount of time. One of these is social networking, and it’s fairly early to temporarily break it (all for productivity of course!).

Mac or Linux users can break example.com like this:

echo "127.0.0.1 example.com www.example.com" >> /etc/hosts

This tells the computer that it hosts example.com, so it wont load it from the internet.

And to compliment this, we have sed, which can delete lines from a file in-place based on a pattern:

sed -i '/example.com/d' /etc/hosts

Replace example.com above with your social network of choice, and have a shot. It will take a few minutes to have an effect, because of open connections and your computer’s DNS cache.

Scheduling it in

Cron is the go-to solution for scheduling any command on Unix. We’ll run this as root, as normal users don’t have permission to edit /etc/hosts:

su
crontab -e

If prompted, select nano as an editor.

If, for example, 6pm — 8pm weekdays is a distraction-free time for you, you would schedule the first command for 18:00 on days 1-5, and the second for 20:00 on days 1-5:

# m h  dom mon dow   command
0 18 * * 1-5 echo "127.0.0.1 example.com www.example.com" >> /etc/hosts
0 20 * * 1-5 sed -i '/example.com/d' /etc/hosts

If your use case calls for something more advanced, consider learning how to use squid to manage web traffic.

When you break something..

If you accidentally delete your /etc/hosts while experimenting, you can fetch its contents from /var/lib/dpkg/info/netbase.postinst (source).

QJoyPad update

As of April, there is now a qjoypad package available in the official Debian repository, see https://packages.debian.org/unstable/main/qjoypad. This program allows you to map joystick events to keyboard and mouse actions. This means that you could use, for example, a USB gamepad to browse the web.

I have previously blogged about the lack of usable, packaged programs to do this, and highly recommend getting your hands on a USB gamepad and giving this a shot. Depending on your distribution, you will soon be able to just run:

sudo apt-get install qjoypad

Then connect the gamepad and type:

qjoypad

You then get a window which shows you what buttons you can map:



Clicking a button prompts you to press a key on your keyboard or select a mouse button, and each profile can be saved and named for later use.

As far as small utility programs go, I now rely on this about as much as the Gnome calculator.

An alternative: AntiMicro

I’ll also give a mention to AntiMicro, which has similar goals, and looks very promising.

As a bit of background, there is a limitation in QJoyPad around adding modifier keys: For example, you simply can’t map a joystick button to <Ctrl>+Q, making it inefficient to use with most applications. The author of AntiMicro, Travis, sent me an email back in September to point out that his program both solves this issue, and has a Debian package available for download.

Whilst I was quite impressed with the functionality in AntiMicro, I found it a whole lot more complex to set up. I think this would be more useful for gamers, as mouse acceleration and key repeats are overkill for my use case (browsing the web and controlling VLC, MythTV, etc).

So, if you are a power user, then I suggest you give it a shot. Power users with apt-get may also consider joy2key, which is the best non-GUI tool for this, and is available in the Debian repositories.

A tour of ReactOS 0.3.15

ReactOS is a project which aims to create an open source operating system which is binary-compatible with Windows. Although it is still cautiously labelled “alpha”, its basic use is about as reliable as Windows once was.

This post runs through the steps to install ReactOS 0.3.15 as a KVM guest on Linux.

Preparation

Before attempting anything, check that you a CPU supports Intel VT or AMD-V. This command will return the number of CPU cores with svm or vmx flags:

cat /proc/cpuinfo | grep -E 'svm|vmx' | wc -l

Now download the ReactOS 0.3.15 disk from reactos.org, extract it to get the .iso, and fetch some packages if you don’t have them installed:

apt-get install libvirt-bin kvm qemu-utils

Prepare a disk image to install to. If your hardware is slower, then a raw image is a better idea than the qcow2:

qemu-img --help
qemu-img create -f qcow2 reactos.img 4G

The working directory now has:

mike@mikebox:~/vm/reactos$ ls -Ahl
total 77M
-rw-r--r-- 1 mike mike  77M May 19  2013 ReactOS-BootCD.iso
-rw-r--r-- 1 mike mike 193K Jan 30 21:05 reactos.img

Installation and first boot

The kvm command will pop up a window with the guest operating system. To boot from the install disk, run:

kvm -hda reactos.img --cdrom ReactOS-BootCD.iso -vga std -localtime -net nic,model=ne2k_pci -net user

The meaning of each of these options is:

-hda reactos.img
Sets the HDD image file.
--cdrom ReactOS-BootCD.iso
Sets the CDROM image file. Because reactos.img is blank, this will boot.
-vga std
Sets the VGA card.
-localtime
Emulates a system clock in local time, rather than UTC.
-net nic,model=ne2k_pci
Sets the network card to something ReactOS will recognise.
-net user
Enables user-mode networking. Your computer will emulate a network and pass on TCP and UDP connections. This is the easiest mode to use, but ICMP packets (such as pings) will not work, and the VM will not be accessible from other computers.

Installation was fast, error-free, and did not require a network connection. The first screen capture below was taken at 16:04:49, and the desktop was captured at 16:06:07 (1 minute 18 seconds later). Most of that time would have been wasted waiting for user input.

ReactOS installer language select
ReactOS install or repair
ReactOS installer disclaimer
Confirm install settings
Select partition
Formatting options for new partition
Formatting confirmation dialog
ReactOS install directory
ReactOS installer copying files
Bootloader options (freeloader)

After copying files, the installer reboots to a more user-friendly mode (similar to the Windows installer):

ReactOS boot menu
ReactOS loading NTOSKRNL.EXE
ReactOS boot screen
ReactOS Install - Installing devices
ReactOS Install - Welcome to the ReactOS Setup Wizard
ReactOS Install - Acknowledgements
ReactOS Install - Personalize your Software
ReactOS Install - Computer name and Administrative Password
ReactOS Install - Regional settings
ReactOS Install - Date and Time
ReactOS Install - Registering Components
ReactOS Install - Completing the ReactOS Setup Wizard
ReactOS desktop after installation

The installed system

After installation, the --cdrom option can be dropped:

kvm -hda reactos.img -vga std -localtime -net nic,model=ne2k_pci -net user

The first thing I did was correct the colour depth, and then attempt to install VLC. This did not turn out well (the console screen is QEMU-monitor):

Reactos display properties
VLC installation in ReactOS Applications Manager
Ctrl+Alt+Del from QEMU monitor
BSOD during VLC installation

I used command prompt to verify that networking was fine (note the lack of ICMP in user-mode networking):

Ping from command prompt with user-mode networking as KVM guest
Testing network on ReactOS

The Firefox 22 install worked, but it went awry after that. Several reboots later I gave up:

Firefox installer on ReactOS
Firefox frozen on startup
BSOD while running firefox on ReactOS

The built-in programs were much more usable:

ReactOS paint
ReactOS paint Save As dialog
ReactOS Explorer
ReactOS Start Menu showing Administrative Tools
ReactOS Device Manager

PuTTY installed flawlessly, and I was able to SSH to the host computer:

PuTTY installation on ReactOS
PuTTY readme in ReactOS notepad
Main PuTTY window after installation
Using command prompt to find host computer address:
PuTTY with host computer address
PuTTY connected to host computer, showing 'uname -a' output

An example of a frozen program causing graphics glitches (Windows up to XP does this as well):


Frozen Application Manager in ReactOS

And an obligatory screenshot of the “Properties for System” dialog, showing the build as 20130518-r59037:


Reactos 'Properties of System' dialog 20130518-r59037

Conclusion

ReactOS is a cool idea and project, but the OS is still very glitchy. The built-in apps are stable and familiar-looking, but you would require a lot of patience (and a lot of rebooting) to use a ReactOS system for more than a few minutes.

Being open source is a big plus, as there is no need to activate the installation or enter software keys. GNU/Linux users will already be accustomed to this.

Recovering auto-saved files in MySQL Workbench

MySQL workbench is an open source tool for designing databases. As version 6.0.8, it is one of those programs where you need to save often, because the window you are working in will vanish every couple of hours.

Bug #1: Can’t recover files that weren’t saved

I was unlucky enough to have forgotten to save my work when it crashed today, and found this nasty flaw in the auto-recover feature:

Auto-save model interval: An open model that has not been saved will automatically be saved after this period. On loading a model file, MySQL Workbench will notify the user if the file was not previously saved correctly, due to a crash or power failure. MySQL Workbench can then attempt to recover the last auto-saved version. For automatic recovery to be available for a new file, it will have to have been saved at least once by the user.

Uh oh! The file hadn’t been saved yet, so it’s gone right? According to wb_model_file.cpp, this is not the case. The auto-save file is always written, but the recovery process wont be started until you try to use it again (which will never happen if you don’t have an old saved version):

/* Auto-saving
 *
 * Auto-saving works by saving the model document file (the XML) to the expanded document folder
 * from time to time, named as document-autosave.mwb.xml. The expanded document folder is
 * automatically deleted when it is closed normally.
 * When a document is opened, it will check if there already is a document folder for that file
 * and if so, the recovery function will kick in, using the autosave XML file.
 */

So under ~/.mysql/workbench/, I found a newmodel.mwbd folder. Workbench files are .zip files in disguise, so I compared it to a test file. It had all the same content, but with a document-autosave.xml, rather than a document.xml (see test file below):

Test archive

Cool, so I’d just rename the file, compress the whole lot and make it a .mwb? No such luck.

Bug #2: File Roller can’t compress ‘@’ files

Possibly because of the -@ command-line option in the zip command, File Roller refused to work with these files.

File Roller bug

Luckily, the document.mwb.xml file alone is enough for the file to be recognised and recovered from the auto-saved files:

File is recovered

The take-away from this? Save your work. In 2014, you still can’t count on auto-save to do this!

Scripted screen captures

This is a script I put together for capturing a window’s contents as it changes, because “Print Screen and crop” gets old very quickly!

It saves me a lot of time when working in virtual machines or creating user docs, as it means that every step (and error message) is captured.

The commands used are in the x11-utils and netpbm and x11-apps packages on Debian.

sudo apt-get install x11-utils netpbm x11-apps

capture.sh

#!/bin/bash
echo "Click a window to start capturing it."
window=`xwininfo -int | grep 'Window id:' | cut -d' ' -f4`
echo -n "Capturing window $window"
prev=""
i=1
empty=`echo -n "" | md5sum | cut -d' ' -f1`
captured="captured.txt"
echo -n "" > $captured
while [ "$prev" != "$empty" ]; do
	md5sum=`xwd -id $window 2> /dev/null | xwdtopnm 2> /dev/null | md5sum | cut -d' ' -f1`
	if grep -Fxq "$md5sum" "$captured"
	then
		echo -n "."
	else
		if [ "$md5sum" != "$empty" ]
		then
			echo $md5sum >> $captured
			echo ""
			echo -n $md5sum
			file=`date --iso`-capture-`printf "%03d" $i`.png
			xwd -id $window | xwdtopnm 2> /dev/null | pnmtopng 2> /dev/null > $file
			i=$[i+1]
		fi
	fi
	sleep 1
	prev=$md5sum
done
echo ""
echo "Empty screen capture received. Quitting. (did you close the window?)"

Example

If you wanted to document a “Malformed Expression” error in Gnome Calculator, you can run capture.sh and then demonstrate it:

$ ./capture.sh
Click a window to start capturing it.
Capturing window 31457283
3bbe32ef05f49ae65922fcfedc842828
c0cef7d3108263fbb1beaa7b52492e6a
fd6df04c4ad844bb4a2f27be29dffb29
6ba0fb7ee1ca85640998013c6a258520.
bb061cc56fa3822f9764c0f6af2156df
5f788568c7f34cda55a1680ac72e1cf0
dca714e6691a3a239914106996905047
0bf916ba3f96f3def57191174e55dea0.
2a4a2589662901d9a55d1e170ffbd322....
Empty screen capture received. Quitting. (did you close the window?)

The lines are checksums of PNM data, and the dots are times when no screenshot was saved. This guarantees that each file in the output is unique:


Example of captured files

The captured.txt file simply contains the list of checksums, and is useless after the script terminates.

Brother HL-2270DW on Linux

The Brother HL-2270DW is one of the best budget laser printers around, with third party consumables readily available on eBay.

The printer has a network port on the back of it, which is great news for GNU/Linux users, because networked printers tend to speak standard protocols.

The fastest way to get this printer working without Windows is to plug it in and log in via the web. The default settings have DHCP enabled. Here are a few pieces of crytic voodoo magic that helped me:

  1. To reset the print server settings, hold “GO” on startup, then let go and press it 6 times.
  2. The default admin login is admin / access
  3. On my printer (Firmware 1.10), printing network settings by holding “GO” for 10 seconds caused the network card (Brother NC-7800w) activity lights to go off, requiring a reboot.

On Debian, there is no “Brother HL-220DW” CUPS driver on the list, but I found the following driver to work fine (and allow duplex):

Brother HL-2170W Foomatic/hpijs-pcl5e (recommended)

To use this driver, you will need to install the HP Linux Printing and Imaging printer driver:

apt-get install printer-driver-hpijs

Missile Launcher on Raspberry Pi

This post covers a few setups to experiment with if you have a DreamCheeky USB missile launcher and a Raspberry Pi.

A newer version is being sold on ThinkGeek, but the one I used was:

DreamCheeky USB Missile Launcher

Setup 1: Direct to PC

The launcher comes with some software to let you connect it straight to a computer. Of course, USB can only go 5 metres, which is not much fun for cubicle warfare:

USB Missile Launcher setup with PC

I included this setup because it is the easiest way for Debian/Ubuntu users to test that they can use this driver, which is needed for the other setups.

Setup 2: Networked with Raspberry Pi

So for this setup, you need a Raspberry Pi Model B. They look like this:

Raspberry Pi Model B

Running Raspbian, upgrade to Debian Jessie, and compile the code:

apt-get install git libusb-1.0-0-dev libncurses-dev gcc g++
git clone --recursive https://github.com/mike42/missile
cd missile
make

You can then place the pi anywhere with network and power:

USB Missile launcher setup with Raspberry Pi

To operate the launcher remotely, use SSH to log in, and run missile/bin/keyboard-ctl.

Setup 3: Wireless with Raspberry Pi and Battery

Of course, network and power can be provided with a power bank and wifi adapter:

Power Bank for mobile phone
USB WiFi Adapter

The wifi adapter will take some work to set up (see Debian Wiki), so I wont document that here. You will need a power bank that has enough power for the Raspberry Pi with launcher and wifi. Mine had to be close to fully charged to work.

An obligatory diagram of this setup:

USB Missile launcher setup with Raspberry Pi (WiFi and Battery)

Wrap-up

The reason this helps with cubicle warfare is simple: The launcher, Raspberry Pi and battery can be fitted into a tissue box or other small space. Proof:

Box interior

On a desk you would see this as:

Box exterior
Box open

And a quick demo for completeness:

In the above, the Pi is connected to DC power, because the battery didn’t have enough juice to power the unit.

Enabling graphical boot on Debian GNU/Linux

Unlike most desktop Linuxes around today, Debian’s default boot screen is still text:

Debian's text-mode booting

I imagine that this is because there is no distinction between “Desktop” and “Server” editions in the Debian world (see tasksel), so a text-mode boot will work on every type of installation.

Luckily, if you want a graphical boot screen, you can simply apt-get install a package called plymouth and configure it according to these instructions.

The result looks more suited to a desktop PC (screen capture from here):

Debian's plymouth boot screen

Plymouth install notes

There is a comment in /etc/default/grub which suggests checking supported graphics modes, which is a Good Idea(TM):

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

The theme for “wheezy” was called Joy, so if you have desktop-base installed, you should:

/usr/sbin/plymouth-set-default-theme joy

I tried to get this working in a virtual machine to get an actual screen capture, but on KVM this appears to be quite tricky, due to emulated graphics.

Installing Debian on a HP dm-1

Getting Debian working on different hardware is always a challenge. This week I am using a HP Pavilion dm1 4306AU.

lspci shows that it has the following hardware:

00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Complex
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler [Radeon HD 7310]
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler HDMI Audio
00:10.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller (rev 03)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode]
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11)
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 11)
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11)
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 11)
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 14)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 01)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11)
00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] FCH PCI Bridge (rev 40)
00:15.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Hudson PCI to PCI bridge (PCIE port 0)
00:15.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Hudson PCI to PCI bridge (PCIE port 1)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 0 (rev 43)
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 6
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 5
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 7
02:00.0 Network controller: Ralink corp. RT3290 Wireless 802.11n 1T/1R PCIe
02:00.1 Bluetooth: Ralink corp. RT3290 Bluetooth
06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)

The Debian installer worked fine, but it booted to a blank screen with a blinking underscore. Steps below to get a working machine.

Fix graphics and wifi

Debian 7 running on a HP dm-1

You need the nonfree firmware in firmware-linux-nonfree. First select ‘recovery mode’ from the boot menu.

From the root terminal, nano /etc/apt/sources.list, and add non-free. Plug in a network cable, then:

apt-get update && apt-get install firmware-linux-nonfree firmware-ralink

After a reboot, you can now get a working desktop and use wifi.

The beep problem

On shutdown, my computer gave a loud PC speaker beep, which could not be muted. The GNOME sound control doesn’t provide a volume bar for the PC speaker, so I installed the gnome-alsamixer package, which has it:

Muting the PC speaker with gnome-alsa-mixer

Strangely, the beep returned after a few reboots, but was no longer as loud.

Brightness keys

The brightness keys did not work originally, but upgrading to “testing” (jessie) fixed this.

Overall

This laptop requires two non-free packages to run, both of which are just firmware blobs.

Writing in Ancient Egyptian with HieroTeX

When I started learning Ancient Egyptian, I wanted to be able to type hieroglyphs alongside regular text, for printing translations. There is a package for the typesetting system LaTeX which does this, called “HieroTeX“. It took me a while to figure out how to use it, but the results are top-notch:

Example of HieroTex output

Because I’ve installed this on quite a few computers, I’m writing up this blog post to make it easier for other GNU/Linux users who are trying to figure it out.

Installation

This is tricky, because:

  • There is no Debian package! Uh oh.
  • Debian is phasing out tetex in favour of texlive
  • The variables.mk file needs to be edited for the install to work (diff to apply / how to apply it). This is because the default installation target is the user’s home directory.

I put togethter this script, hierotex-install-3.5.sh, which will get a working HieroTeX install on any recent version of Debian.

#!/bin/sh
# Script to download and install HieroTeX on a Debian computer.
# Use at your own risk.
#
# Some packages you should install first:
# 	apt-get install texlive make gcc

# Get and extract the files
wget -c "http://webperso.iut.univ-paris8.fr/~rosmord/archives/HieroTeX-3.5.tgz" && 
tar xvzf "HieroTeX-3.5.tgz" && 
cd HieroTeX && 
wget -c "http://webperso.iut.univ-paris8.fr/~rosmord/archives/HieroType1-3.1.4.tgz" && 
tar xvzf "HieroType1-3.1.4.tgz"

# Patch variable.mk to install for the whole system
wget http://mike42.me/blog/files/variable.patch && 
patch variable.mk < variable.patch

# Run the installer
sudo make tetex-install

Note: This page is great, but the variables.mk suggested for Debian/Ubuntu does not include the documentation folder, which will cause the installer to crash. It also suggests using tetex, which will not exist in future Debian releases! This is probably fine if you are on a .rpm-flavoured distro.

How to use

Firstly, you will need to know a little bit about the LaTeX typesetting system. See wikibooks.

HieroTeX accepts markup in Manuel de Codage format, which you will either need to learn, or get a tool which helps you mark up text in it. This Linux for Egyptologists page has some excellent suggestions.

The block of LaTeX code below is from my tex-examples repo, and was used to generate the image of Tutankhamun’s cartouche above.

\documentclass[a4paper]{article}
\usepackage{hiero}
\usepackage{egypto}
\begin{document}
	\section*{Egyptian hieroglyph example}

	\begin{hieroglyph}zA ra < i-mn:n-t-G43-t-S34 HqA-iwn-Sma >\end{hieroglyph} \\
	{\em Tutankhamun Hekaiunushema} \\
	Living Image of Amun, ruler of Upper Heliopolis
\end{document}

To build the file, you need to filter it through sesh command. Something like this would work:

cat hierotex-example.tex | sesh > hierotex-example-2.tex
latex hierotex-example-2.tex

The actual example uses a Makefile to do this.

Update May 2016: The original website for HieroTeX has gone offline, but is available via the Internet Archive: webperso.iut.univ-paris8.fr/~rosmord/archives/