Installing R and R Studio on Ubuntu 13.04 "Raring Ringtail"

Using the mirror at UCLA:

sudo add-apt-repository "deb http://cran.stat.ucla.edu/bin/linux/ubuntu raring/"


Installing the gpg key for R packages

gpg --keyserver keyserver.ubuntu.com --recv-key E084DAB9
gpg -a --export E084DAB9 | sudo apt-key add -

sudo apt-get update

Installing R and the libjpeg62 library needed by R Studio


sudo apt-get install r-base libjpeg62

Getting the pre-built deb package and installing it:

wget http://download1.rstudio.org/rstudio-0.97.551-i386.deb
sudo dpkg -i rstudio-0.97.551-i386.deb

Wacom Tablet Aspect Ratio for Widescreen

Recently purchased a Wacom Bamboo Pen graphics tablet. In its default setup, tracing a coin on the tablet draws an oval (I think that's because the tablet's 4:3 and my monitor is 16:9, but it may be something more arcane due to a dual monitor setup).

This command seems to make the aspect ratio correct whilst allowing me to reach all parts of my main screen.


xinput set-int-prop "Wacom Bamboo Connect Pen stylus" "Wacom Tablet Area" 32 0 00 23175 8600

Preventing Postgresql from Autostarting just because it's Installed on Ubuntu

sudo update-rc.d -f postgresql remove

Upgrading from loop-aes to dmcrypt

Once upon a time, I had an encrypted external disk that I would mount thus:

# losetup -e AES128 /dev/loop1 /dev/sdb1
# fsck /dev/loop1
# mount /dev/loop1 /mnt/wd
# ls /wd


There are those that say that the modern way to do this is:

# apt-get install cryptsetup
# cryptsetup -c aes-plain -s 128 -h sha256 create wd /dev/sdb1

# fsck /dev/mapper/wd

# mount /dev/mapper/wd /mnt/wd

You can then remove the mount with

# umount /mnt/wd
# cryptsetup remove wd

Copying Audio CDs on Ubuntu ( with cdrdao )

You should be able to (assuming that your cd is called foo) rip the data using:

cdrdao read-cd foo.toc

and then write it using:

cdrdao write foo.toc

For various reasons too annoying and mysterious to explain, I ended up using:

sudo cdrdao write --driver generic-mmc-raw foo.toc 

to write, but that's probably just the peculiarities of my dell mini netbook / lite-on external drive

Debian / Ubuntu Package Commands ( apt-get / apt-file / apt-cache )

sudo apt-get update
sudo apt-get upgrade --dry-run
sudo apt-get upgrade


apt-cache search maven     # too much information
apt-cache search ^maven$   # misleading information
apt-cache search mvn       # no information



apt-file search mvn            # too much information
apt-file search ^mvn$          # no information

which mvn
apt-file search /usr/bin/mvn   # glory

apt-cache show maven2          # description and dependencies
apt-cache showpkg maven2       # package info
apt-cache showsrc maven2       # source files

Website Debugging with Curl : The Web Browser of the Gods

The Web Browser of the Gods

watch -d -n 1 curl -sv -b cookiejar.txt -c cookiejar.txt http://localhost:8080

For Gods who are mostly interested in the headers:


watch -d -n 1 curl -sv -b cookiejar.txt -c cookiejar.txt -o delete.me http://localhost:8080

Long Version


Curl's a nice way to analyse what's going on with a website:



When debugging a server running on your own machine:

curl http://localhost

If it's on port 8080

curl http://localhost:8080

If you're after a sub-path

curl http://localhost:8080/favicon.ico

I prefer:

curl -sv http://localhost:8080

-s turns off the information about download percentage, progress
-v adds the details of the header transaction

You can send both data and progress messages to a file with:

curl -sv http://localhost:8080 2&>curl.out

Poll the website every second, highlighting changes with:

watch -d -n 1 curl -sv http://localhost:8080

Pass in a cookie thus:

curl -sv http://localhost:8080 -b "yo=doom"

See the cookies that come back:

curl -sv http://localhost:8080 -c -

Save cookies that come back:

curl -sv http://localhost:8080 -b "yo=doom" -c cookiejar.txt

Or read and write cookies from a cookie file like:

curl -sv http://localhost:8080 -b cookiejar.txt -c cookiejar.txt

Finally, you can throw away the document itself and just display transaction and the cookies with:

curl -sv http://localhost:8080 -b "cook=ie" -c /dev/stderr >/dev/null