Install IPython on Ubuntu

IPython is a much more powerful shell than the usual Python shell. As Ubuntu and Linux Mint are already shipped with python and pip, installing IPython is trivial:

sudo pip install ipython

Voilà!

Ubuntu wakes up immediately after suspend

Sometimes when you try to suspend the Ubuntu operating system, it wakes up immediately. This is often because certain devices are in “awake” state. To fix it, first you need to find out which device it is. Do:

acpitool -w

You might see output like the following:

   Device	S-state	  Status   Sysfs node
  ---------------------------------------
  1. P0P1	  S4	*disabled
  2. GLAN	  S4	*disabled
  3. XHC	  S4	*enabled

To disable ‘XHC’, do:

echo 'XHC' > /proc/acpi/wakeup

with superuser privilege.

Typical suspects are USB devices. To find out the USB devices in your system, do:

lspci | grep USB

Multiple instances of gThumb on Linux Mint 17

gThumb is my favorite image viewer. However, gThumb 3.2.7 (which comes with Linux Mint 17) has a bug where only one instance of gThumb is allowed. See this bug report. The suggested solution is to use gThumb 3.2.8 which can be grabbed from the Ubuntu 14.10 (Utopic Unicorn) repository.

So, download the .deb files from:
– https://launchpad.net/ubuntu/utopic/amd64/libexiv2-13/0.24-2ubuntu1
– https://launchpad.net/ubuntu/utopic/amd64/gthumb/3:3.3.1.is.3.2.8-0ubuntu1build1
– https://launchpad.net/ubuntu/utopic/amd64/gthumb-data/3:3.3.1.is.3.2.8-0ubuntu1build1

Then, install them:

sudo dpkg -i libexiv2-13_0.24-2ubuntu1_amd64.deb gthumb_3.3.1.is.3.2.8-0ubuntu1build1_amd64.deb gthumb-data_3.3.1.is.3.2.8-0ubuntu1build1_all.deb 

Problem solved. =)

Install TikZ/PGF and PGFPlots on Ubuntu

The installation of TikZ/PGF and PGFPlots on Ubuntu-based distros is mostly straight forward. First, download the latest TDS releases from http://pgf.sourceforge.net/ and http://pgfplots.sourceforge.net/. They are pgf_3.0.1.tds.zip and pgfplots_1.13.tds.zip at the time of writing. Create the directory ~/texmf if it doesn’t exist. Unzip the zip files into ~/texmf:

unzip -d ~/texmf pgf_3.0.1.tds.zip
unzip -d ~/texmf pgfplots_1.13.tds.zip

That’s it!

Install nginx on Ubuntu 14.04

This is yet another guide about how to install nginx on Ubuntu 14.04. nginx is an open source web server that has recently gained popularity. It’s particularly well suited for serving static content.

nginx ver 1.4.6 is available from the official Ubuntu repository, so:

sudo apt-get install nginx

is all you have to do. The configuration file nginx.conf is located at /etc/nginx/nginx.conf. The default configuration is good enough so you don’t have to change anything there. To start serving a static site, just modify /etc/nginx/sites-enabled/default to set the ip address, the root directory, and the domain. See Ubunto nginx doc.

After that, reload nginx by doing either

sudo service nginx reload

or

sudo nginx -s reload

Put an index.html file in the root directory. Then, point your browser to the ip address to see it. Voila!

References:
* Ubuntu nginx doc: https://help.ubuntu.com/community/Nginx
* Official nginx doc: https://www.nginx.com/resources/admin-guide/serving-static-content/
* Introduction to Nginx and LEMP on Ubuntu 14.04 by Justin Ellingwood: https://www.digitalocean.com/community/tutorials/how-to-set-up-nginx-server-blocks-virtual-hosts-on-ubuntu-14-04-lts