Let’s assume you downloaded a PDF file with 700 pages. But you want to send by email only pages 7 to 27.
Ghostscript to the rescue! Available in every UNIX/Linux distribution, you can leverage the gs command to do this.
gs -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dSAFER / -dFirstPage=7 -dLastPage=27 / -sOutputFile=name_of_outfile.pdf name_of_inputfile.pdf
To perform basic HTTP benchmarks against a web application, you can start with ab – Apache HTTP server benchmarking tool. 
If you use Ubuntu, the installation is very simple:
sudo apt-get install apache2-utils
I used this tool to benchmark NeoQuotes application, testing how Jetty with JRuby-Rack are performing against multiple concurrent requests.
First, start up Jetty with mvn jetty:run or with the command defined in project Procfile (sh target/bin/jruby -S config/jetty.rb for NeoQuotes).
Next, execute multiple times the following command:
ab -n 10000 -c 25 http://localhost:8080/
where n = number of requests and c = concurrency level.
Is worth to look to the number of requests per second, that are increasing every time the benchmark is executed. This happens thanks to JIT!
Below some results after running ab -n 10000 -c 25 http://localhost:55012/ three times in a commodity hardware (all tests were performed on the application homepage where there is no interaction with Neo4j and no cache mechanism is configured):
First execution:
Time taken for tests: 73.162 seconds Requests per second: 136.68 [#/sec] (mean)
Second execution:
Time taken for tests: 67.006 seconds Requests per second: 149.24 [#/sec] (mean)
Third execution:
Time taken for tests: 65.725 seconds Requests per second: 152.15 [#/sec] (mean)
Also, take a look at Min and Max threads of Jetty QueuedThreadPool, at config/jetty.rb configuration.
Depending of your hardware and your VM configuration,the more threads you configure into min and max, the worse your throughput gets when your VM starts to reach its resource limits.
Recently I encountered myself executing so many times the following unix commands:
1: $ netstat -anp | grep :port_number
2: (search manually the output for the PID that is using the given :port_number)
3: $ kill -9 :pid
Bored, I challenged my friend Alisson to build a command to perform those three steps, in one single line.
He came up with the following solution:
Coderwall
Githubkill -9 $(sudo netstat -anp | grep :[port_number] | awk '{print $7}' | cut -d '/' -f 1)
Congratulations man! You deserve a very cold Heineken!
Still using Subversion?
Are you using Ubuntu, under a network which has a proxy configured?
And, after installing the Subclipse Eclipse plugin you are getting the “RA layer request failed” error?
Configuring proxy by entering the address and port number in Eclipse preferences will not solve this.
Proceed with the following:
Note: Make sure you don’t leave a space before the statements after uncommenting the two lines as said above, else you are likely to get the error Cannot map the project with svn provider.
ps: tested using Ubuntu 10.04; SVN interface: JavaHL (JNI) 1.6.6
sudo apt-get install libsvn-java, to install the JavaHL interface.
The default installation dir is: /usr/lib/jni
If Eclipse do not pick automatically this directory, add the following line to your eclipse.ini, as a argument bellow of “-vmargs”:
-Djava.library.path=/usr/lib/jni
sorces:
http://varshamyspace.blogspot.com/2010/08/setting-up-proxy-for-subclipse-in.html
http://islandlinux.org/howto/installing-javahl-subclipseeclipse-ubuntu
For windows follow the follow blog:
http://java-espresso.blogspot.com/2011/09/orgtigrissubversionjavahlclientexceptio.html
Very useful Nautilus plugin:
nautilus-open-terminal is a proof-of-concept Nautilus extension
which allows you to open a terminal in arbitrary local folders.
To install this quick launch to the terminal, simply run:
sudo apt-get install nautilus-open-terminal
and restart your gnome session for the change to take effect.
Afterwards you’ll have a “open terminal” button on your right-click menu anywhere within nautilus or gnome-desktop area.
Localize o diretório de instalação do Firefox, mais precisamente a pasta “firefox-addons/plugins” (normalmente em: /usr/lib/firefox-addons/plugins).
A JDK contém o plugin para o browser. Está localizado em:
<JDK>/jre/lib/i386/libnpjp2.so
Apenas um plugin do java pode ser utilizado pelo navegador. Portanto elimine qualquer link simbólico que aponte para javaplugin-oji.so e libnpjp2.so.
Feito isso, crie um link simbólico para o plugin distribuído com a JDK, utilizando o comando abaixo:
/usr/lib/firefox-addons/plugins$ sudo ln -s <JDK>/jre/lib/i386/libnpjp2.so
Reinicie o Firefox, e digite about:plugins na barra de endereços. Localize o plugin do java, confirmando a instalação.
Muito obrigado!!!
Registro aqui alguns passos para instalação da Sun JDK 6 no Ubuntu (10.04 – lucid), para fins de consulta pessoal. Se foi útil para você, deixe seu registro.
Abra o arquivo ~/.profile com o editor de sua preferência e adicione no final do arquivo:
JAVA_HOME=/usr/local/java/jdk export JAVA_HOME PATH="$JAVA_HOME/bin:$PATH"
obs.1: repare na utilização do link simbólico na variável de ambiente JAVA_HOME
obs.2: para executar alguns dos comandos listados serão necessárias permissões de super usuário.
Dharmvir Singh and 
mtn are discussing. 
Yves is discussing. 
Im facing the same problem but on windows 7 instead of ubuntu