Global search in vi and list results

We use the simple command to search a pattern (or a fragment of text),

:/{pattern}

Sometimes, there would be a few dozens of matches that you want to list and browse quickly.  Use this command,

:g/{pattern}

It lists the search results in one buffer.  If you want to search the pattern case insensitive, add \c in the command, like

:g/\c{pattern}

Monitor disk IO activities on a Linux host

1. Use df first to find all the devices
2. Use iostat

iostat -dx <device> <time-interval>

For example,
iostat -dx /dev/sdb 5

to display disk IO activities every 5 seconds.

Find CPU information on a Linux

A good tip for finding out CPU and 32/64 bit kernel information on a Linux host, at http://www.cyberciti.biz/faq/linux-how-to-find-if-processor-is-64-bit-or-not/

In short, use

uname -a 

and

cat /proc/cpuinfo

Find directory path of the current groovy script

Bash or PHP script has a function that returns the directory path of the current script file.

$my_dir=dirname(__FILE__);

Groovy script lacks such a capability but an alternative is available by calling

def my_dir = new File(getClass().protectionDomain.codeSource.location.path).parent

Skip download when groovy code annotated with Grapes

Grapes is a great utility to manage class path automation when coding with groovy.
http://groovy.codehaus.org/Grape
But it slows down the start-up if there are a lot of dependent jars to download.  Even all the dependent jar files have been downloaded to local m2 and grapes store previously, the download process still takes place, which slow things down unnecessarily.

Use the following options to ask groovy look into local storage directly.
groovy -Dgroovy.grape.autoDownload=false [groovy file path] [arguments ......]

Suppress test stage during maven build

Use
 -Dmaven.test.skip.exec=true
to skip running test cases without skipping test jar build

A class path with all jar files in a folder

Typing in all the jar files to form a class path is not a fun job.  This quick trick may alleviate some of the pain.

export CLASSPATH=`echo $PWD/*.jar | sed 's/ /:/g'`

Customize the "echo" part to get all the files needed.

Such as

export CLASSPATH=`echo $PWD/*.jar . $HOME/lib | sed 's/ /:/g'`