The environment modules package can be used to dynamically configure your shell environment for different software packages. If you have two versions of the R statistics package you could easily switch between the two using the module command:

$ type -a R
R is /usr/bin/R
$ module load R/2.11.0
$ type -a R
R is /paracel/paracel/biosoft/R/2.11.0/bin/R
R is /usr/bin/R

Ever need to search through all your files for a certain word or phrase? You probably know about the grep command, but did you know it's recursive?

Here's an example. In this case we're searching for the word "modules":

grep -r "modules" .

By using the "-r" switch, we're telling grep to scan files in the current directory and all sub-directories. It will return a list of files the string was found in, and a copy of the line it was found on.

If you'd rather just get the file names and skip the rest of the output, use the "-l" switch, like so:

grep -lr "modules" .

Here's another tip: grep also supports regular expressions, so matching against a wildcard pattern is easy:

grep -lr "mod.*" .

That command will print a list of files containing any word starting with "mod".

You can also use grep to search for multiple words:

grep -r "drupal\|joomla\|wordpress" .

And, of course, grep supports file name wildcards in the standard unix fashion. In this example, grep will search only file names starting with "log":

grep -lr "mod.*" ./log*

GNU screen is a terminal multiplexer. That means you can run multiple terminals inside one terminal. It has other advanced features like detaching/reattaching, which comes in handy when you use a poor network link and you have important jobs running on the remote end.

• Start screen by typing screen in a new shell window.
• To get help, just use “Ctrl-A” then “?”.
• Create a new window: C-a c (Control-a c)
• Switch to the previous window: C-a p
• Switch to the next window: C-a n
• Alternate between two windows: C-a a
• Switch to a window by number: C-a 1 or C-a 2, etc.
• List active screen's: screen -ls
• Re-attach to screen: screen -x or screen -r session_name
• Detach from the window using Ctrl-A d. This will drop you into your shell. All screen windows are still there and you can re-attach to them later.
• To scroll window, press Ctrl + a + [ or Ctrl + a + esc to enter Copy Mode, then scroll up/down using keys j or k or:

   C-u -  Scrolls a half page up
   C-b -  Scrolls a full page up
   C-d -  Scrolls a half page down
   C-f -  Scrolls the full page down

To make your screen a little easier to use, add these lines to the appropriate files and your screen will show a status bar at the bottom with a list of programs running, time, date, etc.

# this is the command used to start a new shell.  The "-" in front means
# it will be a login shell (and will process normal bash startup files).
shell -/bin/bash

defscrollback 2048
vbell off
msgwait 1
msgminwait 1

#dynamic titles
shelltitle '$ | bash'

#Display date and other information in colorred window
hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %{..Y} %Y/%m/%d %0c:%s%A "

# PS1 with the escape sequence for dynamic titles in screen
export PS1='\[\033k\033\\\][\u@\h: \w]\$ '

sudo apt-get install obextool gnome-vfs-obexftp blueman

 ./configure LDFLAGS=-static 

 make LDFLAGS=-all-static