Delete lines inside a file matching a pattern

You can use pattern matching of sed to do so !

sed -i '/pattern/d' filename

Example: To remove the lines containing "server" from foo.txt ,do this

sed -i '/server/d' foo.txt

I felt this usefull often . For more SED tutorials , visit http://www.grymoire.com/Unix/Sed.html

MRTG Start Up Script for Ubuntu

MRTG as a Start Up Service in Ubuntu

I am monitoring a lot of routers and switches of my organization using MRTG ( Multi Router Traffic Grapher ) . It is one of the best tools to give you an overview of bandwidth utilizations, CPU/Memory Utilizations etc. Here is a small bash script to make all these MRTG process act as a service which is automatically start up at reboot.

Details of MRTG

I am using MRTG with RRDTool using routers.cgi script. My MRTG configurations arrangements are like

• Location1 Folder
  • router.cfg
  • switch.cfg
  • servers.cfg
• Location2 Folder
  • router.cfg
  • switch.cfg
  • servers.cfg
• Location3 Folder
  • SubLocation1 Folder
    • router.cfg
    • switch.cfg
    • servers.cfg
  • SubLocation2 Folder
    • router.cfg
    • switch.cfg
    • servers.cfg
  • router.cfg

Keyboard shortcut to Open terminal in Ubuntu

CTRL + ALT + T

is the default key combination to open command line terminal ( BASH terminal ) in Ubuntu. This can be further changed by going to System -> Preferences -> Keyboard Shortcuts

Installing / Uninstalling .deb files in Ubuntu

In Ubuntu , the package files are in .deb files . To install the packages file , you should be having administrative password.

Installing .deb debian package file in Ubuntu

• Double click the .deb file , it will be automatically opened with the GDebi Package manager and you can install it
• From command line , use this command to install a package .
  

  sudo dpkg -i PACKAGEFILE.deb

Uninstalling a package in Ubuntu

• From command line, use this command
  

  sudo dpkg -r PACKAGENAME

tweeting from the BASH terminal

i feel this an awesome script..tweet from command line terminal in linux..
script is as follows:

#!/bin/bash

username="yourUserName" ;
password="yourPassword";

URL="http://twitter.com/statuses/update.xml" ;

if [ $(echo "$1" | wc -c ) -gt 140 ]
then
echo "Whoo: Its more than 140 characters"
exit 0;
fi

result=$(curl -u $username:$password -d status="$1" $URL) ;

exit 0 ;

save this in some file name "tweet" and make it executable ( chmod +x tweet )
And for simplicty add an alias ..
Now tweet from terminal using the command

tweet "tweeting from the command line"

Add file to VLC playlist by right clicking

I found a simple nautilus script which is very usefull for those who usually plays something in VLC. Script to add a file to VLC playlist by simple right clicking on the file .

What to do ?

cd ~/.gnome2/nautilus-scripts

touch "Add to VLC Playlist"

then copy the following to the file "Add to Playlist"

Pre-requisite: Install zenity from your package manager

#!/bin/bash

## Ny Narendra Sisodiya, for SchoolOS
## narendra.sisodiya@gmail.com
## modified by: IRFAN NASEEF P
##             irfan@nitc.ac.in

checkFileType()
{
  file $1 | grep -i "audio" || file $1 | grep -i "video" || file $1 | grep -i "ogv" || file $1 | grep -i "mpeg"
  RES=$?
  if [ $RES -eq 0 ]
  then
      return 0
  else
      zenity --error --title "VLC says: " --text "Error: $FILENAME is not an audio/video file"
      return 1
 
   
   fi
}

IFS=$'\n'
for FILENAME in $NAUTILUS_SCRIPT_SELECTED_FILE_PATHS
do
  checkFileType $FILENAME

  if [ $? -eq 0 ]
  then
    vlc --started-from-file --one-instance-when-started-from-file --playlist-enqueue "$FILENAME"
    
 fi
done

exit 0

################

Then save ..

Now you can see a 'Scripts' option when you right click , and a 'Add to VLC Playlist' in it. Now you can directly add files to playlist by simply right clicking .