for sLine in $(< url-list.txt); do
  echo "Checking $sLine"
  sStatus=`curl -s -I $sLine | grep -i "HTTP/1.1 "`
  echo -e "\t$sStatus"
  sStatusCode=`echo $sStatus | awk '{ print $2}'`
  if [ "$sStatusCode" -eq "200" ]; then
    echo $sLine >> valid-urls-list.txt
    echo -e "\tValid => \e[33;1m$sLine\e[0m"
  else
    echo $sStatus
    echo -e "\tInvalid => \e[31;1m$sLine\e[0m"
  fi
done

Some websites in North America do allow access to people from the rest of the world. You can access them via publicly available proxy IP addresses in that region. There are many websites that provide lists of proxy IP addresses (http://pastebin.com/search?q=proxies). Some proxies work on a special port. You just need to append the port number to the IP with a colon in between. For example, 46.165.250.235:3128. I usually copy the table to Calc (spreadsheet program) and then data-transform the pasted text to obtain the IP:port combination.

Testing the IPs in the list can be a hassle if you have do it manually using a browser. This BASH script can automate it. Just run it and see which proxy is fast. Press Ctrl+C when you find a good proxy. This script expects the proxy IP addresses to be placed in a file named proxy-list.

sed '/^$/d' proxy-list.txt > proxy-list2.txt

for sLine in $(< proxy-list2.txt); do
  export http_proxy="http://$sLine"
  echo "Testing $sLine"
  wget --spider --timeout=5 --tries=1 http://www.example.com
done
rm proxy-list2.txt

Output of the BASH script to check for working proxy IP addresses.

From the output of this script, you need to pick up those IPs that return “200 OK” status and put in a list of good working proxies. Then, create a new Firefox profile (firefox -ProfileManager) and changes its proxy to one from the working proxies list.

After that, whenever you need to access a site that is not available directly from your ISP, use the new Firefox profile that you created (firefox -P proxy-profile-name). Proxies tend to fail after some time but you can just use another from the list.

The pkill command kills a named application but it does not work all the time. It can even when used with sudo. The good old kill command is the ultimate solution. Hence, I have use this alias in my .bashrc file in the home directory.

alias kll='bash ~/Scripts/kll.txt'

In the script file, I have this code:

for sID in `pgrep $1`
do
  ps $sID
  kill -STOP $sID
done

for sID in `pgrep $1`
do
  ps $sID
  kill -KILL $sID
done

To kill an app, I type kll PROCESS-NAME. If it does not work, I would sudo it.

I was writing a Nautilus Actions Configuration script for adding a directory to the playlist of Audacious (the Winamp clone for Linux).

Strangely, I forgot the name of the app. I did a search for command-line players but could not find it. Even cvlc was not listed. It was listed in the Ubuntu Software Manager. It is called Quark.

Quark calls itself as the anti-GUI player. It sits in the tray and you interact with it using a context menu from the tray – similar to Subhash VCDPlayer.

The GUI command for it is strange-quark. The CLI command is charm-quark.

Here is the script. You need to start the player with strange-quark.

charm-quark clear
for sFilename in $1/*
do
  sExtension="${sFilename##*.}"
  if [ $sExtension = "ogg" -o \
       $sExtension = "OGG" -o \
       $sExtension = "mp3" -o \
       $sExtension = "MP3" -o \
       $sExtension = "wav" -o \
       $sExtension = "WAV" -o \
       $sExtension = "wma" -o \
       $sExtension = "WMA" ] 
  then
    charm-quark append "$sFilename"
    echo "$sFilename" 
  fi    
done
charm-quark play

Here is another script to load a directory in Audacious2. There is some difficulty when reading pathnames with spaces. There are a few roundabout ways to do this. My solution is to just cd into the directory.

cd "$1"

for sFileName in *
do
  sExtension="${sFileName##*.}"
  if [ $sExtension = "ogg" -o \
       $sExtension = "OGG" -o \
       $sExtension = "mp3" -o \
       $sExtension = "MP3" -o \
       $sExtension = "wav" -o \
       $sExtension = "WAV" -o \
       $sExtension = "wma" -o \
       $sExtension = "WMA" ]
  then
    sPlayList="$sPlaylist $1/$sFileName"
  fi
done

audacious2 -E "$sPlaylist" &
audacious2 -p &

Encrypted PDF documents can have two passwords – owner and user. Shortly after I wrote the article “How To Remove Passwords From PDF Documents Using Linux Bash Command Line” (https://vsubhash.wordpress.com/2013/08/06/how-to-remove-passwords-from-pdf-documents-using-linux-bash/), ICICI Bank changed its system so that they now sent PDF documents encrypted with an owner password. pdftk was not going to work. qpdf to the rescue.

• Install qpdf.

  sudo apt-get install qpdf
  

• Create a text file at some location in your computer (with extension txt as a precautionary measure). Replace my username (comacho) with yours.

  read -p "Enter pathname of PDF for encryption: " sInputFileName
  sOutputFileName=$(basename "$sInputFileName")
  sOutputFileName=/home/comacho/Desktop/${sOutputFileName%.*}-unencrypted.pdf
  stty -echo
  read -p "Enter password to decrypt PDF: " sPassword
  stty echo
  qpdf --password=$sPassword --decrypt "$sInputFileName" "$sOutputFileName"
  

To decrypt PDF, just use the following command in Terminal:

sh path-to-the-txt-file

It will ask you for the pathname of the file. Copy the pathname of the file and paste it into the terminal. Next, it will ask you for the password (it will not be echoed to the screen). Then, your document will be decrypted and saved to your desktop.