How to operate xsel in Linux?

1. first download xsel in Linux by using this command: sudo apt-get install xsel
   or
   download the xsel(the link is in my other blog–Link Collection)
   modify the ~/.bashrc by vim or emacs
   For example:

   vim ~/.bashrc
   in the last line add: export PATH='~/XselDirectory/'
   source ~/.bashrc //make the operation effective

2. Some operation
   xsel < file //read file content to xsel
   xsel > file //write xsel content to xsel
   xsel // show xsel content
   cat file | xsel -b -i //file to xsel
   cat file | xsel -b -a //add file content to xsel last line

more content can read README in XselDirectory