How to add a column from other file?

view full story

http://www.unix.com – Dear all, Lets say, I've a file a.txt containing two columns, like Code: a1  b1 ..  .. ..  .. and another file b.txt containg two columns, like Code: a1  c1 ..  .. ..  .. I need to put c1 column from b.txt file to the a.txt file. So, the output should be Code: a1  b1  c1 ..  ..  .. ..  ..  .. Do anyone can help me ASAP? Any suggestion appreciated. (HowTos)