How to add a column from other file?

Shell Programming and Scripting
1

Dear all,
Lets say, I've a file a.txt containing two columns, like

a1  b1
..   ..
..   ..

and another file b.txt containg two columns, like

a1  c1
..   ..
..   ..

I need to put c1 column from b.txt file to the a.txt file. So, the output should be

a1  b1  c1
..   ..   ..
..   ..   ..

Do anyone can help me ASAP? Any suggestion appreciated.

2

Check man page for join . One of the examples therein could solve your problem.

BTW, you've posted this in the wrong forum. Mods, please move the thread.

3

Thanks, actually I'm new in this forum. So, I'll try to move this.

4

Moved. Also please use code tags next time for your code and data, thanks.

5

col 1 in both the file is same