I have created these files in a particular directory
a_1.txt
a_2.txt
...
..
a_n.txt

Each file has a single line.

I want to write a output file a.txt, which will have concantated value of string from all the files.

which utility should i use. copy, cat or paste????

Can anyone help me for this shell script for this.
thanks a ton in advance.
reagrds
vin