How can I write in nth column of a file in awk?

Question

For example:

abc
xyz
123
546

input.txt:

asdad
asdad
adghf
dfytr

I wanted to add the above column in 2nd c

Answer 1

paste is the easiest solution. Here's an awk example that doesn't have to store the entire first file in memory:

awk '{getline second < "example"; printf("%s\t%s\n",$0,second)}' input.txt