Concatenating every other line with the next

Question

In a text document I want to concatenate every other line with the next. I guess sed is the thing to use? How would this be done?

Answer 1

Simple awk solution:

awk '{getline b;printf("%s %s\n",$0,b)}' file

Test:

[jaypal:~/Temp] seq 11 > file
[jaypal:~/Temp] awk '{getline b;printf("%s %s\n",$0,b)}' file
1 2
3 4
5 6
7 8
9 10
11