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

Unless you're really insistent that it need be sed, just pipe it through

paste -d" " - -

Answer 2

This might work for you:

seq 10 | sed '$!N;s/\n/ /'
1 2
3 4
5 6
7 8
9 10

If is not the last line, append the following line to current line and replace the newline by a space.

Answer 3

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 

Answer 4

This is easiest using paste:

paste -s -d' \n' input.txt 

Although there's a Famous Sed One-Liner (38) to emulate this as in potong's answer.

Answer 5

What do you mean by "in a text document"? If you are editing the file with vim, you can do:

:g/./normal J