Bash - Format a Textfile - Pair every two lines

Question

Hi,

With a simple bash script i generate a text file with many entrys like this:

192.168.1.1
hostname1
192.168.1.2
hostname2
192.168.1.3
hostname3

Now i want to reformat this file, that it looks like this:

192.168.1.1 hostname1
192.168.1.2 hostname2
192.168.1.3 hostname3

Some ideas to solve this? Sed maybe?

Thanks for help and best regards. :)

Answer 1

$ sed '$!N;s/\n/ /' infile
192.168.1.1 hostname1
192.168.1.2 hostname2
192.168.1.3 hostname3

Answer 2

Here's a shell-only alternative:

while read first; do read second; echo "$first $second"; done