how can I combine these lines

Question

How can I combine these lines (NOTE: this is just an excerpt from a much larger file):

interface GigabitEthernet0/0
 no ip proxy-arp
interface GigabitEthernet0/0         


        

Answer 1

Try this sed one-liner:

sed 'N;s/\n/ | /;s/\r//g' file.txt