Read n lines at a time using Bash

Question

I read the help read page, but still don\'t quite make sense. Don\'t know which option to use.

How can I read N lines at a time using Bash?

Answer 1

Awk is a funny way for this case:

~$ cat test.txt 
tom
tom@gmail.com
jack
jack@gmail.com
marry
marry@gmail.com
gogo
gogo@gmail.com
~$ cat test.txt | awk 'BEGIN{c=1}{a=c;if(a==2){print b" "$0;c=1} if(a==1){b=$0;c=2}}'
tom tom@gmail.com
jack jack@gmail.com
marry marry@gmail.com
gogo gogo@gmail.com