Terminal command equivalent of PHP implode when combining lines

Question

I have a couple of lines and want to group the line into 5 and then implode it for MySQL IN () query.

I have made it out until this

awk          


        

Answer 1

pr is the tool for this

$ seq 6 | pr -5ats,
1,2,3,4,5
6

$ seq 18 | pr -5ats, 
1,2,3,4,5
6,7,8,9,10
11,12,13,14,15
16,17,18