Variables in SED command

Shell Programming and Scripting
1

Hi all,

I want write a script to display 5rows at times from a input file.
my out like:
echo " display started"
r1
r2
r3
r4
r5
... Some action items...

again i need next 5 lines.

can you please advise.

2 
#!/bin/ksh
current_line=1
total_line=$(cat input_file | wc -l)
while [ $current_line -le $total_line ]; do
     awk -v c=$current_line 'NR >= c && NR < c+5' input_file
     <Some action items>
     <Some action items>
     ...........................
     ...........................
     $current_line=$(expr $current_line + 5)
done
3

Just thinking...
built-in to some flavors of unix is the more command.
so a

more testfile -n5

??