addition of text upper and lower end of file

Hello folks,

I have a file that size is over 20GB. if i open in vi it takes ages. i want to add three lines at the top of file and three lines at the end of files. lines are as follows

upper three lines

114444bbbbbb
dddd4544d4cc
rrrr4dddddddd5

at the end of file need to add three lines.

ppppp44ppppp
ttttt55ppeeeep
yyy33pprruuuu

#!/usr/bin/perl
open (FILE, "myfile");

print "114444bbbbbb\n";
print "dddd4544d4cc\n";
print "rrrr4dddddddd5\n";

while (<FILE>)
{
print $_;
}

print "ppppp44ppppp\n";
print "ttttt55ppeeeep\n";
print "yyy33pprruuuu\n";

echo "114444bbbbbb
dddd4544d4cc
rrrr4dddddddd5
$(cat file)
ppppp44ppppp
ttttt55ppeeeep
yyy33pprruuuu" >file