use strict;

 open FH, "foo" or die "Can't open: $!";
 my @recs;
 while (<FH>) {
     chomp;
     push @{$recs[int(($.-1) / 5)]}, split /,?\s/;
 }
 close FH or die "Can't close: $!";

 open FH, ">foo.new" or die "Can't open: $!";
 print FH map join('|', @$_) . "\n", @recs;
 close FH;