If it is something like what graff had pointed out then here is a simple solution. I keep track of the count instead of file size as suggested by graff

#!/usr/bin/perl -w

# filename: catskiphead
# Merge files skipping the first line from the seocnd file onwards
my $line = 1;
while(<>) {
    next if ($line++ == 0);
    $line = 0 if eof;
    print ($_);
}
[download]

Input

file1:
header
1
2
3
file2:
header
4
5
6
file3:
header
7
8
9
<p><c>Usage: catskiphead file1 file2 file3
[download]

Output

header
1
2
3
4
5
6
7
8
9
[download]

cheers

SK

PS: Note that you can change the print to take file handles and also do any checking on the input records before you write out.