Shell Programming and Scripting

#!/usr/bin/perl

# Just modify the following two variables
$NUM_LINES=10;
$HEADER_STRING="This is my header";

$count=0;
$file_num=0;

while (<>) {
  if ( $count == 0 ) {
     $filename = join("","file",$file_num);
     open( FILE, ">> $filename" );
     print( FILE "$HEADER_STRING\n" );
     print( FILE "$_" );
     $count++;
  } elsif ( $count == $NUM_LINES ) {
     close( FILE );
     $count = 0;
     $file_num++;
  } else {
     # just write the line!
     print( FILE "$_" );
     $count++;
  }
}

awk -v rows=3 -v filespec=outfile%03d '
    NR == 1 { 
        header = $0
        next
    }
    (row++ % rows) == 0 { 
        close(filename)
        filename = sprintf(filespec, ++filecount)
        print header > filename
    }
    {print $0 > filename}
' infile

$ head infile outfile???
==> infile <==
h1
d1
d2
d3
d4
d5
d6
d7

==> outfile001 <==
h1
d1
d2
d3

==> outfile002 <==
h1
d4
d5
d6

==> outfile003 <==
h1
d7