#!/usr/bin/perl -w 
use strict;

sub add_header_and_footer_to_files { 
    my @files = @_; 
    my $header = `cat header.txt`;
    my $footer = `cat footer.txt`;
    for my $filename (@files) { 
        my $file = `cat $filename`; 
        open OUT, '>', "new_$filename" 
            or die "Couldn't open $filename.new for writing: $!\n"; 
        print OUT $header, $file, $footer; 
    } 
}

add_header_and_footer_to_files(@ARGV);