#! /usr/bin/perl -w
    eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
        if 0; #$running_under_some_shell

use strict;
use File::Find ();
use Getopt::Std;

my %opts;
getopts("n:l", \%opts);

my $notice_filename = $opts{n};

if(!$notice_filename || $#ARGV < 0) {
    print "Usage: $0 [-l] -n <copyright-notice> list-of-endings...\n";
    print "\n";
    print "  The copyright-notice should be in a form which has the proper comment\n";
    print "  structure for the files in question.\n\n";
    print "  The list-of-endings should be the suffix for each file of the type\n";
    print "  You wish to change, e.g. .cxx .hxx for files ending in .cxx / .hxx\n\n";
    print "Example usage:\n\n";
    print "$0 -n ../LICENSE-CXX .c .h .cxx .hxx\n\n";
    print "  where ../LICENSE-CXX is a file with the LICENSE in C comment style (e.g.\n";
    print "  what is at the head of most C++ files in the code).\n";
    print "  This will prepend the text of LICENSE-CXX to each file ending in .c, .h,\n";
    print "  .cxx, and .hxx in this directory and all subdirectories of this directory.\n";
    print "  If you do NOT want to descend, then use the -l option.\n";
    
    exit();
}

# get the copyright notice

my $notice;

open(NOTICE, $notice_filename) || die "cannot read $notice_filename: $!";
while(<NOTICE>) {
    $notice .= $_;
}
close(NOTICE);

#$notice = qq{$notice};

#print $notice;

#exit();
# Set the variable $File::Find::dont_use_nlink if you're using AFS,
# since AFS cheats.

# for the convenience of &wanted calls, including -eval statements:
use vars qw/*name *dir *prune/;
*name   = *File::Find::name;
*dir    = *File::Find::dir;
*prune  = *File::Find::prune;

if(!$opts{l}) {
    # Traverse desired filesystems
    File::Find::find({wanted => \&wanted}, '.');
} else {
    opendir(DIRZ, ".") || die "cannot read files in .: $!";
    my @filelist = grep(!/^\.\.?$/  && -f $_, readdir(DIRZ));
    closedir(DIRZ);
    my $file_entry;
    foreach $file_entry (@filelist) {
	&add_notice($file_entry);
    }
    
}
exit;

sub wanted {
    my ($dev,$ino,$mode,$nlink,$uid,$gid);

    (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) 
      && -f _ 
	  && &add_notice($_);
}


sub add_notice {
    my ($file) = @_;
    my $filedata = "";
    my $has_copyright = 0;
    my $ending;
    my $proper_ending = 0;

    foreach $ending (@ARGV) {
	if($file =~ /\Q$ending\E$/) {
	    $proper_ending = 1;
	}
    }

    if($proper_ending) {
	open(F, $file) || die "cannot read $file: $!";
	while(<F>) {
	    $filedata .= $_;
	    $has_copyright = 1 if($_ =~ /copyright.*all\s+rights\s+reserved/i);
	}
	close(F);
	
	$has_copyright=1 if $filedata =~ /\Q$notice\E/m;
	
	if(!$has_copyright) {
	    # rename the file
	    rename $file, "$file.bak" || "cannot move file $file out of the way: $!";
	    open(F, ">$file") || die "cannot write $file: $!";
	    print F $notice;
	    print F "\n";
	    print F $file;
	    close(F);
	    print "changing $file...\n";
	} else {
	    print "skipping $file (already has copyright...)\n";
	}
    } else {
	print "skipping $file (not proper ending...)\n";
    }
}