#!/apps/perl5/bin/perl -w

use strict;
use Getopt::Long qw(GetOptions);
use File::DirSync;

my $usage   = undef;
my $rebuild = undef;
my $nocache = undef;
my $verbose = undef;
my $localmode = undef;
my $concur  = undef;
my $skew = undef;
my $gentle = undef;
my $proctitle = undef;
my @ignore  = ();
my @only    = ();

GetOptions
  ("help"    => \$usage,
   "rebuild" => \$rebuild,
   "nocache" => \$nocache,
   "verbose" => \$verbose,
   "skew"    => \$skew,
   "ignore=s"=> \@ignore,
   "only=s"  => \@only,
   "local"   => \$localmode,
   "concur=s"=> \$concur,
   "gentle=s"=> \$gentle,
   proctitle => \$proctitle,
   ) || &usage();

$| = 1 if $verbose;

&usage() if $usage;

my $maxskew = (defined $skew) ? 0 : undef;
my $dirsync = new File::DirSync {
  verbose => $verbose,
  nocache => $nocache,
  localmode => $localmode,
  maxskew => $maxskew,
};

if ($concur) {
  $dirsync->lockfile( $concur );
}

if ($gentle) {
  my ($percent,$ops) = split /:/, $gentle;
  if ($percent and $percent =~ /^\d+$/) {
    if ($ops) {
      if ($ops !~ /^\d+$/) {
        usage("Invliad OPS setting for --gentle=[PERCENT:OPS] option.");
      }
    } else {
      $ops = undef;
    }
    $dirsync->gentle($percent, $ops);
  } else {
    usage("Invalid PERECNT setting for --gentle=[PERCENT:OPS] option.");
  }
}

$dirsync->proctitle if $proctitle;

my $dir_from = shift;
my $dir_to = shift;

if ((!defined $dir_from) || (!length $dir_from)) {
  &usage("Missing <source_dir>\n");
}

if (!$rebuild &&
    ((!defined $dir_to) || (!length $dir_to))) {
  &usage("Missing <dest_dir>\n");
}

if (!-d $dir_from) {
  &usage("Not a directory [$dir_from]\n");
}

$dirsync->ignore( @ignore );

if ($rebuild) {
  foreach my $dir (@only) {
    if ($dir =~ /^$dir_from/) {
      $dirsync->only( $dir );
    } else {
      &usage("$dir is not a subdirectory of $dir_from\n");
    }
  }
  $dirsync->rebuild( $dir_from );
}

if ($dir_to) {
  $dirsync->dirsync( $dir_from, $dir_to );
  exit;
}

sub usage {
  if (@_) {
    print STDERR @_;
    sleep 2;
  }
  my $me = $1 if $0 =~ m%^([\w\.\-/]+)$%;
  %ENV =( PATH => "/bin:/usr/bin:/usr/local/bin",
          TERM => $ENV{TERM} );
  exec perldoc => $me
    or exit 1;
}

__END__

=head1 NAME

dirsync - Syncronize two directories rapidly

$Id: dirsync,v 1.15 2007/08/04 07:33:29 rob Exp $

=head1 SYNOPSIS

  # Rebuild the source cache for rapid updating.
  dirsync  [ options ]  --rebuild  <source_dir>

  # Quickly update source to destination.
  dirsync  [ options ]  <source_dir> <dest_dir>

    -or-

  # Mirror source to destination ignoring cache.
  # (almost like: cp -a <source_dir>/. <dest_dir>/.
  #  except files may be deleted in destination
  #  to ensure exact consistency with source.)
  dirsync  [ options ]  --nocache <source_dir> <dest_dir>

=head1 DESCRIPTION

This is just a wrapper script for easy commandline
access to File::DirSync.  It mirrors all files and
symlinks recursively from source_dir to dest_dir.

=head1 OPTIONS

=head2 --help (or -h)

Show this help screen

=head2 --rebuild (or -r)

Rebuilds the dirsync cache on source_dir.
Write access to source_dir is required to rebuild.
If dest_dir is not specified when this option is,
then nothing is mirrored to anywhere after the
cache is rebuilt.

=head2 --local (or -l)

Local directory only, no recursion.

=head2 --nocache (or -n)

When mirroring from source_dir to dest_dir, do not
assume that --rebuild has built the dirsync cache
on source_dir already.  It is ignored and all files
are mirrored.  This option will significantly slow
the performance of the mirroring process.

=head2 --ignore <dir> (or -i=<dir>)

Avoid recursing into directories named <dir> within
the entire descent of source_dir.  This option
applies to both the --rebuild option and the mirroring
process if a second directory is supplied.  It may be
specified multiple times to ignore several directories.

=head2 --only <node> (or -o=<node>)

If this option is used, this will be the only node
checked for changes, but the cache will still be
rebuilt all the way to source_dir.  This only node
must always be a subdirectory or a file within a
subdirectory of source_dir.  This option only applies
to the --rebuild option.  It may be specified multiple
times to rebuild several nodes.

=head2 --skew (or -s)

Enable clock skew protection.  If a file or directory
is found within source_dir modified in the future,
the timestamp will be reset back to "now" to prevent
corrupting the directory cache into the future.

=head2 --concur <lockfile> (or -c=<lockfile>)

If this option is used, <lockfile> will be used to
ensure that only one dirsync process is running at
a time.  If another process is concurrently running,
this process will immediately abort without doing
anything.  If <lockfile> does not exist, it will be
created.

=head2 --gentle <percent>[:<ops>] (or -g=<percent>:<ops>)

If this option is specified, then dirsync will spend
<percent> % of the time sleeping instead of syncing.
If <ops> is specified, it will perform <ops> disk
operations in between each pause cycle.
If this option is not specified, dirsync will burn
continually until the process has completed.

=head2 --proctitle (or -p)

If this option is specified, the process name will be
modified to show the current operation.  This can be
useful for viewing or monitoring the progress.

=head2 --verbose (or -v)

Show extra details.

=head1 AUTHOR

Rob Brown, bbb@cpan.org

=head1 COPYRIGHT

Copyright (C) 2001-2006, Rob Brown, bbb@cpan.org

All rights reserved.

This may be copied, modified, and distributed under the same
terms as Perl itself.

=head1 SEE ALSO

L<cp(1)>,
L<perl(1)>

=cut