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File::Find   Module

Note that Find:File always handles files and directories separately, typically
all the files first, then all the directories, though each group is in the
order in which the user sorted them. No option is provided to traverse both
files and directories in either, the order they are sorted into.

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Basic Find File Script and notes.

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use $File::Find;

my %find_opts = (
    preprocess  => \&sort_dir,   # sort the contents of a directory
    postprocess => \&end_dir,    # just mark the end of a recursive step
    wanted      => \&do_files,   # process each item in directory
  );

my $recurse = 1, shift  if $1 eq "-r";

File::Find::find(\%find_opts, "$1" );
exit 0;

sub sort_dir {
  # preprocess
  # this is called after the directory contents have been read
  # with a list of the filenames from that direcory (order?)
  #
  print "Traverse: $File::Find::dir (", scalar @_, ")\n";

  if ( $File::Find::dir eq "/...../this_dir" ) {
      return;  # This prunes all sub-files and sub-dirs from search,
               # but only AFTER the directory was passed to the
               # "wanted=\&do_files" sub-routine;
  }

  return ( sort @_ );  # Sort filenames.
  #return ( sort { $b cmp $a } @_ );  # Sort filenames in reverse order
  #return ( sort { $a <=> $b } @_ );  # Sort filenames numerically
  #return ( @_ );        # Don't Sort filenames.

}

sub end_dir {   # postprocess
  print "   <---: $File::Find::dir\n";
}

sub do_files {

  if ( -d $_ && $File::Find::dir eq "/...../that_dir" ) {
    $File::Find::prune = 1;  # Removes directory from search,
                             # The directory is NOT read, and the
                             # "preprocess=\&sort_dir" is not called
  }

  if ( -d $_ ) {                   # effective way to stop recursion beyond
    $File::Find::prune = $sub_dir; # the sub-directory that was given to
    $sub_dir=!$recurse;            # look at.
  }

  # print "\t$_\n";      # just the name

  printf "\t%-4s $_\n",  # name and file type
         -d $_ ? "DIR" : -f _ ? "FILE" : "???";

  # printf "\t%-4s $File::Find::name\n",    # full file path
  #         -d $_ ? "DIR" : -f _ ? "FILE" : "???";
}
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