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sub batch_from_file {
	my $class = CORE::shift( @_ );
	my $fh = CORE::shift( @_ );
	my $case_inse = CORE::shift( @_ );
	my $max_obj_num = CORE::shift( @_ );  # if <= 0, read all records
	my $use_empty = $_[3];  # fourth remaining argument

	ref( $fh ) eq 'GLOB' or return( undef );

	my @mvh_list = ();
	my $remaining_obj_count = ($max_obj_num <= 0) ? -1 : $max_obj_num;

	GET_ANOTHER_REC: {
		eof( $fh ) and last;

		my $mvh = CGI::MultiValuedHash->new( $case_inse );

		defined( $mvh->from_file( $fh, @_ ) ) or return( undef );

		CORE::push( @mvh_list, $mvh );

		--$remaining_obj_count != 0 and redo GET_ANOTHER_REC;
	}

	# if file is of nonzero length and contains no records, or if it has a 
	# record separator followed by no records, then we would end up with an 
	# empty last record in our list even if empty records aren't allowed, 
	# so we get rid of said disallowed here
	if( !$use_empty and @mvh_list and !$mvh_list[-1]->keys_count() ) {
		CORE::pop( @mvh_list );
	}

	return( \@mvh_list );
}

######################################################################

1;
__END__

=head1 THE DEFAULT URL-ENCODED FORMAT

When the to_url_encoded_string() and from_url_encoded_string() methods and their 
derivatives are used with the fewest number of arguments, they default to an 
encoding format used in query strings, such as $ENV{QUERY_STRING}.  Normal query 
strings look like this:

	name=name&type=textfield&visible_title=What%27s+your+name%3f

Here's another example with a multi-valued field (it is actually a single line, 
but appears on two here for clarity:

	name=color&type=popup_menu&values=red&values=green&values=blue&
	values=chartreuse&visible_title=What%27s+your+favorite+colour%3f

Some query strings are the result of ISINDEX queries, and they look different:

	tell&me&about&stuff

Cookie strings such as $ENV{HTTP_COOKIE} are different yet and look like:

	name=color; type=popup_menu; values=red&green&blue&chartreuse

In the argument lists for the above methods, DELIM refers to the "&" in normal 
query strings and the "; " in cookies, whereas VALSEP is meaningless with normal 
query strings and is the "&" in "isindex" queries and cookie strings.

=head1 THE DEFAULT FILE FORMAT

When the to_file() and from_file() methods and their derivatives are used with 
the fewest number of arguments, they default to an encoding format that is quite 
easy for humans to read.  This common format is capable of storing an ordered 
list of variable-length records where the fields of each record are stored in 
name=value pairs, one field value per line.

Each record can have different fields from the others, and each field can have
either one or several values.  In the latter case, the field name is repeated for
each value.  Records are delimited by lines that contain only a "=" and are
otherwise empty.  The order of individual fields in the file doesn't matter, but
the order of parts of multivalued fields does; this order is preserved.  

All field names and values are url-escaped, so we are capable of storing binary
data without corrupting it.

The following example shows 4 MVH objects encoded in the default format:

	=
	name=name
	type=textfield
	visible_title=What%27s+your+name%3f
	=
	default=eenie
	default=minie
	name=words
	type=checkbox_group
	values=eenie
	values=meenie
	values=minie
	values=moe
	visible_title=What%27s+the+combination%3f
	=
	name=color
	type=popup_menu
	values=red
	values=green
	values=blue
	values=chartreuse
	visible_title=What%27s+your+favorite+colour%3f
	=
	type=submit

This file format is identical to that used by CGI.pm when saving its state, so 
such files could be used and manipulated by either that class or this one as you 
see fit.  Furthermore, this format is identical to that used by the Whitehead
Genome Center's data exchange format, and can be manipulated and even databased
using Boulderio utilities.  (That may not be url-escaped, however.)  See
"http://www.genome.wi.mit.edu/genome_software/other/boulder.html" for further
details.  However, this compatability does not extend to all of Boulderio's 
features, so Boulderio can store more complex data structures than this class.