0
 ?÷         use warnings ;
    use IO::Compress::Gzip qw(gzip $GzipError) ;

    for my $input ( glob "/my/home/*.txt" )
    {
        my $output = "$input.gz" ;
        gzip $input => $output 
            or die "Error compressing '$input': $GzipError\n";
    }

=head1 OO Interface

=head2 Constructor

The format of the constructor for C<IO::Compress::Gzip> is shown below

    my $z = new IO::Compress::Gzip $output [,OPTS]
        or die "IO::Compress::Gzip failed: $GzipError\n";

It returns an C<IO::Compress::Gzip> object on success and undef on failure. 
The variable C<$GzipError> will contain an error message on failure.

If you are running Perl 5.005 or better the object, C<$z>, returned from 
IO::Compress::Gzip can be used exactly like an L<IO::File|IO::File> filehandle. 
This means that all normal output file operations can be carried out 
with C<$z>. 
For example, to write to a compressed file/buffer you can use either of 
these forms

    $z->print("hello world\n");
    print $z "hello world\n";

The mandatory parameter C<$output> is used to control the destination
of the compressed data. This parameter can take one of these forms.

=over 5

=item A filename

If the C<$output> parameter is a simple scalar, it is assumed to be a
filename. This file will be opened for writing and the compressed data
will be written to it.

=item A filehandle

If the C<$output> parameter is a filehandle, the compressed data will be
written to it.
The string '-' can be used as an alias for standard output.

=item A scalar reference 

If C<$output> is a scalar reference, the compressed data will be stored
in C<$$output>.

=back

If the C<$output> parameter is any other type, C<IO::Compress::Gzip>::new will
return undef.

=head2 Constructor Options

C<OPTS> is any combination of the following options:

=over 5

=item C<< AutoClose => 0|1 >>

This option is only valid when the C<$output> parameter is a filehandle. If
specified, and the value is true, it will result in the C<$output> being
closed once either the C<close> method is called or the C<IO::Compress::Gzip>
object is destroyed.

This parameter defaults to 0.

=item C<< Append => 0|1 >>

Opens C<$output> in append mode. 

The behaviour of this option is dependent on the type of C<$output>.

=over 5

=item * A Buffer

If C<$output> is a buffer and C<Append> is enabled, all compressed data
will be append to the end of C<$output>. Otherwise C<$output> will be
cleared before any data is written to it.

=item * A Filename

If C<$output> is a filename and C<Append> is enabled, the file will be
opened in append mode. Otherwise the contents of the file, if any, will be
truncated before any compressed data is written to it.

=item * A Filehandle

If C<$output> is a filehandle, the file pointer will be positioned to the
end of the file via a call to C<seek> before any compressed data is written
to it.  Otherwise the file pointer will not be moved.

=back

This parameter defaults to 0.

=item C<< Merge => 0|1 >>

This option is used to compress input data and append it to an existing
compressed data stream in C<$output>. The end result is a single compressed
data stream stored in C<$output>. 

It is a fatal error to attempt to use this option when C<$output> is not an
RFC 1952 data stream.

There are a number of other limitations with the C<Merge> option:

=over 5 

=item 1

This module needs to have been built with zlib 1.2.1 or better to work. A
fatal error will be thrown if C<Merge> is used with an older version of
zlib.  

=item 2

If C<$output> is a file or a filehandle, it must be seekable.

=back

This parameter defaults to 0.

=item -Level 

Defines the compression level used by zlib. The value should either be
a number between 0 and 9 (0 means no compression and 9 is maximum
compression), or one of the symbolic constants defined below.

   Z_NO_COMPRESSION
   Z_BEST_SPEED
   Z_BEST_COMPRESSION
   Z_DEFAULT_COMPRESSION

The default is Z_DEFAULT_COMPRESSION.

Note, these constants are not imported by C<IO::Compress::Gzip> by default.

    use IO::Compress::Gzip qw(:strategy);