io::compress::zip.3

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

\&    use IO::Compress::Zip qw(zip $ZipError) ;
\&
\&    my $input = "file1.txt";
\&    zip $input => "$input.zip"
\&        or die "zip failed: $ZipError\en";
.Ve
.PP
To read from an existing Perl filehandle, \f(CW$input\fR, and write the
compressed data to a buffer, \f(CW$buffer\fR.
.PP
.Vb 4
\&    use strict ;
\&    use warnings ;
\&    use IO::Compress::Zip qw(zip $ZipError) ;
\&    use IO::File ;
\&
\&    my $input = new IO::File "<file1.txt"
\&        or die "Cannot open \*(Aqfile1.txt\*(Aq: $!\en" ;
\&    my $buffer ;
\&    zip $input => \e$buffer 
\&        or die "zip failed: $ZipError\en";
.Ve
.PP
To compress all files in the directory \*(L"/my/home\*(R" that match \*(L"*.txt\*(R"
and store the compressed data in the same directory
.PP
.Vb 3
\&    use strict ;
\&    use warnings ;
\&    use IO::Compress::Zip qw(zip $ZipError) ;
\&
\&    zip \*(Aq</my/home/*.txt>\*(Aq => \*(Aq<*.zip>\*(Aq
\&        or die "zip failed: $ZipError\en";
.Ve
.PP
and if you want to compress each file one at a time, this will do the trick
.PP
.Vb 3
\&    use strict ;
\&    use warnings ;
\&    use IO::Compress::Zip qw(zip $ZipError) ;
\&
\&    for my $input ( glob "/my/home/*.txt" )
\&    {
\&        my $output = "$input.zip" ;
\&        zip $input => $output 
\&            or die "Error compressing \*(Aq$input\*(Aq: $ZipError\en";
\&    }
.Ve
.SH "OO Interface"
.IX Header "OO Interface"
.Sh "Constructor"
.IX Subsection "Constructor"
The format of the constructor for \f(CW\*(C`IO::Compress::Zip\*(C'\fR is shown below
.PP
.Vb 2
\&    my $z = new IO::Compress::Zip $output [,OPTS]
\&        or die "IO::Compress::Zip failed: $ZipError\en";
.Ve
.PP
It returns an \f(CW\*(C`IO::Compress::Zip\*(C'\fR object on success and undef on failure. 
The variable \f(CW$ZipError\fR will contain an error message on failure.
.PP
If you are running Perl 5.005 or better the object, \f(CW$z\fR, returned from 
IO::Compress::Zip can be used exactly like an IO::File filehandle. 
This means that all normal output file operations can be carried out 
with \f(CW$z\fR. 
For example, to write to a compressed file/buffer you can use either of 
these forms
.PP
.Vb 2
\&    $z\->print("hello world\en");
\&    print $z "hello world\en";
.Ve
.PP
The mandatory parameter \f(CW$output\fR is used to control the destination
of the compressed data. This parameter can take one of these forms.
.IP "A filename" 5
.IX Item "A filename"
If the \f(CW$output\fR parameter is a simple scalar, it is assumed to be a
filename. This file will be opened for writing and the compressed data
will be written to it.
.IP "A filehandle" 5
.IX Item "A filehandle"
If the \f(CW$output\fR parameter is a filehandle, the compressed data will be
written to it.
The string '\-' can be used as an alias for standard output.
.IP "A scalar reference" 5
.IX Item "A scalar reference"
If \f(CW$output\fR is a scalar reference, the compressed data will be stored
in \f(CW$$output\fR.
.PP
If the \f(CW$output\fR parameter is any other type, \f(CW\*(C`IO::Compress::Zip\*(C'\fR::new will
return undef.
.Sh "Constructor Options"
.IX Subsection "Constructor Options"
\&\f(CW\*(C`OPTS\*(C'\fR is any combination of the following options:
.ie n .IP """AutoClose => 0|1""" 5
.el .IP "\f(CWAutoClose => 0|1\fR" 5
.IX Item "AutoClose => 0|1"
This option is only valid when the \f(CW$output\fR parameter is a filehandle. If
specified, and the value is true, it will result in the \f(CW$output\fR being
closed once either the \f(CW\*(C`close\*(C'\fR method is called or the \f(CW\*(C`IO::Compress::Zip\*(C'\fR
object is destroyed.
.Sp
This parameter defaults to 0.
.ie n .IP """Append => 0|1""" 5
.el .IP "\f(CWAppend => 0|1\fR" 5
.IX Item "Append => 0|1"
Opens \f(CW$output\fR in append mode.
.Sp
The behaviour of this option is dependent on the type of \f(CW$output\fR.
.RS 5
.IP "\(bu" 5
A Buffer
.Sp
If \f(CW$output\fR is a buffer and \f(CW\*(C`Append\*(C'\fR is enabled, all compressed data
will be append to the end if \f(CW$output\fR. Otherwise \f(CW$output\fR will be
cleared before any data is written to it.
.IP "\(bu" 5
A Filename
.Sp
If \f(CW$output\fR is a filename and \f(CW\*(C`Append\*(C'\fR 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.
.IP "\(bu" 5
A Filehandle
.Sp
If \f(CW$output\fR is a filehandle, the file pointer will be positioned to the
end of the file via a call to \f(CW\*(C`seek\*(C'\fR before any compressed data is written
to it.  Otherwise the file pointer will not be moved.
.RE
.RS 5
.Sp
This parameter defaults to 0.
.RE
.ie n .IP """Name => $string""" 5
.el .IP "\f(CWName => $string\fR" 5
.IX Item "Name => $string"
Stores the contents of \f(CW$string\fR in the zip filename header field. If
\&\f(CW\*(C`Name\*(C'\fR is not specified, no zip filename field will be created.
.ie n .IP """Time => $number""" 5
.el .IP "\f(CWTime => $number\fR" 5
.IX Item "Time => $number"
Sets the last modified time field in the zip header to \f(CW$number\fR.
.Sp
This field defaults to the time the \f(CW\*(C`IO::Compress::Zip\*(C'\fR object was created
if this option is not specified.
.ie n .IP """ExtAttr => $attr""" 5
.el .IP "\f(CWExtAttr => $attr\fR" 5
.IX Item "ExtAttr => $attr"
This option controls the \*(L"external file attributes\*(R" field in the central
header of the zip file. This is a 4 byte field.
.Sp
This option defaults to 0.
.ie n .IP """exTime => [$atime, $mtime, $ctime]""" 5
.el .IP "\f(CWexTime => [$atime, $mtime, $ctime]\fR" 5
.IX Item "exTime => [$atime, $mtime, $ctime]"
This option expects an array reference with exactly three elements:
\&\f(CW$atime\fR, \f(CW\*(C`mtime\*(C'\fR and \f(CW$ctime\fR. These correspond to the last access
time, last modification time and creation time respectively.
.Sp
It uses these values to set the extended timestamp field in the local zip
header to the three values, \f(CW$atime\fR, \f(CW$mtime\fR, \f(CW$ctime\fR and sets the extended
timestamp field in the central zip header to \f(CW$mtime\fR.
.Sp
If any of the three values is \f(CW\*(C`undef\*(C'\fR that time value will not be used.
So, for example, to set only the \f(CW$mtime\fR you would use this
.Sp
.Vb 1
\&    exTime => [undef, $mtime, undef]
.Ve
.Sp
If the \f(CW\*(C`Minimal\*(C'\fR option is set to true, this option will be ignored.
.Sp
By default no extended time field is created.
.ie n .IP """Comment => $comment""" 5
.el .IP "\f(CWComment => $comment\fR" 5
.IX Item "Comment => $comment"
Stores the contents of \f(CW$comment\fR in the Central File Header of
the zip file.
.Sp
By default, no comment field is written to the zip file.
.ie n .IP """ZipComment => $comment""" 5
.el .IP "\f(CWZipComment => $comment\fR" 5
.IX Item "ZipComment => $comment"
Stores the contents of \f(CW$comment\fR in the End of Central Directory record
of the zip file.
.Sp
By default, no comment field is written to the zip file.
.ie n .IP """Method => $method""" 5
.el .IP "\f(CWMethod => $method\fR" 5
.IX Item "Method => $method"
Controls which compression method is used. At present three compression
methods are supported, namely Store (no compression at all), Deflate and
Bzip2.
.Sp
The symbols, \s-1ZIP_CM_STORE\s0, \s-1ZIP_CM_DEFLATE\s0 and \s-1ZIP_CM_BZIP2\s0 are used to
select the compression method.
.Sp
These constants are not imported by \f(CW\*(C`IO::Compress::Zip\*(C'\fR by default.
.Sp
.Vb 3
\&    use IO::Compress::Zip qw(:zip_method);
\&    use IO::Compress::Zip qw(:constants);
\&    use IO::Compress::Zip qw(:all);
.Ve
.Sp
Note that to create Bzip2 content, the module \f(CW\*(C`IO::Compress::Bzip2\*(C'\fR must
be installed. A fatal error will be thrown if you attempt to create Bzip2
content when \f(CW\*(C`IO::Compress::Bzip2\*(C'\fR is not available.
.Sp
The default method is \s-1ZIP_CM_DEFLATE\s0.
.ie n .IP """Stream => 0|1""" 5
.el .IP "\f(CWStream => 0|1\fR" 5
.IX Item "Stream => 0|1"
This option controls whether the zip file/buffer output is created in
streaming mode.
.Sp
Note that when outputting to a file with streaming mode disabled (\f(CW\*(C`Stream\*(C'\fR
is 0), the output file must be seekable.
.Sp
The default is 1.
.ie n .IP """Zip64 => 0|1""" 5
.el .IP "\f(CWZip64 => 0|1\fR" 5
.IX Item "Zip64 => 0|1"
Create a Zip64 zip file/buffer. This option should only be used if you want
to store files larger than 4 Gig.
.Sp
If you intend to manipulate the Zip64 zip files created with this module
using an external zip/unzip make sure that it supports streaming Zip64.
.Sp
In particular, if you are using Info-Zip you need to have zip version 3.x
or better to update a Zip64 archive and unzip version 6.x to read a zip64
archive. At the time of writing both are beta status.
.Sp
When the \f(CW\*(C`Zip64\*(C'\fR option is enabled, the \f(CW\*(C`Stream\*(C'\fR option \fImust\fR be
enabled as well.
.Sp
The default is 0.
.ie n .IP """TextFlag => 0|1""" 5
.el .IP "\f(CWTextFlag => 0|1\fR" 5
.IX Item "TextFlag => 0|1"
This parameter controls the setting of a bit in the zip central header. It
is used to signal that the data stored in the zip file/buffer is probably
text.
.Sp
The default is 0.
.ie n .IP """ExtraFieldLocal => $data""\fR =item \f(CW""ExtraFieldCentral => $data""" 5
.el .IP "\f(CWExtraFieldLocal => $data\fR =item \f(CWExtraFieldCentral => $data\fR" 5
.IX Item "ExtraFieldLocal => $data =item ExtraFieldCentral => $data"
These options allows additional metadata to be stored in the local and
central headers in the zip file/buffer.
.Sp
An extra field consists of zero or more subfields. Each subfield consists
of a two byte header followed by the subfield data.
.Sp
The list of subfields can be supplied in any of the following formats
.Sp
.Vb 4
\&    ExtraFieldLocal => [$id1, $data1,
\&                        $id2, $data2,
\&                         ...
\&                       ]
\&
\&    ExtraFieldLocal => [ [$id1 => $data1],
\&                         [$id2 => $data2],
\&                         ...
\&                       ]
\&
\&    ExtraFieldLocal => { $id1 => $data1,
\&                         $id2 => $data2,
\&                         ...
\&                       }
.Ve
.Sp
Where \f(CW$id1\fR, \f(CW$id2\fR are two byte subfield \s-1ID\s0's.
.Sp
If you use the hash syntax, you have no control over the order in which
the ExtraSubFields are stored, plus you cannot have SubFields with
duplicate \s-1ID\s0.
.Sp
Alternatively the list of subfields can by supplied as a scalar, thus
.Sp
.Vb 1
\&    ExtraField => $rawdata
.Ve
.Sp
The Extended Time field, set using the \f(CW\*(C`exTime\*(C'\fR option, is an example of
an extended field.
.Sp
If the \f(CW\*(C`Minimal\*(C'\fR option is set to true, this option will be ignored.
.Sp
The maximum size of an extra field 65535 bytes.
.ie n .IP """Minimal => 1|0""" 5
.el .IP "\f(CWMinimal => 1|0\fR" 5
.IX Item "Minimal => 1|0"
If specified, this option will disable the creation of all extended fields
in the zip local and central headers. So the \f(CW\*(C`exTime\*(C'\fR, \f(CW\*(C`ExtraFieldLocal\*(C'\fR
and \f(CW\*(C`ExtraFieldCentral\*(C'\fR options will be ignored.
.Sp
This parameter defaults to 0.
.ie n .IP """BlockSize100K => number""" 5
.el .IP "\f(CWBlockSize100K => number\fR" 5
.IX Item "BlockSize100K => number"
Specify the number of 100K blocks bzip2 uses during compression.
.Sp
Valid values are from 1 to 9, where 9 is best compression.
.Sp
This option is only valid if the \f(CW\*(C`Method\*(C'\fR is \s-1ZIP_CM_BZIP2\s0. It is ignored
otherwise.
.Sp
The default is 1.
.ie n .IP """WorkFactor => number""" 5
.el .IP "\f(CWWorkFactor => number\fR" 5
.IX Item "WorkFactor => number"
Specifies how much effort bzip2 should take before resorting to a slower
fallback compression algorithm.
.Sp
Valid values range from 0 to 250, where 0 means use the default value 30.
.Sp
This option is only valid if the \f(CW\*(C`Method\*(C'\fR is \s-1ZIP_CM_BZIP2\s0. It is ignored
otherwise.
.Sp
The default is 0.
.IP "\-Level" 5
.IX 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.
.Sp
.Vb 4
\&   Z_NO_COMPRESSION
\&   Z_BEST_SPEED
\&   Z_BEST_COMPRESSION
\&   Z_DEFAULT_COMPRESSION
.Ve
.Sp
The default is Z_DEFAULT_COMPRESSION.
.Sp
Note, these constants are not imported by \f(CW\*(C`IO::Compress::Zip\*(C'\fR by default.
.Sp
.Vb 3