IO::Compress::Zip(3p) Perl Programmers Reference Guide IO::Compress::Zip(3p) #
IO::Compress::Zip(3p) Perl Programmers Reference Guide IO::Compress::Zip(3p)
NNAAMMEE #
IO::Compress::Zip - Write zip files/buffers
SSYYNNOOPPSSIISS #
use IO::Compress::Zip qw(zip $ZipError) ;
my $status = zip $input => $output [,OPTS]
or die "zip failed: $ZipError\n";
my $z = IO::Compress::Zip->new( $output [,OPTS] )
or die "zip failed: $ZipError\n";
$z->print($string);
$z->printf($format, $string);
$z->write($string);
$z->syswrite($string [, $length, $offset]);
$z->flush();
$z->tell();
$z->eof();
$z->seek($position, $whence);
$z->binmode();
$z->fileno();
$z->opened();
$z->autoflush();
$z->input_line_number();
$z->newStream( [OPTS] );
$z->deflateParams();
$z->close() ;
$ZipError ;
# IO::File mode
print $z $string;
printf $z $format, $string;
tell $z
eof $z
seek $z, $position, $whence
binmode $z
fileno $z
close $z ;
DDEESSCCRRIIPPTTIIOONN #
This module provides a Perl interface that allows writing zip compressed
data to files or buffer.
The primary purpose of this module is to provide streaming write access
to zip files and buffers.
At present the following compression methods are supported by
IO::Compress::Zip
Store (0)
Deflate (8)
Bzip2 (12)
To write Bzip2 content, the module "IO::Uncompress::Bunzip2" must be
installed.
Lzma (14)
To write LZMA content, the module "IO::Uncompress::UnLzma" must be
installed.
Zstandard (93)
To write Zstandard content, the module "IO::Compress::Zstd" must be
installed.
Xz (95)
To write Xz content, the module "IO::Uncompress::UnXz" must be
installed.
For reading zip files/buffers, see the companion module
IO::Uncompress::Unzip.
FFuunnccttiioonnaall IInntteerrffaaccee A top-level function, “zip”, is provided to carry out “one-shot” compression between buffers and/or files. For finer control over the compression process, see the “OO Interface” section.
use IO::Compress::Zip qw(zip $ZipError) ;
zip $input_filename_or_reference => $output_filename_or_reference [,OPTS]
or die "zip failed: $ZipError\n";
The functional interface needs Perl5.005 or better.
zziipp $$iinnppuutt__ffiilleennaammee__oorr__rreeffeerreennccee ==>> $$oouuttppuutt__ffiilleennaammee__oorr__rreeffeerreennccee [[,, OOPPTTSS]] “zip” expects at least two parameters, $input_filename_or_reference and $output_filename_or_reference and zero or more optional parameters (see “Optional Parameters”)
_T_h_e _$_i_n_p_u_t___f_i_l_e_n_a_m_e___o_r___r_e_f_e_r_e_n_c_e _p_a_r_a_m_e_t_e_r
The parameter, $input_filename_or_reference, is used to define the source
of the uncompressed data.
It can take one of the following forms:
A filename
If the $input_filename_or_reference parameter is a simple scalar, it
is assumed to be a filename. This file will be opened for reading
and the input data will be read from it.
A filehandle
If the $input_filename_or_reference parameter is a filehandle, the
input data will be read from it. The string '-' can be used as an
alias for standard input.
A scalar reference
If $input_filename_or_reference is a scalar reference, the input
data will be read from $$input_filename_or_reference.
An array reference
If $input_filename_or_reference is an array reference, each element
in the array must be a filename.
The input data will be read from each file in turn.
The complete array will be walked to ensure that it only contains
valid filenames before any data is compressed.
An Input FileGlob string
If $input_filename_or_reference is a string that is delimited by the
characters "<" and ">" "zip" will assume that it is an _i_n_p_u_t
_f_i_l_e_g_l_o_b _s_t_r_i_n_g. The input is the list of files that match the
fileglob.
See File::GlobMapper for more details.
If the $input_filename_or_reference parameter is any other type, "undef"
will be returned.
In addition, if $input_filename_or_reference is a simple filename, the
default values for the "Name", "Time", "TextFlag", "ExtAttr", "exUnixN"
and "exTime" options will be sourced from that file.
If you do not want to use these defaults they can be overridden by
explicitly setting the "Name", "Time", "TextFlag", "ExtAttr", "exUnixN"
and "exTime" options or by setting the "Minimal" parameter.
_T_h_e _$_o_u_t_p_u_t___f_i_l_e_n_a_m_e___o_r___r_e_f_e_r_e_n_c_e _p_a_r_a_m_e_t_e_r
The parameter $output_filename_or_reference is used to control the
destination of the compressed data. This parameter can take one of these
forms.
A filename
If the $output_filename_or_reference parameter is a simple scalar,
it is assumed to be a filename. This file will be opened for
writing and the compressed data will be written to it.
A filehandle
If the $output_filename_or_reference parameter is a filehandle, the
compressed data will be written to it. The string '-' can be used
as an alias for standard output.
A scalar reference
If $output_filename_or_reference is a scalar reference, the
compressed data will be stored in $$output_filename_or_reference.
An Array Reference
If $output_filename_or_reference is an array reference, the
compressed data will be pushed onto the array.
An Output FileGlob
If $output_filename_or_reference is a string that is delimited by
the characters "<" and ">" "zip" will assume that it is an _o_u_t_p_u_t
_f_i_l_e_g_l_o_b _s_t_r_i_n_g. The output is the list of files that match the
fileglob.
When $output_filename_or_reference is an fileglob string,
$input_filename_or_reference must also be a fileglob string.
Anything else is an error.
See File::GlobMapper for more details.
If the $output_filename_or_reference parameter is any other type, "undef"
will be returned.
NNootteess When $input_filename_or_reference maps to multiple files/buffers and $output_filename_or_reference is a single file/buffer the input files/buffers will each be stored in $output_filename_or_reference as a distinct entry.
OOppttiioonnaall PPaarraammeetteerrss The optional parameters for the one-shot function “zip” are (for the most part) identical to those used with the OO interface defined in the “Constructor Options” section. The exceptions are listed below
"AutoClose => 0|1"
This option applies to any input or output data streams to "zip"
that are filehandles.
If "AutoClose" is specified, and the value is true, it will result
in all input and/or output filehandles being closed once "zip" has
completed.
This parameter defaults to 0.
"BinModeIn => 0|1"
This option is now a no-op. All files will be read in binmode.
"Append => 0|1"
The behaviour of this option is dependent on the type of output data
stream.
• A Buffer
If "Append" is enabled, all compressed data will be append to
the end of the output buffer. Otherwise the output buffer will
be cleared before any compressed data is written to it.
• A Filename
If "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.
• A Filehandle
If "Append" is enabled, the filehandle will be positioned to
the end of the file via a call to "seek" before any compressed
data is written to it. Otherwise the file pointer will not be
moved.
When "Append" is specified, and set to true, it will _a_p_p_e_n_d all
compressed data to the output data stream.
So when the output is a filehandle it will carry out a seek to the
eof before writing any compressed data. If the output is a filename,
it will be opened for appending. If the output is a buffer, all
compressed data will be appended to the existing buffer.
Conversely when "Append" is not specified, or it is present and is
set to false, it will operate as follows.
When the output is a filename, it will truncate the contents of the
file before writing any compressed data. If the output is a
filehandle its position will not be changed. If the output is a
buffer, it will be wiped before any compressed data is output.
Defaults to 0.
EExxaammpplleess Here are a few example that show the capabilities of the module.
_S_t_r_e_a_m_i_n_g
This very simple command line example demonstrates the streaming
capabilities of the module. The code reads data from STDIN, compresses
it, and writes the compressed data to STDOUT.
$ echo hello world | perl -MIO::Compress::Zip=zip -e 'zip \*STDIN => \*STDOUT' >output.zip
The special filename "-" can be used as a standin for both "\*STDIN" and
"\*STDOUT", so the above can be rewritten as
$ echo hello world | perl -MIO::Compress::Zip=zip -e 'zip "-" => "-"' >output.zip
One problem with creating a zip archive directly from STDIN can be
demonstrated by looking at the contents of the zip file, output.zip, that
we have just created.
$ unzip -l output.zip
Archive: output.zip
Length Date Time Name
--------- ---------- ----- ----
12 2019-08-16 22:21
--------- -------
12 1 file
The archive member (filename) used is the empty string.
If that doesn't suit your needs, you can explicitly set the filename used
in the zip archive by specifying the Name option, like so
echo hello world | perl -MIO::Compress::Zip=zip -e 'zip "-" => "-", Name => "hello.txt"' >output.zip
Now the contents of the zip file looks like this
$ unzip -l output.zip
Archive: output.zip
Length Date Time Name
--------- ---------- ----- ----
12 2019-08-16 22:22 hello.txt
--------- -------
12 1 file
_C_o_m_p_r_e_s_s_i_n_g _a _f_i_l_e _f_r_o_m _t_h_e _f_i_l_e_s_y_s_t_e_m
To read the contents of the file "file1.txt" and write the compressed
data to the file "file1.txt.zip".
use strict ;
use warnings ;
use IO::Compress::Zip qw(zip $ZipError) ;
my $input = "file1.txt";
zip $input => "$input.zip"
or die "zip failed: $ZipError\n";
_R_e_a_d_i_n_g _f_r_o_m _a _F_i_l_e_h_a_n_d_l_e _a_n_d _w_r_i_t_i_n_g _t_o _a_n _i_n_-_m_e_m_o_r_y _b_u_f_f_e_r
To read from an existing Perl filehandle, $input, and write the
compressed data to a buffer, $buffer.
use strict ;
use warnings ;
use IO::Compress::Zip qw(zip $ZipError) ;
use IO::File ;
my $input = IO::File->new( "<file1.txt" )
or die "Cannot open 'file1.txt': $!\n" ;
my $buffer ;
zip $input => \$buffer
or die "zip failed: $ZipError\n";
_C_o_m_p_r_e_s_s_i_n_g _m_u_l_t_i_p_l_e _f_i_l_e_s
To create a zip file, "output.zip", that contains the compressed contents
of the files "alpha.txt" and "beta.txt"
use strict ;
use warnings ;
use IO::Compress::Zip qw(zip $ZipError) ;
zip [ 'alpha.txt', 'beta.txt' ] => 'output.zip'
or die "zip failed: $ZipError\n";
Alternatively, rather than having to explicitly name each of the files
that you want to compress, you could use a fileglob to select all the
"txt" files in the current directory, as follows
use strict ;
use warnings ;
use IO::Compress::Zip qw(zip $ZipError) ;
my @files = <*.txt>;
zip \@files => 'output.zip'
or die "zip failed: $ZipError\n";
or more succinctly
zip [ <*.txt> ] => 'output.zip'
or die "zip failed: $ZipError\n";
OOOO IInntteerrffaaccee CCoonnssttrruuccttoorr The format of the constructor for “IO::Compress::Zip” is shown below
my $z = IO::Compress::Zip->new( $output [,OPTS] )
or die "IO::Compress::Zip failed: $ZipError\n";
It returns an "IO::Compress::Zip" object on success and undef on failure.
The variable $ZipError will contain an error message on failure.
If you are running Perl 5.005 or better the object, $z, 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 $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 $output is used to control the destination of the
compressed data. This parameter can take one of these forms.
A filename
If the $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.
A filehandle
If the $output parameter is a filehandle, the compressed data will
be written to it. The string '-' can be used as an alias for
standard output.
A scalar reference
If $output is a scalar reference, the compressed data will be stored
in $$output.
If the $output parameter is any other type, "IO::Compress::Zip"::new will
return undef.
CCoonnssttrruuccttoorr OOppttiioonnss “OPTS” is any combination of zero or more the following options:
"AutoClose => 0|1"
This option is only valid when the $output parameter is a
filehandle. If specified, and the value is true, it will result in
the $output being closed once either the "close" method is called or
the "IO::Compress::Zip" object is destroyed.
This parameter defaults to 0.
"Append => 0|1"
Opens $output in append mode.
The behaviour of this option is dependent on the type of $output.
• A Buffer
If $output is a buffer and "Append" is enabled, all compressed
data will be append to the end of $output. Otherwise $output
will be cleared before any data is written to it.
• A Filename
If $output is a filename and "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.
• A Filehandle
If $output is a filehandle, the file pointer will be positioned
to the end of the file via a call to "seek" before any
compressed data is written to it. Otherwise the file pointer
will not be moved.
This parameter defaults to 0.
_F_i_l_e _N_a_m_i_n_g _O_p_t_i_o_n_s
A quick bit of zip file terminology -- A zip archive consists of one or
more _a_r_c_h_i_v_e _m_e_m_b_e_r_s, where each member has an associated filename, known
as the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e.
The options listed in this section control how the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e
(or filename) is stored the zip archive.
"Name => $string"
This option is used to explicitly set the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e in the
zip archive to $string. Most of the time you don't need to make use
of this option. By default when adding a filename to the zip
archive, the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e will match the filename.
You should only need to use this option if you want the _a_r_c_h_i_v_e
_m_e_m_b_e_r _n_a_m_e to be different from the uncompressed filename or when
the input is a filehandle or a buffer.
The default behaviour for what _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e is used when the
"Name" option is _n_o_t specified depends on the form of the $input
parameter:
• If the $input parameter is a filename, the value of $input will
be used for the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e .
• If the $input parameter is not a filename, the _a_r_c_h_i_v_e _m_e_m_b_e_r
_n_a_m_e will be an empty string.
Note that both the "CanonicalName" and "FilterName" options can
modify the value used for the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e.
Also note that you should set the "Efs" option to true if you are
working with UTF8 filenames.
"CanonicalName => 0|1"
This option controls whether the _a_r_c_h_i_v_e _m_e_m_b_e_r _n_a_m_e is _n_o_r_m_a_l_i_z_e_d
into Unix format before being written to the zip file.
It is recommended that you enable this option unless you really need
to create a non-standard Zip file.
This is what APPNOTE.TXT has to say on what should be stored in the
zip filename header field.
The name of the file, with optional relative path.
The path stored should not contain a drive or
device letter, or a leading slash. All slashes
should be forward slashes '/' as opposed to
backwards slashes '\' for compatibility with Amiga
and UNIX file systems etc.
This option defaults to ffaallssee.
"FilterName => sub { ... }"
This option allow the _a_r_c_h_i_v_e _m_e_m_b_e_r name to be modified before it
is written to the zip file.
This option takes a parameter that must be a reference to a sub. On
entry to the sub the $_ variable will contain the name to be
filtered. If no filename is available $_ will contain an empty
string.
The value of $_ when the sub returns will be used as the _a_r_c_h_i_v_e
_m_e_m_b_e_r _n_a_m_e.
Note that if "CanonicalName" is enabled, a normalized filename will
be passed to the sub.
If you use "FilterName" to modify the filename, it is your
responsibility to keep the filename in Unix format.
Although this option can be used with the OO interface, it is of
most use with the one-shot interface. For example, the code below
shows how "FilterName" can be used to remove the path component from
a series of filenames before they are stored in $zipfile.
sub compressTxtFiles
{
my $zipfile = shift ;
my $dir = shift ;
zip [ <$dir/*.txt> ] => $zipfile,
FilterName => sub { s[^$dir/][] } ;
}
"Efs => 0|1"
This option controls setting of the "Language Encoding Flag" (EFS)
in the zip archive. When set, the filename and comment fields for
the zip archive MUST be valid UTF-8.
If the string used for the filename and/or comment is not valid
UTF-8 when this option is true, the script will die with a "wide
character" error.
Note that this option only works with Perl 5.8.4 or better.
This option defaults to ffaallssee.
_O_v_e_r_a_l_l _Z_i_p _A_r_c_h_i_v_e _S_t_r_u_c_t_u_r_e
"Minimal => 1|0"
If specified, this option will disable the creation of all extra
fields in the zip local and central headers. So the "exTime",
"exUnix2", "exUnixN", "ExtraFieldLocal" and "ExtraFieldCentral"
options will be ignored.
This parameter defaults to 0.
"Stream => 0|1"
This option controls whether the zip file/buffer output is created
in streaming mode.
Note that when outputting to a file with streaming mode disabled
("Stream" is 0), the output file must be seekable.
The default is 1.
"Zip64 => 0|1"
Create a Zip64 zip file/buffer. This option is used if you want to
store files larger than 4 Gig or store more than 64K files in a
single zip archive.
"Zip64" will be automatically set, as needed, if working with the
one-shot interface when the input is either a filename or a scalar
reference.
If you intend to manipulate the Zip64 zip files created with this
module using an external zip/unzip, make sure that it supports
Zip64.
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.
The default is 0.
_D_e_f_l_a_t_e _C_o_m_p_r_e_s_s_i_o_n _O_p_t_i_o_n_s
-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 "IO::Compress::Zip" by
default.
use IO::Compress::Zip qw(:strategy);
use IO::Compress::Zip qw(:constants);
use IO::Compress::Zip qw(:all);
-Strategy
Defines the strategy used to tune the compression. Use one of the
symbolic constants defined below.
Z_FILTERED #
Z_HUFFMAN_ONLY #
Z_RLE #
Z_FIXED #
Z_DEFAULT_STRATEGY #
The default is Z_DEFAULT_STRATEGY.
_B_z_i_p_2 _C_o_m_p_r_e_s_s_i_o_n _O_p_t_i_o_n_s
"BlockSize100K => number"
Specify the number of 100K blocks bzip2 uses during compression.
Valid values are from 1 to 9, where 9 is best compression.
This option is only valid if the "Method" is ZIP_CM_BZIP2. It is
ignored otherwise.
The default is 1.
"WorkFactor => number"
Specifies how much effort bzip2 should take before resorting to a
slower fallback compression algorithm.
Valid values range from 0 to 250, where 0 means use the default
value 30.
This option is only valid if the "Method" is ZIP_CM_BZIP2. It is
ignored otherwise.
The default is 0.
_L_z_m_a _a_n_d _X_z _C_o_m_p_r_e_s_s_i_o_n _O_p_t_i_o_n_s
"Preset => number"
Used to choose the LZMA compression preset.
Valid values are 0-9 and "LZMA_PRESET_DEFAULT".
0 is the fastest compression with the lowest memory usage and the
lowest compression.
9 is the slowest compression with the highest memory usage but with
the best compression.
This option is only valid if the "Method" is ZIP_CM_LZMA. It is
ignored otherwise.
Defaults to "LZMA_PRESET_DEFAULT" (6).
"Extreme => 0|1"
Makes LZMA compression a lot slower, but a small compression gain.
This option is only valid if the "Method" is ZIP_CM_LZMA. It is
ignored otherwise.
Defaults to 0.
_O_t_h_e_r _O_p_t_i_o_n_s
"Time => $number"
Sets the last modified time field in the zip header to $number.
This field defaults to the time the "IO::Compress::Zip" object was
created if this option is not specified and the $input parameter is
not a filename.
"ExtAttr => $attr"
This option controls the "external file attributes" field in the
central header of the zip file. This is a 4 byte field.
If you are running a Unix derivative this value defaults to
0100644 << 16
This should allow read/write access to any files that are extracted
from the zip file/buffer`.
For all other systems it defaults to 0.
"exTime => [$atime, $mtime, $ctime]"
This option expects an array reference with exactly three elements:
$atime, "mtime" and $ctime. These correspond to the last access
time, last modification time and creation time respectively.
It uses these values to set the extended timestamp field (ID is
"UT") in the local zip header using the three values, $atime,
$mtime, $ctime. In addition it sets the extended timestamp field in
the central zip header using $mtime.
If any of the three values is "undef" that time value will not be
used. So, for example, to set only the $mtime you would use this
exTime => [undef, $mtime, undef]
If the "Minimal" option is set to true, this option will be ignored.
By default no extended time field is created.
"exUnix2 => [$uid, $gid]"
This option expects an array reference with exactly two elements:
$uid and $gid. These values correspond to the numeric User ID (UID)
and Group ID (GID) of the owner of the files respectively.
When the "exUnix2" option is present it will trigger the creation of
a Unix2 extra field (ID is "Ux") in the local zip header. This will
be populated with $uid and $gid. An empty Unix2 extra field will
also be created in the central zip header.
Note - The UID & GID are stored as 16-bit integers in the "Ux"
field. Use "exUnixN" if your UID or GID are 32-bit.
If the "Minimal" option is set to true, this option will be ignored.
By default no Unix2 extra field is created.
"exUnixN => [$uid, $gid]"
This option expects an array reference with exactly two elements:
$uid and $gid. These values correspond to the numeric User ID (UID)
and Group ID (GID) of the owner of the files respectively.
When the "exUnixN" option is present it will trigger the creation of
a UnixN extra field (ID is "ux") in both the local and central zip
headers. This will be populated with $uid and $gid. The UID & GID
are stored as 32-bit integers.
If the "Minimal" option is set to true, this option will be ignored.
By default no UnixN extra field is created.
"Comment => $comment"
Stores the contents of $comment in the Central File Header of the
zip file.
Set the "Efs" option to true if you want to store a UTF8 comment.
By default, no comment field is written to the zip file.
"ZipComment => $comment"
Stores the contents of $comment in the End of Central Directory
record of the zip file.
By default, no comment field is written to the zip file.
"Method => $method"
Controls which compression method is used. At present the
compression methods supported are: Store (no compression at all),
Deflate, Bzip2, Zstd, Xz and Lzma.
The symbols ZIP_CM_STORE, ZIP_CM_DEFLATE, ZIP_CM_BZIP2, ZIP_CM_ZSTD,
ZIP_CM_XZ and ZIP_CM_LZMA are used to select the compression method.
These constants are not imported by "IO::Compress::Zip" by default.
use IO::Compress::Zip qw(:zip_method);
use IO::Compress::Zip qw(:constants);
use IO::Compress::Zip qw(:all);
Note that to create Bzip2 content, the module "IO::Compress::Bzip2"
must be installed. A fatal error will be thrown if you attempt to
create Bzip2 content when "IO::Compress::Bzip2" is not available.
Note that to create Lzma content, the module "IO::Compress::Lzma"
must be installed. A fatal error will be thrown if you attempt to
create Lzma content when "IO::Compress::Lzma" is not available.
Note that to create Xz content, the module "IO::Compress::Xz" must
be installed. A fatal error will be thrown if you attempt to create
Xz content when "IO::Compress::Xz" is not available.
Note that to create Zstd content, the module "IO::Compress::Zstd"
must be installed. A fatal error will be thrown if you attempt to
create Zstd content when "IO::Compress::Zstd" is not available.
The default method is ZIP_CM_DEFLATE.
"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.
In one-shot mode this flag will be set to true if the Perl "-T"
operator thinks the file contains text.
The default is 0.
"ExtraFieldLocal => $data"
"ExtraFieldCentral => $data"
The "ExtraFieldLocal" option is used to store additional metadata in
the local header for the zip file/buffer. The "ExtraFieldCentral"
does the same for the matching central header.
An extra field consists of zero or more subfields. Each subfield
consists of a two byte header followed by the subfield data.
The list of subfields can be supplied in any of the following
formats
ExtraFieldLocal => [$id1, $data1,
$id2, $data2,
...
]
ExtraFieldLocal => [ [$id1 => $data1],
[$id2 => $data2],
...
]
ExtraFieldLocal => { $id1 => $data1,
$id2 => $data2,
...
}
Where $id1, $id2 are two byte subfield ID's.
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 ID.
Alternatively the list of subfields can by supplied as a scalar,
thus
ExtraField => $rawdata
In this case "IO::Compress::Zip" will check that $rawdata consists
of zero or more conformant sub-fields.
The Extended Time field (ID "UT"), set using the "exTime" option,
and the Unix2 extra field (ID "Ux), set using the "exUnix2" option,
are examples of extra fields.
If the "Minimal" option is set to true, this option will be ignored.
The maximum size of an extra field 65535 bytes.
"Strict => 0|1"
This is a placeholder option.
EExxaammpplleess
TODO #
MMeetthhooddss pprriinntt Usage is
$z->print($data)
print $z $data
Compresses and outputs the contents of the $data parameter. This has the
same behaviour as the "print" built-in.
Returns true if successful.
pprriinnttff Usage is
$z->printf($format, $data)
printf $z $format, $data
Compresses and outputs the contents of the $data parameter.
Returns true if successful.
ssyysswwrriittee Usage is
$z->syswrite $data
$z->syswrite $data, $length
$z->syswrite $data, $length, $offset
Compresses and outputs the contents of the $data parameter.
Returns the number of uncompressed bytes written, or "undef" if
unsuccessful.
wwrriittee Usage is
$z->write $data
$z->write $data, $length
$z->write $data, $length, $offset
Compresses and outputs the contents of the $data parameter.
Returns the number of uncompressed bytes written, or "undef" if
unsuccessful.
fflluusshh Usage is
$z->flush;
$z->flush($flush_type);
Flushes any pending compressed data to the output file/buffer.
This method takes an optional parameter, $flush_type, that controls how
the flushing will be carried out. By default the $flush_type used is
"Z_FINISH". Other valid values for $flush_type are "Z_NO_FLUSH",
"Z_SYNC_FLUSH", "Z_FULL_FLUSH" and "Z_BLOCK". It is strongly recommended
that you only set the "flush_type" parameter if you fully understand the
implications of what it does - overuse of "flush" can seriously degrade
the level of compression achieved. See the "zlib" documentation for
details.
Returns true on success.
tteellll Usage is
$z->tell()
tell $z
Returns the uncompressed file offset.
eeooff Usage is
$z->eof();
eof($z);
Returns true if the "close" method has been called.
sseeeekk $z->seek($position, $whence); seek($z, $position, $whence);
Provides a sub-set of the "seek" functionality, with the restriction that
it is only legal to seek forward in the output file/buffer. It is a
fatal error to attempt to seek backward.
Empty parts of the file/buffer will have NULL (0x00) bytes written to
them.
The $whence parameter takes one the usual values, namely SEEK_SET,
SEEK_CUR or SEEK_END.
Returns 1 on success, 0 on failure.
bbiinnmmooddee Usage is
$z->binmode
binmode $z ;
This is a noop provided for completeness.
ooppeenneedd $z->opened()
Returns true if the object currently refers to a opened file/buffer.
aauuttoofflluusshh my $prev = $z->autoflush() my $prev = $z->autoflush(EXPR)
If the $z object is associated with a file or a filehandle, this method
returns the current autoflush setting for the underlying filehandle. If
"EXPR" is present, and is non-zero, it will enable flushing after every
write/print operation.
If $z is associated with a buffer, this method has no effect and always
returns "undef".
NNoottee that the special variable $| ccaannnnoott be used to set or retrieve the
autoflush setting.
iinnppuutt__lliinnee__nnuummbbeerr $z->input_line_number() $z->input_line_number(EXPR)
This method always returns "undef" when compressing.
ffiilleennoo $z->fileno() fileno($z)
If the $z object is associated with a file or a filehandle, "fileno" will
return the underlying file descriptor. Once the "close" method is called
"fileno" will return "undef".
If the $z object is associated with a buffer, this method will return
"undef".
cclloossee $z->close() ; close $z ;
Flushes any pending compressed data and then closes the output
file/buffer.
For most versions of Perl this method will be automatically invoked if
the IO::Compress::Zip object is destroyed (either explicitly or by the
variable with the reference to the object going out of scope). The
exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these
cases, the "close" method will be called automatically, but not until
global destruction of all live objects when the program is terminating.
Therefore, if you want your scripts to be able to run on all versions of
Perl, you should call "close" explicitly and not rely on automatic
closing.
Returns true on success, otherwise 0.
If the "AutoClose" option has been enabled when the IO::Compress::Zip
object was created, and the object is associated with a file, the
underlying file will also be closed.
nneewwSSttrreeaamm(([[OOPPTTSS]])) Usage is
$z->newStream( [OPTS] )
Closes the current compressed data stream and starts a new one.
OPTS consists of any of the options that are available when creating the
$z object.
See the "Constructor Options" section for more details.
ddeeffllaatteePPaarraammss Usage is
$z->deflateParams
TODO #
IImmppoorrttiinngg A number of symbolic constants are required by some methods in “IO::Compress::Zip”. None are imported by default.
:all Imports "zip", $ZipError and all symbolic constants that can be used
by "IO::Compress::Zip". Same as doing this
use IO::Compress::Zip qw(zip $ZipError :constants) ;
:constants
Import all symbolic constants. Same as doing this
use IO::Compress::Zip qw(:flush :level :strategy :zip_method) ;
:flush
These symbolic constants are used by the "flush" method.
Z_NO_FLUSH #
Z_PARTIAL_FLUSH #
Z_SYNC_FLUSH #
Z_FULL_FLUSH #
Z_FINISH #
Z_BLOCK #
:level
These symbolic constants are used by the "Level" option in the
constructor.
Z_NO_COMPRESSION #
Z_BEST_SPEED #
Z_BEST_COMPRESSION #
Z_DEFAULT_COMPRESSION #
:strategy
These symbolic constants are used by the "Strategy" option in the
constructor.
Z_FILTERED #
Z_HUFFMAN_ONLY #
Z_RLE #
Z_FIXED #
Z_DEFAULT_STRATEGY #
:zip_method
These symbolic constants are used by the "Method" option in the
constructor.
ZIP_CM_STORE #
ZIP_CM_DEFLATE #
ZIP_CM_BZIP2 #
EEXXAAMMPPLLEESS #
AAppaacchhee::::GGZZiipp RReevviissiitteedd See IO::Compress::FAQ
WWoorrkkiinngg wwiitthh NNeett::::FFTTPP See IO::Compress::FAQ
SSUUPPPPOORRTT #
General feedback/questions/bug reports should be sent to
<https://github.com/pmqs/IO-Compress/issues> (preferred) or
<https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.
SSEEEE AALLSSOO #
Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip,
IO::Compress::Deflate, IO::Uncompress::Inflate, IO::Compress::RawDeflate,
IO::Uncompress::RawInflate, IO::Compress::Bzip2, IO::Uncompress::Bunzip2,
IO::Compress::Lzma, IO::Uncompress::UnLzma, IO::Compress::Xz,
IO::Uncompress::UnXz, IO::Compress::Lzip, IO::Uncompress::UnLzip,
IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf,
IO::Uncompress::UnLzf, IO::Compress::Zstd, IO::Uncompress::UnZstd,
IO::Uncompress::AnyInflate, IO::Uncompress::AnyUncompress
IO::Compress::FAQ
File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib
For RFC 1950, 1951 and 1952 see
<https://datatracker.ietf.org/doc/html/rfc1950>,
<https://datatracker.ietf.org/doc/html/rfc1951> and
<https://datatracker.ietf.org/doc/html/rfc1952>
The _z_l_i_b compression library was written by Jean-loup Gailly
"gzip@prep.ai.mit.edu" and Mark Adler "madler@alumni.caltech.edu".
The primary site for the _z_l_i_b compression library is
<http://www.zlib.org>.
The primary site for gzip is <http://www.gzip.org>.
AAUUTTHHOORR #
This module was written by Paul Marquess, "pmqs@cpan.org".
MMOODDIIFFIICCAATTIIOONN HHIISSTTOORRYY #
See the Changes file.
CCOOPPYYRRIIGGHHTT AANNDD LLIICCEENNSSEE #
Copyright (c) 2005-2022 Paul Marquess. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.36.3 2023-02-15 IO::Compress::Zip(3p)