IO::Uncompress::AnyUncompress - man - phpman

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NAME
IO::Uncompress::AnyUncompress - Uncompress gzip, zip, bzip2, zstd, xz, lzma, lzip, lzf or lzop
file/buffer

SYNOPSIS
use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;

my $status = anyuncompress $input => $output [,OPTS]
or die "anyuncompress failed: $AnyUncompressError\n";

my $z = IO::Uncompress::AnyUncompress->new( $input [OPTS] )
or die "anyuncompress failed: $AnyUncompressError\n";

$status = $z->read($buffer)
$status = $z->read($buffer, $length)
$status = $z->read($buffer, $length, $offset)
$line = $z->getline()
$char = $z->getc()
$char = $z->ungetc()
$char = $z->opened()

$data = $z->trailingData()
$status = $z->nextStream()
$data = $z->getHeaderInfo()
$z->tell()
$z->seek($position, $whence)
$z->binmode()
$z->fileno()
$z->eof()
$z->close()

$AnyUncompressError ;

# IO::File mode

<$z>
read($z, $buffer);
read($z, $buffer, $length);
read($z, $buffer, $length, $offset);
tell($z)
seek($z, $position, $whence)
binmode($z)
fileno($z)
eof($z)
close($z)

DESCRIPTION
This module provides a Perl interface that allows the reading of files/buffers that have been
compressed with a variety of compression libraries.

The formats supported are:

RFC 1950
RFC 1951 (optionally)
gzip (RFC 1952)
zip
zstd (Zstandard)
bzip2
lzop
lzf
lzma
lzip
xz

The module will auto-detect which, if any, of the supported compression formats is being used.

Functional Interface
A top-level function, "anyuncompress", is provided to carry out "one-shot" uncompression between
buffers and/or files. For finer control over the uncompression process, see the "OO Interface"
section.

use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;

anyuncompress $input_filename_or_reference => $output_filename_or_reference [,OPTS]
or die "anyuncompress failed: $AnyUncompressError\n";

The functional interface needs Perl5.005 or better.

anyuncompress $input_filename_or_reference => $output_filename_or_reference [, OPTS]
"anyuncompress" expects at least two parameters, $input_filename_or_reference and
$output_filename_or_reference and zero or more optional parameters (see "Optional Parameters")

The $input_filename_or_reference parameter
The parameter, $input_filename_or_reference, is used to define the source of the compressed
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 uncompressed.

An Input FileGlob string
If $input_filename_or_reference is a string that is delimited by the characters "<" and ">"
"anyuncompress" will assume that it is an *input fileglob string*. 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.

The $output_filename_or_reference parameter
The parameter $output_filename_or_reference is used to control the destination of the
uncompressed 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 uncompressed data will be written to
it.

A filehandle
If the $output_filename_or_reference parameter is a filehandle, the uncompressed 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 uncompressed data will be
stored in $$output_filename_or_reference.

An Array Reference
If $output_filename_or_reference is an array reference, the uncompressed 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
">" "anyuncompress" will assume that it is an *output fileglob string*. 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.

Notes
When $input_filename_or_reference maps to multiple compressed files/buffers and
$output_filename_or_reference is a single file/buffer, after uncompression
$output_filename_or_reference will contain a concatenation of all the uncompressed data from
each of the input files/buffers.

Optional Parameters
The optional parameters for the one-shot function "anyuncompress" 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 "anyuncompress" 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 "anyuncompress" has completed.

This parameter defaults to 0.

"BinModeOut => 0|1"
This option is now a no-op. All files will be written 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 uncompressed data will be append to the end of the output
buffer. Otherwise the output buffer will be cleared before any uncompressed 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 uncompressed 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 uncompressed data is written to it. Otherwise the file
pointer will not be moved.

When "Append" is specified, and set to true, it will *append* all uncompressed 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
uncompressed data. If the output is a filename, it will be opened for appending. If the
output is a buffer, all uncompressed 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
uncompressed 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 uncompressed data is output.

Defaults to 0.

"MultiStream => 0|1"
If the input file/buffer contains multiple compressed data streams, this option will
uncompress the whole lot as a single data stream.

Defaults to 0.

"TrailingData => $scalar"
Returns the data, if any, that is present immediately after the compressed data stream once
uncompression is complete.

This option can be used when there is useful information immediately following the
compressed data stream, and you don't know the length of the compressed data stream.

If the input is a buffer, "trailingData" will return everything from the end of the
compressed data stream to the end of the buffer.

If the input is a filehandle, "trailingData" will return the data that is left in the
filehandle input buffer once the end of the compressed data stream has been reached. You
can then use the filehandle to read the rest of the input file.

Don't bother using "trailingData" if the input is a filename.

If you know the length of the compressed data stream before you start uncompressing, you
can avoid having to use "trailingData" by setting the "InputLength" option.

Examples
To read the contents of the file "file1.txt.Compressed" and write the uncompressed data to the
file "file1.txt".

use strict ;
use warnings ;
use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;

my $input = "file1.txt.Compressed";
my $output = "file1.txt";
anyuncompress $input => $output
or die "anyuncompress failed: $AnyUncompressError\n";

To read from an existing Perl filehandle, $input, and write the uncompressed data to a buffer,
$buffer.

use strict ;
use warnings ;
use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;
use IO::File ;

my $input = IO::File->new( "<file1.txt.Compressed" )
or die "Cannot open 'file1.txt.Compressed': $!\n" ;
my $buffer ;
anyuncompress $input => \$buffer
or die "anyuncompress failed: $AnyUncompressError\n";

To uncompress all files in the directory "/my/home" that match "*.txt.Compressed" and store the
compressed data in the same directory

use strict ;
use warnings ;
use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;

anyuncompress '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
or die "anyuncompress failed: $AnyUncompressError\n";

and if you want to compress each file one at a time, this will do the trick

use strict ;
use warnings ;
use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;

for my $input ( glob "/my/home/*.txt.Compressed" )
{
my $output = $input;
$output =~ s/.Compressed// ;
anyuncompress $input => $output
or die "Error compressing '$input': $AnyUncompressError\n";
}

OO Interface
Constructor
The format of the constructor for IO::Uncompress::AnyUncompress is shown below

my $z = IO::Uncompress::AnyUncompress->new( $input [OPTS] )
or die "IO::Uncompress::AnyUncompress failed: $AnyUncompressError\n";

Returns an "IO::Uncompress::AnyUncompress" object on success and undef on failure. The variable
$AnyUncompressError will contain an error message on failure.

If you are running Perl 5.005 or better the object, $z, returned from
IO::Uncompress::AnyUncompress can be used exactly like an IO::File filehandle. This means that
all normal input file operations can be carried out with $z. For example, to read a line from a
compressed file/buffer you can use either of these forms

$line = $z->getline();
$line = <$z>;

The mandatory parameter $input is used to determine the source of the compressed data. This
parameter can take one of three forms.

A filename
If the $input parameter is a scalar, it is assumed to be a filename. This file will be
opened for reading and the compressed data will be read from it.

A filehandle
If the $input parameter is a filehandle, the compressed data will be read from it. The
string '-' can be used as an alias for standard input.

A scalar reference
If $input is a scalar reference, the compressed data will be read from $$input.

Constructor Options
The option names defined below are case insensitive and can be optionally prefixed by a '-'. So
all of the following are valid

-AutoClose
-autoclose
AUTOCLOSE
autoclose

OPTS is a combination of the following options:

"AutoClose => 0|1"
This option is only valid when the $input parameter is a filehandle. If specified, and the
value is true, it will result in the file being closed once either the "close" method is
called or the IO::Uncompress::AnyUncompress object is destroyed.

This parameter defaults to 0.

"MultiStream => 0|1"
Allows multiple concatenated compressed streams to be treated as a single compressed
stream. Decompression will stop once either the end of the file/buffer is reached, an error
is encountered (premature eof, corrupt compressed data) or the end of a stream is not
immediately followed by the start of another stream.

This parameter defaults to 0.

"Prime => $string"
This option will uncompress the contents of $string before processing the input
file/buffer.

This option can be useful when the compressed data is embedded in another file/data
structure and it is not possible to work out where the compressed data begins without
having to read the first few bytes. If this is the case, the uncompression can be *primed*
with these bytes using this option.

"Transparent => 0|1"
If this option is set and the input file/buffer is not compressed data, the module will
allow reading of it anyway.

In addition, if the input file/buffer does contain compressed data and there is
non-compressed data immediately following it, setting this option will make this module
treat the whole file/buffer as a single data stream.

This option defaults to 1.

"BlockSize => $num"
When reading the compressed input data, IO::Uncompress::AnyUncompress will read it in
blocks of $num bytes.

This option defaults to 4096.

"InputLength => $size"
When present this option will limit the number of compressed bytes read from the input
file/buffer to $size. This option can be used in the situation where there is useful data
directly after the compressed data stream and you know beforehand the exact length of the
compressed data stream.

This option is mostly used when reading from a filehandle, in which case the file pointer
will be left pointing to the first byte directly after the compressed data stream.

This option defaults to off.

"Append => 0|1"
This option controls what the "read" method does with uncompressed data.

If set to 1, all uncompressed data will be appended to the output parameter of the "read"
method.

If set to 0, the contents of the output parameter of the "read" method will be overwritten
by the uncompressed data.

Defaults to 0.

"Strict => 0|1"
This option controls whether the extra checks defined below are used when carrying out the
decompression. When Strict is on, the extra tests are carried out, when Strict is off they
are not.

The default for this option is off.

"RawInflate => 0|1"
When auto-detecting the compressed format, try to test for raw-deflate (RFC 1951) content
using the "IO::Uncompress::RawInflate" module.

The reason this is not default behaviour is because RFC 1951 content can only be detected
by attempting to uncompress it. This process is error prone and can result is false
positives.

Defaults to 0.

"UnLzma => 0|1"
When auto-detecting the compressed format, try to test for lzma_alone content using the
"IO::Uncompress::UnLzma" module.

The reason this is not default behaviour is because lzma_alone content can only be detected
by attempting to uncompress it. This process is error prone and can result is false
positives.

Defaults to 0.

Examples
TODO

Methods
read
Usage is

$status = $z->read($buffer)

Reads a block of compressed data (the size of the compressed block is determined by the "Buffer"
option in the constructor), uncompresses it and writes any uncompressed data into $buffer. If
the "Append" parameter is set in the constructor, the uncompressed data will be appended to the
$buffer parameter. Otherwise $buffer will be overwritten.

Returns the number of uncompressed bytes written to $buffer, zero if eof or a negative number on
error.

read
Usage is

$status = $z->read($buffer, $length)
$status = $z->read($buffer, $length, $offset)

$status = read($z, $buffer, $length)
$status = read($z, $buffer, $length, $offset)

Attempt to read $length bytes of uncompressed data into $buffer.

The main difference between this form of the "read" method and the previous one, is that this
one will attempt to return *exactly* $length bytes. The only circumstances that this function
will not is if end-of-file or an IO error is encountered.

Returns the number of uncompressed bytes written to $buffer, zero if eof or a negative number on
error.

getline
Usage is

$line = $z->getline()
$line = <$z>

Reads a single line.

This method fully supports the use of the variable $/ (or $INPUT_RECORD_SEPARATOR or $RS when
"English" is in use) to determine what constitutes an end of line. Paragraph mode, record mode
and file slurp mode are all supported.

getc
Usage is

$char = $z->getc()

Read a single character.

ungetc
Usage is

$char = $z->ungetc($string)

getHeaderInfo
Usage is

$hdr = $z->getHeaderInfo();
@hdrs = $z->getHeaderInfo();

This method returns either a hash reference (in scalar context) or a list or hash references (in
array context) that contains information about each of the header fields in the compressed data
stream(s).

tell
Usage is

$z->tell()
tell $z

Returns the uncompressed file offset.

eof
Usage is

$z->eof();
eof($z);

Returns true if the end of the compressed input stream has been reached.

seek
$z->seek($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 input file/buffer. It is a fatal error to attempt to seek backward.

Note that the implementation of "seek" in this module does not provide true random access to a
compressed file/buffer. It works by uncompressing data from the current offset in the
file/buffer until it reaches the uncompressed offset specified in the parameters to "seek". For
very small files this may be acceptable behaviour. For large files it may cause an unacceptable
delay.

The $whence parameter takes one the usual values, namely SEEK_SET, SEEK_CUR or SEEK_END.

Returns 1 on success, 0 on failure.

binmode
Usage is

$z->binmode
binmode $z ;

This is a noop provided for completeness.

opened
$z->opened()

Returns true if the object currently refers to a opened file/buffer.

autoflush
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".

Note that the special variable $| cannot be used to set or retrieve the autoflush setting.

input_line_number
$z->input_line_number()
$z->input_line_number(EXPR)

Returns the current uncompressed line number. If "EXPR" is present it has the effect of setting
the line number. Note that setting the line number does not change the current position within
the file/buffer being read.

The contents of $/ are used to determine what constitutes a line terminator.

fileno
$z->fileno()
fileno($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".

close
$z->close() ;
close $z ;

Closes the output file/buffer.

For most versions of Perl this method will be automatically invoked if the
IO::Uncompress::AnyUncompress 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::Uncompress::AnyUncompress object was
created, and the object is associated with a file, the underlying file will also be closed.

nextStream
Usage is

my $status = $z->nextStream();

Skips to the next compressed data stream in the input file/buffer. If a new compressed data
stream is found, the eof marker will be cleared and $. will be reset to 0.

Returns 1 if a new stream was found, 0 if none was found, and -1 if an error was encountered.

trailingData
Usage is

my $data = $z->trailingData();

Returns the data, if any, that is present immediately after the compressed data stream once
uncompression is complete. It only makes sense to call this method once the end of the
compressed data stream has been encountered.

This option can be used when there is useful information immediately following the compressed
data stream, and you don't know the length of the compressed data stream.

If the input is a buffer, "trailingData" will return everything from the end of the compressed
data stream to the end of the buffer.

If the input is a filehandle, "trailingData" will return the data that is left in the filehandle
input buffer once the end of the compressed data stream has been reached. You can then use the
filehandle to read the rest of the input file.

Don't bother using "trailingData" if the input is a filename.

If you know the length of the compressed data stream before you start uncompressing, you can
avoid having to use "trailingData" by setting the "InputLength" option in the constructor.

Importing
No symbolic constants are required by IO::Uncompress::AnyUncompress at present.

:all Imports "anyuncompress" and $AnyUncompressError. Same as doing this

use IO::Uncompress::AnyUncompress qw(anyuncompress $AnyUncompressError) ;

EXAMPLES
SUPPORT
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>.

SEE ALSO
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::Compress::FAQ

File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib

AUTHOR
This module was written by Paul Marquess, "pmqs AT cpan.org".

MODIFICATION HISTORY
See the Changes file.

This program is free software; you can redistribute it and/or modify it under the same terms as
Perl itself.