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Perl version 5.10.0 documentation - IO::Uncompress::Inflate

NAME

IO::Uncompress::Inflate - Read RFC 1950 files/buffers

SYNOPSIS

use IO::Uncompress::Inflate qw(inflate $InflateError) ;

my $status = inflate $input => $output [,OPTS]

or die "inflate failed: $InflateError\n";

my $z = new IO::Uncompress::Inflate $input [OPTS]

or die "inflate failed: $InflateError\n";

$status

$line =

$char =

= $z->read($buffer)

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

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

$z->getline()

$z->getc()

$z->ungetc()

$z->opened()

$status = $z->inflateSync()

$data = $z->trailingData()

$status = $z->nextStream()

$data = $z->getHeaderInfo()

$z->tell()

$z->seek($position, $whence)

$z->binmode()

$z->fileno()

$z->eof()

$z->close()

$InflateError ;

# 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 conform to RFC

1950.

For writing RFC 1950 files/buffers, see the companion module IO::Compress::Deflate.

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Perl version 5.10.0 documentation - IO::Uncompress::Inflate

Functional Interface

A top-level function,

inflate,

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::Inflate qw(inflate $InflateError) ;

inflate $input => $output [,OPTS]

or die "inflate failed: $InflateError\n";

The functional interface needs Perl5.005 or better.

inflate $input => $output [, OPTS]

inflate

expects at least two parameters,

$input

and

$output.

The $input parameter

The parameter,

$input,

is used to define the source of the compressed data.

It can take one of the following forms:

A filename

If the

$input

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

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

$input

is a scalar reference, the input data will be read from

$$input.

An array reference

$input

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

$input

is a string that is delimited by the characters "<" and ">"

inflate

will assume

that it is an

input fileglob string.

The input is the list of files that match the fileglob.

If the fileglob does not match any files ...

See

File::GlobMapper

for more details.

If the

$input

parameter is any other type,

undef

will be returned.

The $output parameter

The parameter

$output

is used to control the destination of the uncompressed 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 uncompressed data will be written to it.

A filehandle

If the

$output

parameter is a filehandle, the uncompressed data will be written to it. The

string '-' can be used as an alias for standard output.

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Perl version 5.10.0 documentation - IO::Uncompress::Inflate

A scalar reference

$output

is a scalar reference, the uncompressed data will be stored in

$$output.

An Array Reference

$output

is an array reference, the uncompressed data will be pushed onto the array.

An Output FileGlob

$output

is a string that is delimited by the characters "<" and ">"

inflate

will assume

that it is an

output fileglob string.

The output is the list of files that match the fileglob.

When

$output

is an fileglob string,

$input

must also be a fileglob string. Anything else is

an error.

If the

$output

parameter is any other type,

undef

will be returned.

Notes

When

$input

maps to multiple compressed files/buffers and

$output

is a single file/buffer, after

uncompression

$output

will contain a concatenation of all the uncompressed data from each of the

input files/buffers.

Optional Parameters

Unless specified below, the optional parameters for

inflate, OPTS,

are the same as those used with

the OO interface defined in the

Constructor Options

section below.

AutoClose => 0|1

This option applies to any input or output data streams to

inflate

that are filehandles.

AutoClose

is specified, and the value is true, it will result in all input and/or output

filehandles being closed once

inflate

has completed.

This parameter defaults to 0.

BinModeOut => 0|1

When writing to a file or filehandle, set

binmode

before writing to the file.

Defaults to 0.

Append => 0|1

TODO

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

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Perl version 5.10.0 documentation - IO::Uncompress::Inflate

can avoid having to use

trailingData

by setting the

InputLength

option.

Examples

To read the contents of the file

file1.txt.1950

and write the compressed data to the file

file1.txt.

use strict ;

use warnings ;

use IO::Uncompress::Inflate qw(inflate $InflateError) ;

my $input = "file1.txt.1950";

my $output = "file1.txt";

inflate $input => $output

or die "inflate failed: $InflateError\n";

To read from an existing Perl filehandle,

$input,

and write the uncompressed data to a buffer,

$buffer.

use

strict ;

warnings ;

IO::Uncompress::Inflate qw(inflate $InflateError) ;

IO::File ;

my $input = new IO::File "<file1.txt.1950"

or die "Cannot open 'file1.txt.1950': $!\n" ;

my $buffer ;

inflate $input => \$buffer

or die "inflate failed: $InflateError\n";

To uncompress all files in the directory "/my/home" that match "*.txt.1950" and store the compressed

data in the same directory

use strict ;

use warnings ;

use IO::Uncompress::Inflate qw(inflate $InflateError) ;

inflate '</my/home/*.txt.1950>' => '</my/home/#1.txt>'

or die "inflate failed: $InflateError\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::Inflate qw(inflate $InflateError) ;

for my $input ( glob "/my/home/*.txt.1950" )

{

my $output = $input;

$output =~ s/.1950// ;

inflate $input => $output

or die "Error compressing '$input': $InflateError\n";

}

http://perldoc.perl.org

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Perl version 5.10.0 documentation - IO::Uncompress::Inflate

OO Interface

Constructor

The format of the constructor for IO::Uncompress::Inflate is shown below

my $z = new IO::Uncompress::Inflate $input [OPTS]

or die "IO::Uncompress::Inflate failed: $InflateError\n";

Returns an

IO::Uncompress::Inflate

object on success and undef on failure. The variable

$InflateError

will contain an error message on failure.

If you are running Perl 5.005 or better the object,

$z,

returned from IO::Uncompress::Inflate 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

$input

is a scalar reference, the compressed data will be read from

$$output.

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

method is called or

the IO::Uncompress::Inflate 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.

http://perldoc.perl.org

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