IO::Unc...Inflate(3)

📦 version 2.220.0, in opensuse-leap 16.0

💖 NAME 💖

Okay bestie, welcome to the IO::Unc...Inflate(3) page — User Contributed Perl Documentation, if you were wondering — and the main character is IO::Uncompress::RawInflate. It reads RFC 1951 files/buffers. That's the whole vibe. 🎀

🌈 SYNOPSIS 🌈

Here's the cheat sheet, aka the group-chat pinned message. Copy these exactly, no improvising:

           use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

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

           my $z = IO::Uncompress::RawInflate->new( $input [OPTS] )
               or die "rawinflate failed: $RawInflateError\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()

           $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()

           $RawInflateError ;

           # 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 🦋

So like, this module gives Perl a whole interface for reading files/buffers that conform to RFC 1951. Raw inflate energy only, no cap. 💅

For writing RFC 1951 files/buffers, see the companion module IO::Compress::RawDeflate.

🌸 Functional Interface 🌸

There's a top-level function, rawinflate, that does the "one-shot" uncompression thing between buffers and/or files. If you want finer control over the uncompression process, check the "OO Interface" section.

           use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

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

Heads up: the functional interface needs Perl5.005 or better. 👑

🫶 `rawinflate $input_filename_or_reference => $output_filename_or_reference [, OPTS]` 🫶

rawinflate expects at least two parameters, $input_filename_or_reference and $output_filename_or_reference, and zero or more optional parameters (see "Optional Parameters"). That's the bare minimum, bestie.

The $input_filename_or_reference parameter

This parameter is used to define the source of the compressed data.

It can take one of the following forms:

A filename — If $input_filename_or_reference is a simple scalar, it's assumed to be a filename. This file will be opened for reading and the input data will be read from it.
A filehandle — If $input_filename_or_reference 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 >, rawinflate 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 $output_filename_or_reference is a simple scalar, it's assumed to be a filename. This file will be opened for writing and the uncompressed data will be written to it.
A filehandle — If $output_filename_or_reference 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 >, rawinflate 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. That's the tea. 🍓

💜 Optional Parameters 💜

The optional parameters for the one-shot function rawinflate are (for the most part) identical to those used with the OO interface defined in the "Constructor Options" section. The exceptions are listed below. Don't @ me.

"AutoClose => 0|1" — This option applies to any input or output data streams to rawinflate 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 rawinflate 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 appended 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" — This option is a no-op.
"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.

Bestie, 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.

🎀 OneShot Examples 🎀

To read the contents of the file file1.txt.1951 and write the uncompressed data to the file file1.txt.

           use strict ;
           use warnings ;
           use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

           my $input = "file1.txt.1951";
           my $output = "file1.txt";
           rawinflate $input => $output
               or die "rawinflate failed: $RawInflateError\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::RawInflate qw(rawinflate $RawInflateError) ;
           use IO::File ;

           my $input = IO::File->new( "<file1.txt.1951" )
               or die "Cannot open 'file1.txt.1951': $!\n" ;
           my $buffer ;
           rawinflate $input => \$buffer
               or die "rawinflate failed: $RawInflateError\n";

To uncompress all files in the directory /my/home that match *.txt.1951 and store the compressed data in the same directory

           use strict ;
           use warnings ;
           use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

           rawinflate '</my/home/*.txt.1951>' => '</my/home/#1.txt>'
               or die "rawinflate failed: $RawInflateError\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::RawInflate qw(rawinflate $RawInflateError) ;

           for my $input ( glob "/my/home/*.txt.1951" )
           {
               my $output = $input;
               $output =~ s/.1951// ;
               rawinflate $input => $output
                   or die "Error compressing '$input': $RawInflateError\n";
           }

💅 OO Interface 💅

okay so now we're doing the object-oriented era and honestly it's giving main character energy. bestie, you get an actual IO::Uncompress::RawInflate object and then you can treat it like a filehandle. iconic.

✨ Constructor ✨

the constructor format for IO::Uncompress::RawInflate is literally this:

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

it takes one mandatory parameter, $input (defined below), and zero or more OPTS (defined in Constructor Options). no cap.

returns an IO::Uncompress::RawInflate object on success and undef on failure. the variable $RawInflateError will contain an error message on failure. slay.

if you're running Perl 5.005 or better, the object $z returned from IO::Uncompress::RawInflate can be used exactly like an IO::File filehandle. this means 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>;

below is a simple exaple of using the OO interface to read the compressed file myfile.1951 and write its contents to stdout.

my $filename = "myfile.1951";
my $z = IO::Uncompress::RawInflate->new($filename)
    or die "IO::Uncompress::RawInflate failed: $RawInflateError\n";

while (<$z>) {
    print $_;
}
$z->close();

see EXAMPLES for further examples. 🫶

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::RawInflate 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::RawInflate 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 is a no-op. 💀

💅 Methods 💅

okay bestie, this is the part where the object actually does stuff. methods, methods, methods — let’s go 🫶

read

usage is:

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

Reads a block of compressed data — the size of that compressed block is set by the Buffer option in the constructor — uncompresses it, and writes any uncompressed data into $buffer. If the Append parameter was set in the constructor, the uncompressed data gets appended to $buffer. Otherwise $buffer gets overwritten, periodt.

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

read

okay this is the second read flavor, and she’s a little different 💅 usage is:

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

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

Attempts 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 where it won’t are 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 variable $/ — or $INPUT_RECORD_SEPARATOR, or $RS when English is in use — to determine what counts as an end of line. Paragraph mode, record mode, and file slurp mode are all supported. iconic behavior honestly ✨

getc

usage is:

$char = $z->getc()

Read a single character.

ungetc

usage is:

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

inflateSync

usage is:

$status = $z->inflateSync()

TODO — yes bestie, the docs literally say TODO here 💀

getHeaderInfo

usage is:

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

This method returns either a hash reference in scalar context, or a list of hash references in array context, containing information about each of the header fields in the compressed data stream(s). very metadata, very main character 🔥

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. Attempting to seek backward is a fatal error. no cap, do not do it 🙈

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. so like… proceed with caution, bestie 💀

The $whence parameter takes one of 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. she’s just here for the vibes 🎀

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. ngl that’s important — don’t try to make $| happen here 🫶

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::RawInflate 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. bestie, just close her yourself 💅

Returns true on success, otherwise 0.

If the AutoClose option has been enabled when the IO::Uncompress::RawInflate 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. like, literally don’t 🙈

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::RawInflate at present.

:all imports rawinflate and $RawInflateError. Same as doing this:

use IO::Uncompress::RawInflate qw(rawinflate $RawInflateError) ;

✨ EXAMPLES ✨

Working with Net::FTP

See IO::Compress::FAQ.

🫶 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::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 zlib 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 zlib compression library is <http://www.zlib.org>.

The primary site for the zlib-ng compression library is <https://github.com/zlib-ng/zlib-ng>.

The primary site for gzip is <http://www.gzip.org>.

💖 AUTHOR 💖

This module was written by Paul Marquess, pmqs@cpan.org.

🦋 MODIFICATION HISTORY 🦋

See the Changes file.

🌸 COPYRIGHT AND LICENSE 🌸

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

and that’s the whole page, bestie 💅 source/version perl v5.42.0, dated 2026-05-17, wrapping up IO::Unc...Inflate(3) — go forth and uncompress something iconic ✨🎀

📦 where this page comes from

opensuse-leap 16.0: perl-IO-Compress 2.220.0-bp160.1.1 · Artistic-1.0 OR GPL-1.0-or-later
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-04: a language model's rewrite of the original, under its terms

IO::Unc...Inflate(3)

💖 NAME 💖

🌈 SYNOPSIS 🌈

🦋 DESCRIPTION 🦋

🌸 Functional Interface 🌸

🫶 rawinflate $input_filename_or_reference => $output_filename_or_reference [, OPTS] 🫶

🌟 Notes 🌟

💜 Optional Parameters 💜

🎀 OneShot Examples 🎀

💅 OO Interface 💅

✨ Constructor ✨

🌸 A filename 🌸

🦋 A filehandle 🦋

🎀 A scalar reference 🎀

👑 Constructor Options 👑

💅 Methods 💅

read

read

getline

getc

ungetc

inflateSync

getHeaderInfo

tell

eof

seek

binmode

opened

autoflush

input_line_number

fileno

close

nextStream

trailingData

🌈 Importing 🌈

✨ EXAMPLES ✨

Working with Net::FTP

🫶 SUPPORT 🫶

👑 SEE ALSO 👑

💖 AUTHOR 💖

🦋 MODIFICATION HISTORY 🦋

🌸 COPYRIGHT AND LICENSE 🌸

🫶 `rawinflate $input_filename_or_reference => $output_filename_or_reference [, OPTS]` 🫶