IO::Unc...:Inflate(3)

📦 version 2.220.0, in opensuse-leap 16.0

🦋 IO::Uncompress::Inflate(3) — User Contributed Perl Documentation 🦋

okay bestie, this is the read RFC 1950 files/buffers module and it is genuinely serving useful-interface energy. 💅

🌸 NAME 🌸

IO::Uncompress::Inflate — Read RFC 1950 files/buffers. That's the whole vibe. 🫶

✨ SYNOPSIS ✨

Here's the shape of it, no cap:

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

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

    my $z = IO::Uncompress::Inflate->new( $input [OPTS] )
        or die "inflate failed: $InflateError\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()

    $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 gives you a Perl interface that lets you read files/buffers that conform to RFC 1950.

For writing RFC 1950 files/buffers, go see the companion module IO::Compress::Deflate. Bestie pairing, honestly. 💖

💫 Functional Interface 💫

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

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

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

The functional interface needs Perl5.005 or better. Periodt.

💅 inflate `$input_filename_or_reference` => `$output_filename_or_reference` [,OPTS] 💅

"inflate" 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 these forms:

A filename — if $input_filename_or_reference 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 $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 ">", "inflate" 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 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 $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 ">", "inflate" 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 lowkey iconic. 💜

🌟 Optional Parameters 🌟

The optional parameters for the one-shot function "inflate" 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 "inflate" 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 "inflate" 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" — 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.

🍓 OneShot Examples 🍓

To read the contents of the file "file1.txt.1950" and write the uncompressed 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 ;
    use warnings ;
    use IO::Uncompress::Inflate qw(inflate $InflateError) ;
    use IO::File ;

    my $input = IO::File->new( "<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";
    }

next up is the OO interface, so stay tuned bestie — part 2 is coming 👀✨

🎀 OO Interface 🎀

Okay so now we're doing the object-oriented era of this module, and honestly? It's giving main character energy. 💅

💖 Constructor 💖

The way you build one of these is literally this, no cap:

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

So the constructor takes exactly one mandatory parameter, $input (we'll get into what that can be in a sec), plus zero or more OPTS, which are all defined down in "Constructor Options". 🫶

It hands you back an "IO::Uncompress::Inflate" object if it slays, and undef if it doesn't. On failure, the variable $InflateError will be holding the error message for you — so check it, bestie, don't just ignore it. 😭

Now, if you're running Perl 5.005 or better, the $z object you get back can be used exactly like an IO::File filehandle. Meaning: every normal input file operation you'd do? You can do it with $z. Obsessed. So to read a line from a compressed file/buffer, either of these works:

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

Here's a simple example of using the OO interface to read the compressed file "myfile.1950" and write its contents out to stdout:

my $filename = "myfile.1950";
my $z = IO::Uncompress::Inflate->new($filename)
    or die "IO::Uncompress::Inflate failed: $InflateError\n";

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

Want more? Peep "EXAMPLES" for further examples. ✨

That mandatory $input parameter is what tells the module where the compressed data is even coming from. It can take one of three forms:

A filename — if $input is a scalar, it's assumed to be a filename. The file gets opened for reading and the compressed data gets read from it. 📁
A filehandle — if $input is a filehandle, the compressed data is read from it. And the string '-' can be used as an alias for standard input. 🖥️
A scalar reference — if $input is a scalar reference, the compressed data is read from $$input. 🦋

🌸 Constructor Options 🌸

Okay so these option names are case insensitive, and they can optionally be prefixed with a -. So all of the following are valid:

-AutoClose
-autoclose
AUTOCLOSE
autoclose

(Yeah. All four. Same option. Live your truth. 💀)

OPTS is a combination of the following options:

AutoClose => 0|1 — this one's only valid when the $input parameter is a filehandle. If you specify it and the value is true, the file gets closed once either the "close" method is called or the IO::Uncompress::Inflate object is destroyed. Defaults to 0. 🎀
MultiStream => 0|1 — lets multiple concatenated compressed streams be treated as one single compressed stream. Decompression stops 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. Defaults to 0. 🔥
Prime => $string — this one uncompresses the contents of $string before it even starts processing the input file/buffer. Super useful when the compressed data is embedded in another file/data structure and there's just no way to work out where the compressed data begins without reading the first few bytes first. In that case, you prime the uncompression with those bytes using this option. 🧚
Transparent => 0|1 — if this is set and the input file/buffer is not compressed data, the module will let you read it anyway. And also: if the input file/buffer does contain compressed data and there's non-compressed data immediately following it, setting this option makes the module treat the whole file/buffer as a single data stream. Defaults to 1. ⭐
BlockSize => $num — when it's reading the compressed input data, IO::Uncompress::Inflate reads it in blocks of $num bytes. Defaults to 4096. 🍓
InputLength => $size — when present, this limits the number of compressed bytes read from the input file/buffer to $size. Handy when there's useful data sitting directly after the compressed data stream and you know beforehand the exact length of that compressed stream. It's mostly used when reading from a filehandle — in which case the file pointer gets left pointing at the first byte directly after the compressed data stream. Defaults to off. 👑
Append => 0|1 — controls what the "read" method does with uncompressed data. If set to 1, all uncompressed data gets appended to the output parameter of the "read" method. If set to 0, the contents of the output parameter of the "read" method get overwritten by the uncompressed data. Defaults to 0. 💜
Strict => 0|1 — controls whether the extra checks listed below get 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. 🙈
1. The ADLER32 checksum field must be present.
2. The value of the ADLER32 field read must match the adler32 value of the uncompressed data actually contained in the file.

✨ Methods ✨

okay bestie, this is the good part — all the actual things you can do with your $z object 💅

read

so there's this form, right? usage is

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

It reads a whole block of compressed data — and the size of that block is decided by the Buffer option you set way back in the constructor, no cap — then it uncompresses it and writes all the uncompressed goodies into $buffer. 🫶

Now here's the tea on $buffer: if you set the Append parameter in the constructor, the uncompressed data gets appended onto $buffer. If you didn't, then $buffer just gets flat-out overwritten. srry not srry 💀

What comes back? The number of uncompressed bytes written into $buffer — or 0 if you hit eof, or a negative number if something went wrong. 😭

read

ooh okay, same name, different form — don't get it twisted 🌀 usage is

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

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

This one tries to read $length bytes of uncompressed data into $buffer. 🎀

The main character difference between this version and the one above is that this one attempts to return exactly $length bytes. The only times it won't are if it hits end-of-file or an IO error shows up. periodt.

Returns the number of uncompressed bytes written to $buffer, 0 if eof, or a negative number on error. same energy as before 💜

getline

usage is

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

Reads a single line. 🦋

And she fully supports using the variable $/ (or $INPUT_RECORD_SEPARATOR, or $RS when English is in use) to decide what counts as an end of line. Paragraph mode, record mode, and file slurp mode are all supported — iconic behaviour honestly 👑

getc

usage is

$char = $z->getc()

Read one single character. that's it, that's the method 🍓

ungetc

usage is

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

(mwah 💋)

inflateSync

usage is

$status = $z->inflateSync()

TODO 🙂 (yes, the docs literally say TODO, and we respect the honesty)

getHeaderInfo

usage is

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

This one returns either a hash reference (if you call it in scalar context) or a list of hash references (in array context) holding all the info about each of the header fields in the compressed data stream(s). 🌸 all the metadata, served on a platter.

tell

usage is

$z->tell()
tell $z

Returns the uncompressed file offset. ⭐

eof

usage is

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

Returns true if you've reached the end of the compressed input stream. 🏁

seek

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

Gives you a sub-set of the seek functionality, with one big restriction: it's only legal to seek forward in the input file/buffer. Trying to seek backward is a fatal error. 💀 no reverse, only forward, main character energy only moves ahead.

heads up bestie: the seek implementation in this module does not give you 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 you passed to seek. For very small files that's fine. For large files it may cause an unacceptable delay — like, embarrassingly slow 😭

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 to be supportive 🫶

opened

$z->opened()

Returns true if the object is currently referring to an opened file/buffer. 👀

autoflush

my $prev = $z->autoflush()
my $prev = $z->autoflush(EXPR)

If your $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 non-zero, it enables flushing after every write/print operation. 🔥

If $z is associated with a buffer, this method has no effect and always returns undef.

important caveat: the special variable $| cannot be used to set or retrieve the autoflush setting. nope. not her. 🙈

input_line_number

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

Returns the current uncompressed line number. If EXPR is present, it sets the line number. But know this: setting the line number does not change your current position within the file/buffer being read. 💅

The contents of $/ are used to determine what counts as a line terminator. 🎀

fileno

$z->fileno()
fileno($z)

If $z is associated with a file or a filehandle, fileno returns the underlying file descriptor. Once the close method has been called, fileno will return undef. 😶

If $z is associated with a buffer, this method returns undef. that's just how it is.

close

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

Closes the output file/buffer. 🚪✨

For most versions of Perl this method gets invoked automatically when the IO::Uncompress::Inflate object is destroyed — either explicitly, or when the variable holding the reference goes out of scope. The exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In those cases the close method will be called automatically, but not until global destruction of all live objects when the program is terminating. 😬 ancient Perl lore.

So: if you want your scripts to run on all versions of Perl, call close explicitly and don't rely on automatic closing. fr fr.

Returns true on success, otherwise 0.

If the AutoClose option was enabled when the IO::Uncompress::Inflate 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 gets cleared and $. gets reset to 0. 🌈

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

trailingData

usage is

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

Returns the data (if any) sitting immediately after the compressed data stream once uncompression is complete. It only makes sense to call this method once you've hit the end of the compressed data stream. 🦋

Use this when there's useful info right after the compressed data stream and you don't know the length of that stream.

If the input is a buffer, trailingData returns everything from the end of the compressed data stream to the end of the buffer. 🎀
If the input is a filehandle, trailingData returns the data 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 even bother using trailingData if the input is a filename. just don't. 🙈

If you already know the length of the compressed data stream before you start uncompressing, you can dodge using trailingData entirely by setting the InputLength option in the constructor. 💜

✨ Importing ✨

No symbolic constants are required by IO::Uncompress::Inflate at present. ⭐

:all — imports inflate and $InflateError. Same as doing this:

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

✨ EXAMPLES ✨

Working with Net::FTP

See IO::Compress::FAQ 🐟

✨ SUPPORT ✨

General feedback / questions / bug reports should go 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::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 zlib compression library was written by Jean-loup Gailly gzip@prep.ai.mit.edu and Mark Adler madler@alumni.caltech.edu. legends, honestly 👑

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. 🫶 ty king

✨ 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. 💖

okay that's a wrap bestie 🎀 this page came from perl v5.42.0 and it's dated 2026-05-17 — go forth and inflate responsibly, ily, bye 💅✨

📦 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)

🦋 IO::Uncompress::Inflate(3) — User Contributed Perl Documentation 🦋

🌸 NAME 🌸

✨ SYNOPSIS ✨

🌈 DESCRIPTION 🌈

💫 Functional Interface 💫

💅 inflate $input_filename_or_reference => $output_filename_or_reference [,OPTS] 💅

🎀 The $input_filename_or_reference parameter 🎀

🎀 The $output_filename_or_reference parameter 🎀

🫶 Notes 🫶

🌟 Optional Parameters 🌟

🍓 OneShot Examples 🍓

🎀 OO Interface 🎀

💖 Constructor 💖

🌸 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 ✨

💅 inflate `$input_filename_or_reference` => `$output_filename_or_reference` [,OPTS] 💅

🎀 The `$input_filename_or_reference` parameter 🎀

🎀 The `$output_filename_or_reference` parameter 🎀