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

📦

version 5.42.3 · 17 versions

💅 NAME 💅

okay so bestie, welcome to the IO::Unc...Inflate(3pm) manual page from the Perl Programmers Reference Guide. This module is IO::Uncompress::AnyInflate, and it's your go-to for uncompressing zlib-based stuff — think zip and gzip files/buffers. iconic behavior, honestly 🫶

✨ SYNOPSIS ✨

    use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

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

    my $z = IO::Uncompress::AnyInflate->new( $input [OPTS] )
        or die "anyinflate failed: $AnyInflateError\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()

    $AnyInflateError ;

    # 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 this module gives you a Perl interface that lets you read files/buffers that have been compressed in a bunch of formats — all of them use the zlib compression library, and it's lowkey a whole vibe 💖

The formats supported are:

RFC 1950
RFC 1951 (optionally)
gzip (RFC 1952)
zip

And like, the best part? The module will auto-detect which, if any, of the supported compression formats is being used. no cap, it just knows 🔥✨

💖 Functional Interface 💖

okay so there's this top-level function called anyinflate, and it is literally here to carry out "one-shot" uncompression between buffers and/or files. if you want finer control over the whole uncompression sitch, the "OO Interface" section is right there, iykyk. 💅

    use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

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

The functional interface needs Perl5.005 or better — no cap.

🎀 anyinflate $input_filename_or_reference => $output_filename_or_reference [, OPTS] 🎀

anyinflate 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 💖

This parameter is used to define the source of the compressed data. bestie, it can take one of these 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 ">", anyinflate 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 ">", anyinflate 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 a 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 anyinflate 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 anyinflate 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 anyinflate 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.Compressed" and write the uncompressed data to the file "file1.txt".

    use strict ;
    use warnings ;
    use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

    my $input = "file1.txt.Compressed";
    my $output = "file1.txt";
    anyinflate $input => $output
        or die "anyinflate failed: $AnyInflateError\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::AnyInflate qw(anyinflate $AnyInflateError) ;
    use IO::File ;

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

    anyinflate '</my/home/*.txt.Compressed>' => '</my/home/#1.txt>'
        or die "anyinflate failed: $AnyInflateError\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::AnyInflate qw(anyinflate $AnyInflateError) ;

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

💅 OO Interface 💅

Okay bestie, this is the object-oriented era of the page: you make an object, and then you use it like a filehandle. Iconic behavior, honestly. 🎀

🌸 Constructor 🌸

Here’s the constructor format, exactly as it lives:

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

It takes one mandatory parameter, $input — defined below — plus zero or more OPTS, which are defined in Constructor Options. ✨

It returns an IO::Uncompress::AnyInflate object on success, and undef on failure. If it fails, $AnyInflateError will hold an error message. No cap. 💅

If you’re running Perl 5.005 or better, the $z object you get back can be used exactly like an IO::File filehandle. That 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 example of using the OO interface to read the compressed file "myfile.Compressed" and write its contents to stdout. Slay. 🦋

my $filename = "myfile.Compressed";
my $z = IO::Uncompress::AnyInflate->new($filename)
    or die "IO::Uncompress::AnyInflate failed: $AnyInflateError\n";

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

See "EXAMPLES" for further examples. 💖

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

A filename — If the $input parameter is a scalar, it’s assumed to be a filename. The file gets opened for reading, and the compressed data is read from it. 📂
A filehandle — If $input is a filehandle, the compressed data is 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 is read from $$input. 🎀

🎀 Constructor Options 🎀

The option names 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. Obsessed with how many there are? Same. 💅

AutoClose => 0|1 — This option is only valid when $input is a filehandle. If you set it and the value is true, the file will be closed once either the close method is called or the IO::Uncompress::AnyInflate object is destroyed. Defaults to 0. 🔥
MultiStream => 0|1 — Lets multiple concatenated compressed streams be treated as a 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 option uncompresses the contents of $string before processing the input file/buffer. It’s useful when the compressed data is embedded in another file/data structure and it’s not possible to work out where the compressed data begins without reading the first few bytes. If that’s 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 makes the module treat the whole file/buffer as a single data stream. Defaults to 1. ✨
BlockSize => $num — When reading the compressed input data, IO::Uncompress::AnyInflate 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. It’s useful when there’s 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. Defaults to off. 👑
Append => 0|1 — Controls what the read method does with uncompressed data. If set to 1, all uncompressed data is appended to the output parameter of the read method. If set to 0, the contents of the output parameter of the read method are overwritten by the uncompressed data. Defaults to 0. 💜
Strict => 0|1 — Controls whether the extra checks below are used when carrying out decompression. When Strict is on, the extra tests are carried out; when Strict is off, they are not. The default is off.

If the input is an RFC 1950 data stream, the following will be checked:

The ADLER32 checksum field must be present.
The value of the ADLER32 field read must match the adler32 value of the uncompressed data actually contained in the file.

If the input is a gzip (RFC 1952) data stream, the following will be checked:

If the FHCRC bit is set in the gzip FLG header byte, the CRC16 bytes in the header must match the crc16 value of the gzip header actually read.
If the gzip header contains a name field (FNAME), it consists solely of ISO 8859-1 characters.
If the gzip header contains a comment field (FCOMMENT), it consists solely of ISO 8859-1 characters plus line-feed.
If the gzip FEXTRA header field is present, it must conform to the sub-field structure as defined in RFC 1952.
The CRC32 and ISIZE trailer fields must be present.
The value of the CRC32 field read must match the crc32 value of the uncompressed data actually contained in the gzip file.
The value of the ISIZE fields read must match the length of the uncompressed data actually read from the file.

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 behavior is because RFC 1951 content can only be detected by attempting to uncompress it. This process is error prone and can result in false positives. Defaults to 0. 😭
ParseExtra => 0|1 — If the gzip FEXTRA header field is present and this option is set, it forces the module to check that it conforms to the sub-field structure as defined in RFC 1952. If Strict is on, it will automatically enable this option. Defaults to 0. 💀

💅 Methods 💅

Okay bestie, this is the methods era of the page, and it is highkey stacked with tools. Let's go. ✨

📖 read (first form)

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. periodt.

📖 read (second form)

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. It'll only fall short 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. same return vibe, different read energy.

📖 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. versatile queen.

📖 getc

Usage is:

$char = $z->getc()

Read a single character.

📖 ungetc

Usage is:

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

That's the whole usage, bestie — no extra lore on this one. 🎀

📖 inflateSync

Usage is:

$status = $z->inflateSync()

TODO

The manual literally says TODO here, so I'm not gonna invent behaviour and lie to you. No cap. 💀

📖 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). header detective realness.

📖 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.

Fatal error, bestie. Do not try to seek backward. This is not a drill. 💅

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. iconic minimal effort.

📖 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::AnyInflate 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::AnyInflate 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. stream-hopping excellence.

📖 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::AnyInflate at present.

:all Imports anyinflate and $AnyInflateError. Same as doing this:

use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;

🎀 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::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::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.

💅 That's the whole page, bestie! This manual page comes from perl v5.42.3, dated 2026-11-03. Stay compressed, stay iconic. 🎀✨

📦 where this page comes from

alpine 3.24: perl-doc 5.42.3-r0 · Artistic-1.0-Perl 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(3pm)

💅 NAME 💅

✨ SYNOPSIS ✨

🌸 DESCRIPTION 🌸

💖 Functional Interface 💖

🎀 anyinflate $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 (first form)

📖 read (second form)

📖 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 💖

💖 The `$input_filename_or_reference` parameter 💖

🦋 The `$output_filename_or_reference` parameter 🦋