IO::Unc...Inflate(3)
okay so the manual name is IO::Unc...Inflate(3), and it's from the User Contributed Perl Documentation β yes, the title looks cut off, that's just the header being dramatic π
β¨ NAME β¨
IO::Uncompress::AnyInflate β Uncompress zlib-based (zip, gzip) file/buffer π«Ά
πΈ SYNOPSIS πΈ
here's the exact code vibe, bestie β no edits, no cap:
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)
π¦ DESCRIPTION π¦
This module provides a Perl interface that lets you read files/buffers compressed in a number of formats that use the zlib compression library. It's giving decoder bestie energy, fr fr π
The formats supported are:
The module will auto-detect which, if any, of the supported compression formats is being used. periodt β¨
β¨ Functional Interface β¨
okay so there's a top-level function called anyinflate and it's literally here to carry out one-shot uncompression between buffers and/or files. For finer control over the whole uncompression sitch, go peek at the OO Interface section. π
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. π«Ά
π 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). β¨
π 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 β If the
$input_filename_or_referenceparameter 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 β If the
$input_filename_or_referenceparameter 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 β If
$input_filename_or_referenceis a scalar reference, the input data will be read from$$input_filename_or_reference. - An array reference β If
$input_filename_or_referenceis an array reference, each element in the array must be a filename.
The input data will be read from each file in turn.
The complete array will be walked to ensure that it only contains valid filenames before any data is uncompressed.
- An Input FileGlob string β If
$input_filename_or_referenceis a string that is delimited by the characters"<"and">"anyinflatewill assume that it is an input fileglob string. The input is the list of files that match the fileglob.
See File::GlobMapper for more details.
If the $input_filename_or_reference parameter is any other type, undef will be returned.
π¦ The $output_filename_or_reference parameter
The parameter $output_filename_or_reference is used to control the destination of the uncompressed data. This parameter can take one of these forms.
- A filename β If the
$output_filename_or_referenceparameter is a simple scalar, it is assumed to be a filename. This file will be opened for writing and the uncompressed data will be written to it. - A filehandle β If the
$output_filename_or_referenceparameter is a filehandle, the uncompressed data will be written to it. The string'-'can be used as an alias for standard output. - A scalar reference β If
$output_filename_or_referenceis a scalar reference, the uncompressed data will be stored in$$output_filename_or_reference. - An Array Reference β If
$output_filename_or_referenceis an array reference, the uncompressed data will be pushed onto the array. - An Output FileGlob β If
$output_filename_or_referenceis a string that is delimited by the characters"<"and">"anyinflatewill 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.
πΈ 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. π
π 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. π
AutoClose => 0|1β This option applies to any input or output data streams toanyinflatethat 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|1β This option is now a no-op. All files will be written in binmode.Append => 0|1β The behaviour of this option is dependent on the type of output data stream.- A Buffer β If
Appendis 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 β If
Appendis 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 β If
Appendis enabled, the filehandle will be positioned to the end of the file via a call toseekbefore any uncompressed data is written to it. Otherwise the file pointer will not be moved.
- A Buffer β If
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|1β 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 => $scalarβ 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.
π OneShot Examples
π Read a compressed file and write it out uncompressed
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";
π§ Read from a Perl filehandle into a buffer
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";
π Uncompress all matching files in a directory
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";
}
π OO Interface π
Okay bestie, this is the part where we go full object-oriented, and honestly? Itβs giving main character energy. Letβs get into it.
β¨ Constructor β¨
The constructor for IO::Uncompress::AnyInflate looks like this, periodt:
my $z = IO::Uncompress::AnyInflate->new( $input [OPTS] )
or die "IO::Uncompress::AnyInflate failed: $AnyInflateError\n";
So hereβs the tea β the constructor takes one mandatory parameter, $input (defined down below π), plus zero or more OPTS, which are all defined in "Constructor Options".
It returns an "IO::Uncompress::AnyInflate" object on success, and undef on failure. If it flops, the variable $AnyInflateError will hold an error message for you. No cap. π
Now, if youβre running Perl 5.005 or better, the object $z you get back from IO::Uncompress::AnyInflate can be used exactly like an IO::File filehandle. Which literally means all the normal input file operations work on $z. For example, to read a line from a compressed file/buffer you can use either of these forms β both slay, pick your fave:
$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. Iconic behaviour honestly:
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 π«Ά
The mandatory parameter $input is what determines the source of the compressed data. This parameter can take one of three forms:
- A filename β if the
$inputparameter is a scalar, itβs assumed to be a filename. The file gets opened for reading and the compressed data gets read from it. - A filehandle β if the
$inputparameter is a filehandle, the compressed data gets read from it. The string'-'can be used as an alias for standard input. - A scalar reference β if
$inputis a scalar reference, the compressed data gets read from$$input.
π Constructor Options π
Quick vibe check first: the option names defined below are case insensitive and can optionally be prefixed by a '-'. So all of the following are valid, bestie, donβt stress:
-AutoClose
-autoclose
AUTOCLOSE
autoclose
OPTS is a combination of the following options:
"AutoClose => 0|1"β this option is only valid when the$inputparameter is a filehandle. If you specify it and the value is true, the file will get closed once either the"close"method is called or theIO::Uncompress::AnyInflateobject is destroyed. This parameter defaults to0."MultiStream => 0|1"β 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. This parameter defaults to0."Prime => $string"β this option will uncompress the contents of$stringbefore processing the input file/buffer. Itβs lowkey so useful when the compressed data is embedded in another file/data structure and itβs not possible to work out where the compressed data begins without having to read the first few bytes. If thatβs the sitch, the uncompression can be primed with these bytes using this option. β¨"Transparent => 0|1"β 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 thereβs 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 to1."BlockSize => $num"β when reading the compressed input data,IO::Uncompress::AnyInflatewill read it in blocks of$numbytes. This option defaults to4096."InputLength => $size"β when present, this option will limit the number of compressed bytes read from the input file/buffer to$size. Itβs the move when thereβs useful data directly after the compressed data stream and you already 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"β this option controls what the"read"method does with uncompressed data. If set to1, all uncompressed data will be appended to the output parameter of the"read"method. If set to0, the contents of the output parameter of the"read"method will be overwritten by the uncompressed data. Defaults to0."Strict => 0|1"β 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.
So if you turn on Strict, and the input is an RFC 1950 data stream, the following get 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.
And if the input is a gzip (RFC 1952) data stream, the following get 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"β when auto-detecting the compressed format, try to test for raw-deflate (RFC 1951) content using the"IO::Uncompress::RawInflate"module. The reason this isnβt default behaviour is because RFC 1951 content can only be detected by attempting to uncompress it. That process is error prone and can result in false positives, ngl. π Defaults to0."ParseExtra => 0|1"β if the gzip FEXTRA header field is present and this option is set, it will force the module to check that it conforms to the sub-field structure as defined in RFC 1952. If the"Strict"is on it will automatically enable this option. Defaults to0.
π METHODS π
okay bestie, this is the good part β all the actual methods you can call on your $z object. every single one, no skips, no cap. π«Ά
read (the block one)
usage is:
$status = $z->read($buffer)
this one reads a block of compressed data (how big that block is? that's decided by the Buffer option you set in the constructor, iykyk), uncompresses it, and writes whatever uncompressed data comes out into $buffer.
here's the vibe check on $buffer: if you set the Append parameter in the constructor, the uncompressed data gets appended to $buffer. if you didn't, $buffer gets overwritten. choose wisely. β¨
returns the number of uncompressed bytes written to $buffer, returns zero if it hit eof, or a negative number if something went wrong. π
read (the exact-length one)
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 form attempts to read $length bytes of uncompressed data into $buffer.
the main character 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 is if end-of-file or an IO error gets encountered. that's it, that's the whole list. π
returns the number of uncompressed bytes written to $buffer, returns zero if it hit eof, or a negative number on error.
getline
usage is:
$line = $z->getline()
$line = <$z>
reads a single line. iconic behaviour, honestly.
this method fully supports the use of the variable $/ (or $INPUT_RECORD_SEPARATOR, or $RS when English is in use) to determine what actually counts as an end of line. paragraph mode, record mode and file slurp mode are all supported. all of them. slay. πΈ
getc
usage is:
$char = $z->getc()
reads a single character. tiny. adorable. one (1) char.
ungetc
usage is:
$char = $z->ungetc($string)
inflateSync
usage is:
$status = $z->inflateSync()
TODO β that's literally what the docs say, bestie. not me making things up, it's just a todo. π
getHeaderInfo
usage is:
$hdr = $z->getHeaderInfo();
@hdrs = $z->getHeaderInfo();
this method returns either a hash reference (when you call it in scalar context) or a list of hash references (in array context) that contains information about each of the header fields in the compressed data stream(s). plural streams, plural headers, we love a generous data structure. π
tell
usage is:
$z->tell()
tell $z
returns the uncompressed file offset. yes. offset of the uncompressed stuff. π
eof
usage is:
$z->eof();
eof($z);
returns true if the end of the compressed input stream has been reached. that's the whole vibe check.
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. like, do not do it. β οΈ
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 awareness, bestie. π
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. it does nothing and it's proud of it. π
opened
$z->opened()
returns true if the object currently refers to an 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. π
note that the special variable $| cannot be used to set or retrieve the autoflush setting. yeah. that one surprised me too.
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 β they're two separate things, okay?
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. buffer girlies get nothing, sorry. π«Ά
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. dramatic much? π
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. fr fr, just call it.
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. two-for-one.
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. three moods. π
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 β timing matters, bestie.
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,
trailingDatawill return everything from the end of the compressed data stream to the end of the buffer. - if the input is a filehandle,
trailingDatawill 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. just don't. π
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. efficiency queen behaviour. π
π¦ IMPORTING π¦
no symbolic constants are required by IO::Uncompress::AnyInflate at present. none. zero. zilch.
:all imports anyinflate and $AnyInflateError. same as doing this:
use IO::Uncompress::AnyInflate qw(anyinflate $AnyInflateError) ;
β¨ EXAMPLES β¨
Working with Net::FTP
see IO::Compress::FAQ. that's the whole pointer, go read it. π
π SUPPORT π
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>. the github one is preferred, just saying. π«Ά
π SEE ALSO π
the whole friend group, in order:
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 lore, basically. π
the zlib compression library was written by Jean-loup Gailly "gzip@prep.ai.mit.edu" and Mark Adler "madler@alumni.caltech.edu". legends, honestly. π
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>.
π AUTHOR π
this module was written by Paul Marquess, "pmqs@cpan.org". main character energy, truly. π
β MODIFICATION HISTORY β
see the Changes file. that's where the receipts live. π§Ύ
π₯ COPYRIGHT AND LICENSE π₯
copyright (c) 2005-2026 Paul Marquess. all rights reserved.
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!! π you made it to the end, which is honestly iconic of you. this copy is from perl v5.42.0, dated 2026-05-17 β screenshot it for the group chat, mwah ππ
π¦ where this page comes from
- opensuse-leap 16.0: perl-IO-Compress 2.220.0-bp160.1.1 Β· Artistic-1.0 OR GPL-1.0-or-later
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms