Compresses the entire Phar archive using Gzip or Bzip2 compression

Description

public Phar::compress(int $compression, ?string $extension = null): ?Phar

Note:
This method requires the php.ini setting phar.readonly to be set to 0 in order to work for Phar objects. Otherwise, a PharException will be thrown.

For tar-based and phar-based phar archives, this method compresses the entire archive using gzip compression or bzip2 compression. The resulting file can be processed with the gunzip command/bunzip command, or accessed directly and transparently with the Phar extension.

For Zip-based phar archives, this method fails with an exception. The zlib extension must be enabled to compress with gzip compression, the bzip2 extension must be enabled in order to compress with bzip2 compression. As with all functionality that modifies the contents of a phar, the phar.readonly INI variable must be off in order to succeed.

In addition, this method automatically renames the archive, appending .gz, .bz2 or removing the extension if passed Phar::NONE to remove compression. Alternatively, a file extension may be specified with the second parameter.

Parameters

compression: Compression must be one of Phar::GZ, Phar::BZ2 to add compression, or Phar::NONE to remove compression.
extension: By default, the extension is .phar.gz or .phar.bz2 for compressing phar archives, and .phar.tar.gz or .phar.tar.bz2 for compressing tar archives. For decompressing, the default file extensions are .phar and .phar.tar.

Return Values

Returns a Phar object, or null on failure.

Errors/Exceptions

Throws BadMethodCallException if the phar.readonly INI variable is on, the zlib extension is not available, or the bzip2 extension is not enabled.

Changelog

Version	Description
8.0.0	`extension` is now nullable.

Examples

Example #1 A Phar::compress() example

<?php
$p = new Phar('/path/to/my.phar', 0, 'my.phar');
$p['myfile.txt'] = 'hi';
$p['myfile2.txt'] = 'hi';
$p1 = $p->compress(Phar::GZ); // copies to /path/to/my.phar.gz
$p2 = $p->compress(Phar::BZ2); // copies to /path/to/my.phar.bz2
$p3 = $p2->compress(Phar::NONE); // exception: /path/to/my.phar already exists
?>

Phar::compress