PharData::compress

Compresses the entire tar/zip archive using Gzip or Bzip2 compression

&reftitle.description; public ``PharData``null```PharData::compress` `int` `compression` ``string``null```extension`&null;

For tar 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 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.

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.

&reftitle.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 `.tar.gz` or `.tar.bz2` for compressing a tar, and `.tar` for decompressing.

&reftitle.returnvalues;

A `PharData` object is returned on success, or &null; on failure.

&reftitle.errors;

Throws `BadMethodCallException` if the zlib extension is not available, or the bzip2 extension is not enabled.

&reftitle.changelog;

&Version; | &Description;
8.0.0 | `extension` is now nullable.

&reftitle.examples;

### A `PharData::compress` example

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

&reftitle.seealso;

- `Phar::compress`