gzencode

(PHP 4 >= 4.0.4)

gzencode -- Create a gzip compressed string

Description

string gzencode ( string data [, int level [, int encoding_mode]])

This function returns a compressed version of the input data compatible with the output of the gzip program, or FALSE if an error is encountered. The optional parameter level can be given as 0 for no compression up to 9 for maximum compression, if not given the default compression level will be the default compression level of the zlib library.

You can also give FORCE_GZIP (the default) or FORCE_DEFLATE as optional third paramter encoding_mode. If you use FORCE_DEFLATE, you get a standard zlib deflated string (inclusive zlib headers) after the gzip file header but without the trailing crc32 checksum.

Note: level was added in PHP 4.2, before PHP 4.2 gzencode() only had the data and (optional) encoding_mode parameters..

The resulting data contains the appropriate headers and data structure to make a standard .gz file, e.g.:

Example 1. Creating a gzip file

<?php
    $data = implode("", file("bigfile.txt"));
    $gzdata = gzencode($data, 9);
    $fp = fopen("bigfile.txt.gz", "w");
    fwrite($fp, $gzdata);
    fclose($fp);
?>

For more information on the GZIP file format, see the document: GZIP file format specification version 4.3 (RFC 1952).

See also gzcompress(). gzuncompress(), gzdeflate(), gzinflate().