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Create a gzip compressed string (PHP 4 >= 4.0.4, PHP 5)
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.

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



The data to encode.


The level of compression. 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.


The encoding mode. Can be FORCE_GZIP (the default) or FORCE_DEFLATE.

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.

Return Values

The encoded string, or FALSE if an error occurred.


4.2.0 The encoding_mode parameter was added


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

Example 2723. Creating a gzip file

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