GZENCODE(3) 1 GZENCODE(3)
gzencode - Create a gzip compressed string
SYNOPSIS
string gzencode (string $data, [int $level = -1], [int $encoding_mode = FORCE_GZIP])
DESCRIPTION
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).
PARAMETERS
o $data
- The data to encode.
o $level
- The level of compression. Can be given as 0 for no compression up to 9 for maximum compression. If not given, the default com-
pression level will be the default compression level of the zlib library.
o $encoding_mode
- The encoding mode. Can be FORCE_GZIP (the default) or FORCE_DEFLATE. Prior to PHP 5.4.0, using FORCE_DEFLATE results in a stan-
dard zlib deflated string (inclusive zlib headers) after a gzip file header but without the trailing crc32 checksum. In PHP 5.4.0
and later, FORCE_DEFLATE generates RFC 1950 compliant output, consisting of a zlib header, the deflated data, and an Adler check-
sum.
RETURN VALUES
The encoded string, or FALSE if an error occurred.
CHANGELOG
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
| 5.4.0 | |
| | |
| | |
| | FORCE_DEFLATE now generates RFC 1950 compliant |
| | output. |
| | |
+--------+---------------------------------------------------+
EXAMPLES
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);
?>
SEE ALSO
gzdecode(3), gzdeflate(3), gzinflate(3), gzuncompress(3), gzcompress(3), ZLIB Compressed Data Format Specification (RFC 1950) .
PHP Documentation Group GZENCODE(3)
