gzdecode
gzcompress produces longer data because it embeds information about the encoding onto the string. If you are compressing data that will only ever be handled on one machine, then you don't need to worry about which of these functions you use. However, if you are passing data compressed with these functions to a different machine you should use gzcompress.
gzdeflate
(PHP 4 >= 4.0.4, PHP 5)
gzdeflate — Deflate a string
Description
string gzdeflate
( string
$data
[, int $level = -1
[, int $encoding = ZLIB_ENCODING_RAW
]] )This function compress the given string using the DEFLATE data format.
For details on the DEFLATE compression algorithm see the document "» DEFLATE Compressed Data Format Specification version 1.3" (RFC 1951).
Parameters
-
data -
The data to deflate.
-
level -
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.
-
encoding -
One of
ZLIB_ENCODING_*constants.
Return Values
The deflated string or FALSE if an error occurred.
Examples
Example #1 gzdeflate() example
<?php
$compressed = gzdeflate('Compress me', 9);
echo $compressed;
?>
Changelog
| Version | Description |
|---|---|
| 5.4.0 |
Added encoding parameter.
|
See Also
- gzinflate() - Inflate a deflated string
- gzcompress() - Compress a string
- gzuncompress() - Uncompress a compressed string
- gzencode() - Create a gzip compressed string
add a note
User Contributed Notes
gzdeflate - [7 notes]
anonymous at php dot net ¶
4 years ago
giunta dot gaetano at sea-aeroportimilano dot it ¶
6 years ago
Take care that that "PHP deflate" != "HTTP deflate".
The deflate encoding used in HTTP is actually zlib encoded.
This is what PHP functions return:
gzencode() == gzip
gzcompress() == zlib (aka. HTTP deflate)
gzdeflate() == *raw* deflate encoding
stockton at wowway dot com ¶
2 days ago
After some searching and experimentation I found that the output from this function cannot be 'inflated' with the objective c 'zlibInflate' wrapper for 'zlib' that is available at http://cocoadev.com/wiki/NSDataCategory but the output from gzcompress() can be. Thank you "anonymous at php dot net" and "tomas at slax dot org" for the clues. I hope this saves someone else the searching.
robin ¶
3 years ago
running 50000 repetitions on various content, i found that gzdeflate() and gzcompress() both performed equally fast regardless content and compression level, but gzinflate() was always about twice as fast as gzuncompress().
tomas at slax dot org ¶
4 years ago
gzcompress() is the same like gzdefflate(), it produces identical data and its speed is the same as well. The only difference is that gzcompress produces 6 bytes bigger result (2 extra bytes at the beginning and 4 extra bytes at the end).
denis dot noessler at red-at dot de ¶
10 years ago
if you have compressed data which is greater than 2 MB (system dependent), you will receive a buffer error by calling the function gzinflate().
be sure to to compress your data by a lower compression level, like 1.
i.e.: gzdeflate($sData, 1);
romain dot lalaut at laposte dot net ¶
5 years ago
@ giunta dot gaetano at sea-aeroportimilano dot it
No, gzdeflate() implements rfc1951.
And rf2616 (http 1.1 specs) says "deflate : The "zlib" format defined in RFC 1950 [31] in combination with the "deflate" compression mechanism described in RFC 1951 [29]."