gzencode
(PHP 4 >= 4.0.4, PHP 5, PHP 7)
gzencode — Create a gzip compressed string
说明
$data
[,
int $level
= -1 [,
int $encoding_mode
= FORCE_GZIP ]] ) :
string
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).
参数
-
data
-
The data to encode.
-
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_mode
-
The encoding mode. Can be
FORCE_GZIP
(the default) orFORCE_DEFLATE
.Prior to PHP 5.4.0, using
FORCE_DEFLATE
results in a standard 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 checksum.
返回值
The encoded string, or FALSE
if an error occurred.
更新日志
版本 | 说明 |
---|---|
5.4.0 | FORCE_DEFLATE now generates RFC 1950 compliant output. |
范例
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);
?>
参见
- gzdecode() - Decodes a gzip compressed string
- gzdeflate() - Deflate a string
- gzinflate() - Inflate a deflated string
- gzuncompress() - Uncompress a compressed string
- gzcompress() - Compress a string
- » ZLIB Compressed Data Format Specification (RFC 1950)