This module enables you to transparently read and write
gzip (.gz) compressed files, through versions of most of
the filesystem functions
which work with gzip-compressed files (and uncompressed files,
too, but not with sockets).
Version 4.0.4 introduced a fopen-wrapper for .gz-files, so that
you can use a special zlib: URL to access
compressed files transparently using the normal f*() file access
functions if you prefix the filename or path with
zlib: when calling fopen(). This
feature requires a C runtime library that provides the
fopencookie() function. Up to now the GNU libc
seems to be the only library that provides this feature.
In PHP 4.3.0, zlib: has been changed to
compress.zlib:// to prevent ambiguities with
filenames containing ':' characters. The
fopencookie() function is not longer required.
More information is available in the section about
the Section called Compression Streams in Appendix N.
Whether to transparently compress pages. If this option is set
to "On" in php.ini or the Apache configuration, pages are
compressed if the browser sends an "Accept-Encoding: gzip" or
"deflate" header. "Content-Encoding: gzip" (respectively
"deflate") and "Vary: Accept-Encoding" headers are added to
In runtime, it can be set only before sending any output.
This option also accepts integer values instead of boolean
"On"/"Off", using this you can set the output buffer size
(default is 4KB).
Note: output_handler must be
empty if this is set 'On' ! Instead you must use zlib.output_handler.