Output Control configuration options

Runtime Runtime

Constants

Title

output_bufferingbool/int

Output buffering for all files can be enabled by setting this directive to "On". To limit the size of the buffer, a number/quantity corresponding to the maximum numbers of bytes allowed can be used instead of "On" for the value of this directive. For example output_buffering=4096. This directive is always Off in PHP-CLI.

output_handlerstring

The output of scripts can be redirected to a function. For example setting output_handler to mb_output_handler(), character encoding will be transparently converted to the specified encoding. Setting any output handler automatically turns on output buffering.

Note

mb_output_handler() and ob_iconv_handler() cannot be used together and ob_gzhandler() and zlib.output_compression cannot be used with any of the following: mb_output_handler(), ob_gzhandler(), zlib.output_compression, the 'URL-Rewriter' handler (see session.use_trans_sid and output_add_rewrite_var()).

Note

Only built-in functions can be used with this directive. For user defined functions, use ob_start().

implicit_flushbool

false by default. Changing this to true tells PHP to tell the output layer to flush itself automatically after every output block. This is equivalent to calling the PHP function flush() after each and every call to any function producing output (such as print() or echo()) and each and every HTML block.

When using PHP within an web environment, turning this option on has serious performance implications and is generally recommended for debugging purposes only. This value defaults to true when operating under the CLI SAPI.

See also ob_implicit_flush().

url_rewriter.tagsstring

url_rewriter.tags specifies HTML tags and attributes in which URLs are rewritten by output_add_rewrite_var() values. Defaults to "form=".

Adding "form=" or any form attribute will add a hidden input element to the form with a name and value attribute for each name-value pair passed to output_add_rewrite_var().

Caution

Adding the same tag more than once to url_rewriter.tags will only use the first occurrence during the URL rewriting process.

Note

Prior to PHP 7.1.0, url_rewriter.tags was used to specify session.trans_sid_tags.

url_rewriter.hostsstring

url_rewriter.hosts specifies which hosts are rewritten to include output_add_rewrite_var() values. Defaults to $_SERVER['HTTP_HOST']. Multiple hosts can be specified by a comma separated list that does not include spaces. For example "php.net,wiki.php.net,bugs.php.net".