PHP Output Buffering Control

The output buffering controls the output data from the PHP scripts.

Example to controls the output of a script

<?php

ob_start();
echo "Hello\n";

setcookie("cookiename", "cookiedata");

ob_end_flush();

?>

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions;

They are part of the PHP core.

Run-time Configuration

The behavior of these functions is affected by settings in php.ini.

Output Control configuration options

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are always available as part of the PHP core.

• PHP_OUTPUT_HANDLER_START (integer)
  • This indicates that output buffering has begun.
• PHP_OUTPUT_HANDLER_WRITE (integer)
  • Indicates that the output buffer is being flushed, and had data to output.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_FLUSH (integer)
  • This indicates that the buffer has been flushed.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_CLEAN (integer)
  • This indicates that the output buffer has been cleaned.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_FINAL (integer)
  • This indicates that this is the final output buffering operation.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_CONT (integer)
  • This indicates that the buffer has been flushed, but output buffering will continue.
  • As of PHP 5.4, this is an alias for PHP_OUTPUT_HANDLER_WRITE.
• PHP_OUTPUT_HANDLER_END (integer)
  • This indicates that output buffering has ended.
  • As of PHP 5.4, this is an alias for PHP_OUTPUT_HANDLER_FINAL.
• PHP_OUTPUT_HANDLER_CLEANABLE (integer)
  • Controls whether an output buffer created by ob_start() can be cleaned.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_FLUSHABLE (integer)
  • Controls whether an output buffer created by ob_start() can be flushed.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_REMOVABLE (integer)
  • Controls whether an output buffer created by ob_start() can be removed before the end of the script.
  • Available since PHP 5.4.
• PHP_OUTPUT_HANDLER_STDFLAGS (integer)
  • The default set of output buffer flags;
  • currently equivalent to PHP_OUTPUT_HANDLER_CLEANABLE | PHP_OUTPUT_HANDLER_FLUSHABLE | PHP_OUTPUT_HANDLER_REMOVABLE.
  • Available since PHP 5.4.

Output Buffering Control Functions

• flush — Flush system output buffer

• ob_clean — Clean (erase) the output buffer

• ob_end_clean — Clean (erase) the output buffer and turn off output buffering

• ob_end_flush — Flush (send) the output buffer and turn off output buffering

• ob_flush — Flush (send) the output buffer

• ob_get_clean — Get current buffer contents and delete current output buffer

• ob_get_contents — Return the contents of the output buffer

• ob_get_flush — Flush the output buffer, return it as a string and turn off output buffering

• ob_get_length — Return the length of the output buffer

• ob_get_level — Return the nesting level of the output buffering mechanism

• ob_get_status — Get status of output buffers

• ob_gzhandler — ob_start callback function to gzip output buffer

• ob_implicit_flush — Turn implicit flush on/off

• ob_list_handlers — List all output handlers in use

• ob_start — Turn on output buffering

• output_add_rewrite_var — Add URL rewriter values

• output_reset_rewrite_vars — Reset URL rewriter values