LXXII. Output Control Functions

The Output Control functions allow you to control when output is sent from the script. This can be useful in several different situations, especially if you need to send headers to the browser after your script has began outputting data. The Output Control functions do not affect headers sent using header() or setcookie(), only functions such as echo() and data between blocks of PHP code.

Example 1. Output Control example

<?php

ob_start();
echo "Hello\n";

setcookie ("cookiename", "cookiedata");

ob_end_flush();

?>

In the above example, the output from echo() would be stored in the output buffer until ob_end_flush() was called. In the mean time, the call to setcookie() successfully stored a cookie without causing an error. (You can not normally send headers to the browser after data has already been sent.)

See also header() and setcookie().

Table of Contents
flush -- Flush the output buffer
ob_start -- Turn on output buffering
ob_get_contents --  Return the contents of the output buffer
ob_get_length --  Return the length of the output buffer
ob_get_level --  Return the nesting level of the output buffering mechanism
ob_gzhandler --  ob_start callback function to gzip output buffer
ob_flush --  Flush (send) the output buffer
ob_clean --  Clean (erase) the output buffer
ob_end_flush --  Flush (send) the output buffer and turn off output buffering
ob_end_clean --  Clean (erase) the output buffer and turn off output buffering
ob_implicit_flush --  Turn implicit flush on/off