PHP4 new Function Introduction-Output information control function, previously forwarded by others

function | control PHP4 new FUNCTION Introduction-Output information control function
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These functions allow you to control the content of your script output. Can be used in a number of different situations, especially if your script has already output information and needs to send a new file header. The output control function does not affect the header information that is sent using header () or Setcookie (), but only those similar to Echo () and PHP code data blocks are useful.

Example 1. Control output

<?php

Ob_start ();
echo "hello\n";

Setcookie ("CookieName", "Cookiedata");

Ob_end_flush ();

?>

In the above example, the output with Echo () is saved in the output buffer until the Ob_end_flush () is invoked. What makes sense is that the contents of the call Setcookie () are stored successfully in the cookie without causing an error. (Normally, you cannot send file header information to the user's browser after the data has been sent.)

The correlation function header () and Setcookie ().

Korean Series table
flush-Flush Output Buffer
Content saved in the output buffer is sent to the browser

ob_start-Open Output Buffer
So all the output information is not sent directly to the browser, but is stored in the output buffer

ob_get_contents-returns the contents of the output buffer
If you want to process the output later, you can call this function to keep a backup

ob_get_length-returns the content length of the output buffer

ob_end_flush-End (send) output buffer content, turn off output buffer

ob_end_clean-Deletes (discards) the contents of the output buffer and closes the output buffer
If your program finds that there is a problem with the output, you can discard all output and prevent some secret information from leaking

ob_implicit_flush-turn on or off direct refresh
Once opened, each script output is sent directly to the browser and no longer needs to invoke flush ().