Output Buffering Control

Introduction
Installing/Configuring
Predefined Constants
Examples
- Basic usage
Output 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

User Contributed Notes

7 years ago


The manual is a little shy on explaining that output buffers are nested, and that "turns off output buffering" means turning off the highest nested buffer.  See ob_get_level (for a useful function, but still no explanation)



<?php

    ob_start();

    echo "1:blah\n";

    ob_start();

    echo "2:blah";

    // ob_get_clean() returns the contents of the last buffer opened.  The first "blah" and the output of var_dump are flushed from the top buffer on exit

    var_dump(ob_get_clean());

    exit;

?>



puts:

    1:blah

    string(6) "2:blah"



Prior to realising this, I had thought PHP's ob functionality left more to be desired.  I *really* wish I knew earlier.