ob_get_flush in PHP

ob_get_flush — Flush the output buffer, return it as a string and turn off output buffering
Syntax: string ob_get_flush ( void )
ob_get_flush() flushes the output buffer, return it as a string and turns off output buffering.
The output buffer must be started by ob_start() with PHP_OUTPUT_HANDLER_FLUSHABLE flag. Otherwise ob_get_flush() will not work.
Note: This function is similar to ob_end_flush(), except that this function returns the buffer as a string.
Return Values:Returns the output buffer or FALSE if no buffering is active.
Example #1

<?php
//using output_buffering=On
print_r(ob_list_handlers());

//save buffer in a file
$buffer = ob_get_flush();
file_put_contents('buffer.txt', $buffer);

print_r(ob_list_handlers());
?>
The above example will output:

Array
(
    [0] => default output handler
)
Array
(
)