About ob_get_contents of ob_end_clean of ob_start of specific usage details

  • 2020-06-19 09:55:12
  • OfStack

ob_get_contents();
ob_end_clean();
ob_start()

Use ob_start() to output that to the buffer instead of to the browser.
Then use ob_get_contents to get the data for the buffer.
ob_start() opens a buffer on the server to hold all output. So any time you use echo, the output is added to the buffer until the program ends or ends with ob_flush(). The contents of the buffer in the server are then sent to the browser, which parses the display.

The ob_end_clean function clears the contents of the buffer and closes it without output.
You need a function ob_get_contents() before ob_end_clean() to get the contents of the buffer.
This way, you can save the contents to a variable before executing ob_end_clean() and then do something with that variable after ob_end_clean().

This is the EG:
ob_start(); // buf1
echo ' multiple ';
ob_start(); // buf2
echo ' buffers work ';
$buf2 = ob_get_contents();
ob_end_clean();
$buf1 = ob_get_contents();
ob_end_clean();
echo $buf1;
echo ' < br/ > ';
echo $buf2;
ob_get_contents

(PHP 4, PHP 5)
ob_get_contents -- Return the contents of the output buffer
Description
string ob_get_contents ( void )
This will return the contents of the output buffer or FALSE, if output buffering isn't active.
See also ob_start() and ob_get_length().
if you use ob_start with a callback function as a parameter, and that function changes ob string (as in example in manual) don't expect that ob_get_contents will return changed ob.
it will work as you would use ob_start with no parameter at all. So don't be confused.
transfer image, another method (alternative to fsockopen or function socket) :
server(192.168.0.1)
makeimage.php
...........
...........
$nameimage="xxxx.jpg"
$comand=exec("plotvelocity.sh $nameimage $paramater1 $paramater2");
ob_start();
readfile($nameimage);
$image_data = ob_get_contents();
ob_end_clean();
echo $image_data;
unlink($nameimage);
Client (192.168.0.2)
$bild="images/newimage2.gif";
$host="192.168.0.1";
$url=file_get_contents("http://$host/makeimage.php?$querystring");
$fp = fopen("$bild", 'wb');
fwrite($fp, $url);
fclose($fp);
echo ' < img src="'.$bild.'" > ';
naturally you can transfer whichever thing and not only images
ob_get_clean

(PHP 4 > = 4.3.0, PHP 5)
ob_get_clean -- Get current buffer contents and delete current output buffer
Description
string ob_get_clean ( void )
This will return the contents of the output buffer and end output buffering. If output buffering isn't active then FALSE is returned. ob_get_clean() essentially executes both ob_get_contents() and ob_end_clean().

Example 1. A simple ob_get_clean() example


<?php
ob_start();
echo "Hello World";
$out = ob_get_clean();
$out = strtolower($out);
var_dump($out);
?>

Our example will output: string(11) "hello world"
See also ob_start() and ob_get_contents().
Notice that the function beneath does not catch errors, so throw in an @ before those ob_* calls
Running PHP4 < 4.3.0, you can simply add the following to use the function anyway:

<?php
if (!function_exists("ob_get_clean")) {
function ob_get_clean() {
$ob_contents = ob_get_contents();
ob_end_clean();
return $ob_contents;
}
}
?>


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