Question

I have a variable ($output) that is set to a string.

To mekt this string an image I’m using the PHP: GD Library.

In particular the imagestring() function, which I’m using with a very slight modification:

<?php
// Create a 100*30 image
$im = imagecreate(100, 30);

// White background and blue text
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);

// Write the string at the top left
imagestring($im, 5, 0, 0, $output, $textcolor); #here is my string $output

// Output the image
header('Content-type: image/png');

imagepng($im);
imagedestroy($im);
?>

This is working as expected: It turns $output into an image.

So, my problem is (or my best guess at least):

header('Content-type: image/png');

Which, doesn’t allow me to output any html after that.

So I read this question, which asks if you can use two headers, which you can’t, but the accepted answer recommends, something like this: <img src="my_img.php" />

This of course would be fine, except I don’t know how would this solve my issues since, since even if I knew the source to this image (which I don’t – so, that would be my first question, what’s the path to the generated image*) I’t would change the fact that the header is there and is not letting me output text.

So, I how would you approach this issue?

Thanks in advance!!

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*I guess that would solve my issues since I could do this on an external file, and the just call the image (but maybe not since I would have to do an include and this would include the header too) as you see I’m a bit confused. Sorry 🙂

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UPDATE:

So I’m seeing my question was confusing so I will add some more code to see if this clarifies my problem a little bit more:

<?php

$x = mt_rand(1,5);
$y = mt_rand(1,5);

function add($x, $y) { return $x + $y; }
function subtract($x, $y) { return $x - $y; }
function multiply($x, $y) { return $x * $y; }

$operators = array(
    'add',
    'subtract', 
    'multiply'
    );

$rdno = $operators[array_rand($operators)];

$result = call_user_func_array($rdno, array($x, $y));
session_start();
$_SESSION['res'] = $result;

if ($rdno == "add") {
    $whato = "+";
}elseif ($rdno == "subtract") {
    $whato = "-";
} else {
    $whato = "*";
}
$output = $x . $whato . $y . " = ";
?>
<form name="input" action="check.php" method="post">
<input type="text" name="result" />
<input type="submit" value="Check" />
</form>

I want $output to be a image so this got me trying to use the PHP:GD script above, but I can’t make put in the same file because of the header.

Answer 1

You need to make a separate PHP script which serves the image, then make an <img> tag that points to this script.

You can send information to the script using the querystring in the image URL.