一个php文件作为img src

i want to print a image by using a img tag which src is a php file, the script will also process some action at server scirpt. Anyone have an example code?

here is my test code but no effect

img.html

<img src="visitImg.php" />

visitImg.php

<?

header('Content-Type: image/jpeg');

echo "<img src=\"btn_search_eng.jpg\" />";

?>

"<img src=\"btn_search_eng.jpg\" />" is not valid image data. You have to actually read the contents of btn_search_eng.jpg and echo them.

See here for the various ways to pass-through files in PHP.

UPDATE

what you can do without using include as said below in the comments:

try this:

<? 
$img="example.gif"; 
header ('content-type: image/gif'); 
readfile($img); 
?> 

The above code is from this site

Original Answer
DON'T try this:

<?

header('Content-Type: image/jpeg');

include 'btn_search_eng.jpg';   // SECURITY issue for uploaded files!

?>

If you are going to use header('Content-Type: image/jpeg'); at the top of your script, then the output of your script had better be a JPEG image! In your current example, you are specifying an image content type and then providing HTML output.

What you're echoing is HTML, not the binary data needed to generate a JPEG image. To get that, you'll need to either read an external file or generate a file using PHP's image manipulation functions.

Directly from the php fpassthru docs:

<?php

// open the file in a binary mode
$name = './img/ok.png';
$fp = fopen($name, 'rb');

// send the right headers
header("Content-Type: image/png");
header("Content-Length: " . filesize($name));

// dump the picture and stop the script
fpassthru($fp);
exit;
?>

As an explanation, you need to pass the image data as output from the script, not html data. You can use other functions like fopen, readfile, etc etc etc

Use readfile:

<?php
header('Content-Type: image/jpeg');
readfile('btn_search_eng.jpg');
?>