输出PHP分隔符（ <?php, ?> ）没有PHP解释分隔符

Question

I run PHP in JavaScript files, eg...

var = '<?php /*some code*/ ?>';).

I need to use JavaScript to scan a string for PHP delimiters (the < ? php and ? > that open and close PHP).

I already know the code using JavaScript...

if (b.value.indexOf('<?php')>-1) {alert('PHP delimiter found.');}

What I'm having trouble with is that I need to keep the ability for PHP to be interpretted in JavaScript files (no exceptions). I simply need to output the delimiter strings to the client in JavaScript and not have them interpreted by the server.

So the final output (from the client's view) would be...

if (b.value.indexOf('<?php')>-1) {alert('PHP delimiter found.');}

With the following code...

if (b.value.indexOf('<?php echo '<?php'; ?>')>-1 || b.value.indexOf('<?php echo '?>'; ?>')>-1)

I get the error: "Parse error: syntax error, unexpected T_LOGICAL_AND"

Answer 1

Javascript will never find the <?php in your strings because simply, they have already been parsed by your PHP Server. Javascript is a client-side script and is executed after your server-side scripts.

Answer 2

You could take advantage of Javascript's ability to parse hex as a character:

if (b.value.indexOf('<\x3fphp')>-1) {alert('PHP delimiter found.');}

In Javascript '<\\x3fphp' is exactly the same thing as '<?php' , but it has no meaning in PHP.

Answer 3

Use output buffering on the PHP, then htmlspecialchars() on the buffered output. You then search for the HTML entities with the JavaScript.

Answer 4

the first thing that came into my mind and should work is this simple, little "cheat":

<?php echo '<'.'?php'; ?>

the php interpreter doesn't see a <?php , but the output is as desired.

Answer 5

<?php echo '<?php'; ?> <?php echo '<?php'; ?> ... <?php echo '?>'; ?> <?php echo '?>'; ?>