It might be a bit unusual, but I need to echo <?php. However, I think that PHP treats it as an actual <?php and starts executing code instead of treating it as a string. How can I escape <?php and ?> so they can be treated as strings? There was nothing in the manual about this.
Thanks, I know this is a bit unusual.
You can use the < and > html entities (to replace '<' and '>'). These are only handled in the browser, so PHP would not attempt to run that code.
<?php echo "<?php echo \"hello\" ?>" ?>
prints out <?php echo "hello" ?>
Check out PHP's sourcecode of functions on how they print out data.
http://in2.php.net/source.php?url=/manual/en/function.htmlentities.php
If this is your code:
<?php
echo '<?php';
?>
And you run that as a web page, you will see nothing. But not because PHP is not echoing your string <?php, but because the browser sees < and thinks that's the start of a tag, and tags are not displayed. It's obviously an error, but that's what the browser is doing.
To get around this, escape the < part, use htmlentities():
<?php
echo htmlentities('<?php');
?>
Which when it gets echoed, will result in HTML source of:
<php
Which when displayed in the browser shows:
<?php
echo '<?php ?>'; // prints <?php ?>
echo "<?php ?>"; // prints <?php ?>
No, you do not have to do anything special.