What's the best way to remove these tags from a string, to prepare it for being passed to eval() ?
for eg. the string can be something like this:
<?php
echo 'hello world';
?>
Hello Again
<?php
echo 'Bye';
?>
Obviously str_replace won't work because the two php tags in the middle need to be there (the the 1st and the last need to be removed)
Usually, you wouldn't want to pass a function to eval. If you're wishing to just remove the tags, string_replace would do the job just fine, however you might be better off using a regex.
preg_replace(array('/<(\?|\%)\=?(php)?/', '/(\%|\?)>/'), array('',''), $str);
This covers old-asp tags, php short-tags, php echo tags, and normal php tags.
Sounds like a bad idea, but if you want the start and end ones removed you could do
$removedPhpWrap = preg_replace('/^<\?php(.*)(\?>)?$/s', '$1', $phpCode);
This should do it (not tested).
Please tell me also why you want to do it, I'm 95% sure there is a better way.
You could do:
eval("?> $string_to_be_evald <?");
which would close the implicit tags and make everything work.
There's no need to use regex; PHP provides functions for removing characters from the beginning or end of a string. ltrim removes characters from the beginning of the string, rtrim from the end of the string, and trim from both ends.
$code = trim ( $code );
$code = ltrim( $code, '<?php' );
$code = rtrim( $code, '?>' );
The first trim() removes any leading or trailing spaces that are present in the siting. If we omitted this and there was whitespace outside of the PHP tags in the string, then the ltrim and rtrim commands would fail to remove the PHP tags.
<? ?>-tags can be present several times in the file, not just at the beginning and end. Actually, if you look at his sample, there are two sets of tags in there. So regex is probably the most viable solution here.
eval(). Anyway, how exactly would a third set of tags be bad??> tag, or an leading space in front of the first <?php tag (or any other whitespace surrouding those tags)
eval. ;) (Only 25% joking actually.)