What are the arguments IN FAVOR of PHP closing tags for PHP only files?

Question

The Zend Framework coding standard mentions the following:

For files that contain only PHP code, the closing tag ("?>") is never permitted. It is not required by PHP, and omitting it prevents the accidental injection of trailing whitespace into the response.

• Zend Framework coding standard: file formatting

However I do remember hearing about an issue (with tooling or including maybe?) where files needed to have closing tag.

Does anyone know of any issues (other than the developer issue of wanting symmetry) where you would need to have closing tags or are they generally a bad idea?

Answer 1

Removing the closing tags when you can is probably a best practice really. The reason for that is because if you have any character (even whitespace) outside of the ?> in a php file it can stop thing such as headers to stop working if the character gets sent to the browser before the header gets set.

Answer 2

If you use closing PHP tags then you can easily find files that have been accidentally truncated (e.g. haven't been uploaded completely).
However such problem should be fixed by making filesystem and transfers reliable rather than adding PHP "canary" tags :)

Another possible reason is that PEAR coding standards require it. They require it, because they require it and you're not allowed to question PEAR coding standards.