PHP prints /f from behind the curtains

Question

I have an old web site which generates PDF reports and sends via email. It uses Zend_Mail, pChart and Zend_Pdf. I've already noticed that PHP prints out /f somewhere in there, but it is mostly not visible since a new browser tab would only show if the PDF report fails somewhere on the way. Then I would sit with only /f as the output. This made be think it only appeared when there was an error.

This becomes a "problem" when I run this whole generating-mailing procedure using the CLI. It happens when I do something like this:

$instance = new $aClassName();

It also only happens the first time I do it. Any ideas?

Answer 1

I finally found out how searched for /f in the beginning of files and found it in more than one file. So there must be some vim command which you are likely to accidentally press, which inserts /f.

It was not me who wrote them though, but I know the guy used vim as an editor.