I found this list useful for binary string manipulation. List of php binary safe string functions:

mb_substr

mb_strlen

mb_str_split

mb_substr_count

str_replace

mb_strpos

mb_substr_replace

The problem is, if the function is not binary safe it will still probably work most of the time. This is not an acceptable level of fault tolerance for the professional. It must work with every string. Good luck with your projects!