const char *path;
This function tells you if the supplied
path is a POSIX-style path (i.e. posix names,
forward slashes, colon delimiters) or a Win32-style path (drive
letters, reverse slashes, semicolon delimiters. The return value is
true if the path is a POSIX path. Note that "_p" means "predicate", a
lisp term meaning that the function tells you something about the
Rather than use a mode to say what the "proper" path list format is, we allow any, and give apps the tools they need to convert between the two. If a ';' is present in the path list it's a Win32 path list. Otherwise, if the first path begins with [letter]: (in which case it can be the only element since if it wasn't a ';' would be present) it's a Win32 path list. Otherwise, it's a POSIX path list.