Function mupdf_sys::fz_has_option

pub unsafe extern "C" fn fz_has_option(
    ctx: *mut fz_context,
    opts: *const c_char,
    key: *const c_char,
    val: *mut *const c_char
) -> c_int

Look for a given option (key) in the opts string. Return 1 if it has it, and update *val to point to the value within opts.