When format strings are used for derived data types whose implementation may vary across platforms (pid_t, time_t, etc.), the safest approach is to use %lld in the format string, and cast the value to (long long).

Be sure not to pass NULL as an argument to satisfy %s format specifier in logging and more generally printf style functions. When mere <null> string is a sufficient output representation in such case, there is crm_str convenient macro. Ternary operator is an apparent choice otherwise.