VOID INT34-C. Use intmax_t for signed integer types or uintmax_t for unsigned integer types where the underlying type is unknown

The C99 intmax_t and uintmax_t types are capable of representing any value representable by any other types of the same signedness.

printf ("request is %" PRIuMAX "\n", (uintmax_t) sym->st_value);

Formatted input and output functions contain a length modifier which provides the above facilities for input/output.  The j specifier in a format string indicates that the following d, i, o, u, x, X, or n conversion specifier will apply to an argument with type pointer to intmax_t or uintmax_t.

length modifiers are j for intmax_t/uintmax_t, z for size_t, and t for ptrdiff_t.

[[ISO/IEC 9899-1999]] Section 7.19.6, "Formatted input/output functions," and Section 7.18.1.5, "Greatest-width integer types"