c - How to printf a 64-bit integer as hex?

Question

(This question already has answers here): question from:https://stackoverflow.com/questions/32112497/how-to-printf-a-64-bit-integer-as-hex

Answer 1

The warning from your compiler is telling you that your format specifier doesn't match the data type you're passing to it.

Try using %lx or %llx. For more portability, include inttypes.h and use the PRIx64 macro.

For example: printf("val = 0x%" PRIx64 " ", val); (note that it's string concatenation)