The header <stdint.h> provides several ﬁxed-width integer type deﬁnitions. These types are optional and only provided if the platform has an integer type of the corresponding width, and if the corresponding signed type has a two's complement representation of negative values.
See the remarks section for usage hints of ﬁxed width types.
/* commonly used types include */
uint32_t u32 = 32; /* exactly 32-bits wide */
uint8_t u8 = 255; /* exactly 8-bits wide */
int64_t i64 = -65 /* exactly 64 bit in two's complement representation */