int32 and int32_t
These two types generally represent a 32-bit integer. int32 may be used in certain programming contexts, while int32_t is defined in the C99 standard and is guaranteed to be 32-bit on any platform. The key difference is that the bit size of int32 may vary across different platforms, whereas int32_t is enforced to be 32-bit. For example, in compilation environments using the C99 or C11 standards, int32_t is an explicit 32-bit signed integer type.
int
int is a basic integer type whose size depends on the implementation; typically it is 32-bit on modern mainstream platforms, but this is not guaranteed. On some older or specialized hardware platforms, int might be 16-bit or another size. This contrasts with int32_t, which is guaranteed to be 32-bit regardless of the platform.
int8 and int8_t
Similar to the relationship between int32 and int32_t, the main difference between int8 and int8_t lies in standardization. The definition of int8 may vary by platform, while int8_t is explicitly defined in the C99 standard as an 8-bit signed integer. This means using int8_t ensures consistency and portability of cross-platform code.
In summary, types with the _t suffix (such as int32_t and int8_t) are explicitly defined fixed-width integers in the ISO C standard. Using these types helps improve code portability and clarity. On the other hand, types without the suffix (such as int32 and int8) may vary depending on the compiler and platform, requiring more attention when used.