test_intsize.c

#include <stddef.h>
#include <stdio.h>
#include <stdint.h>
#include <unistd.h>

void
print_size( char const * const desc, const size_t size )
{
    printf("  %10s: %zu bytes\n", desc, size);
}

#define PRINT_SIZE(T) print_size(#T, sizeof(T));

int
main ( void ) {

    printf("Sanity checks for reference:\n");
    PRINT_SIZE(int32_t);
    PRINT_SIZE(int64_t);

    puts("");
    PRINT_SIZE(size_t);
    PRINT_SIZE(ssize_t);
    // PRINT_SIZE(ptrdiff_t); // an alternative to ssize_t

    puts("");
    PRINT_SIZE(int);
    PRINT_SIZE(short);
    PRINT_SIZE(long);
    PRINT_SIZE(long long);

    return 0;
}