Linux下的整型数据输出格式。

写代码的时候常常会用到这些这些off_t, time_t这样的数据类型，转了一份老外的代码。

#define _FILE_OFFSET_BITS 64
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <time.h>      /* for time_t */
#include <sys/types.h> /* for off_t */

#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
#define TYPE_MAX(t) \
  ((t) (! TYPE_SIGNED (t) \
        ? (t) -1 \
        : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))))

int main(void)
{
    uint32_t uint32=0xffffFFFF;
    uintmax_t uintmax=UINTMAX_MAX;
    off_t offset=TYPE_MAX(off_t); /* Depends on _FILE_OFFSET_BITS */
    time_t time=TYPE_MAX(time_t); /* May be float! */
    size_t size=TYPE_MAX(size_t); /* Depends on int size */

    printf("native int bits%20u %16x\n", sizeof(int)*CHAR_BIT, UINT_MAX);
    printf("uint32_t max   %20"PRIu32" %16"PRIx32"\n"
           "uintmax_t max  %20ju %16jx\n" /* try PRIuMAX if %ju unsupported */
           "off_t max      %20jd %16jx\n" /* try PRIdMAX if %jd unsupported */
           "time_t max     %20jd %16jx\n"
           "size_t max     %20zu %16zx\n",
           uint32, uint32,
           uintmax, uintmax,
           (intmax_t)offset, (intmax_t)offset,
           (intmax_t)time, (intmax_t)time,
           size, size);

    return 0;
}
原文链接：
http://www.pixelbeat.org/programming/gcc/int_types/