dev_t 和 ino_t 是否必须是整数类型? [英] Are dev_t and ino_t required to be integer types?

问题描述

glibc 的文档仍然是整数类型(不比 unsigned int 窄)，但我没有找到说明它们必须是整数类型的标准参考(另见 time_t).

The documentation for glibc stays they are integer types (no narrower than unsigned int), but I'm not finding a standards reference that says they have to be an integer type (see also time_t).

所以最后，问题变成了:是

So in the end, the question becomes: Is

#include <stdio.h>
#include <stdint.h>
struct stat st;

if (stat("somefile", &st) == 0) {
        printf("%ju %ju\n", (uintmax_t)st.st_dev, (uintmax_t)st.st_ino);
}

便携.

推荐答案

POSIX 标准要求 dev_t 为整数类型，ino_t 为无符号整数.

POSIX standard requires dev_t to be an integer type and ino_t to be an unsigned integer.

dev_t 应为整数类型.

dev_t shall be an integer type.

fsblkcnt_t、fsfilcnt_t 和 ino_t 应定义为无符号整数类型.

fsblkcnt_t, fsfilcnt_t, and ino_t shall be defined as unsigned integer types.

由于 intmax_t 和 uintmax_t 应该是最大宽度"整数，因此您的代码是安全的.以防万一 st_dev 碰巧为负，您可以将其写为:

Since intmax_t and uintmax_t are supposed to be the "greatest width" integers, your code is safe. Just to be sure in case st_dev happens to be negative, you could write it as:

    printf("%jd %ju\n", (intmax_t)st.st_dev, (uintmax_t)st.st_ino);

否则，您的代码是安全的.

Otherwise, your code is safe.

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