timespec linux

struct timespec {
    time_t tv_sec;  // 秒
    long   tv_nsec; // 纳秒
};

#include <stdio.h>
#include <time.h>

int main() {
    struct timespec currentTime;
    if (clock_gettime(CLOCK_REALTIME, &currentTime) == -1) {
        perror("clock_gettime");
        return 1;
    }
    printf("Current time: %ld.%09ld seconds\n", currentTime.tv_sec, currentTime.tv_nsec);
    return 0;
}

#include <stdio.h>
#include <time.h>

void calculate_time_difference(struct timespec start, struct timespec end) {
    long seconds = end.tv_sec - start.tv_sec;
    long nanoseconds = end.tv_nsec - start.tv_nsec;
    double elapsed = seconds + nanoseconds * 1e-9;
    printf("Elapsed time: %.9f seconds\n", elapsed);
}

int main() {
    struct timespec start, end;

    clock_gettime(CLOCK_MONOTONIC, &start);
    // 模拟一些操作
    for (int i = 0; i < 1000000; ++i) {}
    clock_gettime(CLOCK_MONOTONIC, &end);

    calculate_time_difference(start, end);
    return 0;
}