linux c获取系统运行时间

#include <stdio.h>
#include <stdlib.h>

int main() {
    FILE *fp;
    char path[1035];
    char *uptime_str;
    double uptime;

    /* 打开 /proc/uptime 文件 */
    fp = popen("cat /proc/uptime", "r");
    if (fp == NULL) {
        printf("无法读取系统运行时间\n");
        exit(1);
    }

    /* 读取文件内容 */
    if (fgets(path, sizeof(path), fp) != NULL) {
        uptime_str = strtok(path, " ");
        if (uptime_str != NULL) {
            uptime = strtod(uptime_str, NULL);
            printf("系统运行时间: %.2f 秒\n", uptime);
        }
    }

    /* 关闭文件 */
    pclose(fp);

    return 0;
}