Linux下如何查看系统启动时间和运行时间安装时间

 1 struct sysinfo {
 2                long uptime;             /* Seconds since boot */
 3                unsigned long loads[3];  /* 1,5,and 15 minute load averages */
 4                unsigned long totalram;  /* Total usable main memory size */
 5                unsigned long freeram;   /* Available memory size */
 6                unsigned long sharedram; /* Amount of shared memory */
 7                unsigned long bufferram; /* Memory used by buffers */
 8                unsigned long totalswap; /* Total swap space size */
 9                unsigned long freeswap;  /* swap space still available */
10                unsigned short procs;    /* Number of current processes */
11                char _f[22];             /* Pads structure to 64 bytes */
12            };

 1 #include <stdio.h>
 2 #include <sys/sysinfo.h>
 3 #include <time.h>
 4 #include <errno.h>
 5 
 6 static int print_system_boot_time()
 7 {
 8     struct sysinfo info;
 9     time_t cur_time = 0;
10     time_t boot_time = 0;
11     struct tm *ptm = NULL;
12     if (sysinfo(&info)) {
13     fprintf(stderr,"Failed to get sysinfo,errno:%u,reason:%sn",14         errno,strerror(errno));
15     return -1;
16     }
17     time(&cur_time);
18     if (cur_time > info.uptime) {
19     boot_time = cur_time - info.uptime;
20     }
21     else {
22     boot_time = info.uptime - cur_time;
23     }
24     ptm = gmtime(&boot_time);
25     printf("System boot time: %d-%-d-%d %d:%d:%dn",ptm->tm_year + 1900,26         ptm->tm_mon + 1,ptm->tm_mday,ptm->tm_hour,ptm->tm_min,ptm->tm_sec);
27    return 0; 
28 }
29 
30 int main()
31 {
32     if (print_system_boot_time() != 0) {
33     return -1;
34     }
35     return 0;
36 }