读取proc/uptime信息。

 #include <stdio.h>
 #include<unistd.h>
 #include<sys/types.h>
 #include<sys/stat.h>
 #include<fcntl.h>
 #include <memory.h>
 int main()
 {
 int fd,size,FileLen = ,cur = ;
 char s [ ]="Linux Programmer!",buffer[]; 

 fd = open("/proc/uptime",O_RDONLY);
 while(){
     FileLen=lseek(fd,,SEEK_END);
     lseek(fd,SEEK_SET,);

 while(size = read(fd,buffer,sizeof(buffer))){
     cur +=size;
     printf("%d---%s\n",size,buffer);

     memset(buffer,,sizeof(buffer));
     if(cur>=FileLen){
         cur = ;
         break;
     }

 }

 lseek(fd,SEEK_SET,);
 sleep();

 }
 close(fd); 

 }