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 = 0,cur = 0; 
char s [ ]="Linux Programmer!",buffer[100]; 

fd = open("/proc/uptime",O_RDONLY);
while(1){
    FileLen=lseek(fd,0,SEEK_END);
    lseek(fd,SEEK_SET,0);

while(size = read(fd,buffer,sizeof(buffer))){
    cur +=size;
    printf("%d---%s\n",size,buffer);
    
    memset(buffer,0,sizeof(buffer));
    if(cur>=FileLen){
        cur = 0;
        break;    
    }

}

lseek(fd,SEEK_SET,0);
sleep(1);

}
close(fd); 

}