#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

#define BUFFER_SIZE 1024
#define SRC_FILE "src_file"
#define DEST_FILE "dest_file"
#define OFFSET 10240
#define errlog(errmsg) perror(errmsg);\
printf("--%s--%s--%d--\n",\
__FILE__, __FUNCTION__, __LINE__);\
return -1;
int main(int argc, const char *argv[])
{
int fds, fdd;
unsigned char buf[BUFFER_SIZE];
ssize_t read_led;

if((fds = open(SRC_FILE, O_RDONLY)) < 0){
errlog("open error");
}

if((fdd = open(DEST_FILE, O_WRONLY|O_CREAT|O_TRUNC, 0664)) < 0){
errlog("open error");
}

lseek(fds, -OFFSET, SEEK_END);

while((read_led = read(fds, buf, sizeof(buf))) > 0){
write(fdd, buf, read_led);
}

close(fds);
close(fdd);

return 0;
}


各位哥哥姐姐，这是文件复制的代码，我看不懂，能解释一下吗？