写了个 write2sd, 提示 write(): No space left on device

[Woodz]

这个程序是用来将 uboot 写到 sd 卡里的.

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

#define BUFSIZE (256 * 1024)

int main(int argc, char **argv)
{
    int dest_dev_fd;  // 目标设备
    int src_file_fd;  // 源文件
    char buf[BUFSIZE];
    ssize_t read_ret;
    ssize_t write_ret;

    if(argc < 3)
    {
        printf("Usage: ./write2sd </dev/dev_name> <src_file>\n");
        exit(1);
    }

    src_file_fd = open(argv[2], O_RDONLY);
    if(src_file_fd == -1)
    {
        perror("open()");
        exit(1);
    }

    dest_dev_fd = open(argv[1], O_WRONLY);
    if(dest_dev_fd == -1)
    {
        perror("open()");
        exit(1);
    }

// 将文件位置指针从文件尾向回定位
    lseek64(dest_dev_fd, -(1 + 8 + 16 + 256) * 1024, SEEK_END);
    
    read_ret = read(src_file_fd, buf, (size_t)(8 * 1024));
    if(read_ret == -1)
    {
        perror("read()");
        exit(1);
    }

    write_ret = write(dest_dev_fd, buf, (size_t)read_ret);
    if(write_ret == -1)
    {
        perror("write()");
        exit(1);
    }


    lseek64(src_file_fd, 0, SEEK_SET);
    
    read_ret = read(src_file_fd, buf, (size_t)(256 * 1024));
    if(read_ret == -1)
    {
        perror("read()");
        exit(1);
    }

    write_ret = write(dest_dev_fd, buf, (size_t)read_ret);
    if(write_ret == -1)
    {
        perror("write()");
        exit(1);
    }


    close(src_file_fd);
    close(dest_dev_fd);

    exit(0);
}


   

[qiyu1988]

lseek64(dest_dev_fd, -(1 + 8 + 16 + 256) * 1024, SEEK_END); 这句返回偏移量成功了吗？ 还是src_file的大小比(1 + 8 + 16 + 256) * 1024大？