从串口读取超过8个字节

Question

我需要从串口读取数据，但read（）函数总是返回8个字节或更少，我该如何获取所有数据  c代码：

readbytes = read(f, bufptr, sizeof(buffer));
buffer[readbytes]='\0';
printf("number of bytes read is %d\n", readbytes);
printf("buffer %s\n", buffer);

我尝试使用do while，但我仍然有相同的结果。

Answer 1

[评论太久了]

试试这段代码：

char buffer[256];
memset(buffer, 0, 256);

size_t bytes_read= 0, bytes_expected = 11; 

do {
  ssize_t result = read(f, buffer + bytes_read, bytes_expected - bytes_read); 
  if (0 >= result)
  {
    if (0 > result)
    {
      perror("read()");
    }

    break;
  }

  bytes_read+= result;
} while (bytes_read < bytes_expected)

fprintf(stderr, "Read %zu out of %zu expected bytes: `%s`\n", bytes_read, bytes_expected, buffer);