But in this case, you must specify that you want to write to the file by using the 'w' modeflag.
但是，在这情况下，必须用' w '模式标记指定要写入文件。
2
After you've written all the data, you close the file and reopen it for reading, again using the binary modeflag.
在写完所有数据之后，关闭文件并重新打开文件进行读取，还是使用二进制模式标记。
3
The error status of the function is captured and tested, but this example ignores a feature of send in non-blocking mode (enabled by the MSG_DONTWAIT flag).