boost::asio - 窥视套接字缓冲区

我使用 boost::asio::read (或者可能是等效的 async_read) 从套接字读取一些数据.

I use boost::asio::read (or may be the equivalent async_read) to read some data from a socket.

是否可以将读取的字节保留在底层套接字中,以便下次在套接字上调用 read 时再次收到该数据?

Is it possible that I leave the bytes read in the underlying socket so that next time I call read on the socket I receive again that data ?

推荐答案

就像 Simon 说的,你不能用 boost::asio::read() (或 boost::asio::async_read()).但是,对于 read() 您可以在套接字上调用 native_handle() 以获取套接字描述符,然后将 ::recvmsg()MSG_PEEK 标志.同样,您可以使用 null_buffers() 作为接收缓冲区调用 async_read(),然后使用 native_handle()/::recvmsg() 技巧来查看数据.查看 本节关于如何使用 null_buffers() 的 boost 文档.

Like Simon said, you can't do it with boost::asio::read() (or boost::asio::async_read()). However, for read() you could call native_handle() on the socket to get the socket descriptor and then use ::recvmsg() with the MSG_PEEK flag. Similarly, you could call async_read() with null_buffers() as the receive buffer and then use the native_handle()/::recvmsg() trick to peek the data. Check out this section of the boost documentation for how to use null_buffers().

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