User: ci
Mosh: the mobile shell
Mosh is a remote terminal application that supports intermittent connectivity, allows roaming, and provides speculative local echo and line editing of user keystrokes.

It aims to support the typical interactive uses of SSH, plus:

Mosh keeps the session alive if the client goes to sleep and wakes up later, or temporarily loses its Internet connection.

Mosh allows the client and server to "roam" and change IP addresses, while keeping the connection alive. Unlike SSH, Mosh can be used while switching between Wi-Fi networks or from Wi-Fi to cellular data to wired Ethernet.

The Mosh client runs a predictive model of the server's behavior in the background and tries to guess intelligently how each keystroke will affect the screen state. When it is confident in its predictions, it will show them to the user while waiting for confirmation from the server. Most typing and uses of the left- and right-arrow keys can be echoed immediately.

As a result, Mosh is usable on high-latency links, e.g. on a cellular data connection or spotty Wi-Fi. In distinction from previous attempts at local echo modes in other protocols, Mosh works properly with full-screen applications such as emacs, vi, alpine, and irssi, and automatically recovers from occasional prediction errors within an RTT. On high-latency links, Mosh underlines its predictions while they are outstanding and removes the underline when they are confirmed by the server.

Mosh does not support X forwarding or the non-interactive uses of SSH, including port forwarding.

Other features
Mosh adjusts its frame rate so as not to fill up network queues on slow links, so "Control-C" always works within an RTT to halt a runaway process.

Mosh warns the user when it has not heard from the server in a while.

Mosh supports lossy links that lose a significant fraction of their packets.

Mosh handles some Unicode edge cases better than SSH and existing terminal emulators by themselves, but requires a UTF-8 environment to run.

Mosh leverages SSH to set up the connection and authenticate users. Mosh does not contain any privileged (root) code.

Getting Mosh
The Mosh web site has information about packages for many operating systems, as well as instructions for building from source.

Note that mosh-client receives an AES session key as an environment variable. If you are porting Mosh to a new operating system, please make sure that a running process's environment variables are not readable by other users. We have confirmed that this is the case on GNU/Linux, OS X, and FreeBSD.

Usage
The mosh-client binary must exist on the user's machine, and the mosh-server binary on the remote host.

The user runs:

$ mosh [user@]host
If the mosh-client or mosh-server binaries live outside the user's $PATH, mosh accepts the arguments --client=PATH and --server=PATH to select alternate locations. More options are documented in the mosh(1) manual page.

There are more examples and a FAQ on the Mosh web site.

How it works
The mosh program will SSH to user@host to establish the connection. SSH may prompt the user for a password or use public-key authentication to log in.

From this point, mosh runs the mosh-server process (as the user) on the server machine. The server process listens on a high UDP port and sends its port number and an AES-128 secret key back to the client over SSH. The SSH connection is then shut down and the terminal session begins over UDP.

If the client changes IP addresses, the server will begin sending to the client on the new IP address within a few seconds.

To function, Mosh requires UDP datagrams to be passed between client and server. By default, mosh uses a port number between 60000 and 61000, but the user can select a particular port with the -p option. Please note that the -p option has no effect on the port used by SSH.

Advice to distributors
A note on compiler flags: Mosh is security-sensitive code. When making automated builds for a binary package, we recommend passing the option --enable-compile-warnings=error to ./configure. On GNU/Linux with g++ or clang++, the package should compile cleanly with -Werror. Please report a bug if it doesn't.

Where available, Mosh builds with a variety of binary hardening flags such as -fstack-protector-all, -D_FORTIFY_SOURCE=2, etc. These provide proactive security against the possibility of a memory corruption bug in Mosh or one of the libraries it uses. For a full list of flags, search for HARDEN in configure.ac. The configure script detects which flags are supported by your compiler, and enables them automatically. To disable this detection, pass --disable-hardening to ./configure. Please report a bug if you have trouble with the default settings; we would like as many users as possible to be running a configuration as secure as possible.

Mosh ships with a default optimization setting of -O2. Some distributors have asked about changing this to -Os (which causes a compiler to prefer space optim


这是什么项目
Assistant: 这是关于一个名为 **Mosh** 的远程终端应用程序的项目说明。Mosh，或称为“移动 Shell”，是一种支持不间断连接、允许漫游并提供用户按键预测本地回显和行编辑的远程终端应用。与传统的 SSH（Secure Shell）不同，Mosh 通过以下特点提升了用户体验：

1. **保持会话活动**：即使客户端设备进入休眠状态并稍后唤醒，或暂时失去 Internet 连接，会话仍会保持活动状态。
   
2. **支持漫游**：客户端和服务器可以更改 IP 地址而保持会话连接，使得 Mosh 可以在客户端在不同网络之间切换（如从 Wi-Fi 切换到蜂窝数据或有线网络）时继续使用。

3. **预测回显**：客户端运行一个服务器行为的预测模型，智能地猜测每次按键如何影响屏幕状态，并在对于预测有信心时，会在等待服务器确认期间向用户展示预测结果。这样在高延迟链接（例如蜂窝数据连接或不稳定的 Wi-Fi）上使用 Mosh 也很顺畅。

4. **不支持某些 SSH 功能**：Mosh 不支持 X 转发或 SSH 的非交互式功能，如端口转发。

Mosh 依赖 SSH 设置连接和认证用户，但在会话开始后转而使用 UDP 进行通信，这使得它在应对网络不稳定性和高延迟方面表现优异。

有关此项目的更多信息，包括安装、使用说明和其他技术细节，可在 Mosh 官方网站上找到。
User: 如何安装
Assistant: