Mosh (Mobile Shell)

Summary

Q: Who wrote Mosh? Mosh was written by Keith Winstein, along with Anders Kaseorg, Quentin Smith, Richard Tibbetts, Keegan McAllister, and John Hood. Q: Why another remote-terminal protocol? Practical latency on the Internet is on the increase, with the rise of bufferbloat and sophisticated wireless links that optimize for throughput over delay. And roaming is more common than ever, now that laptops and handheld devices have largely displaced desktops. SSH is great, but frustrating to use when you want to change IP addresses or have a long-delay link or a dodgy connection. Moreover, TELNET had some good things going for it — a local-echo mode and a well-defined network virtual terminal. Even today, SSH doesn't properly support UTF-8 end-to-end on a POSIX system. Q: Are the mosh principles relevant to other network applications? We think so. The design principles that Mosh stands for are conservative: warning the user if the state being displayed is out of date, serializing and checkpointing all transactions so that if there are no warnings, the user knows every prior transaction has succeeded, and handling expected events (like roaming from one WiFi network to another) gracefully. Those don't seem too controversial, but fancy apps like Gmail-in-Chromium or on Android still behave atrociously on dodgy connections or after switching IP addresses. (Have you ever had Gmail leave an e-mail message in "Sending..." for ten hours while merrily retrieving new mail and not indicating any kind of error? Us too.) We think there may be considerable room for improvement in many network user interfaces from the application of these values. Q: I'm getting "mosh requires a UTF-8 locale." How can I fix this? To diagnose the problem, run locale on the local terminal, and ssh remotehost locale. To use Mosh, both sides of the connection will need to show a UTF-8 locale, like LC_CTYPE="en_US.UTF-8". On many systems, SSH will transfer the locale-related environment variables, which are the...