File transfer over SSH? ZMODEM support?

[dev-zero]

Not sure a terminal emulator is the right place for this, but since there's an SSH client integrated it might be:

I am occasionally logged in via SSH to some machine (possibly via a number of jumps) and would like to transfer files (mostly fetching a file from the machine I am logged in). At the moment this either needs a second tab with an SCP/SFTP session, or curl-pasting the file to some service. I am currently experimenting with forwarding a socket to a locally running webserver which receives the files, but since wezterm is anyway interpreting the character stream one could also think about implementing something like the ZMODEM sx, sb, sz or is that already available and I haven't found it?
It seems that Tabby implements it.

[wez]

I'm not sure about making a full blown SCP client in wezterm, as it feels like a very large amount of UI that isn't 100% aligned to being a terminal emulator, but your comment about zmodem: wezterm supports the iTerm2 image protocol which is really a file transfer mechanism under the covers, although I wouldn't recommend it for really large files.

If we can agree to a limited UX around the receiving side, something like:

• Always save to a configurable downloads folder (defaulting to the typical Downloads folder for the user)
• Don't prompt for a filename.
• Use the filename from the server side if it wouldn't conflict
• Else, stick a unique-ifying numeric suffix on the end to avoid conflict
• Use a toast notification to announce status so that the remote host isn't silently filling up the local downloads folder

then teaching wezterm to do that for non-inline iterm images feels doable (you'd need https://iterm2.com/utilities/it2dl on the remote host), and might lay some foundation for potentially supporting zmodem later.

zmodem is a lot more complex though: I think it might be as invasive as the tmux-cc PR in terms of making it work transparently in the terminal.

[fengjiawang]

It works perfectly when using "wezterm ssh". However, it fails when using "wezterm connect". Is there a way to fix it? Thanks

[wez]

@fengjiawang please file an issue for that

[JasonChen89]

Itrem2 natively does not support zmodem too.
But its triggers can be extended to use zmodem。
So I think what wezterm needs to do is just adding a feature which can trigger silent coprocss.

https://iterm2.com/triggers.html
https://github.com/kuoruan/iterm2-zmodem

[YiuTerran]

currently, I use trzsz instead.

[expnn]

I have written a plugin (wezrs) that allows the use of trzsz for file transfers within wezterm. This plugin supports usage within an already opened mux domain, eliminating the need to log in using trzsz ssh. I believe this solves @fengjiawang's problem.

Alright, I was lying. Actually, I achieve this by utilizing shell to set a User Var, then listening for the user-var-changed event in wezterm, and automatically creating a tab. In this tab, I initiate trzsz ssh login and submit the file transfer command in the login window.

Currently, this plugin might not be robust enough, as any step in the aforementioned process could go wrong. However, I haven't found a way to check for execution failures in the existing Lua API. Therefore, any errors are silently ignored, which may lead to the execution of unexpected commands. For example:

• I need to use window:perform_action() to execute KeyAssignment, but I can't check if the execution was successful. This is reasonable in scenarios where shortcuts are used because we don't want to give feedback to the user every time a shortcut is pressed. However, when writing automation scripts, we want to get a return status to determine the next step.
• I use pane:send_text() to send the command to the pane. Since it always returns nil, I cannot check if the command was executed correctly. Additionally, this command seems to be asynchronous, so I can't check when the command has actually finished executing. As a result, the current plugin cannot automatically close the newly created tab. I suspect that the original intention of this function was not to execute commands in the pane, but merely to send a piece of text to it. It just so happens that when the sent text is a command, that command can be executed in the pane.

Below are videos I recorded of the usage:

• Upload:
  

• Download:
  

P.S. I hope that wezterm can provide more powerful interfaces to make implementing plugins like this easier. @wez