Benefits of GNU Screen/tmux vs direct terminals

gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

[Moderator note: this post, and the first 14 responses were originally attached to the topic What's the real reason Gentoo never got an installer?. I split them to let that thread stay on its original purpose, and not discourage discussion of terminal multiplexers. As a convenience, I edited the quote attributions in this post to link back to their origin posts. -Hu]

Hu · Moderator Joined: 06 Mar 2007 Posts: 16508

If you haven't yet, I suggest you also look at tmux. It is intended to serve the most commonly used purposes of screen, but has some user-visible differences that some people find desirable. (It also has the advantage of a name you can put into a search engine and have a chance of finding something relevant.)

CasperVector · Apprentice Joined: 03 Apr 2012 Posts: 156

gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

Note: thread drift...

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 2969 Location: Canada

I know about "screen" for years (hm, decades), even have it installed. But never figured out why do I need it in a multi windowed environment.

John R. Graham · Posted: Wed Feb 26, 2020 5:55 pm Post subject:

So you can restart your desktop environment without halting an in-progress emerge.

- John
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gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 2969 Location: Canada

Jaglover · Posted: Wed Feb 26, 2020 6:31 pm Post subject:

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 2969 Location: Canada

gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 2969 Location: Canada

gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

duane · Posted: Wed Feb 26, 2020 6:57 pm Post subject:

Tmux (or screen) is especially useful if, like me, you don't run a giant desktop suite, like kde. I run openbox and xterm, and I generally have two xterm windows open with tmux in them, pretty much full time -- one local, and one remote. Konsole might be able to do the same things, but it would involve loading a bunch of extra libraries and dbus.

Since I don't use a taskbar, my tmux instances run a little script that outputs system load, temperature, frequency, free memory and local time for each system at the bottom of the xterm window. (The output is a lot smaller than it sounds, and leaves plenty of room for the tmux "window tabs".)

I was skeptical about tmux until I tried it. Now I'm hooked.

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 2969 Location: Canada

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gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 2969 Location: Canada

eccerr0r · Posted: Sat Jul 25, 2020 2:23 am Post subject:

I couldn't get myself to use tmux, use screen too much ever since I learned of it years ago... it's one of those critical pieces of software to me. I just wish that its split screen modes wasn't so clunky, alas it is what it is... I end up using app-misc/splitvt in screen to fix that...
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gtwrek · n00b Joined: 10 Mar 2017 Posts: 48 Location: San Jose, CA

Since this thread's been bumped an update on what I've tried . I gave xpra a try again - Version 3.0.2 on my main gentoo desktop. The performance is quite good; however I'm still having trouble with clipboard across sessions. It only works about 50% of the time for me. If I have time I may try and work with the developers, but to me, it's still "not quite there"...

It's eye-opening to me how complicated managing clipboards could be. I've just always relied on the X left, middle, right mouse clicks, and it always worked reliably, no matter where my X connection server is with respect to the client since, well, forever. I understand it's an entirely different concept with respect to the remote frame buffer and compositors...

eccerr0r · Posted: Sat Jul 25, 2020 4:56 am Post subject:

Whatever happened to VNC?
Alas screen still wins in bandwidth... low bandwidth links sucks with any GUI...
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Hu · Moderator Joined: 06 Mar 2007 Posts: 16508

The problem with VNC is that the VNC client displays a single X window that displays the contents of the VNC server, and all the programs connected to the VNC server are managed on the server. According to your local window manager, you have exactly one relevant window: the VNC client viewer. You can't use your local window manager to focus/move/iconify/resize remote windows, because as far as your local window manager is concerned, you are just displaying a window with a picture in it. In contrast, xpra generates one local X window for each remote X window, so your local window manager can focus/move/etc. the individually forwarded Xpra X windows. Further, because the forwarded windows have local windows, you can do complicated things like have one remote window fully visible and raised (possibly even in a layer that keeps it above other windows), while other remote windows are buried by local windows. With VNC, either your VNC client is buried or it isn't. If it is not buried, it buries every local window that overlaps it, even if you are only using it to show one relatively small remote X window that would not, on its own, require burying any local windows. You may be able to work around that by adjusting window layering in your window manager, but you may find yourself adjusting layers rather frequently to try to get the right mix of local and remote content visible. Making all the windows map to local X windows provides a much more natural flow for raising/lowering the parts you want.

gtwrek: sorry to see that xpra is still not working well for you. I continue to use it daily, and it's fine for me, so there must be something different in our environments. I am currently on 3.0.5-r1, but I had 3.0.2 for a while and I do not recall any clipboard failures with it. It does seem to lag about 0.5-1 seconds when I try to paste from one side to the other, which is annoying, but it always succeeds after the stall, which seems to be different from what you describe. Xpra logs some debug output to its starting terminal by default, and you may be able to increase verbosity to try to run down the problem.

eccerr0r · Posted: Sat Jul 25, 2020 5:23 pm Post subject:

I've always thought that to be better that all remote windows are kept together so I don't need to micromanage which window is related to what machine... Yes it is a bother if you manage multiple machines and want to monitor different parts of each machine, though it's never been an issue for me at least, unlike keeping track of which machine each window belongs to...

Nesting connections however doesn't help...hah.
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Hu · Moderator Joined: 06 Mar 2007 Posts: 16508

I usually want to see a mixture of my local and remote windows, and I like having window manager bindings able to manage remote windows without needing to execute a keyboard grab for VNC. If you want to focus on just one system, yes, having all its windows confined in a box that you maximize to fill the local screen could be a better choice. I sometimes want to use different size physical displays for viewing the same remote content, and that is easier if I always run the local X server at native resolution and float the remote windows freely as Xpra X windows. If I used VNC, then either the small display system would cut off part of the VNC client, the large display system would waste some of its visual space, or I would need to tell VNC to resize its server when I switch displays.