I want to run a game server inside my Ubuntu machine. I want to run it in the background and write the live output of that process inside a log file. I tried using nohup and running the game server using "&" at the end but I couldn't make it work the way I wanted.
Then I started reading about named pipes and actually gave it a go. I made a simple script that in theory should work. But, of course I am missing something.
First, I made a pipe using the mkfifo command.
mkfifo testpipe
Then I created a small script:
#!/bin/bash
./mta-server64 > pipe &
pid=$!
echo $pid // so I know the pid of the process
cat < pipe > log.txt &
(Note: I wrote this code from memory.)
The code works only when there is an error and the process stops. It actually records the game console error. But when the game server is running I get no output in the log file.
I want to read the output (stdout and stderr if I am not mistaken) of a process running in background and record it those inside a log file.
I also thought about using screen as it logs everything inside a file but I would prefer not using it if there is a better solution.
EDIT:
First of all: thank you for the interest you had in helping me. In the same way, I have to apologize for only giving scarce details about what I intend to do with this small project and for my limited understanding of stdout and stderr.
Let's go to the first base.
I want to run a game server named Multi Theft Auto (https://multitheftauto.com/). This is GTA San Andreas but multiplayer.
I can easily run this game server in my Ubuntu server by calling the executable ./mta-server-64. After calling it the game server console appears:
[|] MTA: San Andreas :: 0/32 players :: 196 resources :: 125 fps (25)
MTA:BLUE Server for MTA:SA
==================================================================
= Multi Theft Auto: San Andreas v1.5.6 [64 bit]
==================================================================
= Server name : Default MTA Server
= Server IP address: auto
= Server port : 22884
=
= Log file : /root/mta/mods/deathmatch/logs/server.log
= Maximum players : 32
= HTTP port : 22564
= Voice Chat : Disabled
= Bandwidth saving : Medium
==================================================================
[09:49:07] Resource 'mapmanager' requests some acl rights. Use the command 'aclrequest list mapmanager'
[09:49:07] Resources: 196 loaded, 0 failed
[09:49:07] Starting resources...
[09:49:07] Server minclientversion is now 1.5.6-9.16588.0
[09:49:07] INFO: MAPMANAGER: Some important ACL permissions are missing. To ensure the correct functioning of Mapmanager, please write: aclrequest allow mapmanager all
[09:49:07] Gamemode 'play' started.
[09:49:07] Authorized serial account protection is enabled for the ACL group(s): `Admin` See http://mtasa.com/authserial
[09:49:07] WARNING: <owner_email_address> not set
[09:49:07] Server started and is ready to accept connections!
[09:49:07] To stop the server, type 'shutdown' or press Ctrl-C
[09:49:07] Type 'help' for a list of commands.
[09:49:07] Querying MTA master server... success! (Auto detected IP:xxx.xxx.xxx.xxx)
I am using the following script to run the process in the background and (try to) get the live output from:
#!/bin/bash
newport=$(shuf -i 22003-22900 -n 1)
newip=$(shuf -i 22003-22900 -n 1)
rm -rf ~/server/*
cp -r /home/user*/ftp/server/mtaserver/serverfiles/* ~/server
sed -i "s/<httpport>[0-9][0-9][0-9][0-9][0-9]<\/httpport>/<httpport>$newport<\/httpport>/g" ~/server/mods/deathmatch/mtaserver.conf
sed -i "s/<serverport>[0-9][0-9][0-9][0-9][0-9]<\/serverport>/<serverport>$newip<\/serverport>/g" ~/server/mods/deathmatch/mtaserver.conf
~/server/mta-server64 2>&1 | tee -a outfile &
mta_pid=$!
echo $mta_pid
sleep 6
pkill $mta_pid
(Note: Because of some technical problems I had to add the first few lines of script which automatically replace the game files with new ones and also replace the existing ports with random ones.)
This script starts the server and tries to log the output of the process. The process is automatically killed after few seconds so there is only one instance of the game server at any given time.
THE ISSUE:
This script only logs the output if there is an error. I still cannot get the live output of the process when it is still running. Maybe this is an issue with the game server but truly believe there should be a way to make it work the way I intend.
I believe you want to use tee command to split the pipe output to log file.
I suggest you read this article and these answers 1 2.
Usually this is enough nohup somecommand > somecommand.log 2>&1 & then, tail -F somecommand.log to follow the logs.
After 2 days I finally figured out a way to make it work (the way I intended to work, without taking in consideration any major security/performance risks).
Reading the comments made me realize I was attacking the wrong point. The stdout of the game server is buffered, thus making it impossible to log it into a log file using the methods I tried when I posted my question At least this is what I came to understand).
I did some research on how to run the application without having the stdout buffered: https://serverfault.com/questions/294218/is-there-a-way-to-redirect-output-to-a-file-without-buffering-on-unix-linux
My code now:
stdbuf -o0 ~/server/mta-server64 >> pipe &
cat < pipe | tee -a outfile &
After creating the named pipe it executes the game server inside that pipe and then appends the stdout into the log file.
The stdbug -o0 command disables the stdout buffering (as noted in the link above).
This works for me and I cannot guarantee it will work for anybody else. I am still not aware if disabling the buffering is a safe approach to my issue but for now it is what I need.
I need to replace a very simple expect script that looks like this:
#!/usr/bin/expect
spawn telnet 192.168.1.175
expect {
"assword" {send "lamepassword\r"}
}
interact
With the equivalent bash script using empty, like this:
#!/bin/bash
empty -f -i in -o out telnet 192.168.1.175
empty -w -i out -o in "assword" "lamepassword\n"
After which I need the user to interact with telnet, which I do not know how to do. The closest thing that comes to my mind is binding stdin and stdout with named pipes using something like socat - in. Any suggestions are more than welcome!
I tried cat out & cat /dev/stdin >in, it works, but it has an extra
newline, tab completion does not work and ctr+c terminates cat and
not the running host process. I am trying to persuade socat to act
according to those needs.
Using socat for transmitting keyboard input to the telnet process is a good idea. Example:
cat out & socat -u -,raw,echo=0 ./in
For allowing Ctrl-C to terminate socat, add escape=3:
cat out & socat -u -,raw,echo=0,escape=3 ./in
But note that this will not terminate the telnet session, since it did start in daemon mode, so you can reconnect to telnet by executing socat again. To end telnet, you could just logout.
I'm running ffmpeg on another machine for screen capture. I'd like to be able to stop it recording remotely. FFMPEG requires that q is pressed to stop encoding as it has to do some finalization to finish the file cleanly. I know I could kill it with kill/killall however this can lead to corrupt videos.
Press [q] to stop encoding
I can't find anything on google specifically for this, but some there is suggestion that echoing into /proc//fd/0 will work.
I've tried this but it does not stop ffmpeg. The q is however shown in the terminal in which ffmpeg is running.
echo -n q > /proc/16837/fd/0
So how can I send a character to another existing process in such a way it is as if it were typed locally? Or is there another way of remotely stopping ffmpeg cleanly.
Here's a neat trick I discovered when I was faced with this problem: Make an empty file (it doesn't have to be a named pipe or anything), then write 'q' to it when it's time to stop recording.
$ touch stop
$ <./stop ffmpeg -i ... output.ext >/dev/null 2>>Capture.log &
$ wait for stopping time
$ echo 'q' > stop
FFmpeg stops as though it got 'q' from the terminal STDIN.
Newer versions of ffmpeg don't use 'q' anymore, at least on Ubuntu Oneiric, instead they say to press Ctrl+C to stop them. So with a newer version you can simply use 'killall -INT' to send them SIGINT instead of SIGTERM, and they should exit cleanly.
Elaborating on the answer from sashoalm, i have tested both scenarios, and here are the results:
My experiments shows that doing
killall --user $USER --ignore-case --signal INT ffmpeg
Produces the following on the console where ffmpeg was running
Exiting normally, received signal 2.
While doing
killall --user $USER --ignore-case --signal SIGTERM ffmpeg
Produces
Exiting normally, received signal 15.
So it looks that ffmpeg is fine with both signals.
System: Debian GNU/Linux 9 (stretch), 2020-02-28
You can also try to use "expect" to automate the execution and stop of the program. You would have to start it using some virtual shell like screen, tmux or byobu and then start the ffmpeg inside of it. This way you would be able to get again the virtual shell screen and give the "q" option.
Locally or remotely start a virtual shell session, lets say with "screen". Name the session with -S option, like screen -S recvideo Then you can start the ffmpeg as you like. You can, optionally, detach from this session with a Ctrl+a + d.
Connect to the machine where the ffmpeg is running inside the screen (or tmux or whatever) and reconnect to it: screen -d -RR recvideo and then send the "q"
To do that from inside a script you can then use expect, like:
prompt="> "
expect << EOF
set timeout 20
spawn screen -S recvideo
expect "$prompt"
send -- "ffmpeg xxxxx\r"
set timeout 1
expect eof
EOF
Then, in another moment or script point or in another script you recover it:
expect << EOF
set timeout 30
spawn screen -d -RR recvideo
expect "$prompt"
send -- "q"
expect "$prompt"
send -- "exit\r"
expect eof
EOF
You can also automate the whole ssh session with expect, passing a sequence of commands and "expects" to do what you want.
The question has already been answered for Linux, but it came up when I was looking for the windows equivalent, so I'm gonna add that to the answers:
On powershell, you start the process like this:
$((Start-Process ffmpeg -passthru -argument "FFMPEG_ARGS").ID)
This sends back the PID of the FFMPEG process that you can store in a variable, or echo, and then you send the windows equivalent of sigint (Ctrl + C) using taskkill
taskkill /pid FFMPEG_PID
I tried with Stop-Process (which is what comes up when looking how to do this on Google) but it actually kills the process. (And yes, taskkill doesn't kill it, it gently asks the process to stop... good naming :D)
Is there a way to manipulate VLC with a Linux shell script without the script waiting for VLC to close.
cvlc test.mp3
echo "Now playing!"
sleep 200
cvlc://pause:60
This code keeps running VLC until the file is completed, and then evidently it is to late to pause the file.
You need to use dbus interface of VLC.
Now, you can use the mpris interface of VLC. It's a standard for most players like clementine, banshee, songbird, spotify etc.
So, lets suppose you want to Pause the currently playing song.
dbus-send --print-reply --session --dest=org.mpris.vlc /Player org.freedesktop.MediaPlayer.Pause
To play a song:
dbus-send --print-reply --session --dest=org.mpris.vlc /Player org.freedesktop.MediaPlayer.Play
I generally use qdbusviewer to know about the dbus-interface available to me.
Dbus is one way but dbus does not exist on all systems. The more common method would be to use the rc interface:
cvlc -I rc --rc-host localhost:11337 -d
Then one can use netcat to pipe commands into the tcp socket. For example:
vlc -I rc --rc-host localhost:11337 test.mp3 -d &
echo "Now playing!"
sleep 200
echo pause | netcat localhost 11337
EDIT:
After testing with a few other interfaces I have discovered the oldrc interface accepts UNIX domain sockets thus the following will work as well with out needing to play around with firewalls or worry about anyone else on the network messing around with your vlc instance.
vlc -I oldrc --rc-unix /var/run/vlc.sock -d
echo "Now Playing!"
sleep 200
echo "pause" | netcat -U /var/run/vlc.sock
It looks like you can redirect from standard input or a named pipe. For more complicated things you could use libvlc.
http://wiki.videolan.org/Uncommon_uses
Borderline ServerFault question, but I'm programming some shell scripts, so I'm trying here first :)
Most *nixes have a command that will let you pipe/redirect output to the local clipboard/pasteboard, and retrieve from same. On OS X these commands are
pbcopy, pbpaste
Is there anyway to replicate this functionality while SSHed into another server? That is,
I'm using Computer A.
I open a terminal window
I SSH to Computer B
I run a command on Computer B
The output of Computer B is redirected or automatically copied to Computer A's clipboard.
And yes, I know I could just (shudder) use my mouse to select the text from the command, but I've gotten so used to the workflow of pipping output directly to the clipboard that I want the same for my remote sessions.
Code is useful, but general approaches are appreciated as well.
My favorite way is ssh [remote-machine] "cat log.txt" | xclip -selection c. This is most useful when you don't want to (or can't) ssh from remote to local.
Edit: on Cygwin ssh [remote-machine] "cat log.txt" > /dev/clipboard.
Edit: A helpful comment from nbren12:
It is almost always possible to setup a reverse ssh connection using SSH port forwarding. Just add RemoteForward 127.0.0.1:2222 127.0.0.1:22 to the server's entry in your local .ssh/config, and then execute ssh -p 2222 127.0.0.1 on the remote machine, which will then redirect the connection to the local machine. – nbren12
I'm resurrecting this thread because I've been looking for the same kind of solution, and I've found one that works for me. It's a minor modification to a suggestion from OSX Daily.
In my case, I use Terminal on my local OSX machine to connect to a linux server via SSH. Like the OP, I wanted to be able to transfer small bits of text from terminal to my local clipboard, using only the keyboard.
The essence of the solution:
commandThatMakesOutput | ssh desktop pbcopy
When run in an ssh session to a remote computer, this command takes the output of commandThatMakesOutput (e.g. ls, pwd) and pipes the output to the clipboard of the local computer (the name or IP of "desktop"). In other words, it uses nested ssh: you're connected to the remote computer via one ssh session, you execute the command there, and the remote computer connects to your desktop via a different ssh session and puts the text to your clipboard.
It requires your desktop to be configured as an ssh server (which I leave to you and google). It's much easier if you've set up ssh keys to facilitate fast ssh usage, preferably using a per-session passphrase, or whatever your security needs require.
Other examples:
ls | ssh desktopIpAddress pbcopy
pwd | ssh desktopIpAddress pbcopy
For convenience, I've created a bash file to shorten the text required after the pipe:
#!/bin/bash
ssh desktop pbcopy
In my case, i'm using a specially named key
I saved it with the file name cb (my mnemonic (ClipBoard). Put the script somewhere in your path, make it executable and voila:
ls | cb
Found a great solution that doesn't require a reverse ssh connection!
You can use xclip on the remote host, along with ssh X11 forwarding & XQuartz on the OSX system.
To set this up:
Install XQuartz (I did this with soloist + pivotal_workstation::xquartz recipe, but you don't have to)
Run XQuartz.app
Open XQuartz Preferences (+,)
Make sure "Enable Syncing" and "Update Pasteboard when CLIPBOARD changes" are checked
ssh -X remote-host "echo 'hello from remote-host' | xclip -selection clipboard"
Reverse tunnel port on ssh server
All the existing solutions either need:
X11 on the client (if you have it, xclip on the server works great) or
the client and server to be in the same network (which is not the case if you're at work trying to access your home computer).
Here's another way to do it, though you'll need to modify how you ssh into your computer.
I've started using this and it's nowhere near as intimidating as it looks so give it a try.
Client (ssh session startup)
ssh username#server.com -R 2000:localhost:2000
(hint: make this a keybinding so you don't have to type it)
Client (another tab)
nc -l 2000 | pbcopy
Note: if you don't have pbcopy then just tee it to a file.
Server (inside SSH session)
cat some_useful_content.txt | nc localhost 2000
Other notes
Actually even if you're in the middle of an ssh session there's a way to start a tunnel but i don’t want to scare people away from what really isn’t as bad as it looks. But I'll add the details later if I see any interest
There are various tools to access X11 selections, including xclip and XSel. Note that X11 traditionally has multiple selections, and most programs have some understanding of both the clipboard and primary selection (which are not the same). Emacs can work with the secondary selection too, but that's rare, and nobody really knows what to do with cut buffers...
$ xclip -help
Usage: xclip [OPTION] [FILE]...
Access an X server selection for reading or writing.
-i, -in read text into X selection from standard input or files
(default)
-o, -out prints the selection to standard out (generally for
piping to a file or program)
-l, -loops number of selection requests to wait for before exiting
-d, -display X display to connect to (eg localhost:0")
-h, -help usage information
-selection selection to access ("primary", "secondary", "clipboard" or "buffer-cut")
-noutf8 don't treat text as utf-8, use old unicode
-version version information
-silent errors only, run in background (default)
-quiet run in foreground, show what's happening
-verbose running commentary
Report bugs to <astrand#lysator.liu.se>
$ xsel -help
Usage: xsel [options]
Manipulate the X selection.
By default the current selection is output and not modified if both
standard input and standard output are terminals (ttys). Otherwise,
the current selection is output if standard output is not a terminal
(tty), and the selection is set from standard input if standard input
is not a terminal (tty). If any input or output options are given then
the program behaves only in the requested mode.
If both input and output is required then the previous selection is
output before being replaced by the contents of standard input.
Input options
-a, --append Append standard input to the selection
-f, --follow Append to selection as standard input grows
-i, --input Read standard input into the selection
Output options
-o, --output Write the selection to standard output
Action options
-c, --clear Clear the selection
-d, --delete Request that the selection be cleared and that
the application owning it delete its contents
Selection options
-p, --primary Operate on the PRIMARY selection (default)
-s, --secondary Operate on the SECONDARY selection
-b, --clipboard Operate on the CLIPBOARD selection
-k, --keep Do not modify the selections, but make the PRIMARY
and SECONDARY selections persist even after the
programs they were selected in exit.
-x, --exchange Exchange the PRIMARY and SECONDARY selections
X options
--display displayname
Specify the connection to the X server
-t ms, --selectionTimeout ms
Specify the timeout in milliseconds within which the
selection must be retrieved. A value of 0 (zero)
specifies no timeout (default)
Miscellaneous options
-l, --logfile Specify file to log errors to when detached.
-n, --nodetach Do not detach from the controlling terminal. Without
this option, xsel will fork to become a background
process in input, exchange and keep modes.
-h, --help Display this help and exit
-v, --verbose Print informative messages
--version Output version information and exit
Please report bugs to <conrad#vergenet.net>.
In short, you should try xclip -i/xclip -o or xclip -i -sel clip/xclip -o -sel clip or xsel -i/xsel -o or xsel -i -b/xsel -o -b, depending on what you want.
If you use iTerm2 on the Mac, there is an easier way. This functionality is built into iTerm2's Shell Integration capabilities via the it2copy command:
Usage: it2copy
Copies to clipboard from standard input
it2copy filename
Copies to clipboard from file
To make it work, choose iTerm2-->Install Shell Integration menu item while logged into the remote host, to install it to your own account. Once that is done, you'll have access to it2copy, as well as a bunch of other aliased commands that provide cool functionality.
The other solutions here are good workarounds but this one is so painless in comparison.
This is my solution based on SSH reverse tunnel, netcat and xclip.
First create script (eg. clipboard-daemon.sh) on your workstation:
#!/bin/bash
HOST=127.0.0.1
PORT=3333
NUM=`netstat -tlpn 2>/dev/null | grep -c " ${HOST}:${PORT} "`
if [ $NUM -gt 0 ]; then
exit
fi
while [ true ]; do
nc -l ${HOST} ${PORT} | xclip -selection clipboard
done
and start it in background.
./clipboard-daemon.sh&
It will start nc piping output to xclip and respawning process after receiving portion of data
Then start ssh connection to remote host:
ssh user#host -R127.0.0.1:3333:127.0.0.1:3333
While logged in on remote box, try this:
echo "this is test" >/dev/tcp/127.0.0.1/3333
then try paste on your workstation
You can of course write wrapper script that starts clipboard-daemon.sh first and then ssh session. This is how it works for me. Enjoy.
Allow me to add a solution that if I'm not mistaken was not suggested before.
It does not require the client to be exposed to the internet (no reverse connections), nor does it use any xlibs on the server and is implemented completely using ssh's own capabilities (no 3rd party bins)
It involves:
Opening a connection to the remote host, then creating a fifo file on it and waiting on that fifo in parallel (same actual TCP connection for everything).
Anything you echo to that fifo file ends up in your local clipboard.
When the session is done, remove the fifo file on the server and cleanly terminate the connections together.
The solution utilizes ssh's ControlMaster functionality to use just one TCP connection for everything so it will even support hosts that require a password to login and prompt you for it just once.
Edit: as requested, the code itself:
Paste the following into your bashrc and use sshx host to connect.
On the remote machine echo SOMETHING > ~/clip and hopefully, SOMETHING will end up in the local host's clipboard.
You will need the xclip utility on your local host.
_dt_term_socket_ssh() {
ssh -oControlPath=$1 -O exit DUMMY_HOST
}
function sshx {
local t=$(mktemp -u --tmpdir ssh.sock.XXXXXXXXXX)
local f="~/clip"
ssh -f -oControlMaster=yes -oControlPath=$t $# tail\ -f\ /dev/null || return 1
ssh -S$t DUMMY_HOST "bash -c 'if ! [ -p $f ]; then mkfifo $f; fi'" \
|| { _dt_term_socket_ssh $t; return 1; }
(
set -e
set -o pipefail
while [ 1 ]; do
ssh -S$t -tt DUMMY_HOST "cat $f" 2>/dev/null | xclip -selection clipboard
done &
)
ssh -S$t DUMMY_HOST \
|| { _dt_term_socket_ssh $t; return 1; }
ssh -S$t DUMMY_HOST "rm $f"
_dt_term_socket_ssh $t
}
More detailed explanation is on my website:
https://xicod.com/2021/02/09/clipboard-over-ssh.html
The simplest solution of all, if you're on OS X using Terminal and you've been ssh'ing around in a remote server and wish to grab the results of a text file or a log or a csv, simply:
1) Cmd-K to clear the output of the terminal
2) cat <filename> to display the contents of the file
3) Cmd-S to save the Terminal Output
You'll have the manually remove the first line and last line of the file, but this method is a bit simpler than relying on other packages to be installed, "reverse tunnels" and trying to have a static IP, etc.
This answer develops both upon the chosen answer by adding more security.
That answer discussed the general form
<command that makes output> | \
ssh <user A>#<host A> <command that maps stdin to clipboard>
Where security may be lacking is in the ssh permissions allowing <user B> on host B> to ssh into host A and execute any command.
Of course B to A access may already be gated by an ssh key, and it may even have a password. But another layer of security can restrict the scope of allowable commands that B can execute on A, e.g. so that rm -rf / cannot be called. (This is especially important when the ssh key doesn't have a password.)
Fortunately, ssh has a built-in feature called command restriction or forced command. See ssh.com, or
this serverfault.com question.
The solution below shows the general form solution along with ssh command restriction enforced.
Example Solution with command restriction added
This security enhanced solution follows the general form - the call from the ssh session on host-B is simply:
cat <file> | ssh <user-A>#<host A> to_clipboard
The rest of this shows the setup to get that to work.
Setup of ssh command restriction
Suppose the user account on B is user-B, and B has an ssh key id-clip, that has been created in the usual way (ssh-keygen).
Then in user-A's ssh directory there is a file
/home/user-A/.ssh/authorized_keys
that recognizes the key id-clip and allows ssh connection.
Usually the contents of each line authorized_keys is exactly the public key being authorized, e.g., the contents of id-clip.pub.
However, to enforce command restriction that public key content is prepended (on the same line) by the command to be executed.
In our case:
command="/home/user-A/.ssh/allowed-commands.sh id-clip",no-agent-forwarding,no-port-forwarding,no-user-rc,no-x11-forwarding,no-pty <content of file id-clip.pub>
The designated command "/home/user-A/.ssh/allowed-commands.sh id-clip", and only that designated command, is executed whenever key id-clip is used initiate an ssh connection to host-A - no matter what command is written the ssh command line.
The command indicates a script file allowed-commands.sh, and the contents of that that script file is
#/bin/bash
#
# You can have only one forced command in ~/.ssh/authorized_keys. Use this
# wrapper to allow several commands.
Id=${1}
case "$SSH_ORIGINAL_COMMAND" in
"to-clipboard")
notify-send "ssh to-clipboard, from ${Id}"
cat | xsel --display :0 -i -b
;;
*)
echo "Access denied"
exit 1
;;
esac
The original call to ssh on machine B was
... | ssh <user-A>#<host A> to_clipboard
The string to-clipboard is passed to allowed-commands.sh by the environment variable SSH_ORIGINAL_COMMAND.
Addition, we have passed the name of the key, id-clip, from the line in authorized_keyswhich is only accessed by id-clip.
The line
notify-send "ssh to-clipboard, from ${Id}"
is just a popup messagebox to let you know the clipboard is being written - that's probably a good security feature too. (notify-send works on Ubuntu 18.04, maybe not others).
In the line
cat | xsel --display :0 -i -b
the parameter --display :0 is necessary because the process doesn't have it's own X display with a clipboard,
so it must be specificied explicitly. This value :0 happens to work on Ubuntu 18.04 with Wayland window server. On other setups it might not work. For a standard X server this answer might help.
host-A /etc/ssh/sshd_config parameters
Finally a few parameters in /etc/ssh/sshd_config on host A that should be set to ensure permission to connect, and permission to use ssh-key only without password:
PubkeyAuthentication yes
PasswordAuthentication no
ChallengeResponseAuthentication no
AllowUsers user-A
To make the sshd server re-read the config
sudo systemctl restart sshd.service
or
sudo service sshd.service restart
conclusion
It's some effort to set it up, but other functions besides to-clipboard can be constructed in parallel the same framework.
Not a one-liner, but requires no extra ssh.
install netcat if necessary
use termbin: cat ~/some_file.txt | nc termbin.com 9999. This will copy the output to the termbin website and prints the URL to your output.
visit that url from your computer, you get your output
Of course, do not use it for sensitive content.
#rhileighalmgren solution is good, but pbcopy will annoyingly copy last "\n" character, I use "head" to strip out last character to prevent this:
#!/bin/bash
head -c -1 | ssh desktop pbcopy
My full solution is here : http://taylor.woodstitch.com/linux/copy-local-clipboard-remote-ssh-server/
Far Manager Linux port supports synchronizing clipboard between local and remote host. You just open local far2l, do "ssh somehost" inside, run remote far2l in that ssh session and get remote far2l working with your local clipboard.
It supports Linux, *BSD and OS X; I made a special putty build to utilize this functionality from windows also.
For anyone googling their way to this:
The best solution in this day and age seem to be lemonade
Various solutions is also mentioned in the neovim help text for clipboard-tool
If you're working over e.g. a pod in a Kubernetes cluster and not direct SSH, so that there is no way for your to do a file transfer, you could use cat and then save the terminal output as text. For example in macOS you can do Shell -> Export as text.