Can someone please help as how can I close the bash terminal completely from inside of TMUX session (closing TMUX session as well)?
Below code is from my .bashrc where TMUX session starts as soon as terminal launches
if command -v tmux &> /dev/null && [ -z "$TMUX" ]; then tmux attach -t default -c "$HOME" || tmux new -s default -c "$HOME" fi
Thanks!
You can use tmux detach -P to both detach and send HUP to the parent process, which should make it exit as well.
I'm trying to use tmux in a script, so that it runs a command that takes some time (let's say 'ping -c 5 8.8.8.8', for example) in a new hidden pane, while blocking the current script itself until the ping ends.
By "hidden pane", I mean running the command in a new pane that would be sent in background, and is still accessible by switching panes in order to monitor and/or interact with it (not necessarily ping).
(cf. EDIT)
Here is some pseudo bash code to show more clearly what I'm trying to do:
echo "Waiting for ping to finish..."
echo "Ctrl-b + p to switch pane and see running process"
tmux new-window -d 'ping -c 5 8.8.8.8' # run command in new "background" window
tmux wait-for # display "Done!" only when ping command has finished
echo "Done!"
I know the tmux commands here don't really have any sense like this, but this is just to illustrate.
I've looked at different solutions in order to either send a command in background, or wait until a process has finished in an other pane, but I still haven't found a way to do both correctly.
EDIT
Thanks to Nicholas Marriott for pointing out the -d option exists when creating a new window to avoid switching to it automatically. Now the only issue is to block the main script until the command ends.
I tried the following, hoping it would work, but it doesn't either (the script doesn't resume).
tmux new-window -d 'ping -c 5 8.8.8.8; tmux wait -S ping' &
tmux wait $!
Maybe there is a way by playing with processes (using fg,bg...), but I still haven't figured it out.
Similar questions:
[1] Make tmux block until programs complete
[2] Bash - executing blocking scripts in tmux
[3] How do you hide a tmux pane
[4] how to wait for first command to finish?
You can use wait-for but you need to give it a channel and signal that channel when your process is done, something like:
tmux neww -d 'ping blah; tmux wait -S ping'
tmux wait ping
echo done
If you think you might run the script several times in parallel, I suggest making a channel name using mktemp or similar (and removing the file when wait-for returns).
wait-for can't automatically wait for stuff like pane or windows exiting, silence in a pane, and so on, but I would like to see that implemented at some point.
The other answers are only working if you're already within a tmux session.
But if you are outside of it you've to use something like this:
tmux new-session -d 'vi /etc/passwd' \; split-window -d 'vi /etc/group' \; attach
If you want to call this within a script you should check whether or not "$TMUX" is set. (Or just unset to force a nested tmux window).
#!/bin/sh
export com1="vi /etc/passwd"
export com2="vi /etc/group"
if [ -z $TMUX ]
then
export doNewSession="new-session -d 'exit 0'"
else
export doNewSession=""
fi
tmux $doNewSession \; split-window -d $com1 \; split-window -d $com2 \; attach;
[ -z $TMUX ] && exit 0
My solution was to make a named pipe and then wait for input using read:
#!/bin/sh
rm -f /wait
mkfifo /wait
tmux new-window -d '/bin/sh -c "ping -c 5 8.8.8.8; echo . > /wait"'
read -t 10 WAIT <>/wait
[ -z "$WAIT" ] &&
echo 'The operation failed to complete within 10 seconds.' ||
echo 'Operation completed successfully.'
I like this approach because you can set a timeout and, if you wanted, you could extend this further with other tmux controls to kill the ongoing process if it doesn't end the way you want.
I have a .sh file which create a new session for tmux and add some windows, the file should be used only when no session exist. For instance:
tmux new-session -A -s `ax` -n ui -d
# add windows and other magic here...
I want prevent creating a session with the same name and recreating the windows in case the .sh file is accidentally re executed and the session is running.
Basically what I need is:
If a tmux session ax does not exist with that session name, create that session. If
I am not attached to a tmux session, attach to that session.
I would like to know how to detect if a tmux session exist and if tmux is attached to it, in this example ax is running and preventing the execution of the .sh script or if the session does not exit I want to re-execute the .sh script.
Currently I was thinking to use:
tmux ls | grep attached
I would like to know if you know a better way.
It's a little hard to understand what you mean. I'm interpreting it as
if a tmux session does not exist with that session name, create it. If I am not attached to a tmux session, attach to that session name.
If this is wrong, please comment.
I have similar functionality in my scripts. All I do is
tmuxstart() {
tmux ls | grep "sess" && { tmux a -t sess; return 0; }
#rest of tmux script to create session named "sess"
tmux a -t sess
}
If the session named "sess" exists, then I execute the next 2 grouped commands on the line (attach to it and exit the function).
Note that I do not have to check if I'm already attached to the function. tmux does this automatically. If you try to attach to a tmux session while in a session, it will respond
sessions should be nested with care, unset $TMUX to force
and not recursively attach. Tmux is smart enough to keep us from shooting ourselves in the foot.
You can use $TMUX to detect if already attached, my code is:
if [ ! "$TMUX" ]; then
tmux attach -t main || tmux new -s main
fi
I use this in my ~/.bashrc so if no sessions exist, start them & detach from all but ipfs session.
IPFS_SESSION=$(tmux attach-session -t ipfs 2>&1)
if [ "$IPFS_SESSION" == "sessions should be nested *" ]; then
unset TMUX
else
if ! tmux has-session -t sql; then tmux new-session -d -s sql; fi
if ! tmux has-session -t tmp; then tmux new-session -d -s tmp; fi
if ! tmux has-session -t ytdl; then tmux new-session -d -s ytdl; fi
if ! tmux has-session -t ipfs; then tmux new-session -s ipfs; fi
fi
I want to write a shell script that does this:
First, create a tmux session
Second, run a ruby script called "run.rb" INSIDE the tmux session
In pseudo-code, what I want to do:
tmux new -s my_session
ruby run.rb # NOTE: I want this to run inside the my_session tmux session.
tmux detach
How do I do this? (More posts I read, more confusing it gets.)
#!/bin/bash
tmux new-session -d -s my_session 'ruby run.rb'
Create a file named my_script.sh and give it the above contents.
Make the file executable by running:
chmod 755 my_script.sh
or
chmod +x my_script.sh
Then run the shell script:
./my_script.sh
Making the shell script executable
When you perform the chmod 755 filename command you allow everyone to read and execute the file, and the file owner is allowed to write to the file as well. You may need this for Perl and other scripts that should be run via a webserver. If you apply 755 to a directory, it means that everyone can go to it and get its file listing.
These permissions are usually translated into textual representation of rwxr-xr-x.
You can alternatively use chmod +x file_name on a file to make it executable.
K M Rakibul Islam's updated code contains an unnecessary detach command at the end which causes an error message "no client found" (my_session has already been detached and thus is not in scope so tmux cannot understand which session you want to detach). The correct code should be:
#!/bin/bash
tmux new-session -d -s my_session 'ruby run.rb'
With some experimenting, I figured out how to control tmux via shell script.
tmux new-session -d -s htop-session 'htop'; # start new detached tmux session, run htop
tmux split-window; # split the detached tmux session
tmux send 'htop -t' ENTER; # send 2nd command 'htop -t' to 2nd pane. I believe there's a `--target` option to target specific pane.
tmux a; # open (attach) tmux session.
The above splits the tmux session into two window, and runs htop in both.
To answer original question, you can run a ruby script and not detached the tmux session with command below:
tmux new-session -s ruby_session 'ruby run.rb'; # open tmux session and run ruby script.
You could use teamocil to do this easily. You could just create a YAML file:
windows:
- name: rubysession
root: ~
layout: tiled
panes:
- ruby run.rb; tmux detach
If you named it 'rubysession.yml' then run:
teamocil rubysession
And that would work perfectly for your purpose and require no hacks. Also teamocil is awesome for loads of other uses!
If you want to keep your tmux session alive after starting some commands, a possible solution is to start a bash with an init file:
tmux new -d -s mysession "bash --init-file foo.script"
where foo.script would contain your commands. Alternatively, you can feed the command to the shell directly from the command line:
tmux new -d -s mysession2 "bash --init-file <(echo ruby run.rb)"
Note that --init-file was meant for reading system wide initialization files like /etc/bash.bashrc so you might want to 'source' these in your script.
I am not sure if this is still interesting for you, but I like to give you an answer / hint: in case you want, for example, start multiple tmux sessions by shell script and execute some command, you can do it like follow:
# just for test and show case
mkdir test_1 test_2
echo "current tmux sessions"
tmux ls
echo "kill all tmux sessions"
tmux kill-server
declare -a directories=("test_1" "test_2")
for i in "${directories[#]}"
do
cd ${i}
pwd
tmux new -d -s ${i} "ls -la"
cd ..
done
For the demonstration, the script will create a folder test_1 and test_2. After that I have defined an array with the two folders and run through the two folders and start a tmux session with the current folder name and execute the command "ls -la".
If you like to run through all sub directories in your current directory, please replace "for i in "${directories[#]}" with "for f in *; do". Here is an example that also exclude symbolic folders:
echo "current tmux sessions"
tmux ls
echo "kill all tmux sessions"
tmux kill-server dependencies
for f in *; do
if [[ -d "$f" && ! -L "$f" ]]; then
cd ${f}
pwd
tmux new -d -s ${i} "ls -la"
cd ..
fi
done
Here is a link to the gist file: https://gist.github.com/AICDEV/cf1497793bb1c27cb9b94d56c209ad6f
This is a follow-on question to the How do you use ssh in a shell script? question. If I want to execute a command on the remote machine that runs in the background on that machine, how do I get the ssh command to return? When I try to just include the ampersand (&) at the end of the command it just hangs. The exact form of the command looks like this:
ssh user#target "cd /some/directory; program-to-execute &"
Any ideas? One thing to note is that logins to the target machine always produce a text banner and I have SSH keys set up so no password is required.
I had this problem in a program I wrote a year ago -- turns out the answer is rather complicated. You'll need to use nohup as well as output redirection, as explained in the wikipedia artcle on nohup, copied here for your convenience.
Nohuping backgrounded jobs is for
example useful when logged in via SSH,
since backgrounded jobs can cause the
shell to hang on logout due to a race
condition [2]. This problem can also
be overcome by redirecting all three
I/O streams:
nohup myprogram > foo.out 2> foo.err < /dev/null &
This has been the cleanest way to do it for me:-
ssh -n -f user#host "sh -c 'cd /whereever; nohup ./whatever > /dev/null 2>&1 &'"
The only thing running after this is the actual command on the remote machine
Redirect fd's
Output needs to be redirected with &>/dev/null which redirects both stderr and stdout to /dev/null and is a synonym of >/dev/null 2>/dev/null or >/dev/null 2>&1.
Parantheses
The best way is to use sh -c '( ( command ) & )' where command is anything.
ssh askapache 'sh -c "( ( nohup chown -R ask:ask /www/askapache.com &>/dev/null ) & )"'
Nohup Shell
You can also use nohup directly to launch the shell:
ssh askapache 'nohup sh -c "( ( chown -R ask:ask /www/askapache.com &>/dev/null ) & )"'
Nice Launch
Another trick is to use nice to launch the command/shell:
ssh askapache 'nice -n 19 sh -c "( ( nohup chown -R ask:ask /www/askapache.com &>/dev/null ) & )"'
If you don't/can't keep the connection open you could use screen, if you have the rights to install it.
user#localhost $ screen -t remote-command
user#localhost $ ssh user#target # now inside of a screen session
user#remotehost $ cd /some/directory; program-to-execute &
To detach the screen session: ctrl-a d
To list screen sessions:
screen -ls
To reattach a session:
screen -d -r remote-command
Note that screen can also create multiple shells within each session. A similar effect can be achieved with tmux.
user#localhost $ tmux
user#localhost $ ssh user#target # now inside of a tmux session
user#remotehost $ cd /some/directory; program-to-execute &
To detach the tmux session: ctrl-b d
To list screen sessions:
tmux list-sessions
To reattach a session:
tmux attach <session number>
The default tmux control key, 'ctrl-b', is somewhat difficult to use but there are several example tmux configs that ship with tmux that you can try.
I just wanted to show a working example that you can cut and paste:
ssh REMOTE "sh -c \"(nohup sleep 30; touch nohup-exit) > /dev/null &\""
You can do this without nohup:
ssh user#host 'myprogram >out.log 2>err.log &'
Quickest and easiest way is to use the 'at' command:
ssh user#target "at now -f /home/foo.sh"
I think you'll have to combine a couple of these answers to get what you want. If you use nohup in conjunction with the semicolon, and wrap the whole thing in quotes, then you get:
ssh user#target "cd /some/directory; nohup myprogram > foo.out 2> foo.err < /dev/null"
which seems to work for me. With nohup, you don't need to append the & to the command to be run. Also, if you don't need to read any of the output of the command, you can use
ssh user#target "cd /some/directory; nohup myprogram > /dev/null 2>&1"
to redirect all output to /dev/null.
This worked for me may times:
ssh -x remoteServer "cd yourRemoteDir; ./yourRemoteScript.sh </dev/null >/dev/null 2>&1 & "
You can do it like this...
sudo /home/script.sh -opt1 > /tmp/script.out &
It appeared quite convenient for me to have a remote tmux session using the tmux new -d <shell cmd> syntax like this:
ssh someone#elsewhere 'tmux new -d sleep 600'
This will launch new session on elsewhere host and ssh command on local machine will return to shell almost instantly. You can then ssh to the remote host and tmux attach to that session. Note that there's nothing about local tmux running, only remote!
Also, if you want your session to persist after the job is done, simply add a shell launcher after your command, but don't forget to enclose in quotes:
ssh someone#elsewhere 'tmux new -d "~/myscript.sh; bash"'
Actually, whenever I need to run a command on a remote machine that's complicated, I like to put the command in a script on the destination machine, and just run that script using ssh.
For example:
# simple_script.sh (located on remote server)
#!/bin/bash
cat /var/log/messages | grep <some value> | awk -F " " '{print $8}'
And then I just run this command on the source machine:
ssh user#ip "/path/to/simple_script.sh"
If you run remote command without allocating tty, redirect stdout/stderr works, nohup is not necessary.
ssh user#host 'background command &>/dev/null &'
If you use -t to allocate tty to run interactive command along with background command, and background command is the last command, like this:
ssh -t user#host 'bash -c "interactive command; nohup backgroud command &>/dev/null &"'
It's possible that background command doesn't actually start. There's race here:
bash exits after nohup starts. As a session leader, bash exit results in HUP signal sent to nohup process.
nohup ignores HUP signal.
If 1 completes before 2, the nohup process will exit and won't start the background command at all. We need to wait nohup start the background command. A simple workaroung is to just add a sleep:
ssh -t user#host 'bash -c "interactive command; nohup backgroud command &>/dev/null & sleep 1"'
The question was asked and answered years ago, I don't know if openssh behavior changed since then. I was testing on:
OpenSSH_8.6p1, OpenSSL 1.1.1g FIPS 21 Apr 2020
I was trying to do the same thing, but with the added complexity that I was trying to do it from Java. So on one machine running java, I was trying to run a script on another machine, in the background (with nohup).
From the command line, here is what worked: (you may not need the "-i keyFile" if you don't need it to ssh to the host)
ssh -i keyFile user#host bash -c "\"nohup ./script arg1 arg2 > output.txt 2>&1 &\""
Note that to my command line, there is one argument after the "-c", which is all in quotes. But for it to work on the other end, it still needs the quotes, so I had to put escaped quotes within it.
From java, here is what worked:
ProcessBuilder b = new ProcessBuilder("ssh", "-i", "keyFile", "bash", "-c",
"\"nohup ./script arg1 arg2 > output.txt 2>&1 &\"");
Process process = b.start();
// then read from process.getInputStream() and close it.
It took a bit of trial & error to get this working, but it seems to work well now.
YOUR-COMMAND &> YOUR-LOG.log &
This should run the command and assign a process id you can simply tail -f YOUR-LOG.log to see results written to it as they happen. you can log out anytime and the process will carry on
If you are using zsh then use program-to-execute &! is a zsh-specific shortcut to both background and disown the process, such that exiting the shell will leave it running.
A follow-on to #cmcginty's concise working example which also shows how to alternatively wrap the outer command in double quotes. This is how the template would look if invoked from within a PowerShell script (which can only interpolate variables from within double-quotes and ignores any variable expansion when wrapped in single quotes):
ssh user#server "sh -c `"($cmd) &>/dev/null </dev/null &`""
Inner double-quotes are escaped with back-tick instead of backslash. This allows $cmd to be composed by the PowerShell script, e.g. for deployment scripts and automation and the like. $cmd can even contain a multi-line heredoc if composed with unix LF.
First follow this procedure:
Log in on A as user a and generate a pair of authentication keys. Do not enter a passphrase:
a#A:~> ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/a/.ssh/id_rsa):
Created directory '/home/a/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/a/.ssh/id_rsa.
Your public key has been saved in /home/a/.ssh/id_rsa.pub.
The key fingerprint is:
3e:4f:05:79:3a:9f:96:7c:3b:ad:e9:58:37:bc:37:e4 a#A
Now use ssh to create a directory ~/.ssh as user b on B. (The directory may already exist, which is fine):
a#A:~> ssh b#B mkdir -p .ssh
b#B's password:
Finally append a's new public key to b#B:.ssh/authorized_keys and enter b's password one last time:
a#A:~> cat .ssh/id_rsa.pub | ssh b#B 'cat >> .ssh/authorized_keys'
b#B's password:
From now on you can log into B as b from A as a without password:
a#A:~> ssh b#B
then this will work without entering a password
ssh b#B "cd /some/directory; program-to-execute &"
I think this is what you need:
At first you need to install sshpass on your machine.
then you can write your own script:
while read pass port user ip; do
sshpass -p$pass ssh -p $port $user#$ip <<ENDSSH1
COMMAND 1
.
.
.
COMMAND n
ENDSSH1
done <<____HERE
PASS PORT USER IP
. . . .
. . . .
. . . .
PASS PORT USER IP
____HERE