i want to run some command on several machine using ssh. I know it can be done by just using the command "ssh user#hostname command". However, the command i want to run print some string on the console. Is there any way that send all the strings back to the console that i'm on?
You could run the commands in a screen:
screen -S test
ssh user#hostname command1
ssh user#hostname2 command2
You can then detach (Ctrl-D) from the screen, let it run for however long it will run, then re-attach (screen -r test) to the screen and see all of the output. This assumes that you won't have a ton of output from the commands, however. Here's a link to a tutorial on screen.
ssh user#hostname command
Does just that. if 'command' outputs something, it'll show on the terminal you ran ssh from.
Try e.g. ssh user#hostname ls -l
But as others have said, GNU screen is invaluable for this type of work.
You probably want to use Gnu Screen for this. You can start a process in a "virtual" terminal, "detach" the terminal and log out for however long you want... Then you can ssh back in and re-attach the terminal to see the console output.
Also have a look at nohup, for example:
ssh user#domain.com nohup script_that_outputs_strings.py > the_strings.txt
Then if you want to go back and monitor the progress, you could check back and tail the file or scp the output back to your local machine.
Why don't you send you an email back?
Or use a log file, and scp it to your current computer?
otherwise, I don't know!
Related
I'm using localhost.run to open tunnels, so I want to launch
ssh -R 80:localhost:8080 ssh.localhost.run
The only problem is that I launch it via LSF as part of a bash script.
I get the error
Pseudo-terminal will not be allocated because stdin is not a terminal.
that I solve by using the option
-T Disable pseudo-tty allocation.
My current command is
ssh -T -R 80:localhost:8080 ssh.localhost.run
and it is the last command of my bash script.
I have also tried using -tt with the same result (https://stackoverflow.com/a/7122115/5133167)
When I launch my script from my tty, I get the expected output (a message like Connect to http://user.localhost.run or https://user.localhost.run)
When I launch it through LSF (using bsub), I don't get any output from SSH (but get the output from the other commands).
I have also tried redirecting the output of ssh to a file: it works fine when launched from the command line but not when launched from LSF.
I have hard requirement of logging into a terminal via SSH from TCL console and relaunch a tcl script from that terminal. For this I use exec command and it does get executed. The only problem is it doesn't return back to parent code.
I have automated SSH login and it works fine from a bash/csh terminal
But from TCL console, the following happens
Simple example
exec ssh hostname pwd
puts "Done"
When I execute this code in TCL, "Done" never gets printed. I just get the output of pwd and that's it.
I have a need of looping SSH into multiple terminals and run TCL jobs on a hardware, but the loop gets stuck after executing the first SSH.
I search the internet for answers and I am not able to find any. Please help.
There could be a lot issues going on here. Running ssh with an explicit command (pwd) will usually default to not allocating a tty (ssh -T) and will run the remote shell in non-interactive mode. And the output of a command called from exec is not normally echoed to standard output, so I would not expect you to see the output if you call it from a script. You have to print the result of exec to see the output of the pwd command. Also, different shell startup scripts are run on the remote host depending on which shell the account is set up with and whether it is an interactive or non-interactive shell. It could be .bashrc, .bash_profile, .profile, .cshrc, etc., and if the script behaves differently when it has a tty vs. when it doesn't, that could explain differing behavior between a bash/csh shell and the TCL console.
Without having access to your system, it is hard for me to troubleshoot. I would start with a script like this:
set result [exec ssh -T hostname pwd]
puts "result = $result"
puts "Done."
Then I would try changing the -T to a -t and trying again. If the output of "pwd" is appearing before the "result =" line, then you can tell that the command is writing the result to a tty instead of standard output, and that's useful information for troubleshooting.
I want to make a bash script that echo's something into one of the screens that I have running (screen -r is how I get to it in SSH).
I was wondering how I would make the script execute itself in screen -r?
I basically just want the script to say something on a minecraft server through the console and would set up a cronjob to say it every x minutes.
Cheers,
You can use the -X option of screen to send commands to a running screen session.
Also the -p option is useful in this case, as you can use it to preselect a window
As an example you can run a script in a running screen session on windows 0 via:
screen -p 0 -X stuff './fancy_script.sh^M'
Note, that you have to append the return key-code to execute the script.
You can look in /dev/pts. I don't have screen here to test, but you can echo something to an opened terminal with, for example, echo "toto" > /dev/pts/0 (it will be echoed on the first opened terminal).
I want to run a script remotely. But the system doesn't recognize the path. It complains that "no such file or directory". Am I using it right?
ssh kev#server1 `./test/foo.sh`
You can do:
ssh user#host 'bash -s' < /path/script.sh
Backticks will run the command on the local shell and put the results on the command line. What you're saying is 'execute ./test/foo.sh and then pass the output as if I'd typed it on the commandline here'.
Try the following command, and make sure that thats the path from your home directory on the remote computer to your script.
ssh kev#server1 './test/foo.sh'
Also, the script has to be on the remote computer. What this does is essentially log you into the remote computer with the listed command as your shell. You can't run a local script on a remote computer like this (unless theres some fun trick I don't know).
If you want to execute a local script remotely without saving that script remotely you can do it like this:
cat local_script.sh | ssh user#remotehost 'bash -'
It works like a charm for me.
I do that even from Windows to Linux given that you have MSYS installed on your Windows computer.
I don't know if it's possible to run it just like that.
I usually first copy it with scp and then log in to run it.
scp foo.sh user#host:~
ssh user#host
./foo.sh
I was able to invoke a shell script using this command:
ssh ${serverhost} "./sh/checkScript.ksh"
Of course, checkScript.ksh must exist in the $HOME/sh directory.
Make the script executable by the user "Kev" and then remove the try it running through the command
sh kev#server1 /test/foo.sh
How do I execute a command every time after ssh'ing from one machine to another?
e.g
ssh mymachine
stty erase ^H
I'd rather just have "stty erase ^H" execute every time after my ssh connection completes.
This command can't simply go into my .zshrc file. i.e. for local sessions, I can't run the command (it screws up my keybindings). But I need it run for my remote sessions.
Put the commands in ~/.ssh/rc
You can put something like this into your shell's startup file:
if [ -n "$SSH_CONNECTION" ]
then
stty erase ^H
end
The -n test will determine if SSH_CONNECTION is set which happens only when logged in via SSH.
If you're logging into a *nix box with a shell, why not put it in your shell startup?
.bashrc or .profile in most cases.
Assuming a linux target, put it in your .profile
Try adding the command below the end of your ~/.bashrc. It should be exited upon logoff. Do you want this command only executed when logging off a ssh session? What about local sessions, etc?
trap 'stty erase ^H; exit 0' 0
You probably could setup a .logout file from /etc/profile using this same pattern as well.
An answer for us, screen/byobu users:
The geocar's solution will not work as screen will complain that "Must be connected to a terminal.". (This is probably caused by the fact that .ssh/rc is processed before shell is started. See LOGIN PROCESS section from man 8 sshd).
Robert's solution is better here but since screen and byobu open it's own bash instance, we need to avoid infinite recursion. So here is adjusted byobu-friendly version:
## RUN BYOBU IF SSH'D ##
## '''''''''''''''''' ##
# (but only if this is a login shell)
if shopt -q login_shell
then
if [ -n "$SSH_CONNECTION" ]
then
byobu
exit
fi
fi
Note that I also added exit after byobu, since IMO if you use byobu in the first place, you normally don't want to do anything outside of it.