I am currently running a python3 script in Ubuntu server 18.04. When i type new commands into the command line it just prints the commands. My terminal window looks like this:
mitch#server:`$ cd /home/mitch/folder
mitch#server:`/folder$ python3 main.py
file running ...
text i input just shows like this
I need to keep the script running and run other commands, how do i navigate back to:
mitch#server:`
I'm new to servers/Ubuntu/commands so this may seem trivial! Thank you
So you can't "navigate" back to that, since you're technically already there, you're just running a script in your shell which is occupying your shell - think of it like you opened a program in full screen.
But you have a few options:
The most basic is to run the script in the 'background' this is a simple as adding a & to the end of your command (note that it will still send any message from the script into your terminal - if your script is programmed to send messages that is).
Another option is to use a terminal multiplex like which lets you have multiple terminals open, as well as split screen terminals and many other features. One of the more popular multiplexers is called tmux, just keep in mind that it does have a bit of a learning curve to it, but is extremely useful once you learn it.
Related
I'm coding a Rust app and since it's fairly small and there don't appear to be any stable UI frameworks, I've made it run in the console using println! and whatnot for input/output. However since this program is intended to be used by people directly after downloading from the internet (due to its use case), they're likely to just double click on it instead of navigating to their downloads directory in a terminal and running it from there.
This is a problem because on Linux, it runs in the background waiting for input and looks like it's not working. On Windows, Rust programs do open in CMD by default. (and in fact many of the search results for my question were about disabling this behavior - the exact opposite of what I want!).
So is it possible to somehow make my application open in the system's default terminal? My preferred way would be to somehow embed in the executable to open in terminal (similar to the -mconsole compiler flag on MinGW). Otherwise would it be possible to detect it's in the background and fork it into a terminal? If that's not possible then is it at least possible to detect that the app is not running in a terminal and throw up a message box telling the user to run in a terminal?
My app is cross-platform but I'm OK with writing code conditionally compiled on one OS.
One typical way would be to distribute a program.sh along with your executable. If .sh extension is bound to opening a terminal in their window manager of choice, it would open automatically. If not - it is enough of a hint for running it from the shell.
Without this file you could:
Detect if the program is already running inside a terminal can be done with isatty(). There's a crate for it.
If not, spawn the terminal app process (see process::Command) and relaunch the program with it by passing its path to the terminal command line options. As #Caesar mentioned there's a bunch of popular terminals that you might want to check for presence on Linux. If nothing is found, xterm could sometimes be a fallback.
I have a python script that takes some inputs from the user & then executes the code based on the input. The code takes some time to complete; during this code runtime the user can close the terminal(the code is run from a Linux machine)
As soon as the user closes the terminal the script stops as well. I know there are options like nohup but it wouldn't accept any input(where input is required in my script).
How can I fix this?
Requirement is -
Run the script, enter the inputs
Let the code run in the background even if the terminal is closed
Also is there a way to write whatever is being printed in the terminal(during the script runtime) to some file
Linux's screen tmux served my purpose.
There is a work around possible,
you can split your programm into two parts.
And start your background task with:
import os
usr_inp=input("test input: ")
os.popen(f"python3 background_task.py {usr_inp} &")
This should start the other programm in the background, there you can use the input over the sys.argv[1] variable.
(Usually it's not recommended using os.popen)
I just ran a script on a server that generates a lot of output on the command window.
However, now, after running it for roughly 4 hours I want to check all the output, but the beginning of the output has already disappeared from the terminal window. When I scroll up, it is not there anymore.
Is there any way to access this? It needs to be via commands in the terminal because I'm running it on a server.
Thanks.
Best way is to redirect the output to a file & open the file to check for all the output.
You can also redirect the script by running it in background & saving the output to a file. Do let me know what type of command you are running for which I can give you the exact command. :)
if it's a real terminal and not a virtual terminal
you need to recompile your kernel and increase the buffer size of your terminal.
in the .config file of your kernel the parameter you need to increase is
CONFIG_VGACON_SOFT_SCROLLBACK_SIZE
Actually, redirecting I/O interferes with many programs (for instance, changing the output from a tty to a plain file). Use the script program to capture all output from programs run in a shell, with minimal interference.
I have to connect to a linux server from my own Ubuntu machine and operate directly on the server.
A dozen of folder names are listed in a LIST file. How to write sth. (like a bash script?) to carry out the following procedures?
for fold_name in LIST {
/******on my own Ubuntu*******/
-- open 2 new tabs of prompt terminal
-- run an ssh command in both
-- then input passwd and log in automatically in both
/******on the linux server*******/
-- cd to directory xxx/fold_name in both
-- run aaa.exe in 1st tab
-- vim sth in the 2nd tab
}
Once the loop of open-tab-login is solved, I guess the second part is routine as simple bash script except that I don't know how to specify between 2 tabs, either.
The point is I want all tabs in the same terminal. To this end, manually, I often Ctrl+Alt+T to create a prompt and Ctrl+Shift+T to open many tabs within it. And ssh...cd...... in each one. You see how annoying and cumbersome it is!
There are a few things you might like to research, which will get you a little closer.
You can run an ssh without a password, if you use an ssh key. Check out ssh-keygen, and the -i option in ssh.
Opening up tabs in gnome-terminal can be done via the method described here: Open a new tab in gnome-terminal using command line
You can run specific commands (e.g. aaa.exe) on a remote box over ssh, by including the command after the ssh: ssh user#remotehost aaa.exe.
If you want multiple commands, try enclosing them in quotes: ssh user#remotehost "cd /xxx; aaa.exe". Vim does not need to be in the directory in question in most cases: ssh user#remotehost vim /xxx/filename"
If you want to do something interactive (like vim), include the -t flag in ssh.
The tabs will be independent of each other - I'd probably run half of the command in one window, the other (e.g. runnning aaa.exe in one window, using one command, and the vim in another window, using another command, that I just happen to run at the same time. This way I can resize the windows, and arrange them relative to each other, and see both at once.
-- open 2 new tabs of prompt terminal
This depends on which desktop you're using. For gnome, gnome-terminal takes the -e option to specify the script to execute in the new terminal window. So, for something like this, you would execute gnome-terminal -e $script &, placing each instance of gnome-terminal in the background.
If you're using a different desktop, other terminal applications typically have a similar option. So, you'd point the terminal application to a script that's going to run in the terminal, and complete the rest of your task for you.
-- run an ssh command in both
-- then input passwd and log in automatically in both
This is going to be more complicated. The classical solution is the expect utility. There might be other similar tools that do similar things, but expect is pretty much the usual way these kinds of things have been done in the past. When it comes to trying to automate an interactive application, expect is really the only way to go. Unfortunately, expect uses a somewhat arkane syntax, that first-time users typically find confusing, and hard to understand. I grumble, every time I see no other alternative but to use expect to automate something, but this is pretty much the only option that's usually available.
I am trying to fully automate my simulation scripting under Linux. Currently, I manually click open a terminal, enter the commands to get the simulation running, click open another terminal, and do the similar things.
What I have done so far is having multiple shell scripts, each of which opens one terminal and does the stuff. Despite having little experience with shell script, I believe this can be automated with one single shell script.
How may I open multiple terminal windows and do different stuff in those terminals from one single shell script?
If you want to execute your commands/scripts in sequence, just write them in a file, each per line, then bash theFile
if you want to start/run a number of job in parallel, you may want to check this out: http://www.gnu.org/software/parallel/
If you want to start/run commands in different terminal but you don't want to manually "click". tmux/screen would be your friend. with tmux, you can define when it starts, open how many windows/panes, and in each window/pane which command should be fired.
tmux link: http://tmux.sourceforge.net
P.S. tmux is very handy tool, I work everyday with it. It is must-have tool 4 me.