Simple question: Is there a way to run a script in the background with out terminal running?
More detail and background: I had an app that read an apps .log file and puled information from it, then provide information and statistics from the information in the log.
An update to the app changed the way the .log file was written and delete information and duplicates the log in a manner that i have been unable to predict.
the app that was designed to interface with the log was not coded to check for such changes. so when it attempts to gather information after the log change it stops working.
A "hack" has been devised to run a tail -f, then hexed the app to point at the new file.
(The "hack" works)
I would like to run the tail in the background so that the user doesn't interrupt it... breaking it...
-sorry for the (possibly) longer than needed description. BUt i figured a more detailed question would get me a precise answer.
Thanks in advance!
~¥oseph
The answer depends on if you need to be able to re-connect to the process after exiting the shell. If the process is non-interactive and can simply be left alone, then "nohup program &" should do the trick. But that won't let you continue to interact with the program after you've closed the shell.
If it's a interactive program, then your best bet is to use screen or one of the other terminal-multiplexers. You start "screen" which gives you a new shell, in this you start whatever program you want, the usual way, say "nano myfile.txt".
When you want to close the shell, but leave the program running, you press C-a d ('Detach') to detach from screen. it keeps running, but in the background, and will keep running even if you log out.
When you then later want to reconnect to screen you open a new shell and type "screen -r" (reconnect), this leaves you right where you where.
Screen also lets you run several different shells in a single terminal-window and is a neat tool overall. Check it out.
Related
I know this question looks like dozen of others: but, I am trying to get insight into why this script acts the way it does and if there is any draw back to it like memory leak or other.
The script its simple:
cd "C:\me\python\.venv" && start C:\me\python\.venv\env\Scripts\activate
There is a windows that opens briefly then closes then another command window opens with the virtual environment open as I need. This question is not about the virtual environment in any way. I am trying to understand the command window.
It seems buggy that a command window opens to change directories then closes and then another opens the virtual environment in another window. I can live with this I guess until I run across a seemless way to do this; but, isn't there a better way to do this?
Is the window opening then closing the behavior of the command prompt when changing directories? No! The script could be written simply as:
start C:\me\python\.venv\env\Scripts\activate
and there is still an occurence of a window opening prior to the window with the virtual environment started.
Is there any after affects from doing it this way, like background process open or memory leak or what have you?
Anyone know where to read the "readme" on this behavior?
Thank you much!
Use this code:
cd "C:\me\python\.venv" && C:\me\python\.venv\env\Scripts\activate
the start command is not necessary and that's what opens one more window and lets the previous one close.
This command create a new windows asynchronously.
I need script which works in the background, waiting for a key to be pressed. I have a script which works when terminal is on. When I try to use & - it's not working correctly. The script works in background but keypress doesn't do anything. When I try use nohup then I have error of read - bad descriptor.
Can someone help me?
When the terminal is on (and is selected, in case of a terminal emulator running on x server), the input (key strokes, etc.) is directed to the terminal; hence, your program works.
Now, consider an example: let's say that you created a script that runs on the background, and it is activated by pressing the letter "a". If pressing "a" triggered your script (with terminal closed), then the user would never be able to (for example) type the letter "a" in a word document or a web search without triggering the script!
Therefore, what you are looking for is a key bind, or a keyboard shortcut, which would bind a key (combination) such as ctl+j+k to launch the script you want.
In Linux, that can be done somewhat easily, see this for Ubuntu or this for Lubuntu.
Important: if your script needs to be root to work, then you generally will have to evoke it via gksu or gksudo, otherwise it will not run
Here I want to ask you to help to bring the console window top most with a shell command. Is it possible?
there was a script execution in my work environment, and will take about several minutes to complete, I will move to other work while running, it is better there are some tips to notify me when script completes run.
So I think bring the window top most is the most direct way.
Please tell me how to achieve this, I'm working on windows, new to MacOS.
Thanks,
Levi
I don't know how to bring the console window to the front, but if you're working in the terminal, you could do something like:
$ path/to/script ; tput bel
or
$ path/to/script ; say "script 1 is done"
Where path/to/script is whatever your usual method of loading the script is.
I recommend the first method, as it flashes the screen, makes a beeping noise, and causes the terminal icon to bounce up and down on my dock in OS X 10.10. The second might be better if you need to figure out which script is done from among a bunch of scripts. If you have coworkers who you don't want to disturb, you can change the preferences in terminal so that an alert only flashes the screen and doesn't also make a noise.
If you have access to the source code of the script, you can also add tput bel or say "command" to the last line of the script and you'll get the same behvaior.
I'm new to programming and have taken some classes in it so I'm not sure if this is possible. I want to use a COTS software called 010 Hex Editor and write a script for the program to automate a couple tasks. These tasks can be run from a batch file according to their documentation.
Then I want to instruct the user to eject the device and reinsert it to clear the cache. (This I want done just with a simple pop-up window.
Then I also want to format the device which I assume can be done in a batch file as it can be done through dos on Windows.
My question is, with these 3 steps, can I build a simple GUI that has a button that says, "Start" or something like that, then the pop up window comes up to eject and reinsert, and then another button to format, and another button to exit. I'm not really familiar with what language this could be done in, and how to do this as the C++/Java classes I've taken have been more about syntax and OOP. Thanks!
You can use the windows messenger service to put up an alert - but on newer windows (vista/7) it's a pain to set all the permissions to allow this.
There are lots of free utilities that will popup a dialog from the command line, with a given message and wait for a response.
They are generally called messagebox or msgbox - sorry can't recommend any in particular
I'm running MATLAB (command line version) from a shell script, and I'd like it to preserve shell behavior where if you press Ctrl-C it exits. But instead it wants to keep control of the terminal and I (or my poor users after me) have to type quit(1) to make it quit and tell the shell it failed.
You can't intercept Ctrl-C with a try/catch block... any other ideas? Anything I could do from the shell side to intercept the keystrokes before they get to MATLAB?
onCleanup seems like an option, but then I'd have to make the whole script thing into a function (it's already a dynamically generated try/catch block thing in a Makefile). But if that's the only thing that will work, then I'll do it...
Use onCleanup:
I wanted to do the same thing but after I read this thread I used onCleanup successfully. My problem was I had a server in Matlab that when pressing CTRL+C would keep listening on the port it was started on -> second run I would get a bind error.
You can try:
stty quit ^C
but I have no matlab to test it.