I'm fairly new with Linux shell scripting but have several years experience using Linux(non-hardcore).
There is an application running on my server(accessing it through SSH/putty) which is a console one. In order to ensure that it will run even even if I close my ssh client(putty), I made it run though screen.
In my script, there is a part where I want to enter this specific screen and "leave a message", then leave the screen to proceed with other things it have to perform.
How to do it exactly? Thanks!
(the console application is actually a vanilla Minecraft server)
check out 'screen' window manager http://www.gnu.org/software/screen/ with session names, see the following article:
http://www.mattcutts.com/blog/a-quick-tutorial-on-screen/
Related
creation of a website through which can access Linux server and where can execute some operations like executing scripts, firing up some commands. need some expert guidance with some concepts.just guide me how can i achieve through, i have goggled a lot unable to get the proper concepts or methods. or is it even possible.
Have you considered using something along the lines of VNC or SSH? As JNevill pointed out, either of these methods would be infinitely more secure. Also, consider using something like cron for scheduled jobs.
However, sometimes a webpage for running a program on a server may be acceptable. e.g. IoT project. To do this, you would setup an API page using a back-end language like PHP (recommended if you're using Linux). In the back-end language you would check your user credentials, and then run the command.
Some guidelines in doing this:
Never allow commands to be entered on the webpage, only allow tasks to be completed using controlled inputs like buttons, selectboxes and sliders. i.e. a button to get an Arduino to close your garage door, or a slider to dim/brighten a light bulb, or a button to start a program to index something, etc.
None of these "command buttons" should ever do anything harmful. i.e. delete a folder or file.
How to realize that?
I need to run a crontab task. At some time, there will be a pop-out window to remind me doing something.
If I input yes in that window, that task will be done, while if no,nothing will happen
Crontab just does things in background. How to interact with it?
I could use, say
echo 'good' >/dev/pts/1
However tty1 does not exists necessarily.
Use zenity and make sure to set the DISPLAY environment variable to :0.0 when executing zenity from within the crontab as this is necessary to start GUI apps on the X server.
The usual division of labor for a problem like this is to divide the code into a server component and a client component. The server runs in the background, detached from your interactive session, and does any actual work, whilst listening for client connections. You run the client from your GUI, either interactively or as part if your GUI session, and it performs any user interactions and communicates your inputs to the server.
I need to get list of all apps which I use most.
I do not want ps aux or top etc.
Need to make a shell script which will show frequently used apps of all time like google chrome , firefox , gedit etc.In this list need to show apps which I have opened , but not those which is default opened by OS
If possible, I want to list down running time of app, idle time.I have Fedora and Ubuntu.So no issue with OS.
Please suggest me some commands, to fulfill my purpose.
Use lastcomm to prints out information about previously executed commands. If
no arguments are specified, lastcomm will print info about all of the
commands in acct (the record file).
Just enable process accounting in your system. There are a lot of information about that over the Internet.
Due to some reason, I have to use "setsid" to run all of my commands.
But, when running "setsid scp ~/aaa user1#10.170.3.17:/tmp/", a dialog box requesting for password arose.
Normally, the prompt arises in command line.
Does it caused by some configuration in ssh?
I want to eliminate the box. How to achieve it?
One of the effects of the setsid command is that process that is started via setsid(1) is detached from it's controlling terminal. Without controlling terminal, scp cannot ask for the password on the terminal from which it was started simply because it does not "see" any. However, what it does "see" is the environment variable telling it that there is an X11 window session where it can show a graphical utility to ask you for the password or passphrase needed to unlock the private SSH key which will be used to authenticate to the remote system.
Even if you would unset the environment variable that it "sees" and uses it to route the x11-ssh-askpass dialogue to your screen (DISPLAY), that would probably not produce the desired effect for you, since required key would be missing and scp operation would fail.
One of solutions that I would recommend here would be setting up a "passwordless" login (if applicable in given security circumstances), using ssh-keygen(1) to produce "identity keys" that will not be password-protected.
You might explore other possibilities, for example providing passphrase in a file or on command line option, whatever works better for you. Please have a look in the ENVIRONMENT section of ssh(1) manpage.
Sorry about the really ambiguous question, I really have no idea how to word it though hopefully I can give you more detail here.
I am developing a project where a user can log into a website and book a server to run a game for a specific amount of time. When the time is up the server stops running and the players on the server are kicked off. The website part is not a problem, I am doing this in PHP and everything works. It has a calendar system to book a server and can generate config files based on what the user wants.
My question is what should I use to run the specific game server on the linux box with those config files at the correct time? I have got this working with bash scripts and cron, but it seems very un-elegant. It literally uses FTP to connect to the website so it can download all the necessary config files and put them in a folder for that game and time. I was wondering if there was a better way of doing this. Perhaps writing a program in C, but I am not sure how to go about doing this.
(I am not asking for someone to hold my hand and tell me "write this code here", just some ideas of a better way of approaching this problem)
Thanks so much guys!
Edit: The webserver is a totaly different machine. I would theoreticaly like to have more than one game server where each of them "connects" (at the moment FTP) to the webserver, gets a file saying what it has to do at a specific time and downloads any associated files then disconnects.
I think at is better suited for running one time jobs than cron.
For a better approach for the downloading files etc, you should give more details on your setup (like, the website and the game server, are they on the same machine? Or the same network? etc etc.
You need a distributed task scheduler. With that, you can:
Schedule command "X" to be run at a certain time.
Specify the machine (or ask it to pick a machine from a pool of available machines)
Webserver would send request to this scheduler via command line or via web service when user selects a game server and a time.
You can have a look at : http://www.acelet.com/super/SuperWatchdog/index.html
EDIT :
One more option :http://jobscheduler.sourceforge.net/