I was wondering if it was possible to execute commands from PHP to a Java prompt which is already running?
I have tried the solution listed here:
How to run a shell command through PHP code?
and this provided no functionality
Let me explain
The java is running on one screen of the linux server
sudo apt-get install screen
and running the .jar file through the command line.
I am then running a webserver, which will have an admin accessibility to restricted areas, which will contain scrips to run specific commands through that already running .jar file?
You can implement some kind of IPC. The java file listens to a port and receives the commands. Or you can write the commands in a specific file which the java programm reads. I think under linux you can also use shared memory: http://www.php.net/manual/en/book.shmop.php
It is possible by sending the command to the screen session. I used this for a minecraft server once.
screen -S <sessionname> -X stuff "<command>\r"
This would (IIRC) provide the same output as if you where inside the screen, typed the command and pressed enter.
I hope this was what you wanted.
Related
So I have a Docker network that has a Docker file with a bunch of information. I have a java program that is going to bring up the enviorment and then produce several commands to run within this enviorment. To be clear, the first command I need to run is NOT inside the Docker enviorment. I am having some challenges with the Process and Runtime classes.
First, say I wanted my java program to launch a new gnome terminal and then run a command to get into the docker network. I have this command,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal"});
Gnome terminal sucessfully comes up but any additional arguments I give in this array are just ignored. For example,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal","ls"});
Does not work. The command I ultimatly want to run would look something like this,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal","sudo","docker","exec","-it","sawtooth-shell-default", "bash"});
Second, Once I have this running, will additional commmands I run work within the Docker enviorment? I have a python file with a Stream handler that specifies the correct commands to run.
Other documentation on related issues was limited.
I made sure my code was wrapped in a runtime exception try catch and that I was running the correct .class file. Any help on this would be great!
Edit: I have also tried to run this in another linux terminal like Hyper and Tilda
I also am able to get a sudo sign in when I run the command like so,
Process process = Runtime.getRuntime().exec(new String[]{"gnome-terminal","--","sudo","docker","exec","-it","sawtooth-shell-default", "bash"});
However it closes immediatly after authorizing.
Okay this is what I was attempting to do.
https://www.atlassian.com/blog/software-teams/deploy-java-apps-with-docker-awesome
This site is outdated and I had to use this link for getting that latest version of the java PPA.
This process basically installs java into the docker contatiner so that I can run a java program that uses Runtime.
Exactly as specified in the title, I'm trying to send data to my ODROID-Show external screen via USB. I'm running a shell script that sends such data. The problem is I can simply run the command through Terminal and it runs successfully and data is sent to my little screen through USB port. When I try to run the same command via Java, Nothing happens.
Process proc = Runtime.getRuntime().exec("/bin/bash -c /home/ahmed/ODROID-SHOW-master/example/linux/images.sh /");
The specified command should have root privileges to run. That, I've switched to root then ran the code and nothing happened. Any thoughts how to solve such problem?
Edit:
IF you can show a code that executes given command prefixed by sudo this will absolutely work.
I was able to run the program as root. but, corrupted data are sent to ODROIDscreen rather than valid images. while it transfers successfully when ran through Terminal, Any thoughts why that happens?
I would check if the script executed by the bash interpreter requires certain environment variables set before execution.
I'd add a debug line in the executed shell script to dump the environment like "env > my_dump_env.txt" then run the script both from command line as well as from Java and do a diff see what is missing or is different.
I have a java program (text-based no GUI) that I have written and compiled and uploaded to a server.
I run it with java -cp myjar.jar mypackage.MyClass which starts it running processing a datafile with 20,000,000+ entries in it and printing output to System.out. I have calculated that it will take a very long time to process the data and I didn't want to have my laptop open for the 10 days of number crunching...
When I log out of my shell however, the process stops.
How can I execute the command and log out without it stopping? What is that even called?
I am using an Amazon Ubuntu EC2 server. I log in using a certificate from Mac OSX with terminal. The server seems to be using a bash shell.
Hope someone can help me out!
Jason.
Consider using screen instead of nohup. It allows you to create a virtual terminal that persists even after you logout/disconnect. When you reconnect to the server, you can immediately jump into the screen session you last had open.
Typical workflow on the server:
type screen (you may need to press space to leave intro page)
type in your command that you want to leave long-running (your java program, or an OS upgrade)
press ctrl a+d to leave screen (make sure to hold ctrl down)
To re-enter screen just use screen -r, and you will see the previous terminal and any running programs as you left it.
You can use nohup
nohup java -cp myjar.jar mypackage.MyClass > yourLogFile.log &
-----> http://ss64.com/bash/nohup.html
I have written a java program with jar file. The java program is to update status of linux server so it need to keep running, but the linux server is in data center, so I need to remote to server to open the program. I use ssh to login linux server. Use command of "java -jar file.jar" to run the program.
However, the java program of the linux server will close if I close the terminal in my computer. Since I cannot keep opening my computer, I wanna know how to open the java programming without holding my computer terminal.
you need to use nohup to keep the program running after you log out.:
server:~name$> nohup java -jar file.jar &
this will keep your program running
Two ways
One
nohup java -jar file.jar &
Another
java -jar file.jar &
In both cases your process will go in background however the process will terminate in the second approach when shell terminates in second case.
If this program is intended to be running on all your machines for monitoring purposes, you should be running it as a service from your server's init system (systemd for most systems these days). You can use the Java Service Wrapper or jsvc or write your own init script.
Another solution apart from the proposed one:
screen -d -m java -jar your.jar
You will then have a detached screen with your java command in it. List with screen -l, reattach with screen -D -RR <screenid_obtained_via_screen_-ls>
I'm writing a Java Swing Application running on Red Hat Enterprise Linux 5 server that I would like to launch jEdit to view log files.
Here is some example code.
public static void main(String[] args) throws IOException, InterruptedException {
String cmd = "sh -c \"java -jar /tmp/jEdit/jedit.jar /tmp/test.txt\"";
System.out.println(cmd);
Runtime.getRuntime().exec(cmd);
}
The output is:
sh -c "java -jar /tmp/jEdit/jedit.jar /tmp/test.txt"
If I copy and paste the cmd output in a terminal window, it runs fine.
I have tried a bunch of cmd values, but I can never get the jEdit window to be visible.
With changes, this process works fine on Windows.
Is what I'm doing possible on Linux?
Thanks in advance!
As jEdit is implemented in Java, perhaps it would be easier to check the source for what the main method (in the class declared in the manifest file included in the jedit.jar) does and do the same thing without using Runtime.getRuntime().exec() at all.
If you do want to stick with it, you could try passing the individual commands as an array to exec(), this often solved such problems for me.
Linux uses the concept of display ports for its X-Windows system. This allows it to maintain a different desktop environment for each user. It also allows a user on remote machine to run a desktop app from the first machine but see the UI on the remote.
Windows, having only one available desktop environment at a time, does not.
First thing you definitely have to do is add the environment variable "DISPLAY=localhost:0" to the environment from which you are launching this. However, you may also need to run 'xhost +localhost' or this may not be allowed.
Double-check, too, that you didn't successfully launch a bunch of jEdit processes that are now zombies (using top) and kill them if necessary (using kill).
Runtime.exec() needs some special attention. The exec method that accepts a String uses the space character as a delimiter to break up the string into commands. You need to use the exec method that accepts a String[]. Read more here, specifically near the bottom.
I´ve done this once and I got the same problem
What I've done is to write the command line into a text file and then execute the text file as a shell script file.
It worked fine for me.
Jedit has a launcher script, /usr/bin/jedit I guess. Simply typing jedit in command prompt runs it, at least in current version, 4.5. Try that script instead of explicit java command.