I need to access and run Linux commands on a remote CentOS machine through Java code. Please suggest me any API to access run the commands and also I need to get the output of the commands to be printed on the Java console.
Check out JSch - it allows you to connect via SSH, execute commands remotely and transfer files.
You can use Java ProcessorBuilder and Process classes to start an ssh process that executes remote command i.e. start an ssh process (e.g. ssh username#REMOTE_MACHINE 'CMD_ON_REMOTE_MACHINE') and read the output of the executed command using getInputStream() method of Process class.
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I wanna programmatically (using Java's Runtime.exec) open Putty on my system and connect to a remote linux system. Is there any syntax to pass Putty private key to the method runtime.exec and connect successfully. I am getting "Access Denied" error on the remote system if I just pass the username and pass-phrase and try to connect.
I am assuming by your comments that you are trying to actually run some commands on a linux server, like
find /some-directory/ -type f -ecec grep -Hnw this-word {} ";"
via bash or other shell as opposed to rcp.
If yes then stop using putty, that is an interactive client for you to login to a remote server and interact with the connected shell.
I would suggest that you would be far better off using something like jssh, assuming it is still a current library.
With that you get fine control of the interaction flow with the remote server and iirc it supports private/public keys.
I have a machine that runs batch scripts over ssh on windows machine using open ssh and cygwin (copssh)
I'm looking to change this mechanism since this tool requires configuration where many mistakes can be made.
I will also need to collect the results of the script
Any ideas on how it can be done?
Thanks
You can use RMI and on the remote side just use Runtime.getRuntime().exec
I am running a process on a remote linux machine through java. I need to retrieve each line of processing in a string in my java code during runtime. How do I achieve this?
I am currently using sshxcute-1.0 jar inorder to connect to my remote machine and run my commands. It has a method Result.sysout which returns the entire console of the processing on my remote machine as a string. But this happens only after the entire process concludes.
I would like to retrieve each and every line of processing as it happens during runtime without closing my connection with the remote machine. Is it possible?
I am trying to make a terminal emulator in Java. The java program will accept the commands from user, and show its output to them. I can emulate simple commands like 'ls', but I don't know how to handle commands like 'cd'. This is because, I am using exec() method for executing terminal commands. So, all the commands are executed at current directory. The commands like 'cd ..' are executed, but then they have no persistent effect, because each command is separately executed by exec().
Any Ideas How I can emulate a whole session??
If you are executing commands with exec(), you are not writing a terminal emulator; you are writing a shell. In that case, you will need to keep track of things the shell keeps track of, like environment variables and working directory.
If you really want to write a terminal emulator, you would be talking to a shell process through a pseudo-terminal. Then your program would just be keeping track of the things a terminal keeps track of, like the line state and what appears on the screen.
Working with a pseudo-terminal from Java will be a little tricky, because most of the documentation assumes you are using a C api. man pty should get you started. Your Java process will have to open the master side of the pseudo-terminal with FileStream objects. I'm not sure there is a way within Java to get a child process to open the slave side of the pseudo-terminal; you might have to invoke a shell command with exec() that starts another shell command with standard input/output/error redirected to the slave side of the pseudo terminal.
JSch is a pure Java implementation of SSH2.
JSch allows you to connect to an sshd server and use port forwarding, X11 forwarding, file transfer, etc., and you can integrate its functionality into your own Java programs.
http://www.jcraft.com/jsch/
You should really give a try to Ganymed.
Ganymed SSH-2 for Java is a library which implements the SSH-2
protocol in pure Java (tested on J2SE 1.4.2 and 5.0). It allows one to
connect to SSH servers from within Java programs. It supports SSH
sessions (remote command execution and shell access), local and remote
port forwarding, local stream forwarding, X11 forwarding, SCP and
SFTP.
http://www.ganymed.ethz.ch/ssh2/
Ganymed along with apache FTP client you can also download and upload files.
Also there is a inbuilt example code for terminal emulation in Ganymed.
The following is a link to a project which is did using Ganymed along with apache FTP client.
GITHUB
Happy Coding!!
How to execute a batch file located on Windows remote system? Batch file should run on remote system.
Abhinav,
For your problem I see RMI is the quickest possible solution
Check out the basics from these links (1,2)
Start the server from where you want to run the batch
In the Remote object on the server side Use Runtime.getRuntime().exec() to run your batch.
From the client machine give call to this remote object and method.
Another approach is to use SSH like sshj. This only requires the remote system to have SSH installed and is more secure than RMI.
You can use Jsch and Expect4j for executing commands on remote machine(window/Linux). Further more, if your system allows, transfer the batch file on remote machine using some FTP utility like Apache Commons Net and then execute commands that executes the script.