Sending commands to server via JSch shell channel

Question

I can\'t figure it out how I can send commands via JSch shell channel.

I do this, but it doesn\'t work:

JSch shell = new JSch();
String command = \"c         


        

Answer 1

Following was a quickly written code for my assignment. Not a well done program. But serves its purpose.

1. Connects via SSH (using Jsch) to a server (using a Private Key File - mykey.pem)
2. Creates a shell script (to mount a volume and mkfs)
3. Runs on the remote machine
4. All the while you can see the output on your stdout

The code follows:

public class connectSSH {

public void connect(String dnsName, String privKey) throws IOException {
    JSch jSch = new JSch();

    try {

                    //Authenticate through Private Key File
        jSch.addIdentity(privKey);
                    //Give the user and dnsName
        Session session = jSch.getSession("root", dnsName, 22);
                    //Required if not a trusted host
        java.util.Properties config = new java.util.Properties(); 
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        System.out.println("Connecting SSH to " + dnsName + " - Please wait for few minutes... ");
        session.connect();
            //Open a shell 
        Channel channel=session.openChannel("shell");
        channel.setOutputStream(System.out);
            //Create a Shell Script
        File shellScript = createShellScript();
            //Convert the shell script to byte stream
        FileInputStream fin = new FileInputStream(shellScript);
        byte fileContent[] = new byte[(int)shellScript.length()];
        fin.read(fileContent);
        InputStream in = new ByteArrayInputStream(fileContent);
            //Set the shell script to the channel as input stream
        channel.setInputStream(in);
            //Connect and have fun!
        channel.connect();          

    } catch (JSchException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

public File createShellScript() {
     String filename = "shellscript.sh";
     File fstream = new File(filename);

     try{
          // Create file 
         PrintStream out = new PrintStream(new FileOutputStream(fstream));
         out.println("#!/bin/bash");
         out.println("echo \"hi\" > /tmp/test.info");
         out.println("echo \"n\" > /tmp/fdisk.in");
         out.println("echo \"p\" >> /tmp/fdisk.in");
         out.println("echo \"1\" >> /tmp/fdisk.in");
         out.println("echo >> /tmp/fdisk.in");
         out.println("echo >> /tmp/fdisk.in");
         out.println("echo \"w\" >> /tmp/fdisk.in");

         out.println("/sbin/fdisk /dev/sdf < /tmp/fdisk.in");
         out.println("mkfs.ext3 /dev/sdf1");
         out.println("mkdir /usr/myebs");
         out.println("mount /dev/sdf1 /usr/myebs");
         out.println("partprobe /dev/sdf1");

         out.println("echo \"Success\"");

         //Close the output stream
         out.close();
     }catch (Exception e){//Catch exception if any
         System.err.println("Error: " + e.getMessage());
     }
     return fstream;

}

public static void main(String[] args) {
    connectSSH ssh = new connectSSH();
    String privKey = "/Users/neo/Desktop/mykey.pem";
    try {
        ssh.connect("yourexampleserver.com", privKey);
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

}