Provide multiple lines of input to command executed on SSH server with JSch

Question

I have a situation where a another pop like password is appearing, Means I need to enter another text after password and I also need to handle it programmatically.

below code is working for password

((ChannelExec)channel).setCommand("cd ~demouser/bin;ls; echo demouser | pbrun democommand");

echo does work for me to enter the password. But just after it I need to enter text just like password and I am not able to do so. so I put an another echo with pipe, but it is not working.

Code I am using for same

((ChannelExec)channel).setCommand("cd ~demouser/bin;ls; echo Automation |  echo demouser | pbrun democommand");

I also tried below refernce and wrote the command as below, still no luck

pipe password to sudo and other data to sudoed command

((ChannelExec)channel).setCommand("cd ~demouser/bin;ls; echo Automation |  { echo demopass; } | pbrun democommand");

Reference screenshot:

Code I am using:

try {
            JSch jsch = new JSch();
            Session session = jsch.getSession(user, host, 22);
            Properties config = new Properties();
            config.put("StrictHostKeyChecking", "no");
            session.setConfig(config);;
            session.setPassword(password);
            System.out.println("user=="+user+"\n host=="+host);
            session.connect();
            System.out.println("connected to host ===="+host);
            String sudo_pass="demopassword";

        Channel channel=session.openChannel("exec");


        System.out.println("cd command");
        ((ChannelExec)channel).setCommand("cd ~demouser/bin;ls; ( echo demopassword && echo Automation )  | pbrun democommand");
        ((ChannelExec) channel).setPty(true);

        InputStream in=channel.getInputStream();
        OutputStream out=channel.getOutputStream();
        ((ChannelExec)channel).setErrStream(System.err);

        channel.connect();

        out.write((sudo_pass+"\n").getBytes());

        out.flush();

        byte[] tmp=new byte[1024];
        while(true){
          while(in.available()>0){
            int i=in.read(tmp, 0, 1024);
            if(i<0)break;
            System.out.print(new String(tmp, 0, i));
          }
          if(channel.isClosed()){
            System.out.println("exit-status: "+channel.getExitStatus());
            break;
          }
          try{Thread.sleep(1000);}catch(Exception ee){}
        }

        channel.disconnect();
        session.disconnect();
      }
      catch(Exception e){
        System.out.println(e);
      }
}

Any workaround will be helpful

Martin Prikryl · Accepted Answer · 2018-05-29T10:32:14.533

1

Bash syntax for providing two lines of an input to a command is:

( echo input1 && echo input2 ) | command

See also Pipe multiple commands into a single command.

You can also provide the input in your Java code rather than using shell constructs:
Providing input/subcommands to command executed over SSH with JSch

edited May 29 '18 at 10:32

answered May 29 '18 at 10:23

Martin Prikryl

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Shubham Jain · Answer 2 · 2022-06-30T05:04:57.910

Thanks to Martin below approach works for me

( echo 'command1' && echo 'command2' ) | command

Below code works for me

try {
        JSch jsch = new JSch();
       Session session = jsch.getSession(user, host, 22);
       Properties config = new Properties();
       config.put("StrictHostKeyChecking", "no");
       session.setConfig(config);;
       session.setPassword(password);
       System.out.println("user=="+user+"\n host=="+host);
       session.connect();
       System.out.println("connected to host ===="+host);
       String sudo_pass="demo123";

   Channel channel=session.openChannel("exec");


   System.out.println("cd command");

   ((ChannelExec)channel).setCommand("cd ~demouser/bin;ls; ( echo 'echo Automation' && echo 'command' )  | pbrun democommand");
   ((ChannelExec) channel).setPty(true);

   InputStream in=channel.getInputStream();
   OutputStream out=channel.getOutputStream();
   ((ChannelExec)channel).setErrStream(System.err);

   channel.connect();

   out.write((sudo_pass+"\n").getBytes());
   out.write(("\n").getBytes());

   out.flush();

   byte[] tmp=new byte[102400];
   while(true){
     while(in.available()>0){
       int i=in.read(tmp, 0, 102400);
       if(i<0)break;
       System.out.print(new String(tmp, 0, i));
     }
     if(channel.isClosed()){
       System.out.println("exit-status: "+channel.getExitStatus());
       break;
     }
     try{Thread.sleep(1000);}catch(Exception ee){
         ee.printStackTrace();
         System.out.println(ee.getMessage());
     }
   }
   channel.disconnect();
   session.disconnect();
 }
 catch(Exception e){
   System.out.println(e);
 }
}

Dependency Used:

    <dependency>
        <groupId>com.jcraft</groupId>
        <artifactId>jsch</artifactId>
        <version>0.1.50</version>
    </dependency>

Provide multiple lines of input to command executed on SSH server with JSch

2 Answers2