Java

SSH Remote Shell Multiple Commands

See more SSH Examples

Demonstrates how to start a shell on a remote SSH server, run a command, and retrieve the output, then run the next command, retrieve the output, etc. Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkSsh ssh = new CkSsh();

    // This is the prompt we'll be expecting to find in
    // the output of the remote shell.
    String myPrompt;
    myPrompt = "chilkat@ubuntu:~/workspace$";

    String cmdOutput;

    // Connect to an SSH server:
    String hostname;
    int port;

    // Hostname may be an IP address or hostname:
    hostname = "www.some-ssh-server.com";
    port = 22;

    success = ssh.Connect(hostname,port);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Wait a max of 10 seconds when reading responses..
    ssh.put_IdleTimeoutMs(10000);

    // Authenticate using login/password:
    success = ssh.AuthenticatePw("myLogin","myPassword");
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Open a session channel.  (It is possible to have multiple
    // session channels open simultaneously.)
    int channelNum;
    channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    String termType = "dumb";
    int widthInChars = 120;
    int heightInChars = 40;
    // Use 0 for pixWidth and pixHeight when the dimensions
    // are set in number-of-chars.
    int pixWidth = 0;
    int pixHeight = 0;
    success = ssh.SendReqPty(channelNum,termType,widthInChars,heightInChars,pixWidth,pixHeight);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Start a shell on the channel:
    success = ssh.SendReqShell(channelNum);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  Run the 1st command in the remote shell, which will be to
    //  "cd" to a subdirectory.
    success = ssh.ChannelSendString(channelNum,"cd workspace\r\n","ansi");
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Retrieve the output.
    success = ssh.ChannelReceiveUntilMatch(channelNum,myPrompt,"ansi",true);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  Display what we've received so far.  This clears
    //  the internal receive buffer, which is important.
    //  After we send the command, we'll be reading until
    //  the next command prompt.  If the command prompt
    //  is already in the internal receive buffer, it'll think it's
    //  already finished...
    cmdOutput = ssh.getReceivedText(channelNum,"ansi");
    if (ssh.get_LastMethodSuccess() != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.println(cmdOutput);

    //  Run the 2nd command in the remote shell, which will be
    //  to "ls" the directory.
    success = ssh.ChannelSendString(channelNum,"ls\r\n","ansi");
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Retrieve and display the output.
    success = ssh.ChannelReceiveUntilMatch(channelNum,myPrompt,"ansi",true);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    cmdOutput = ssh.getReceivedText(channelNum,"ansi");
    if (ssh.get_LastMethodSuccess() != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.println(cmdOutput);

    //  Start the final command in the remote shell.  This example
    //  will send a "ls -l" command to retrieve the long format directory listing.
    success = ssh.ChannelSendString(channelNum,"ls -l\r\n","ansi");
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Send an EOF.  This tells the server that no more data will 
    // be sent on this channel.  The channel remains open, and
    // the SSH client may still receive output on this channel.
    success = ssh.ChannelSendEof(channelNum);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Read whatever output may already be available on the
    // SSH connection.  ChannelReadAndPoll returns the number of bytes
    // that are available in the channel's internal buffer that
    // are ready to be "picked up" by calling GetReceivedText
    // or GetReceivedData.
    // A return value of -1 indicates failure.
    // A return value of -2 indicates a failure via timeout.

    // The ChannelReadAndPoll method waits
    // for data to arrive on the connection usingi the IdleTimeoutMs
    // property setting.  Once the first data arrives, it continues
    // reading but instead uses the pollTimeoutMs passed in the 2nd argument:
    // A return value of -2 indicates a timeout where no data is received.
    int n;
    int pollTimeoutMs = 2000;
    n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs);
    if (n < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Close the channel:
    success = ssh.ChannelSendClose(channelNum);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Perhaps we did not receive all of the commands output.
    // To make sure,  call ChannelReceiveToClose to accumulate any remaining
    // output until the server's corresponding "channel close" is received.
    success = ssh.ChannelReceiveToClose(channelNum);
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    cmdOutput = ssh.getReceivedText(channelNum,"ansi");
    if (ssh.get_LastMethodSuccess() != true) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.println(cmdOutput);

    // Disconnect
    ssh.Disconnect();
  }
}