(Java) Multiple SendReqExec on Same Connection

Shows how to execute a series of commands on an SSH server and retrieve each command's output (using SendReqExec). Each call to SendReqExec requires its own logical channel. This is not a separate SSH connection -- it's simply a new session channel on the existing SSH connection.

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

    CkSsh ssh = new CkSsh();

    // Hostname may be an IP address or domain:
    String hostname = "172.16.16.46";
    int port = 22;

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

    // If receiving output from a command stalls for more than 5 seconds, then stop waiting.
    ssh.put_IdleTimeoutMs(5000);

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

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

    // Request a directory listing on the remote server:
    // If your server is Linux/UNIX, change the string from "dir" to "ls"
    // Note: Some SSH servers require a CRLF instead of a bare-LF
    String cmd = "ls -al\n";
    success = ssh.SendReqExec(channelNum,cmd);
    if (success == false) {
        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 pollTimeoutMs = 2000;
    int n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs);
    if (n < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

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

    // Get the accumulated output of the command:
    String cmdOutput;
    cmdOutput = ssh.getReceivedText(channelNum,"ansi");
    if (ssh.get_LastMethodSuccess() == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    // Display the remote shell's command output:
    System.out.println(cmdOutput);
    System.out.println("----");

    // -----------------------------------------------------------------
    // Now for the 2nd SendReqExe (on the same connection,
    // but on a separate logical channel).
    // -----------------------------------------------------------------

    channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    cmd = "nslookup chilkatsoft.com\n";
    success = ssh.SendReqExec(channelNum,cmd);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    pollTimeoutMs = 2000;
    n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs);
    if (n < 0) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    success = ssh.ChannelSendClose(channelNum);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    success = ssh.ChannelReceiveToClose(channelNum);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

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

    System.out.println(cmdOutput);
  }
}