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 session channel. This is not a separate TCP/IP connection -- it's simply a new session channel on the existing connection. The sequence of Chilkat SSH calls would look like this:

Connect
AuthenticatePw (or AuthenticatePk)

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

...

OpenSessionChannel
SendReqExec
<retrieve command output...>
SendChannelClose
ChannelReceiveToClose (to make sure all remaining output is received)

Disconnect

Download Chilkat Java Library

Download Chilkat Java x64 Library

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[])
  {
    //  Important: It is helpful to send the contents of the
    //  ssh.LastErrorText property when requesting support.

    CkSsh ssh = new CkSsh();

    //  Any string automatically begins a fully-functional 30-day trial.
    boolean success;
    success = ssh.UnlockComponent("Anything for 30-day trial");
    if (success != true) {
        System.out.println(ssh.lastErrorText());
        return;
    }

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

    //  Hostname may be an IP address or hostname:
    hostname = "192.168.1.117";
    port = 22;

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

    //  Wait a max of 5 seconds when reading responses..
    ssh.put_IdleTimeoutMs(5000);

    //  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;
    }

    //  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
    success = ssh.SendReqExec(channelNum,"ls -al\n");
    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;
    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;
    }

    //  Let's pickup the accumulated output of the command:
    String cmdOutput;
    cmdOutput = ssh.getReceivedText(channelNum,"ansi");
    if (cmdOutput == null ) {
        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;
    }

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

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

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

    System.out.println(cmdOutput);

    //  Disconnect
    ssh.Disconnect();
  }
}