(Node.js) 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.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var ssh = new chilkat.Ssh();

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

    var success = ssh.Connect(hostname,port);
    if (success == false) {
        console.log(ssh.LastErrorText);
        return;
    }

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

    // Authenticate using login/password:
    success = ssh.AuthenticatePw("myLogin","myPassword");
    if (success == false) {
        console.log(ssh.LastErrorText);
        return;
    }

    // Open a session channel.  (It is possible to have multiple
    // session channels open simultaneously.)
    var channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        console.log(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
    var cmd = "ls -al\n";
    success = ssh.SendReqExec(channelNum,cmd);
    if (success == false) {
        console.log(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.
    var pollTimeoutMs = 2000;
    var n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs);
    if (n < 0) {
        console.log(ssh.LastErrorText);
        return;
    }

    // Close the channel:
    success = ssh.ChannelSendClose(channelNum);
    if (success == false) {
        console.log(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) {
        console.log(ssh.LastErrorText);
        return;
    }

    // Get the accumulated output of the command:
    var cmdOutput;
    cmdOutput = ssh.GetReceivedText(channelNum,"ansi");
    if (ssh.LastMethodSuccess == false) {
        console.log(ssh.LastErrorText);
        return;
    }

    // Display the remote shell's command output:
    console.log(cmdOutput);
    console.log("----");

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

    channelNum = ssh.OpenSessionChannel();
    if (channelNum < 0) {
        console.log(ssh.LastErrorText);
        return;
    }

    cmd = "nslookup chilkatsoft.com\n";
    success = ssh.SendReqExec(channelNum,cmd);
    if (success == false) {
        console.log(ssh.LastErrorText);
        return;
    }

    pollTimeoutMs = 2000;
    n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs);
    if (n < 0) {
        console.log(ssh.LastErrorText);
        return;
    }

    success = ssh.ChannelSendClose(channelNum);
    if (success == false) {
        console.log(ssh.LastErrorText);
        return;
    }

    success = ssh.ChannelReceiveToClose(channelNum);
    if (success == false) {
        console.log(ssh.LastErrorText);
        return;
    }

    cmdOutput = ssh.GetReceivedText(channelNum,"ansi");
    if (ssh.LastMethodSuccess == false) {
        console.log(ssh.LastErrorText);
        return;
    }

    console.log(cmdOutput);

}

chilkatExample();