(JavaScript) SSH Remote Shell Multiple Commands

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.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

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

var ssh = new CkSsh();

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

var cmdOutput;

// Connect to an SSH server:
var hostname;
var 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) {
    console.log(ssh.LastErrorText);
    return;
}

// Wait a max of 10 seconds when reading responses..
ssh.IdleTimeoutMs = 10000;

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

// Open a session channel.  (It is possible to have multiple
// session channels open simultaneously.)
var channelNum;
channelNum = ssh.OpenSessionChannel();
if (channelNum < 0) {
    console.log(ssh.LastErrorText);
    return;
}

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

// Start a shell on the channel:
success = ssh.SendReqShell(channelNum);
if (success !== true) {
    console.log(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) {
    console.log(ssh.LastErrorText);
    return;
}

// Retrieve the output.
success = ssh.ChannelReceiveUntilMatch(channelNum,myPrompt,"ansi",true);
if (success !== true) {
    console.log(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.LastMethodSuccess !== true) {
    console.log(ssh.LastErrorText);
    return;
}

console.log(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) {
    console.log(ssh.LastErrorText);
    return;
}

// Retrieve and display the output.
success = ssh.ChannelReceiveUntilMatch(channelNum,myPrompt,"ansi",true);
if (success !== true) {
    console.log(ssh.LastErrorText);
    return;
}

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

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

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

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

console.log(cmdOutput);

// Disconnect
ssh.Disconnect();