Swift

SSH Remote Shell

See more SSH Examples

Demonstrates how to start a shell on a remote SSH server, run a command, and retrieve the output. Swift

func chilkatTest() {
    var success: Bool = false

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

    let ssh = CkoSsh()!

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

    // Connect to an SSH server:
    success = ssh.connect(hostname: hostname, port: port)
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Wait a max of 5 seconds when reading responses..
    ssh.idleTimeoutMs = 5000

    // Authenticate using login/password:
    success = ssh.authenticatePw(login: "myLogin", password: "myPassword")
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Open a session channel.  (It is possible to have multiple
    // session channels open simultaneously.)
    var channelNum: Int
    channelNum = ssh.openSessionChannel().intValue
    if channelNum < 0 {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Some SSH servers require a pseudo-terminal
    // If so, include the call to SendReqPty.  If not, then 
    // comment out the call to SendReqPty.
    // Note: The 2nd argument of SendReqPty is the terminal type,
    // which should be something like "xterm", "vt100", "dumb", etc.
    // A "dumb" terminal is one that cannot process escape sequences.
    // Smart terminals, such as "xterm", "vt100", etc. process
    // escape sequences.  If you select a type of smart terminal,
    // your application will receive these escape sequences
    // included in the command's output.  Use "dumb" if you do not
    // want to receive escape sequences.  (Assuming your SSH
    // server recognizes "dumb" as a standard dumb terminal.)
    var termType: String? = "dumb"
    var widthInChars: Int = 120
    var heightInChars: Int = 40
    // Use 0 for pixWidth and pixHeight when the dimensions
    // are set in number-of-chars.
    var pixWidth: Int = 0
    var pixHeight: Int = 0
    success = ssh.sendReqPty(channelNum: channelNum, xTermEnvVar: termType, widthInChars: widthInChars, heightInRows: heightInChars, pixWidth: pixWidth, pixHeight: pixHeight)
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Start a shell on the channel:
    success = ssh.sendReqShell(channelNum: channelNum)
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Start a command in the remote shell.  This example
    // will send a "ls" command to retrieve the directory listing.
    success = ssh.channelSendString(channelNum: channelNum, strData: "ls\r\n", charset: "ansi")
    if success != true {
        print("\(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: channelNum)
    if success != true {
        print("\(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: Int
    var pollTimeoutMs: Int = 2000
    n = ssh.channelReadAndPoll(channelNum: channelNum, pollTimeoutMs: pollTimeoutMs).intValue
    if n < 0 {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Close the channel:
    success = ssh.channelSendClose(channelNum: channelNum)
    if success != true {
        print("\(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.channelReceive(toClose: channelNum)
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Let's pickup the accumulated output of the command:
    var cmdOutput: String? = ssh.getReceivedText(channelNum: channelNum, charset: "ansi")
    if ssh.lastMethodSuccess != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Display the remote shell's command output:
    print("\(cmdOutput!)")

    // Disconnect
    ssh.disconnect()

}