Swift

Using sudo in an SSH Shell Session

See more SSH Examples

Demonstrates how to run a command as sudo in a shell session. Swift

func chilkatTest() {
    var success: Bool = false

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

    let ssh = CkoSsh()!

    var port: Int = 22
    success = ssh.connect(hostname: "the-ssh-server.com", port: port)
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

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

    // Start a shell session.
    // (The QuickShell method was added in Chilkat v9.5.0.65)
    var channelNum: Int = ssh.quickShell().intValue
    if channelNum < 0 {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Construct a StringBuilder with our command ("ls") run with "sudo"
    // Note: The line-endings are potentially important.  Some SSH servers may
    // require either LF or CRLF line endings.  (Unix/Linux/OSX servers typically
    // use bare-LF line endings.  Windows servers likely use CRLF line endings.)

    // Using "sudo -S" causes the sudo prompt to be written to stderr,
    // and the password is read from stdin (i.e. from the echo command ouput).
    // The sudo commands -p option allows us to set the prompt, and we can set it to
    // the empty string, thus eliminating the prompt from the stderr completely.
    // This allows us to run the command as root (super-user) with no prompt.
    let sbCommands = CkoStringBuilder()!
    sbCommands.append(value: "echo \"theSshPassword\" | sudo -S -p \"\" ls\n")

    // Add another command to echo a marker string that
    // we'll use in ChannelReceiveUntilMatch below.
    // The use of single quotes around 'IS' is a trick so that the output
    // of the command is "THIS IS THE END OF THE SCRIPT", but the terminal echo
    // includes the single quotes.  This allows us to read until we see the actual
    // output of the last command.
    sbCommands.append(value: "echo THIS 'IS' THE END OF THE SCRIPT\n")

    // Send the commands..
    success = ssh.channelSendString(channelNum: channelNum, strData: sbCommands.getAsString(), charset: "ansi")
    if success != true {
        print("\(ssh.lastErrorText!)")
        return
    }

    // Send an EOF to indicate no more commands will be sent.
    // For brevity, we're not checking the return values of each method call.
    // Your code should check the success/failure of each call.
    success = ssh.channelSendEof(channelNum: channelNum)

    // Receive output up to our marker.
    success = ssh.channelReceive(untilMatch: channelNum, matchPattern: "THIS IS THE END OF THE SCRIPT", charset: "ansi", caseSensitive: true)

    // Close the channel.
    // It is important to close the channel only after receiving the desired output.
    success = ssh.channelSendClose(channelNum: channelNum)

    // Get any remaining output..
    success = ssh.channelReceive(toClose: channelNum)

    // Get the complete output for all the commands in the session.
    print("--- output ----")
    print("\(ssh.getReceivedText(channelNum: channelNum, charset: "ansi")!)")

}