(C# UWP/WinRT) Using sudo in an SSH Shell Session

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

Note: This example requires Chilkat v9.5.0.65 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// This example assumes Chilkat SSH/SFTP to have been previously unlocked.
// See Unlock SSH for sample code.

Chilkat.Ssh ssh = new Chilkat.Ssh();

int port = 22;
bool success = await ssh.ConnectAsync("the-ssh-server.com",port);
if (success != true) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

// Authenticate using login/password:
success = await ssh.AuthenticatePwAsync("theSshLogin","theSshPassword");
if (success != true) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

// Start a shell session.
// (The QuickShell method was added in Chilkat v9.5.0.65)
int channelNum = await ssh.QuickShellAsync();
if (channelNum < 0) {
    Debug.WriteLine(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.
Chilkat.StringBuilder sbCommands = new Chilkat.StringBuilder();
sbCommands.Append("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("echo THIS 'IS' THE END OF THE SCRIPT\n");

// Send the commands..
success = await ssh.ChannelSendStringAsync(channelNum,sbCommands.GetAsString(),"ansi");
if (success != true) {
    Debug.WriteLine(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 = await ssh.ChannelSendEofAsync(channelNum);

// Receive output up to our marker.
success = await ssh.ChannelReceiveUntilMatchAsync(channelNum,"THIS IS THE END OF THE SCRIPT","ansi",true);

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

// Get any remaining output..
success = await ssh.ChannelReceiveToCloseAsync(channelNum);

// Get the complete output for all the commands in the session.
Debug.WriteLine("--- output ----");
Debug.WriteLine(ssh.GetReceivedText(channelNum,"ansi"));