SSH Quick/Simple Shell Session

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Demonstrates the simplified way to run multiple commands in a shell session using QuickShell, which combines OpenSessionChannel, SendReqPty, and SendReqShell into one call. The commands are built in a StringBuilder, sent together, and the output is read up to a marker echoed by the final command.

Dim success As Boolean
success = False

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

//  Demonstrates the simplified way to run multiple commands in a shell session using QuickShell.
//  
//  Note: QuickShell internally does OpenSessionChannel, SendReqPty, and SendReqShell, so it DOES
//  allocate a pseudo-terminal.  The remote shell therefore runs interactively: it prints a
//  command prompt and echoes back the commands that are sent to it.  Both the echoed input and
//  the real output appear in what is received.

Dim ssh As New Chilkat.Ssh

Dim port As Int32
port = 22
success = ssh.Connect("ssh.example.com",port)
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
Dim password As String
password = "mySshPassword"

success = ssh.AuthenticatePw("mySshLogin",password)
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

//  Start the shell session.  A negative return value indicates failure.
Dim channelNum As Int32
channelNum = ssh.QuickShell()
If (channelNum < 0) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

//  Build the commands, one per line.  Line endings matter: Unix/Linux servers typically expect
//  a bare LF, while Windows servers may require CRLF.
Dim sbCommands As New Chilkat.StringBuilder
success = sbCommands.Append("echo hello world" + EndOfLine.Unix)
success = sbCommands.Append("date" + EndOfLine.Unix)
success = sbCommands.Append("df" + EndOfLine.Unix)

//  The final command echoes a marker used to detect the end of the output.  The single quotes
//  around 'IS' are a trick: the terminal echo of the typed command includes the quotes, while
//  the command's actual output does not.  Matching the unquoted form therefore matches the real
//  output rather than the echo.
success = sbCommands.Append("echo THIS 'IS' THE END OF THE SCRIPT" + EndOfLine.Unix)

Dim commands As String
commands = sbCommands.GetAsString()
success = ssh.ChannelSendString(channelNum,commands,"utf-8")
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

//  IMPORTANT: Set a read timeout before receiving until a match.  ReadTimeoutMs defaults to 0,
//  which means no limit -- without it, this call waits forever if the received data never
//  contains a match.
ssh.ReadTimeoutMs = 15000

Dim caseSensitive As Boolean
caseSensitive = True
success = ssh.ChannelReceiveUntilMatch(channelNum,"THIS IS THE END OF THE SCRIPT","utf-8",caseSensitive)
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

//  Indicate that no more commands will be sent, then close the channel.  Close only after the
//  desired output has been received.
success = ssh.ChannelSendEof(channelNum)
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

success = ssh.ChannelSendClose(channelNum)
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

//  Collect any remaining output.
success = ssh.ChannelReceiveToClose(channelNum)
If (success = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

Dim sessionOutput As String
sessionOutput = ssh.GetReceivedText(channelNum,"utf-8")
If (ssh.LastMethodSuccess = False) Then
    System.DebugLog(ssh.LastErrorText)
    Return
End If

System.DebugLog("--- output ----")
System.DebugLog(sessionOutput)

ssh.Disconnect