(VB.NET UWP/WinRT) SSH ReceiveUntilMatchN

Demonstrates how to call the SSH ChannelReceiveUntilMatchN method.

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

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

Dim ssh As New Chilkat.Ssh
Dim success As Boolean

' For the sake of the example, pretend the remote shell prompt
' will be any of the following:
Dim saPrompts As New Chilkat.StringArray

saPrompts.Append("~$")
saPrompts.Append("mars#")
saPrompts.Append("jupiter%")
saPrompts.Append("chilkat$")
saPrompts.Append("admin>")


Dim cmdOutput As String

' Connect to an SSH server:
' Hostname may be an IP address or hostname:
Dim hostname As String = "www.some-ssh-server.com"
Dim port As Integer = 22

success = Await ssh.ConnectAsync(hostname,port)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


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

' Authenticate using login/password:
success = Await ssh.AuthenticatePwAsync("myLogin","myPassword")
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' Open a session channel.  (It is possible to have multiple
' session channels open simultaneously.)
Dim channelNum As Integer = Await ssh.OpenSessionChannelAsync()
If (channelNum < 0) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


Dim termType As String = "dumb"
Dim widthInChars As Integer = 120
Dim heightInChars As Integer = 40
' Use 0 for pixWidth and pixHeight when the dimensions
' are set in number-of-chars.
Dim pixWidth As Integer = 0
Dim pixHeight As Integer = 0
success = Await ssh.SendReqPtyAsync(channelNum,termType,widthInChars,heightInChars,pixWidth,pixHeight)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' Start a shell on the channel:
success = Await ssh.SendReqShellAsync(channelNum)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  Run the 1st command in the remote shell, which will be to
'  "cd" to a subdirectory.
success = Await ssh.ChannelSendStringAsync(channelNum,"cd workspace" & vbLf,"utf-8")
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' Retrieve the output to the next prompt:
Dim caseSensitiveMatch As Boolean = True
success = Await ssh.ChannelReceiveUntilMatchNAsync(channelNum,saPrompts,"utf-8",caseSensitiveMatch)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  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,"utf-8")
If (ssh.LastMethodSuccess <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If

Debug.WriteLine(cmdOutput)

'  Run the 2nd command in the remote shell, which will be
'  to "ls" the directory.
success = Await ssh.ChannelSendStringAsync(channelNum,"ls" & vbLf,"utf-8")
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' Retrieve and display the output.
success = Await ssh.ChannelReceiveUntilMatchNAsync(channelNum,saPrompts,"utf-8",caseSensitiveMatch)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


cmdOutput = ssh.GetReceivedText(channelNum,"utf-8")
If (ssh.LastMethodSuccess <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If

Debug.WriteLine(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 = Await ssh.ChannelSendStringAsync(channelNum,"ls -l" & vbLf,"utf-8")
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If



' 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 = Await ssh.ChannelSendEofAsync(channelNum)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' 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.
Dim pollTimeoutMs As Integer = 2000
Dim n As Integer = Await ssh.ChannelReadAndPollAsync(channelNum,pollTimeoutMs)
If (n < 0) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' Close the channel:
success = Await ssh.ChannelSendCloseAsync(channelNum)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


' 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 = Await ssh.ChannelReceiveToCloseAsync(channelNum)
If (success <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


cmdOutput = ssh.GetReceivedText(channelNum,"utf-8")
If (ssh.LastMethodSuccess <> True) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If

Debug.WriteLine(cmdOutput)

' Disconnect
ssh.Disconnect()