Get the Exit Status of a Remote SSH Command

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Demonstrates the Chilkat Ssh.GetChannelExitStatus method, which returns the remote process exit status for a channel. The only argument is the channel number. Call it only after ChannelReceivedExitStatus returns true.

Dim success As Boolean = False

'  Demonstrates the Ssh.GetChannelExitStatus method, which returns the remote process exit
'  status for a channel.  The only argument is the channel number.  Call it only after
'  ChannelReceivedExitStatus returns True.

Dim ssh As New Chilkat.Ssh

Dim sshPort As Integer = 22
success = ssh.Connect("ssh.example.com",sshPort)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
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 = "mySshPassword"

success = ssh.AuthenticatePw("mySshLogin",password)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


Dim channelNum As Integer = ssh.OpenSessionChannel()
If (channelNum < 0) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


success = ssh.SendReqExec(channelNum,"grep -q root /etc/passwd")
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  IMPORTANT: Set a read timeout.  ReadTimeoutMs defaults to 0, which means no limit -- without
'  it, this call waits forever if the server never sends channel close.
ssh.ReadTimeoutMs = 15000

success = ssh.ChannelReceiveToClose(channelNum)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  Retrieve the exit status immediately, before calling unrelated SSH methods or releasing the
'  channel, because the completed channel record can be discarded.
If (ssh.ChannelReceivedExitStatus(channelNum)) Then
    Dim exitStatus As Integer = ssh.GetChannelExitStatus(channelNum)
    Debug.WriteLine("Exit status: " & exitStatus)

    '  By convention, 0 means the remote command succeeded.
    If (exitStatus = 0) Then
        Debug.WriteLine("The remote command succeeded.")
    Else
        Debug.WriteLine("The remote command reported a failure.")
    End If

End If


ssh.Disconnect()