PowerBuilder

Receive an SSH Channel Until Close

Demonstrates the Chilkat Ssh.ChannelReceiveToClose method, which receives data on a channel until the server sends and Chilkat processes channel CLOSE. The only argument is the channel number. EOF alone does not complete this method.

Important: Set the ReadTimeoutMs property before calling this method. It defaults to 0, meaning no limit, so without it the call waits forever if the server never sends channel close.

Background: This is the simplest and most reliable way to collect the complete output of a one-shot exec command, because the server closes the channel when the command finishes. It is not appropriate for an interactive shell, which never closes on its own — use the poll-based methods there instead. Both stdout and stderr are processed, merged or kept separate according to StderrToStdout.

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integer li_rc
integer li_Success
oleobject loo_Ssh
integer li_SshPort
string ls_Password
integer li_ChannelNum
string ls_Output

li_Success = 0

//  Demonstrates the Ssh.ChannelReceiveToClose method, which receives data on a channel until the
//  server sends channel CLOSE.  The only argument is the channel number.  EOF alone does not
//  complete this method.

loo_Ssh = create oleobject
li_rc = loo_Ssh.ConnectToNewObject("Chilkat.Ssh")
if li_rc < 0 then
    destroy loo_Ssh
    MessageBox("Error","Connecting to COM object failed")
    return
end if

li_SshPort = 22
li_Success = loo_Ssh.Connect("ssh.example.com",li_SshPort)
if li_Success = 0 then
    Write-Debug loo_Ssh.LastErrorText
    destroy loo_Ssh
    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.
ls_Password = "mySshPassword"

li_Success = loo_Ssh.AuthenticatePw("mySshLogin",ls_Password)
if li_Success = 0 then
    Write-Debug loo_Ssh.LastErrorText
    destroy loo_Ssh
    return
end if

li_ChannelNum = loo_Ssh.OpenSessionChannel()
if li_ChannelNum < 0 then
    Write-Debug loo_Ssh.LastErrorText
    destroy loo_Ssh
    return
end if

li_Success = loo_Ssh.SendReqExec(li_ChannelNum,"ls -l /tmp")
if li_Success = 0 then
    Write-Debug loo_Ssh.LastErrorText
    destroy loo_Ssh
    return
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.
loo_Ssh.ReadTimeoutMs = 15000

//  Receive everything the command produces, up to and including channel close.
li_Success = loo_Ssh.ChannelReceiveToClose(li_ChannelNum)
if li_Success = 0 then
    Write-Debug loo_Ssh.LastErrorText
    destroy loo_Ssh
    return
end if

ls_Output = loo_Ssh.GetReceivedText(li_ChannelNum,"utf-8")
if loo_Ssh.LastMethodSuccess = 0 then
    Write-Debug loo_Ssh.LastErrorText
    destroy loo_Ssh
    return
end if

Write-Debug ls_Output

loo_Ssh.Disconnect()


destroy loo_Ssh