Lianja

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.

Chilkat Lianja Downloads

Download Chilkat for Lianja

Lianja

llSuccess = .F.

//  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.

loSsh = createobject("CkSsh")

lnSshPort = 22
llSuccess = loSsh.Connect("ssh.example.com",lnSshPort)
if (llSuccess = .F.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

//  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.
lcPassword = "mySshPassword"

llSuccess = loSsh.AuthenticatePw("mySshLogin",lcPassword)
if (llSuccess = .F.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

lnChannelNum = loSsh.OpenSessionChannel()
if (lnChannelNum < 0) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

llSuccess = loSsh.SendReqExec(lnChannelNum,"ls -l /tmp")
if (llSuccess = .F.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

//  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.
loSsh.ReadTimeoutMs = 15000

//  Receive everything the command produces, up to and including channel close.
llSuccess = loSsh.ChannelReceiveToClose(lnChannelNum)
if (llSuccess = .F.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

lcOutput = loSsh.GetReceivedText(lnChannelNum,"utf-8")
if (loSsh.LastMethodSuccess = .F.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

? lcOutput

loSsh.Disconnect()


release loSsh