PowerShell

Check Whether SSH Channel EOF Was Received

Demonstrates the Chilkat Ssh.ChannelReceivedEof method, which reports whether an SSH EOF message has been received for a channel. The only argument is the channel number. EOF means the server will send no more ordinary channel data, but it does not close the channel.

Background: EOF and CLOSE are separate events, and the distinction matters when deciding whether a command has truly finished. A server commonly sends EOF first and CLOSE afterward; in that interval this method is true while ChannelReceivedClose is still false, and the channel remains open and counted. EOF is the signal that all output has been produced — useful when you want to stop reading without waiting for the full close handshake. It returns false for an invalid, released, or locally closed channel.

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Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

#  Demonstrates the Ssh.ChannelReceivedEof method, which reports whether an SSH EOF message has
#  been received for a channel.  The only argument is the channel number.  EOF means the server
#  will send no more ordinary channel data, but it does not close the channel.

$ssh = New-Object Chilkat.Ssh

$sshPort = 22
$success = $ssh.Connect("ssh.example.com",$sshPort)
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

#  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.
$password = "mySshPassword"

$success = $ssh.AuthenticatePw("mySshLogin",$password)
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

$channelNum = $ssh.OpenSessionChannel()
if ($channelNum -lt 0) {
    $($ssh.LastErrorText)
    exit
}

$success = $ssh.SendReqExec($channelNum,"ls -l /tmp")
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

#  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 -eq $false) {
    $($ssh.LastErrorText)
    exit
}

if ($ssh.ChannelReceivedEof($channelNum)) {
    $("EOF was received -- no more ordinary channel data will arrive.")
}
else {
    $("No EOF has been received.")
}

$ssh.Disconnect()