PowerShell

Start a Remote Shell with QuickShell

Demonstrates the Chilkat Ssh.QuickShell method, which starts a remote shell using the simplified sequence OpenSessionChannel → SendReqPty → SendReqShell. It takes no arguments and returns the shell channel number, or -1 on failure. The default PTY size is 80 columns by 24 rows.

Background: Note that QuickShell does allocate a PTY, so unlike a bare SendReqShell the remote shell runs interactively: it prints a command prompt, echoes the commands you send, and runs interactive login scripts. That is convenient for terminal-style work but means the output contains prompts and echoed input that scripted parsing must tolerate. The method returns as soon as the shell request is accepted — it does not consume the initial login text or prompt, so read and discard that before relying on command output.

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

$success = $false

#  Demonstrates the Ssh.QuickShell method, which starts a remote shell using the simplified
#  sequence OpenSessionChannel, SendReqPty, and SendReqShell.  It takes no arguments and returns
#  the shell channel number, or -1 on failure.  The default PTY size is 80 columns by 24 rows.

$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
}

#  Start the shell.  Note that QuickShell allocates a PTY, so the remote shell runs
#  interactively: it prints a command prompt and echoes the commands that are sent to it.
$channelNum = $ssh.QuickShell()
if ($channelNum -lt 0) {
    $($ssh.LastErrorText)
    exit
}

#  QuickShell returns as soon as the shell request is accepted -- it does not wait for or
#  consume the initial login text or prompt.
$success = $ssh.ChannelSendString($channelNum,"uname -a; echo DONE_MARKER`n","utf-8")
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

#  IMPORTANT: Set a read timeout before receiving until a match.  ReadTimeoutMs defaults to 0,
#  which means no limit -- without it, this call waits forever if the received data never
#  contains a match.
$ssh.ReadTimeoutMs = 15000

$caseSensitive = $false
$success = $ssh.ChannelReceiveUntilMatch($channelNum,"DONE_MARKER","utf-8",$caseSensitive)
if ($success -eq $false) {
    $($ssh.LastErrorText)
    exit
}

$output = $ssh.GetReceivedText($channelNum,"utf-8")
if ($ssh.LastMethodSuccess -eq $false) {
    $($ssh.LastErrorText)
    exit
}

$($output)

$ssh.Disconnect()