Lua

Get the Type of an Active SSH Channel

Demonstrates the Chilkat Ssh.GetChannelType method, which returns the type of the channel at a zero-based enumeration index. The only argument is the index — an enumeration position, not a channel number. Values include session, x11, forwarded-tcpip, and direct-tcpip.

Background: Paired with GetChannelNumber, this turns the channel collection into a readable inventory of what a connection is currently doing — which channels are running commands (session) versus tunneling TCP traffic (direct-tcpip). That is valuable for diagnostics and for application code that manages several channel kinds at once. An out-of-range index causes the string-returning method to report failure.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the Ssh.GetChannelType method, which returns the type of the channel at a
-- zero-based enumeration index.  The only argument is the index, which is an enumeration
-- position and not a channel number.  Values include "session" and "direct-tcpip".

local ssh = chilkat.Ssh.new()

local sshPort = 22
local success = ssh:connect("ssh.example.com", sshPort)
if not success then
    print(ssh.last_error_text)
    return
end

-- 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.
local password = "mySshPassword"

success = ssh:authenticate_pw("mySshLogin", password)
if not success then
    print(ssh.last_error_text)
    return
end

local channelNum = ssh:open_session_channel()
if channelNum < 0 then
    print(ssh.last_error_text)
    return
end

-- Enumerate the active channels and report each one's number and type.
local n = ssh.num_open_channels
for i = 0, n - 1 do
    local chNum = ssh:get_channel_number(i)
    local chType = ssh:get_channel_type(i)
    if not ssh.last_method_success then
        print(ssh.last_error_text)
        return
    end

    print("Channel " .. chNum .. " is of type " .. chType)
end

ssh:disconnect()