SSH Quick/Simple Shell Session

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Demonstrates the simplified way to run multiple commands in a shell session using QuickShell, which combines OpenSessionChannel, SendReqPty, and SendReqShell into one call. The commands are built in a StringBuilder, sent together, and the output is read up to a marker echoed by the final command.

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

-- Demonstrates the simplified way to run multiple commands in a shell session using QuickShell.
--
-- Note: QuickShell internally does OpenSessionChannel, SendReqPty, and SendReqShell, so it DOES
-- allocate a pseudo-terminal.  The remote shell therefore runs interactively: it prints a
-- command prompt and echoes back the commands that are sent to it.  Both the echoed input and
-- the real output appear in what is received.

local ssh = chilkat.Ssh.new()

local port = 22
local success = ssh:connect("ssh.example.com", port)
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

-- Start the shell session.  A negative return value indicates failure.
local channelNum = ssh:quick_shell()
if channelNum < 0 then
    print(ssh.last_error_text)
    return
end

-- Build the commands, one per line.  Line endings matter: Unix/Linux servers typically expect
-- a bare LF, while Windows servers may require CRLF.
local sbCommands = chilkat.StringBuilder.new()
sbCommands:append("echo hello world\n")
sbCommands:append("date\n")
sbCommands:append("df\n")

-- The final command echoes a marker used to detect the end of the output.  The single quotes
-- around 'IS' are a trick: the terminal echo of the typed command includes the quotes, while
-- the command's actual output does not.  Matching the unquoted form therefore matches the real
-- output rather than the echo.
sbCommands:append("echo THIS 'IS' THE END OF THE SCRIPT\n")

local commands = sbCommands:get_as_string()
success = ssh:channel_send_string(channelNum, commands, "utf-8")
if not success then
    print(ssh.last_error_text)
    return
end

-- 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.read_timeout_ms = 15000

local caseSensitive = true
success = ssh:channel_receive_until_match(channelNum, "THIS IS THE END OF THE SCRIPT", "utf-8", caseSensitive)
if not success then
    print(ssh.last_error_text)
    return
end

-- Indicate that no more commands will be sent, then close the channel.  Close only after the
-- desired output has been received.
success = ssh:channel_send_eof(channelNum)
if not success then
    print(ssh.last_error_text)
    return
end

success = ssh:channel_send_close(channelNum)
if not success then
    print(ssh.last_error_text)
    return
end

-- Collect any remaining output.
success = ssh:channel_receive_to_close(channelNum)
if not success then
    print(ssh.last_error_text)
    return
end

local sessionOutput = ssh:get_received_text(channelNum, "utf-8")
if not ssh.last_method_success then
    print(ssh.last_error_text)
    return
end

print("--- output ----")
print(sessionOutput)

ssh:disconnect()