Lua

Socket Receive String Until Specific Byte Value is Received

Demonstrates the Chilkat Socket ReceiveStringUntilByte method. Lua

local chilkat = require("chilkat")

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

local sock = chilkat.Socket.new()

-- --------------------------------------------------------------------
-- This example uses the public TCP echo service at https://tcpbin.com/
-- --------------------------------------------------------------------

local useTls = false
local port = 4242
local maxWaitMs = 5000
local success = sock:connect("tcpbin.com", port, useTls, maxWaitMs)
if not success then
    print(sock.last_error_text)
    return
end

-- Wait a max of 2 seconds for a response..
sock.max_read_idle_ms = 2000

-- Send some strings, each terminated by a 0 byte.
sock:send_string("This is the 1st string")
sock:send_byte(0)
sock:send_string("This is string number 2")
sock:send_byte(0)

-- The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
sock:send_byte(10)

-- Now let's receive what is echoed back....
-- Receive each string and the NULL byte.
-- The call to ReceiveStringUntilByte will receive incoming data until the lookForByte is encountered.
-- The lookForByte is receive and discarded (it is not returned in the string)
local lookForByte = 0
local s1 = sock:receive_string_until_byte(lookForByte)
if not sock.last_method_success then
    print(sock.last_error_text)
    return
end

print(s1)

local s2 = sock:receive_string_until_byte(lookForByte)
if not sock.last_method_success then
    print(sock.last_error_text)
    return
end

print(s2)

-- The echo server will also echo back the final LF
sock:receive_byte(true)
maxWaitMs = 100
sock:close(100)

-- Output:
-- This is the 1st string
-- This is string number 2