wiki.netio-products.com - User contributions [en]

NETIO Lua Manual

2017-05-06T08:34:56Z

Jturon: /* Data types and variables */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types and variables ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

local keyword limits the variable scope to the block (ended by end) where it is declared. To access an upvalue (variable defined outside of the scope), just omit the local keyword.

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 supplies power")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is idle")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead). Additionally, Netio Lua implementation limits the loop iterations to 32k.

=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace()) -- only first return value is used
local free,total = diskSpace() -- values are stored into LHS var-list
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-05-06T08:16:10Z

Jturon:

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types and variables ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 supplies power")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is idle")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead). Additionally, Netio Lua implementation limits the loop iterations to 32k.

=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace()) -- only first return value is used
local free,total = diskSpace() -- values are stored into LHS var-list
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

Welcome to NETIO resources & projects & documentation overview

2017-05-06T07:46:59Z

Jturon:

<div style="text-align: center; white-space: nowrap;">
<div style="display: inline-block; padding: 0 2em; margin-bottom: 2em; width: 40%; min-width: 15em; text-align: justify; vertical-align: top; white-space: normal;">
<div style="margin-bottom: 0.5em; margin-top: 50px; height: 50px;">[[Soubor:Netio-mainlogo.png|200px]]</div>
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== A simple NETIO application ===
Coming soon.
</div><div style="display: inline-block; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify; white-space: normal;">
<div style="margin-bottom: 0.5em; height: 100px">[[Soubor:Netio-lua.png]]</div>
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</div>

__NOTOC__

File:Netio-lua.png

2017-05-06T07:38:02Z

Jturon: Jturon načetl novou verzi Soubor:Netio-lua.png

File:Netio-mainlogo.png

2017-05-06T07:37:22Z

Jturon: Jturon načetl novou verzi Soubor:Netio-mainlogo.png

File:Netio-mainlogo.png

2017-05-06T07:34:33Z

Jturon:

File:Netio-lua.png

2017-05-06T07:24:23Z

Jturon:

Welcome to NETIO resources & projects & documentation overview

2017-05-06T07:14:44Z

Jturon:

<div style="text-align: center">[[Soubor:Netio-logo.png]]</div>

<div style="text-align: center; white-space: nowrap;">
<div style="display: inline-block; padding: 0 2em; margin-bottom: 2em; width: 40%; min-width: 15em; text-align: justify; vertical-align: top; white-space: normal;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== A simple NETIO application ===
Coming soon.
</div><div style="display: inline-block; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify; white-space: normal;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</div>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-06T07:14:08Z

Jturon:

<div style="text-align: center">[[Soubor:Netio-logo.png]]</div>

<div style="text-align: center; white-space: nowrap;">
<div style="display: inline-block; padding: 0 2em; margin-bottom: 2em; width: 40%; min-width: 15em; text-align: justify; vertical-align: top;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== A simple NETIO application ===
Coming soon.
</div><div style="display: inline-block; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</div>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-06T07:11:38Z

Jturon:

<div style="text-align: center">[[Soubor:Netio-logo.png]]</div>

<div style="text-align: center">
<div style="display: inline-block; padding: 0 2em; margin-bottom: 2em; width: 40%; min-width: 15em; text-align: justify; vertical-align: top;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== A simple NETIO application ===
Coming soon.
</div><div style="display: inline-block; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</div>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-06T07:09:53Z

Jturon:

<div style="text-align: center">[[Soubor:Netio-logo.png]]</div>

<div style="text-align: center">
<div style="display: inline-block; padding: 0 2em; margin-bottom: 2em; width: 40%; min-width: 15em; text-align: justify; vertical-align: top;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== A simple NETIO application ===
Coming soon.
</div>
<div style="display: inline-block; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</div>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-05T19:02:07Z

Jturon:

<center>[[Soubor:Netio-logo.png]]</center>

<center>
<div style="inline-block; float: left; padding: 0 2em; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== A simple NETIO application ===
Coming soon.
</div>
<div style="inline-block; float: left; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</center>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-05T19:01:33Z

Jturon:

<center>[[Soubor:Netio-logo.png]]</center>

<center>
<div style="inline-block; float: left; padding: 0 2em; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
NETIO sockets can operate just like any socket, but it can be connected as a network node and communicate in many protocols with various devices.

=== NETIO Features ===
Coming soon.

=== Connect NETIO to your network ===
Coming soon.

=== NETIO web interface ===
Coming soon.

=== Programming simple NETIO application ===
Coming soon.
</div>
<div style="inline-block; float: left; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</center>

__NOTOC__

NETIO Lua Reference

2017-05-05T18:24:36Z

Jturon: Jturon přesunul stránku Netio Lua Reference na NETIO Lua Reference

== Outlet Management ==
<big> devices.system </big>
* function [[Function devices.system.SetOut()|.SetOut()]] - turns the outlet on or off
* function [[Function devices.system.ResetOut()|.ResetOut()]] - turns the outlet off and then resets its previous state
* string [[String devices.system.output1_state|.output1_state]] - outlet's state
* number [[Number devices.system.output1_consumption|.output1_consumption]] - outlet's consumption (in Watts)
* number [[Number devices.system.output1_cumulatedConsumption|.output1_cumulatedConsumption]] - outlet's consumed energy (in Watthours)
* function [[Function devices.system.resetCumulativeConsumption()|.resetCumulativeConsumption()]] - resets outlet's energy counter
* string [[String devices.system.output1_consumptionStart|.output1_consumptionStart]] - date and time since the last energy counter reset

== Socket System Management ==
<big> devices.system </big>
* number [[number devices.system.averageLoad|.averageLoad]] - socket's CPU load
* function [[Function devices.system.Reboot()|.Reboot()]] - reboot socket's system
* number [[Number devices.system.sessionCount|.sessionCount]] - number of connected users
* number [[Number devices.system.freeSpace|.freeSpace]] - free disk space
* number [[Number devices.system.totalSpace|.totalSpace]] - total disk space

== Socket Communication ==
* function [[Function ping()|ping()]] - tests socket's network responsivity
* function [[Function mail()|mail()]] - sends e-mail
* function [[Function devices.system.CustomCGI()|devices.system.CustomCGI()]] - send HTTP request
* function [[Function cgiGet()|cgiGet()]] <code>2.3.5</code> - send HTTP request and receive response
* table [[Table event.args|event.args]] - HTTP GET /event variables table

== XML Processing <code>2.3.6</code> ==
<big>xml</big>
* function [[Function xml.escape()|.escape()]] - escapes XML string to fit xml node contents
* function [[Function xml.check()|.check()]] - tests if string is well-formed XML
* function [[Function xml.parse()|.parse()]] - parses XML string into [[Function xml.parse()#XmlElement|XmlElement]] object

== Standard Lua Functions ==
* function [https://www.lua.org/pil/8.3.html assert(), error()] issues an error
* function [https://www.lua.org/pil/7.3.html ipairs(), pairs(), next()] traverse tables
* function [https://www.lua.org/pil/2.4.html tonumber(), tostring()] data type conversion
* function [https://www.lua.org/pil/8.4.html pcall()] protected call function (handles error inside the function)
* function [https://www.lua.org/pil/5.2.html select()] selects from multiple return value
* function [https://www.lua.org/pil/2.html unpack] converts table into multiple values
* function [https://www.lua.org/pil/2.html type()] returns variable type
* function [https://www.lua.org/pil/22.1.html os.date(), os.time()] system date and time
* function os.difftime() returns time span between two times

== Miscellaneous ==
* function [[Function log()|log()]] - insert a record to the socket's event log
* function [[Function logf()|logf()]] - insert a formated record (incl. numbers) to the socket's event log
* function [[Function delay()|delay()]] - execute function with delay (seconds)
* function [[Function milliDelay()|milliDelay()]] - execute function with delay (milliseconds)
* function [[Function toboolean()|toboolean()]] - converts any variable to boolean type

Netio Lua Reference

2017-05-05T18:24:36Z

Jturon: Jturon přesunul stránku Netio Lua Reference na NETIO Lua Reference

#PŘESMĚRUJ [[NETIO Lua Reference]]

NETIO Lua Manual

2017-05-05T18:24:03Z

Jturon: Jturon přesunul stránku Netio Lua Manual na NETIO Lua Manual

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 supplies power")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is idle")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead). Additionally, Netio Lua implementation limits the loop iterations to 32k.

=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace()) -- only first return value is used
local free,total = diskSpace() -- values are stored into LHS var-list
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

Netio Lua Manual

2017-05-05T18:24:03Z

Jturon: Jturon přesunul stránku Netio Lua Manual na NETIO Lua Manual

#PŘESMĚRUJ [[NETIO Lua Manual]]

Welcome to NETIO resources & projects & documentation overview

2017-05-05T18:23:13Z

Jturon:

<center>[[Soubor:Netio-logo.png]]</center>

<center>
<div style="inline-block; float: left; padding: 0 2em; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
</div>
<div style="inline-block; float: left; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</center>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-05T18:22:55Z

Jturon:

Welcome to NETIO resources & projects & documentation overview

2017-05-05T18:19:28Z

Jturon:

Welcome to NETIO resources & projects & documentation overview

2017-05-05T18:18:50Z

Jturon:

<center>[[Soubor:Netio-logo.png]]</center>

<center>
<div style="inline-block; float: left; padding: 0 2em; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
</div>
<div style="inline-block; float: left; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</center>

__NOTOC__

Welcome to NETIO resources & projects & documentation overview

2017-05-05T18:17:41Z

Jturon:

<center>[[Soubor:Netio-logo.png]]</center>

<center>
<div style="inline-block; float: left; padding: 0 2em; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
</div>
<div style="inline-block; float: left; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</center>

__NOTOC__
__NOTITLE__

Welcome to NETIO resources & projects & documentation overview

2017-05-05T18:16:37Z

Jturon:

<center>[[Soubor:Netio-logo.png]]</center>

<center>
<div style="inline-block; float: left; padding: 0 2em; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> Introducing NETIO </h2>
</div>
<div style="inline-block; float: left; padding: 0 2em; border-left: 1px solid gray; width: 40%; min-width: 15em; text-align: justify;">
<h2 style="background: #005f41; color: #FFF; margin: 0 -1em; padding: 0 1em;"> NETIO Programming </h2>
NETIO uses Lua as its scripting language. To master it, follow these references:

=== [https://www.lua.org/pil/contents.html Lua tutorial] ===
If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to NETIO Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.

=== [[NETIO Lua Manual]] ===
A quick jump into NETIO Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that NETIO Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.

=== [[NETIO Lua Reference]] ===
If you can already code in Lua, NETIO-specific Lua functions is your main guide to programm NETIO Sockets.

=== [https://www.lua.org/manual/5.3/ Lua manual] ===
Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

</div>
</center>

__NOTOC__

NETIO programming

2017-05-05T17:51:04Z

Jturon: Založena nová stránka s textem „Netio uses Lua as its scripting language. To master it, follow these references: * [https://www.lua.org/pil/contents.html Lua tutorial] - If you are new to…“

Netio uses Lua as its scripting language. To master it, follow these references:
* [https://www.lua.org/pil/contents.html Lua tutorial] - If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to Netio Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.
* [[Netio Lua Manual]] - A quick jump into Netio Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that Netio Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.
* [[Netio Lua Reference]] - If you can already code in Lua, Netio-specific Lua functions is your main guide to programm Netio Sockets.
* [https://www.lua.org/manual/5.3/ Lua manual] - Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.

Function devices.system.SetOut()

2017-05-05T17:28:00Z

Jturon:

{{DISPLAYTITLE:function devices.system.SetOut()}}
Changes the state (on or off) of the outlet.
nil devices.system.SetOut(table <code>config</code>)

=== Parameters ===
table config{<code>output</code>, <code>value</code>}
* number <code>output</code> outlet to change (1 to 4)
* boolean <code>value</code>
** <tt>true</tt> = turn on
** <tt>false</tt> = turn off

=== Return value ===
nil

=== Usage ===
-- turns outlet No.1 on
devices.system.SetOut{output=1,value=true}

=== See also ===
* [[Function devices.system.ResetOut()|devices.system.ResetOut()]] to conveniently reset the state

__NOTOC__

Function devices.system.ResetOut()

2017-05-05T17:27:39Z

Jturon:

{{DISPLAYTITLE:function devices.system.ResetOut()}}
Resets the outlet: if it was off, it stays off. If it was on, it is turned off for specified time (its led blinks green), and then turned on again.
nil devices.system.ResetOut(table <code>config</code>)

=== Parameters ===
table config{<code>output</code>, <code style="color: #777">resetDelay</code>}
* number <code>output</code> outlet to reset (1 to 4)
* optional number <code>resetDelay</code> time period (in seconds) to keep the outlet off (default 1)

=== Return value ===
nil

=== Usage ===
-- turns outlet No.1 off and resets its previous state after 10 seconds
devices.system.ResetOut{output=1,resetDelay=10}

__NOTOC__

Function ping()

2017-05-05T17:25:20Z

Jturon:

{{DISPLAYTITLE:function ping()}}
Test connection to specified IP or URL using ICMP packet

nil ping(table <code>config</code>)

=== Parameters ===
table config{<code>address</code>, <code style="color: #777">timeout</code>, <code>callback</code>}
* string <code>address</code> IP or URL (without http://) to test
* optional number <code>timeout</code> maximal wait for response (in seconds)
* function{response} <code>callback</code> this function is called when response arrives or timeout is reached

=== Callback Parameters ===
table response{<code>success</code>, <code>duration</code>, <code>errorInfo</code>}
* boolean <code>success</code> false = timeout reached, true = response confirmed before timeout
* number <code>duration</code> response delay (in milliseconds); if not success, duration is <tt>nil</tt>
* string <code>errorInfo</code> error info in case of failure. If success, it contains "No error, return OK"

=== Return value ===
nil

=== Usage ===
-- callback function
local function logPingResult(o)
if o.success then
logf("Response lag: %dms", o.duration)
else
logf("Ping failed, reason: %s", o.errorInfo)
end
end

-- test ping www.google.com
ping{address="www.google.com", timeout=10, callback=logPingResult}

-- test ping ip address
ping{address="77.75.79.39", callback=logPingResult}

-- test ping non-existent address
ping{address="Pandora", timeout=2, callback=logPingResult}

__NOTOC__

Function devices.system.CustomCGI()

2017-05-05T17:24:51Z

Jturon:

{{DISPLAYTITLE:function devices.system.CustomCGI()}}
Execute HTTP GET call to given url. The call is one-way only. To read the HTTP response, use [[CgiGet()]].

nil devices.system.CustomCGI(table <code>config</code>)

=== Parameters ===
table config{<code>url</code>}
* string <code>url</code> address to call

=== Return value ===
nil

=== Usage ===
-- sends HTTP GET request
devices.system.CustomCGI{url="http://192.168.0.1/handler.cgi?outlet=1&state=0"}

=== See also ===
* [[CgiGet()]] to send HTTP request and handle HTTP response

__NOTOC__

Function cgiGet()

2017-05-05T17:23:49Z

Jturon:

{{DISPLAYTITLE:function cgiGet()}}
Execute HTTP GET call to given url and read the response. The call is asynchronous: the code execution proceeds immediately and when the response arrives, callback function is called. To perform simple HTTP GET call without response handling, use simpler [[Devices.system.CustomCGI()|devices.system.CustomCGI()]]

nil devices.system.cgiGet(table <code>config</code>)

=== Parameters ===
table config{<code>url</code>, <code>callback</code>, <code style="color: #777">timeout</code>, <code style="color: #777">bufferSize</code>}
* string <code>url</code> address to call
* function{response} <code>callback</code> this function is called when response arrives
* optional number <code>timeout</code> maximum seconds to wait for response (default 30)
* optional number <code>bufferSize</code> bytes of memory to allocate for response (min. 4k, max 1M)

=== Callback Parameters ===
table response{<code>result</code>, <code>errInfo</code>, <code>received</code>, <code>buffer</code>}
* number <code>result</code> error code of the response (see below)
* string <code>errInfo</code> error description (if result>0)
* number <code>received</code> response length
* string <code>buffer</code> response body

=== Error Code of the response ===
* 0 success, response HTTP/GET 2xx
* 22 response HTTP/GET 4xx
* 27 buffer overflow
* 28 response is timed out

=== Return value ===
nil

=== Usage ===
-- callback function to read the response
local function getResponse{response}
if response.result > 0 then
logf("response failed with error code %d.", response.result)
else
logf("current credit is %d", tonumber(response.buffer))
end
end

-- sends HTTP request and handles the response
devices.system.CgiGet{url="http://example.com/getcredit?id=42",getResponse}

=== Requirements ===
Netio FirmWare 2.3.5+

=== See also ===
* [[Devices.system.CustomCGI()|devices.system.CustomCGI()]] to send HTTP request without response handling

__NOTOC__

Function toboolean()

2017-05-05T17:22:37Z

Jturon:

{{DISPLAYTITLE:function toboolean()}}
Converts variable to boolean (true or false) value (the only type usable in conditions).

boolean toboolean(mixed <code>variable</code>)

=== Parameters ===
* mixed <code>variable</code> will be converted to boolean value.

=== Return value ===
Falsy values are:
* number 0
* boolean false
* string ""
* table {}

Anything else converts to true.

=== Usage ===
local answer = 42
if toboolean(answer) then
log("42 is true!")
else
log("42 is false!")
end

To use inverse conversion (boolean to number) use 'x and 1 or 0' idiom:

local x = true
logf("x is %d", x and 1 or 0)

=== See also ===
Lua system's tonumber() and tostring() functions.

__NOTOC__

Function logf()

2017-05-05T17:21:42Z

Jturon:

{{DISPLAYTITLE:function log()}}
Insert a formated record into the socket's event log. Suitable for debugging purposes.

nil logf(string <code>message</code>)

=== Parameters ===
* string <code>message</code> will be inserted into the event log. Can use tokens described below. The tokens will be replaced by following parameters (variable arguments).

=== Tokens ===
* <code>%d</code> is substituted by following argument as a number
* <code>%s</code> is substituted by following argument as a number

There is no <code>%b</code> token to display boolean values. To display boolean x as a number, use 'x and 1 or 0' idiom (true as 1, false as 0).

=== Return value ===
nil

=== Usage ===
local a = 42
local b = false
local c = "Hello";

-- displays 'test: 42, 0, Hello.'
log("test: %d, %d, %s.", a, b and 1 or 0, c)

=== See also ===
* [[Function log()|log()]] to display unformatted string and system properties

__NOTOC__

Function log()

2017-05-05T17:21:24Z

Jturon:

{{DISPLAYTITLE:function log()}}
Insert a record into the socket's event log. Suitable for debugging purposes.

nil log(string <code>message</code>)

=== Parameters ===
* string <code>message</code> will be inserted into the event log. Can display socket properties using ${property} syntax - see the example below.

=== Return value ===
nil

=== Usage ===
-- prints i.e. 'The power of outlet 1 is 17 Watts.'
log("The power of outlet 1 is ${devices.system.output1_consumption} Watts.")

=== See also ===
* [[Function logf()|logf()]] to display formatted string

__NOTOC__

Function xml.parse()

2017-05-05T17:20:10Z

Jturon:

{{DISPLAYTITLE:function xml.check()}}
Parses xml string.
XmlElement xml.parse(string <code>xml</code>)

=== Parameters ===
* string <code>xml</code> string to parse

=== Return value ===
XmlElement

Consecutive spaces are trimmed to single space.

== XmlElement ==

=== string <code>name</code> ===
name of the node
log(xml.parse("<note>something</note>").name) -- note

=== string <code>text</code> ===
text content of the node (excluding the contents of child nodes). To read all content as a text, use .innerXml (see below)
local data = xml.parse("<note>something <big>really</big> good</note>")
log(data.text) -- something good

=== string/nil <code>attr(string name)</code> ===
returns the value of a single attribute; if the attribute doesn't exists, ruturns nil
local data = xml.parse('<note from="ann" to="bob">hello</note>')
log(data.attr("from")) -- ann

=== table <code>attr()</code> ===
returns all attributes as a table
local data = xml.parse('<note from="ann" to="bob">hello</note>')
local attrs = data.attr()
logf("%s -> %s", attrs.from, attrs["to"]) -- ann -> bob

=== XmlElement/nil <code>child(string name)</code> ===
returns first child node with given name, nil if no such element is found
local data = [[
<papers>
<book>Bible</book>
<magazine>Automoto Revue</magazine>
<book>Quran</book>
</papers>
]]
local parsed = xml.parse(data)
log(parsed.child("book").text) -- Bible

=== array <code>children(optional string name)</code> ===
returns all child nodes; if name is provided, the nodes are filtered by the name
local data = [[
<papers>
<book>Bible</book>
<magazine>Automoto Revue</magazine>
<book>Quran</book>
</papers>
]]
local parsed = xml.parse(data)
log(parsed.children("book")[2].text) -- Quran
log(parsed.children()[2].text) -- Automoto Revue

===XmlElement/nil <code>get(string/number...)</code> ===
traverses the xml tree and filters the result for each argument:
* string descend into first node of given name
* number descend into n-th node of name specified by previous argument
local data = [[
<root>
<papers>
<book>Bible</book>
</papers>
<papers>
<magazine>Automoto Revue</magazine>
<book>Quran</book>
</papers>
</root>
]]
local parsed = xml.parse(data)
log(parsed.get("papers",2,"book").text) -- Quran

=== XmlElement/nil <code>next</code> ===
next sibling node of the same name
local data = [[
<papers>
<book>Bible</book>
<magazine>Automoto Revue</magazine>
<book>Quran</book>
</papers>
]]
local parsed = xml.parse(data)
log(parsed.child("book").next.text) -- Quran

=== string <code>xml</code> ===
inner xml of parent XmlElement
local data = [[
<papers>
<book>Bible</book>
<magazine>Automoto Revue</magazine>
<book>Quran</book>
</papers>
]]
local parsed = xml.parse(data)
log(parsed.child("book").xml)
-- <book>Bible</book> <magazine>Automoto Revue</magazine> <book>Quran</book>

=== string <code>innerXml</code> ===
inner xml of parent XmlElement
local data = [[
<papers>
<book>Bible</book>
<magazine>Automoto Revue</magazine>
<book>Quran</book>
</papers>
]]
local parsed = xml.parse(data)
log(parsed.innerXml)
-- <book>Bible</book> <magazine>Automoto Revue</magazine> <book>Quran</book>

=== XmlElement/nil <code>parent</code> ===
parent node
local data = [[
<papers>
<book>Bible</book>
<magazine>Automoto Revue</magazine>
<bool>Quran</bool>
</papers>
]]
local magazine = xml.parse(data).child("magazine")
log(magazine.parent.name) -- papers

=== XmlElement/nil <code>root</code> ===
root node (nil for root)

Function xml.escape()

2017-05-05T17:19:00Z

Jturon:

{{DISPLAYTITLE:function xml.escape()}}
Escapes XML string to fit xml node contents.
string xml.escape(string <code>xml</code>)

=== Parameters ===
* string <code>xml</code> string to escape

=== Return value ===
string
Escaped characters are
{| class="wikitable"
|-
! input !! output
|-
| < || &lt;
|-
| > || &gt;
|-
| " || &quot;
|-
| ' || &apos;
|-
| & || &amp;
|}

=== Usage ===
-- escape string
local note = xml.escape("3<5")
-- put the escaped string "3<5" into xml node
local node = "<note>"..note.."</note>"
-- parse the node
local result = xml.parse(node)
-- check the contents (text is unescaped: "3<5")
log(result.text)

=== See also ===

__NOTOC__

Function xml.check()

2017-05-05T17:17:43Z

Jturon:

{{DISPLAYTITLE:function xml.check()}}
Tests if string is well-formed XML.
boolean xml.check(string <code>xml</code>)

=== Parameters ===
* string <code>xml</code> string to escape

=== Return value ===
boolean
* true if <code>xmlstring</code> is well-formed xml
* false if not

=== Usage ===
local badnode = "<note>".."3<5".."</note>"
local goodnode = "<note>"..xml.escape("3<5").."</note>"
log(tostring(xml.check(badnode))) -- false
log(tostring(xml.check(goodnode))) -- true

=== See also ===
* [[Function xml.escape()|xml.escape()]] to xml-escape string

__NOTOC__

NETIO Lua Manual

2017-05-03T09:50:54Z

Jturon: /* Loops */

NETIO Lua Manual

2017-04-26T09:45:34Z

Jturon: /* Functions */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 supplies power")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is idle")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace()) -- only first return value is used
local free,total = diskSpace() -- values are stored into LHS var-list
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-26T09:42:14Z

Jturon: /* Conditions */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 supplies power")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is idle")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-26T09:40:10Z

Jturon: /* Operators */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T11:35:29Z

Jturon: /* Data types */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types ==
Lua supports these data types:
* nil (to assign nil value effectively deletes the variable)
* boolean (falsy values are nil and false only; "" and 0 evaluates as true)
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. (Tables with numeric indices are, well, just arrays.)

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T11:34:36Z

Jturon:

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Data types ==
Lua supports these data types:
* nil to assign nil value effectively deletes the variable
* boolean falsy values are nil and false only; "" and 0 evaluates as true
* number (decimals only in standard Lua, integers only in Netio Lua)
* string (same strings share same address, so equality operator measures both address and value)
* tables are associative arrays. Tables with numeric indices are, well, just arrays.

local numbers = {2,3,7,5} -- array (first index = 1)
local dictionary = {one=1, two=2, three=3} -- table
local numbersZeroBased = {[0]=2,3,7,5} -- array (first index = 0)

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T11:24:57Z

Jturon: /* Numeric for */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are one-based (in indices are not specified, the first one is 1, not 0).
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T11:24:39Z

Jturon: /* Numeric for */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
Arrays in Lua are 1 based (in indices are not specified, the first one is 1, not 0)
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T11:11:26Z

Jturon: /* Conditions */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has casual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

Function mail()

2017-04-25T11:09:30Z

Jturon:

{{DISPLAYTITLE:function mail()}}
Send SMTP mail. Don't forget to set SMTP server in Settings → E-mail in Netio web interface.

nil mail(string <code>recipient</code>, string <code>subject</code>, string <code>body</code>)

=== Parameters ===
* string <code>recipient</code> - e-mail address of the recipient (To)
* string <code>subject</code> subject of the e-mail
* string <code>body</code> body of the e-mail

=== Return value ===
nil

=== Usage ===
-- sends HTTP GET request
mail("johndoe@example.com","Socket S0732 warning","Warning: S0732 consumption exceeded 10kWh.")

__NOTOC__

NETIO Lua Manual

2017-04-25T11:06:48Z

Jturon:

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Operators ==
Lua has its own manners:
* <code>~=</code> is inequality operator
* <code>..</code> is string concatenation (don't use plus)
* <code><s>i++</s></code> no increment/decrement operator <code>i = i + 1</code>
* <code><s>max = a</code> no ternary operator. Use (and get used to) and idiom instead: <code>max = (a<b) and b or a</code>
* or idiom works: <code>x = x or 42</code> is equivalent to <code>if not x then x = 42 end</code>

== Conditions ==
Lua conditions has usual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T10:57:59Z

Jturon: /* Conditions */

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Conditions ==
Lua conditions has usual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

Note that falsy values are nil and false only. Empty string and 0 evaluates as true. If you come from C, you might be surprised by following snippet:

if devices.system.output1_consumption then
-- always happens, even if the consumption is 0
log("Outlet 1 is on")
end

if not devices.system.output1_consumption then
-- never happens, even if the consumption is 0
log("Outlet 1 is off")
end

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T10:38:49Z

Jturon:

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Conditions ==
Lua conditions has usual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

== Functions ==

Lua allows multiple results (comma separated):

function diskSpace()
return devices.system.freeSpace, devices.system.totalSpace
end

logf("Free space: %d MB", diskSpace())
local free,total = diskSpace()
logf("Free space: %d %%", 100*free/total)

Variable-length arguments are also available:

function sum(...)
local result = 0
for _,v in ipairs(arg) do
result = result + v
end
return result
end

logf("Sum: %d", sum(2,3,5))

NETIO Lua Manual

2017-04-25T09:15:00Z

Jturon:

== Debugging ==
To debug your code, use [[Function log()|log()]] and [[Function logf()|logf()]] functions. See the output in system events log.

== Conditions ==
Lua conditions has usual syntax, see [https://www.lua.org/pil/4.3.1.html here]. Just keep in mind to merge <code>else</code> and <code>if</code> to <code>elseif</code> or multiple <code>end</code>s are required.

== Loops ==
Lua has <code>break</code> statement, but no <code>continue</code> (use condition inside loop instead).
=== While ===
While syntax is not different to other languages:
local i = 0
while i~=3 do
i = i + 1
logf("%d",i)
end

=== Repeat until ===
Repeat until syntax is the same as Pascal's, other languages have similar do-while loops:
local i = 0
repeat
i = i + 1
logf("%d",i)
until i==3

=== Numeric for ===
local arr = {2,3,7,5}
for i=1,#arr do logf("%d",arr[i]) end
<code>for initVar,limit,increment do</code>
* number assignment <code>initVar</code> inits loop-local variable
* number <code>limit</code> loops until initVar reaches this value
* optional number <code>increment</code> after each loop initVar increment by this value (default 1)

=== Generic for ===
Is rather sophisticated. Most common example (the order of elements in <code>pairs()</code> is not guaranteed):
local tab = {one=1, two=2, three=3}
for key,val in pairs(tab) do logf("%s:%d",key,val) end
Generic for syntax
for var_1, ..., var_n in explist do block end
is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
do
local _f, _s, _var = explist
while true do
local var_1, ... , var_n = _f(_s, _var)
_var = var_1
if _var == nil then break end
block
end
end

Iterator closure that holds its state
function iter(a)
local i = 0
return function()
i = i+1
return a[i]
end
end

local arr = {2,3,7,5}
for value in iter(arr) do
logf("%d",value)
end

Stateless iterator (in this case returns variable list: key and value)
function iter(a,i)
i = i+1
if a[i] then return i,a[i] end
end

local arr = {2,3,7,5}
for k,v in iter,arr,0 do
logf("%d:%d",k,v)
end

Same effect using <code>ipairs()</code> Lua function (without initial state)
for k,v in ipairs(arr) do
logf("%d:%d",k,v)
end

Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].

Welcome to NETIO resources & projects & documentation overview

2017-04-25T09:02:23Z

Jturon: /* Netio Programming */

== Netio Programming ==
Netio uses Lua as its scripting language. To master it, follow these references:
* [https://www.lua.org/pil/contents.html Lua tutorial] - If you are new to Lua and programming as such and if you are eager to learn, this is your starting point. Before you proceed to Netio Sockets, this [https://www.lua.org/demo.html online environment] will be a good place to test your first scripts.
* [[Netio Lua Manual]] - A quick jump into Netio Lua programming if you mastered another programming language. If you already know Lua, just keep in mind that Netio Lua loops are limited to 32k cycles and all numbers are integers, not decimals like in standard Lua.
* [[Netio Lua Reference]] - If you can already code in Lua, Netio-specific Lua functions is your main guide to programm Netio Sockets.
* [https://www.lua.org/manual/5.3/ Lua manual] - Although you won't need everything mentioned here, it is worth to peek here from time to time to grasp the concepts of effective Lua programming.