ComputerCraft Wiki - User contributions [en]

Calculator Tutorial

2012-05-06T03:18:30Z

24.20.222.206: Fix num1 and num2 variables

<code>

-- anything after two dashes is a comment, and wont be compiled.
--[[ this is also a comment
and so is this
]]--

--this tutorial will teach you the basics of the print() and read() functions, if statements, as well as some variable use and math operations.

print("Do you want to add, subtract, multiply or divide?") -- this code displays the question within the quotation marks
op = read() -- this code creates a variable called 'op', the read() function stalls the program to accept user input, which is stored in op
print("") -- just gives us some space to work with

print("what is the first number to be operated on?")

num1 = tonumber(read()) -- accepts the first number to be stored in the variable 'number1'
print("")

print("and the second number?")
num2 = tonumber(read())
print("")

-- now we operate on the number depending on what the user typed first

if op == "add" then -- if you need help with conditional statements, see this page: [http://www.troubleshooters.com/codecorn/lua/luaif.htm]
result = num1+num2
end

if op == "multiply" then
result = num1*num2 -- asterisk represents multiply
end

if op == "divide" then
result = num1/num2
end

if op == "subtract" then
result = num1-num2
end

</code>

Download

2012-05-05T17:53:06Z

24.20.222.206: Undo spam, there's been SOO much spam recently

=== You can download the latest version of ComputerCraft [http://www.minecraftforum.net/topic/892282-11-computercraft-13/ here]. ===

{{Changelog}}
[[Category:Lists]]

Template:News

2012-04-25T16:17:56Z

24.20.222.206:

ComputerCraft is currently at version 1.33 for Minecraft 1.2.5.

Template:News

2012-04-25T16:16:16Z

24.20.222.206: Undo revision 1361 by 24.20.222.206 (talk)

ComputerCraft is currently at version '"1.33"' for Minecraft '''1.2.5''.

Template:News

2012-04-25T16:15:59Z

24.20.222.206:

ComputerCraft is currently at version "'1.33'" for Minecraft '''1.2.5''.

Template:News

2012-04-25T16:15:32Z

24.20.222.206:

ComputerCraft is currently at version '"1.33"' for Minecraft '''1.2.5''.

Template:News

2012-04-25T16:15:02Z

24.20.222.206:

ComputerCraft is currently at version '''1.33''' for Minecraft '''1.2.5''.

Template:News

2012-04-25T16:14:47Z

24.20.222.206:

ComputerCraft is currently at version '''1.33'' for Minecraft '''1.2.5''.

Template:News

2012-04-25T16:14:36Z

24.20.222.206:

ComputerCraft is currently at version '''1.33''' for Minecraft '''1.2.5''.

Getting Started

2012-04-25T16:07:14Z

24.20.222.206: Update '1.2.4' to '1.2.5'

== Perquisite: Installing the mods ==
'''It is very important to read everything carefully before asking questions.'''
'''Also, the latest version this mod may not be compatible with the current Minecraft release.'''

# Install [http://www.minecraftforum.net/topic/75440- Risugami's ModLoader 1.2.5]
# Install [http://lexmanos.no-ip.org:8080/job/Forge/Recommended/ Minecraft Forge Recommended Build 1.2.5]
# Download the latest version of [http://www.minecraftforum.net/topic/892282- ComputerCraft 1.33 (1.2.5)]
# Extract the .zip file in *minecraft folder*\mods\. (Tip: If on Windows, on the main screen of Minecraft, go to 'Texture Packs' and click on 'Open texture pack folder'. Go up one folder, there's your Minecraft folder. If on Mac, open Finder, hit Command+Shift+G and type ~/Library/ then hit enter, open 'Application Support' then open 'minecraft')

== Step 1: Crafting the console ==
The recipe is simple: 
{{Crafting grid
|A1=stone |B1=stone |C1=stone
|A2=stone |B2=redstone |C2=stone
|A3=stone |B3=glass pane |C3=stone
|Output=console
}}
 

Right click on the console to use it. 
These are important to remember:
{| border="1" cellpadding="2" cellspacing="0"
!style="background:#EEE" width="200px"|Shortcut
!style="background:#EEE" width="*"|Usage
|-
|CTRL + T
|Closes the current program.
|-
|CTRL + R
|Reboots the console.
|-
|CTRL + S
|Forcefully shuts down the computer.
|}
NOTE: You have to hold the keyboard shortcuts down for at least 1 second! 
These are forced and will close the current program, even if it is still running.

== Step 2: Wiring it all up ==
The console accepts many forms of redstone. For simple structures, such as a password protected door, only a single line of redstone is needed.
However, this mod can do much more. If you need to connect multiple wires to one side, you can just use RedPower's cables. Easy peasy.
Or, you don't do anything in this part. The computer has some great games shipped with and it is even capable of loading web pages.

== Step 3: Programming your system ==
If you've programmed before this shouldn't be hard. It'll feel very comfortable.

Type
edit <filename>
in the terminal to open the included feature-rich  text editor. To get the hang of Lua if you're new, use
edit /rom/programs/redset
to view the code of a simple program 'redset'.

Navigating is easy.
> ls
rom
> cd rom
rom> ls
apis help programs
startup
rom>cd programs
rom/programs>cd /
>
To say it in English: ls '''l'''i'''s'''ts the files and folders in a directory, while cd changes the '''c'''urrent '''d'''irectory. / is the root of the computer.
Again, you don't have to program, but it's a big part of the mod. But you can still play those games.

== Step 4: Test it ==
Make sure that your program is bug-proof before using it as something important. A system controlling the state of an IndustrialCraft² Mark-III Nuclear Reactor to prevent it from overheating shouldn't crash every now and then with "Too long without yielding".

== Step 5: Extend it ==
Give back your part to the community. Help others on the forums or improve the wiki. Or, make your own OS or shell to run on the computers and share it with everybody. You can even create your own peripheral blocks using the API to create even a bigger system. A mainframe, for example.

Talk:Making a Password Protected Door

2012-04-22T17:49:47Z

24.20.222.206:

== I think this can be more "Noob" friendly ==

i am a noob and have just started to use Computer Craft. I was learning how to make a password protected lock and i understood all of it, until it said, " Now to start it, we have the computer call the function after it declares it." This confused me very much and i was hoping someone could clarify or edit the page to be even more "Noob" friendly.

24.20.22.206:
Try the 'Better / Alternative Code', you might understand that more.

Talk:Making a Password Protected Door

2012-04-22T17:49:19Z

24.20.222.206:

== In response to 24.20.222.206 who reverted my changes and commented "Make code better, again" ==

How is it 'better' to leave the computer running when it's not needed?
Assuming this is the desired behaviour, why is it 'better' to reboot the computer each time instead of using a loop?
And assuming ''that'' is the desired behaviour, why is it 'better' to have the call to os.reboot() repeated inside the if blocks instead of once after the if?
<pre>
24.20.22.206:
Loop uses more memory. Also, there's no difference, do you really care that much?
</pre>
::I reverted changes from two users. This guide is supposed to be a reasonably low level tutorial. Simply slapping code on a page is not a tutorial, hence the previous version with screen shots is more noob friendly. Secondly, the latter version used variables that don't need to be variables. [[Special:Contributions/121.45.75.253|121.45.75.253]] 14:07, 16 April 2012 (UTC)

== I think this can be more "Noob" friendly ==

i am a noob and have just started to use Computer Craft. I was learning how to make a password protected lock and i understood all of it, until it said, " Now to start it, we have the computer call the function after it declares it." This confused me very much and i was hoping someone could clarify or edit the page to be even more "Noob" friendly.

24.20.22.206:
Try the 'Better / Alternative Code', you might understand that more.

Talk:Making a Delay function

2012-04-21T23:51:31Z

24.20.222.206: Created page with "==Useless Page?== There's already sleep(seconds), there's no need for this page?"

==Useless Page?==
There's already sleep(seconds), there's no need for this page?

Making a Password Protected Door

2012-04-18T20:04:12Z

24.20.222.206: /* How to make it */

This tutorial covers on how to make a computer output redstone current when the right password is typed in. The current is then used to trigger an iron door.

__TOC__
= How to make it =

A password protected door is actually pretty easy, if you break it into steps.

First, you need to craft a computer, and connect the back to an iron door with redstone. Like this:
[[File:Tutorial1.png]]
[[File:cTutorial2.png]]

Once you're done with the basics, open the computer and edit the "startup" file. (type in 'edit startup')
This will make it so the program will be executed when the computer boots.

Once you access the startup file, enter in these two lines.
[[File:CTutorial3.png]]
(alternatively, if you don't want people looking at your password, E.G in a server, type this code ( instead of 't = io.read()' ): t = read("*") , that will * out the password)
The first line defines a function, so that we can repeat the program if a password is entered,
and the second line is assigning whatever the user types to the variable, "t",
So for example, if I typed "qwerty", it would be t = "qwerty". It also overrides anything else the user types in,
so if I typed in "programs", it would just be t = "programs", and not act as the programs command in the regular
OS. This can very useful.

After you're done with the previous lines, enter in the following line:
[[File:CTutorial4.png]]

This makes it so the program checks if the variable that we declared earlier, "t", equals "password". (You can change password to what you want the actual password to be.)

But now you'll need to put in what to do, depending on if the user typed in the right password.
This next set of lines will do that:

[[File:CTutorial5.png]]

Now, this may seem complicated, but it's really simple. The four lines after the if line, determine what the computer will do if the password is correct. So if it's correct, It'll set the redstone output from it's back to true (on), and open the door. (this is the "redstone.setOutput("back", true)" command.) It'll then wait two seconds, and turn the redstone back off again. It'll then repeat the function, so you don't need to reboot the computer.

However, the last two lines dictate what the computer will do if the password is wrong, which is really just not opening the door, and repeating the function.

And now the finishing touches:

[[File:CTutorial6.png]]

This adds the "Ends" to the if which is inside the function, and the function. So we've declared our function.
Now to start it, we have the computer call the function after it declares it.

Well, you should have your own password protected door!
Feel free to change the script around, maybe add a few success/failure messages, etc, etc.

(NOTE: If the program fails somehow, Pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally, see the [http://computercraft.info/wiki/index.php?title=Making_a_Password_Protected_Door#Stop_people_from_terminating_your_lock No termination section] to stop people from exiting your lock, if someone exits your lock, they could edit your lock file, and finding out your password, now you don't want that!)

= Alternative / Better code =

Type 'edit startup' and type in this code:
(Use Ctrl + T to terminate the program, all code is explained in the comments, the --'s. It's good to read the comments, so you actually know what the code does, you do not need to have the comments in your code, of course)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboot the computer, reopening the lock
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboot the computer, reopening the lock
end
</pre>
= Stop people from terminating your lock =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Making a Password Protected Door

2012-04-18T20:02:58Z

24.20.222.206: /* How to make it */

This tutorial covers on how to make a computer output redstone current when the right password is typed in. The current is then used to trigger an iron door.

__TOC__
= How to make it =

A password protected door is actually pretty easy, if you break it into steps.

First, you need to craft a computer, and connect the back to an iron door with redstone. Like this:
[[File:Tutorial1.png]]
[[File:cTutorial2.png]]

Once you're done with the basics, open the computer and edit the "startup" file. (type in 'edit startup')
This will make it so the program will be executed when the computer boots.

Once you access the startup file, enter in these two lines.
[[File:CTutorial3.png]]
(alternatively, if you don't want people looking at your password, E.G in a server, type this code ( instead of 't = io.read()' ): t = read("*") , that will * out the password)
The first line defines a function, so that we can repeat the program if a password is entered,
and the second line is assigning whatever the user types to the variable, "t",
So for example, if I typed "qwerty", it would be t = "qwerty". It also overrides anything else the user types in,
so if I typed in "programs", it would just be t = "programs", and not act as the programs command in the regular
OS. This can very useful.

After you're done with the previous lines, enter in the following line:
[[File:CTutorial4.png]]

This makes it so the program checks if the variable that we declared earlier, "t", equals "password". (You can change password to what you want the actual password to be.)

But now you'll need to put in what to do, depending on if the user typed in the right password.
This next set of lines will do that:

[[File:CTutorial5.png]]

Now, this may seem complicated, but it's really simple. The four lines after the if line, determine what the computer will do if the password is correct. So if it's correct, It'll set the redstone output from it's back to true (on), and open the door. (this is the "redstone.setOutput("back", true)" command.) It'll then wait two seconds, and turn the redstone back off again. It'll then repeat the function, so you don't need to reboot the computer.

However, the last two lines dictate what the computer will do if the password is wrong, which is really just not opening the door, and repeating the function.

And now the finishing touches:

[[File:CTutorial6.png]]

This adds the "Ends" to the if which is inside the function, and the function. So we've declared our function.
Now to start it, we have the computer call the function after it declares it.

Well, you should have your own password protected door!
Feel free to change the script around, maybe add a few success/failure messages, etc. etc.

(NOTE: If the program fails somehow, Pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally, see the [http://computercraft.info/wiki/index.php?title=Making_a_Password_Protected_Door#Stop_people_from_terminating_your_lock No termination section] to stop people from exiting your lock)

= Alternative / Better code =

Type 'edit startup' and type in this code:
(Use Ctrl + T to terminate the program, all code is explained in the comments, the --'s. It's good to read the comments, so you actually know what the code does, you do not need to have the comments in your code, of course)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboot the computer, reopening the lock
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboot the computer, reopening the lock
end
</pre>
= Stop people from terminating your lock =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Making a Password Protected Door

2012-04-18T20:01:04Z

24.20.222.206: /* How to make it */

This tutorial covers on how to make a computer output redstone current when the right password is typed in. The current is then used to trigger an iron door.

__TOC__
= How to make it =

A password protected door is actually pretty easy, if you break it into steps.

First, you need to craft a computer, and connect the back to an iron door with redstone. Like this:
[[File:Tutorial1.png]]
[[File:cTutorial2.png]]

Once you're done with the basics, open the computer and edit the "startup" file. (type in 'edit startup')
This will make it so the program will be executed when the computer boots.

Once you access the startup file, enter in these two lines.
[[File:CTutorial3.png]]
(alternatively, if you don't want people looking at your password, E.G in a server, type this code ( instead of 't = io.read()' ): t = read("*") , that will * out the password)
The first line defines a function, so that we can repeat the program if a password is entered,
and the second line is assigning whatever the user types to the variable, "t",
So for example, if I typed "qwerty", it would be t = "qwerty". It also overrides anything else the user types in,
so if I typed in "programs", it would just be t = "programs", and not act as the programs command in the regular
OS. This can very useful.

After you're done with the previous lines, enter in the following line:
[[File:CTutorial4.png]]

This makes it so the program checks if the variable that we declared earlier, "t", equals "password". (You can change password to what you want the actual password to be.)

But now you'll need to put in what to do, depending on if the user typed in the right password.
This next set of lines will do that:

[[File:CTutorial5.png]]

Now, this may seem complicated, but it's really simple. The four lines after the if line, determine what the computer will do if the password is correct. So if it's correct, It'll set the redstone output from it's back to true (on), and open the door. (this is the "redstone.setOutput("back", true)" command.) It'll then wait two seconds, and turn the redstone back off again. It'll then repeat the function, so you don't need to reboot the computer.

However, the last two lines dictate what the computer will do if the password is wrong, which is really just not opening the door, and repeating the function.

And now the finishing touches:

[[File:CTutorial6.png]]

This adds the "Ends" to the if which is inside the function, and the function. So we've declared our function.
Now to start it, we have the computer call the function after it declares it.

Well, you should have your own password protected door!
Feel free to change the script around, maybe add a few success/failure messages, etc. etc.

(NOTE: If the program fails somehow, Pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally)

= Alternative / Better code =

Type 'edit startup' and type in this code:
(Use Ctrl + T to terminate the program, all code is explained in the comments, the --'s. It's good to read the comments, so you actually know what the code does, you do not need to have the comments in your code, of course)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboot the computer, reopening the lock
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboot the computer, reopening the lock
end
</pre>
= Stop people from terminating your lock =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Making a Password Protected Door

2012-04-18T20:00:12Z

24.20.222.206: /* How to make it */

This tutorial covers on how to make a computer output redstone current when the right password is typed in. The current is then used to trigger an iron door.

__TOC__
= How to make it =

A password protected door is actually pretty easy, if you break it into steps.

First, you need to craft a computer, and connect the back to an iron door with redstone. Like this:
[[File:Tutorial1.png]]
[[File:cTutorial2.png]]

Once you're done with the basics, open the computer and edit the "startup" file. (type in 'edit startup')
This will make it so the program will be executed when the computer boots.

Once you access the startup file, enter in these two lines.
[[File:CTutorial3.png]]
(alternatively, if you don't want people looking at your password, E.G in a server, type this code ( instead of 't = io.read()' ): <pre>t = read("*")</pre>
The first line defines a function, so that we can repeat the program if a password is entered,
and the second line is assigning whatever the user types to the variable, "t",
So for example, if I typed "qwerty", it would be t = "qwerty". It also overrides anything else the user types in,
so if I typed in "programs", it would just be t = "programs", and not act as the programs command in the regular
OS. This can very useful.

After you're done with the previous lines, enter in the following line:
[[File:CTutorial4.png]]

This makes it so the program checks if the variable that we declared earlier, "t", equals "password". (You can change password to what you want the actual password to be.)

But now you'll need to put in what to do, depending on if the user typed in the right password.
This next set of lines will do that:

[[File:CTutorial5.png]]

Now, this may seem complicated, but it's really simple. The four lines after the if line, determine what the computer will do if the password is correct. So if it's correct, It'll set the redstone output from it's back to true (on), and open the door. (this is the "redstone.setOutput("back", true)" command.) It'll then wait two seconds, and turn the redstone back off again. It'll then repeat the function, so you don't need to reboot the computer.

However, the last two lines dictate what the computer will do if the password is wrong, which is really just not opening the door, and repeating the function.

And now the finishing touches:

[[File:CTutorial6.png]]

This adds the "Ends" to the if which is inside the function, and the function. So we've declared our function.
Now to start it, we have the computer call the function after it declares it.

Well, you should have your own password protected door!
Feel free to change the script around, maybe add a few success/failure messages, etc. etc.

(NOTE: If the program fails somehow, Pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally)

= Alternative / Better code =

Type 'edit startup' and type in this code:
(Use Ctrl + T to terminate the program, all code is explained in the comments, the --'s. It's good to read the comments, so you actually know what the code does, you do not need to have the comments in your code, of course)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboot the computer, reopening the lock
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboot the computer, reopening the lock
end
</pre>
= Stop people from terminating your lock =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Making a Password Protected Door

2012-04-18T19:57:14Z

24.20.222.206:

This tutorial covers on how to make a computer output redstone current when the right password is typed in. The current is then used to trigger an iron door.

__TOC__
= How to make it =

A password protected door is actually pretty easy, if you break it into steps.

First, you need to craft a computer, and connect the back to an iron door with redstone. Like this:
[[File:Tutorial1.png]]
[[File:cTutorial2.png]]

Once you're done with the basics, open the computer and edit the "startup" file. (type in 'edit startup')
This will make it so the program will be executed when the computer boots.

Once you access the startup file, enter in these two lines.
[[File:CTutorial3.png]]

The first line defines a function, so that we can repeat the program if a password is entered,
and the second line is assigning whatever the user types to the variable, "t",
So for example, if I typed "qwerty", it would be t = "qwerty". It also overrides anything else the user types in,
so if I typed in "programs", it would just be t = "programs", and not act as the programs command in the regular
OS. This can very useful.

After you're done with the previous lines, enter in the following line:
[[File:CTutorial4.png]]

This makes it so the program checks if the variable that we declared earlier, "t", equals "password". (You can change password to what you want the actual password to be.)

But now you'll need to put in what to do, depending on if the user typed in the right password.
This next set of lines will do that:

[[File:CTutorial5.png]]

Now, this may seem complicated, but it's really simple. The four lines after the if line, determine what the computer will do if the password is correct. So if it's correct, It'll set the redstone output from it's back to true (on), and open the door. (this is the "redstone.setOutput("back", true)" command.) It'll then wait two seconds, and turn the redstone back off again. It'll then repeat the function, so you don't need to reboot the computer.

However, the last two lines dictate what the computer will do if the password is wrong, which is really just not opening the door, and repeating the function.

And now the finishing touches:

[[File:CTutorial6.png]]

This adds the "Ends" to the if which is inside the function, and the function. So we've declared our function.
Now to start it, we have the computer call the function after it declares it.

Well, you should have your own password protected door!
Feel free to change the script around, maybe add a few success/failure messages, etc. etc.

(NOTE: If the program fails somehow, Pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally)

= Alternative / Better code =

Type 'edit startup' and type in this code:
(Use Ctrl + T to terminate the program, all code is explained in the comments, the --'s. It's good to read the comments, so you actually know what the code does, you do not need to have the comments in your code, of course)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboot the computer, reopening the lock
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboot the computer, reopening the lock
end
</pre>
= Stop people from terminating your lock =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Talk:Making a Password Protected Door

2012-04-16T02:51:57Z

24.20.222.206: /* In response to 24.20.222.206 who reverted my changes and commented "Make code better, again" */

Talk:Making a Password Protected Door

2012-04-16T02:51:37Z

24.20.222.206: /* In response to 24.20.222.206 who reverted my changes and commented "Make code better, again" */

Getting Started

2012-04-15T18:01:58Z

24.20.222.206: /* Perquisite: Installing the mods */

== Perquisite: Installing the mods ==
'''It is very important to read everything carefully before asking questions.'''
'''Also, the latest version this mod may not be compatible with the current Minecraft release.'''

# Install [http://www.minecraftforum.net/topic/75440- Risugami's ModLoader 1.2.4]
# Install [http://www.minecraftforum.net/topic/86765- SDK's ModLoaderMP 1.2.4]
# Install [http://lexmanos.no-ip.org:8080/job/Forge/Recommended/ Minecraft Forge Recommended Build 1.2.4]
# Download the latest version of [http://www.minecraftforum.net/topic/892282- ComputerCraft 1.32 (1.2.4)]
# Extract the .zip file in *minecraft folder*\mods\. (Tip: If on Windows, on the main screen of Minecraft, go to 'Texture Packs' and click on 'Open texture pack folder'. Go up one folder, there's your Minecraft folder. If on Mac, open Finder, hit Command+Shift+G and type ~/Library/ then hit enter, open 'Application Support' then open 'minecraft')

== Step 1: Crafting the console ==
The recipe is simple: 
{{Crafting grid
|A1=stone |B1=stone |C1=stone
|A2=stone |B2=redstone |C2=stone
|A3=stone |B3=glass pane |C3=stone
|Output=console
}}
 

Right click on the console to use it. 
These are important to remember:
{| border="1" cellpadding="2" cellspacing="0"
!style="background:#EEE" width="200px"|Shortcut
!style="background:#EEE" width="*"|Usage
|-
|CTRL + T
|Closes the current program.
|-
|CTRL + R
|Reboots the console.
|-
|CTRL + S
|Forcefully shuts down the computer.
|}
NOTE: You have to hold the keyboard shortcuts down for at least 1 second! 
These are forced and will close the current program, even if it is still running.

== Step 2: Wiring it all up ==
The console accepts many forms of redstone. For simple structures, such as a password protected door, only a single line of redstone is needed.
However, this mod can do much more. If you need to connect multiple wires to one side, you can just use RedPower's cables. Easy peasy.
Or, you don't do anything in this part. The computer has some great games shipped with and it is even capable of loading web pages.

== Step 3: Programming your system ==
If you've programmed before this shouldn't be hard. It'll feel very comfortable.

Type
edit <filename>
in the terminal to open the included feature-rich  text editor. To get the hang of Lua if you're new, use
edit /rom/programs/redset
to view the code of a simple program 'redset'.

Navigating is easy.
> ls
rom
> cd rom
rom> ls
apis help programs
startup
rom>cd programs
rom/programs>cd /
>
To say it in English: ls '''l'''i'''s'''ts the files and folders in a directory, while cd changes the '''c'''urrent '''d'''irectory. / is the root of the computer.
Again, you don't have to program, but it's a big part of the mod. But you can still play those games.

== Step 4: Test it ==
Make sure that your program is bug-proof before using it as something important. A system controlling the state of an IndustrialCraft² Mark-III Nuclear Reactor to prevent it from overheating shouldn't crash every now and then with "Too long without yielding".

== Step 5: Extend it ==
Give back your part to the community. Help others on the forums or improve the wiki. Or, make your own OS or shell to run on the computers and share it with everybody. You can even create your own peripheral blocks using the API to create even a bigger system. A mainframe, for example.

Getting Started

2012-04-15T18:01:33Z

24.20.222.206: Permanent links

== Perquisite: Installing the mods ==
'''It is very important to read everything carefully before asking questions.'''
'''Also, the latest version this mod may not be compatible with the current Minecraft release.'''

# Install [http://www.minecraftforum.net/topic/75440- Risugami's ModLoader 1.2.4]
# Install [http://www.minecraftforum.net/topic/86765- SDK's ModLoaderMP 1.2.4]
# Install [http://lexmanos.no-ip.org:8080/job/Forge/Recommended/ Minecraft Forge Recommended Build 1.2.4]
# Download the latest version of [http://www.minecraftforum.net/topic/892282-123-computercraft-131-now-updated-and-with-monitors/ ComputerCraft 1.32 (1.2.4)]
# Extract the .zip file in *minecraft folder*\mods\. (Tip: If on Windows, on the main screen of Minecraft, go to 'Texture Packs' and click on 'Open texture pack folder'. Go up one folder, there's your Minecraft folder. If on Mac, open Finder, hit Command+Shift+G and type ~/Library/ then hit enter, open 'Application Support' then open 'minecraft')

== Step 1: Crafting the console ==
The recipe is simple: 
{{Crafting grid
|A1=stone |B1=stone |C1=stone
|A2=stone |B2=redstone |C2=stone
|A3=stone |B3=glass pane |C3=stone
|Output=console
}}
 

Right click on the console to use it. 
These are important to remember:
{| border="1" cellpadding="2" cellspacing="0"
!style="background:#EEE" width="200px"|Shortcut
!style="background:#EEE" width="*"|Usage
|-
|CTRL + T
|Closes the current program.
|-
|CTRL + R
|Reboots the console.
|-
|CTRL + S
|Forcefully shuts down the computer.
|}
NOTE: You have to hold the keyboard shortcuts down for at least 1 second! 
These are forced and will close the current program, even if it is still running.

== Step 2: Wiring it all up ==
The console accepts many forms of redstone. For simple structures, such as a password protected door, only a single line of redstone is needed.
However, this mod can do much more. If you need to connect multiple wires to one side, you can just use RedPower's cables. Easy peasy.
Or, you don't do anything in this part. The computer has some great games shipped with and it is even capable of loading web pages.

== Step 3: Programming your system ==
If you've programmed before this shouldn't be hard. It'll feel very comfortable.

Type
edit <filename>
in the terminal to open the included feature-rich  text editor. To get the hang of Lua if you're new, use
edit /rom/programs/redset
to view the code of a simple program 'redset'.

Navigating is easy.
> ls
rom
> cd rom
rom> ls
apis help programs
startup
rom>cd programs
rom/programs>cd /
>
To say it in English: ls '''l'''i'''s'''ts the files and folders in a directory, while cd changes the '''c'''urrent '''d'''irectory. / is the root of the computer.
Again, you don't have to program, but it's a big part of the mod. But you can still play those games.

== Step 4: Test it ==
Make sure that your program is bug-proof before using it as something important. A system controlling the state of an IndustrialCraft² Mark-III Nuclear Reactor to prevent it from overheating shouldn't crash every now and then with "Too long without yielding".

== Step 5: Extend it ==
Give back your part to the community. Help others on the forums or improve the wiki. Or, make your own OS or shell to run on the computers and share it with everybody. You can even create your own peripheral blocks using the API to create even a bigger system. A mainframe, for example.

Making a Password Protected Door

2012-04-15T17:55:59Z

24.20.222.206: Make code better, again

This tutorial covers on how to make a Computer output redstone current when the right password is typed in. The current is used to trigger an iron door on the left side of the Computer, you can change the side, of course.

__TOC__
= How to make it =
Here's the code for it, I'll explain what everything does in the comments. (the --'s).
In your Computer, type 'edit startup'. Then write this code into there. (You don't need the comments (the --'s) in the final code)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboots the computer, effectively reopening the lock.
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboots the computer, effectively reopening the lock.
end
</pre>

(NOTE: If the program fails somehow, pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally. Visit the 'No Termination' section to stop people from exiting your lock.)

= No Termination =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Making a Password Protected Door

2012-04-15T17:55:27Z

24.20.222.206: /* How to make it */

This tutorial covers on how to make a Computer output redstone current when the right password is typed in. The current is used to trigger an iron door on the left side of the Computer, you can change the side, of course.

__TOC__
= How to make it =
Here's the code for it, I'll explain what everything does in the comments. (the --'s).
In your Computer, type 'edit startup'. Then write this code into there. (You don't need the comments (the --'s) in the final code)
<pre>
local side = "left" -- Change left to whatever side your door / redstone is on, E.G: left, right, front, back, bottom, top. Be sure to leave the "s around it, though
local password = "bacon" -- Change bacon to what you want your password to be. Be sure to leave the "s around it, though
local opentime = 5 -- Change 5 to how long (in seconds) you want the redstone current to be on. Don't put "s around it, though
term.clear() -- Clears the screen
term.setCursorPos(1,1) -- Fixes the cursor position
write("Password: ") -- Prints 'Password: ' to the screen
local input = read("*") -- Makes the variable 'input' have the contents of what the user types in, the "*" part sensors out the password
if input == (password) then -- Checks if the user inputted the correct password
term.clear() -- Already explained up top
term.setCursorPos(1,1)
print("Password correct!") -- Prints 'Password correct!' to the screen
rs.setOutput(side,true) -- Output a redstone current to the side you specified
sleep(opentime) -- Wait the amount of seconds you specifed, then..
rs.setOutput(side,false) -- Stop outputting a redstone current
os.reboot() -- Reboots the computer, effectively reopening the lock.
else -- Checks if the user didn't input the correct password
term.clear()
term.setCursorPos()
print("Password incorrect!") -- Prints 'Password incorrect!' to the screen
sleep(2) -- Waits 2 seconds
os.reboot() -- Reboots the computer, effectively reopening the lock.
end
</pre>

(NOTE: If the program fails somehow, pressing and holding Ctrl + T will terminate it, and allow you to edit it like normally. Visit the 'No Termination' section to stop people from exiting your lock.)

= Alternative Ending =

If you want your program to start again when it gets to the end instead of shutting down the computer, add 'do while true' before the first line, delete the last line 'os.shutdown' and add an extra 'end' at the end so there are two of them.
do while (condition) ... end is a loop structure. While the condition equates to true, it will keep executing the code that lies between the do while (condition) and the end. We can make it always loop by simply writing true as the condition.

= No Termination =

If you don't want people holding CTRL+T and quitting your lock, use this code at the top of your program:
<pre>os.pullEvent = os.pullEventRaw</pre>

[[Category:Tutorials]]

Talk:Turtle Tutorial

2012-03-26T18:15:29Z

24.20.222.206:

i need help,i get this error from my code

mine:1: attempt to call nil

PS ( mine is the name of the program)
What is your code?

Wireless Modem

2012-02-24T04:18:30Z

24.20.222.206:

PAGE CURRENTLY IN BETA

Wireless Modem

2012-02-24T04:17:50Z

24.20.222.206: Created page with "The modem is a wireless modem, it does shtuff."

The modem is a wireless modem, it does shtuff.