os

The os API allows interacting with the current computer.

loadAPI(path)Source

🛈 Deprecated

When possible it's best to avoid using this function. It pollutes the global table and can mask errors.

require should be used to load libraries instead.

Loads the given API into the global environment.

This function loads and executes the file at the given path, and all global variables and functions exported by it will by available through the use of myAPI.<function name>, where myAPI is the base name of the API file.

Parameters

1. path string The path of the API to load.

Returns

1. boolean Whether or not the API was successfully loaded.

Changes

• New in version 1.2

unloadAPI(name)Source

🛈 Deprecated

See os.loadAPI for why.

Unloads an API which was loaded by os.loadAPI.

This effectively removes the specified table from _G.

Parameters

1. name string The name of the API to unload.

Changes

• New in version 1.2

pullEvent([filter])Source

Pause execution of the current thread and waits for any events matching filter.

This function yields the current process and waits for it to be resumed with a vararg list where the first element matches filter. If no filter is supplied, this will match all events.

Unlike os.pullEventRaw, it will stop the application upon a "terminate" event, printing the error "Terminated".

Parameters

1. filter? string Event to filter for.

Returns

1. string event The name of the event that fired.
2. any param... Optional additional parameters of the event.

Usage

• Listen for mouse_click events.

  while true do
      local event, button, x, y = os.pullEvent("mouse_click")
      print("Button", button, "was clicked at", x, ",", y)
  end

• Listen for multiple events.

  while true do
      local eventData = {os.pullEvent()}
      local event = eventData[1]
  
      if event == "mouse_click" then
          print("Button", eventData[2], "was clicked at", eventData[3], ",", eventData[4])
      elseif event == "key" then
          print("Key code", eventData[2], "was pressed")
      end
  end

See also

• os.pullEventRaw To pull the terminate event.

Changes

• Changed in version 1.3: Added filter argument.

pullEventRaw([filter])Source

Pause execution of the current thread and waits for events, including the terminate event.

This behaves almost the same as os.pullEvent, except it allows you to handle the terminate event yourself - the program will not stop execution when Ctrl+T is pressed.

Parameters

1. filter? string Event to filter for.

Returns

1. string event The name of the event that fired.
2. any param... Optional additional parameters of the event.

Usage

• Listen for terminate events.

  while true do
      local event = os.pullEventRaw()
      if event == "terminate" then
          print("Caught terminate event!")
      end
  end

See also

• os.pullEvent To pull events normally.

sleep(time)Source

Pauses execution for the specified number of seconds, alias of _G.sleep.

Parameters

1. time number The number of seconds to sleep for, rounded up to the nearest multiple of 0.05.

version()Source

Get the current CraftOS version (for example, CraftOS 1.9).

This is defined by bios.lua. For the current version of CC:Tweaked, this should return CraftOS 1.9.

Returns

1. string The current CraftOS version.

Usage

• os.version()

run(env, path, ...)Source

Run the program at the given path with the specified environment and arguments.

This function does not resolve program names like the shell does. This means that, for example, os.run("edit") will not work. As well as this, it does not provide access to the shell API in the environment. For this behaviour, use shell.run instead.

If the program cannot be found, or failed to run, it will print the error and return false. If you want to handle this more gracefully, use an alternative such as loadfile.

Parameters

1. env table The environment to run the program with.
2. path string The exact path of the program to run.
3. ... The arguments to pass to the program.

Returns

1. boolean Whether or not the program ran successfully.

Usage

• Run the default shell from within your program:

  os.run({}, "/rom/programs/shell.lua")

See also

• shell.run
• loadfile

queueEvent(name, ...)Source

Adds an event to the event queue. This event can later be pulled with os.pullEvent.

Parameters

1. name string The name of the event to queue.
2. ... The parameters of the event. These can be any primitive type (boolean, number, string) as well as tables. Other types (like functions), as well as metatables, will not be preserved.

See also

• os.pullEvent To pull the event queued

startTimer(time)Source

Starts a timer that will run for the specified number of seconds. Once the timer fires, a timer event will be added to the queue with the ID returned from this function as the first parameter.

As with sleep, the time will automatically be rounded up to the nearest multiple of 0.05 seconds, as it waits for a fixed amount of world ticks.

Parameters

1. time number The number of seconds until the timer fires.

Returns

1. number The ID of the new timer. This can be used to filter the timer event, or cancel the timer.

Throws

• If the time is below zero.

See also

• cancelTimer To cancel a timer.

cancelTimer(token)Source

Cancels a timer previously started with startTimer. This will stop the timer from firing.

Parameters

1. token number The ID of the timer to cancel.

See also

• startTimer To start a timer.

Changes

• New in version 1.6

setAlarm(time)Source

Sets an alarm that will fire at the specified in-game time. When it fires, * an alarm event will be added to the event queue with the ID * returned from this function as the first parameter.

Parameters

1. time number The time at which to fire the alarm, in the range [0.0, 24.0).

Returns

1. number The ID of the new alarm. This can be used to filter the alarm event, or cancel the alarm.

Throws

• If the time is out of range.

See also

• cancelAlarm To cancel an alarm.

Changes

• New in version 1.2

cancelAlarm(token)Source

Cancels an alarm previously started with setAlarm. This will stop the alarm from firing.

Parameters

1. token number The ID of the alarm to cancel.

See also

• setAlarm To set an alarm.

Changes

• New in version 1.6

shutdown()Source

Shuts down the computer immediately.

reboot()Source

Reboots the computer immediately.

getComputerID()Source

Returns the ID of the computer.

Returns

1. number The ID of the computer.

computerID()Source

Returns the ID of the computer.

Returns

1. number The ID of the computer.

getComputerLabel()Source

Returns the label of the computer, or nil if none is set.

Returns

1. string | nil The label of the computer.

Changes

• New in version 1.3

computerLabel()Source

Returns the label of the computer, or nil if none is set.

Returns

1. string | nil The label of the computer.

Changes

• New in version 1.3

setComputerLabel([label])Source

Set the label of this computer.

Parameters

1. label? string The new label. May be nil in order to clear it.

Changes

• New in version 1.3

clock()Source

Returns the number of seconds that the computer has been running.

Returns

1. number The computer's uptime.

Changes

• New in version 1.2

time([locale])Source

Returns the current time depending on the string passed in. This will always be in the range [0.0, 24.0).

• If called with ingame, the current world time will be returned. This is the default if nothing is passed.
• If called with utc, returns the hour of the day in UTC time.
• If called with local, returns the hour of the day in the timezone the server is located in.

This function can also be called with a table returned from date, which will convert the date fields into a UNIX timestamp (number of seconds since 1 January 1970).

Parameters

1. locale? string | table The locale of the time, or a table filled by os.date("*t") to decode. Defaults to ingame locale if not specified.

Returns

1. any The hour of the selected locale, or a UNIX timestamp from the table, depending on the argument passed in.

Throws

• If an invalid locale is passed.

Usage

• Print the current in-game time.

  textutils.formatTime(os.time())

See also

• textutils.formatTime To convert times into a user-readable string.
• date To get a date table that can be converted with this function.

Changes

• New in version 1.2
• Changed in version 1.80pr1: Add support for getting the local local and UTC time.
• Changed in version 1.82.0: Arguments are now case insensitive.
• Changed in version 1.83.0: time now accepts table arguments and converts them to UNIX timestamps.

day([args])Source

Returns the day depending on the locale specified.

• If called with ingame, returns the number of days since the world was created. This is the default.
• If called with utc, returns the number of days since 1 January 1970 in the UTC timezone.
• If called with local, returns the number of days since 1 January 1970 in the server's local timezone.

Parameters

1. args? string The locale to get the day for. Defaults to ingame if not set.

Returns

1. number The day depending on the selected locale.

Throws

• If an invalid locale is passed.

Changes

• New in version 1.48
• Changed in version 1.82.0: Arguments are now case insensitive.

epoch([args])Source

Returns the number of milliseconds since an epoch depending on the locale.

• If called with ingame, returns the number of in-game milliseconds since the world was created. This is the default.
• If called with utc, returns the number of milliseconds since 1 January 1970 in the UTC timezone.
• If called with local, returns the number of milliseconds since 1 January 1970 in the server's local timezone.

🛈 info

The ingame time zone assumes that one Minecraft day consists of 86,400,000 milliseconds. Since one in-game day is much faster than a real day (20 minutes), this will change quicker than real time - one real second is equal to 72000 in-game milliseconds. If you wish to convert this value to real time, divide by 72000; to convert to ticks (where a day is 24000 ticks), divide by 3600.

Parameters

1. args? string The locale to get the milliseconds for. Defaults to ingame if not set.

Returns

1. number The milliseconds since the epoch depending on the selected locale.

Throws

• If an invalid locale is passed.

Usage

• Get the current time and use date to convert it to a table.

  -- Dividing by 1000 converts it from milliseconds to seconds.
  local time = os.epoch("local") / 1000
  local time_table = os.date("*t", time)
  print(textutils.serialize(time_table))

Changes

• New in version 1.80pr1

date([format [, time]])Source

Returns a date string (or table) using a specified format string and optional time to format.

The format string takes the same formats as C's strftime function. The format string can also be prefixed with an exclamation mark (!) to use UTC time instead of the server's local timezone.

If the format is exactly *t (optionally prefixed with !), a table will be returned instead. This table has fields for the year, month, day, hour, minute, second, day of the week, day of the year, and whether Daylight Savings Time is in effect. This table can be converted to a UNIX timestamp (days since 1 January 1970) with date.

Parameters

1. format? string The format of the string to return. This defaults to %c, which expands to a string similar to "Sat Dec 24 16:58:00 2011".
2. time? number The time to convert to a string. This defaults to the current time.

Returns

1. any The resulting format string.

Throws

• If an invalid format is passed.

Usage

• Print the current date in a user-friendly string.

  os.date("%A %d %B %Y") -- See the reference above!

Changes

• New in version 1.83.0