Differences

This shows you the differences between two versions of the page.

--- api:computer [2014/07/07 15:00]
sangar
+++ api:computer [2021/04/23 15:04] (current)
heaven31415 [Computer API] Add information about the valid values of frequency for computer.beep() method
@@ Line 5: / Line 5: @@
 - `computer.address(): string`
   The [[:component:component_access|component address]] of this computer.
-- <del>`computer.romAddress(): string`</del>
-  The component address of the computer's ROM file system, used for mounting it on startup. **Deprecated**: this method has been removed in OC 1.3, since there is no ROM anymore starting with OC 1.3.
 - `computer.tmpAddress(): string`
   The component address of the computer's temporary file system (if any), used for mounting it on startup.
 - `computer.freeMemory(): number`
-  The amount of memory currently unused, in bytes. If this gets close to zero your computer will probably soon crash with an out of memory error.
+  The amount of memory currently unused, in bytes. If this gets close to zero your computer will probably soon crash with an out of memory error. Note that for OpenOS, it is highly recommended to at least have 1x tier 1.5 RAM stick or more. The os will boot on a single tier 1 ram stick, but quickly and easily run out of memory.
 - `computer.totalMemory(): number`
   The total amount of memory installed in this computer, in bytes.
@@ Line 17: / Line 15: @@
 - `computer.maxEnergy(): number`
   The maximum amount of energy that can be stored in the network the computer is in. For a robot this is the size of the robot's internal buffer (what you see in the robot's GUI).
-- <del>`computer.isRobot(): boolean`</del>
-  Whether this computer is a robot or not. Mostly useful to allow failing early in some programs, such as the built-in `dig` program. **Deprecated**: This method is deprecated, it was removed in OC 1.3. Use `component.isAvailable("robot")` instead.
 - `computer.uptime(): number`
   The time in real world seconds this computer has been running, measured based on the world time that passed since it was started - meaning this will not increase while the game is paused, for example.
 - `computer.shutdown([reboot: boolean])`
   Shuts down the computer. Optionally reboots the computer, if `reboot` is true, i.e. shuts down, then starts it again automatically. This function never returns.
+  This example will reboot the computer if it has been running for at least 300 seconds(5 minutes)
+```lua
+local computer = require("computer")
+if computer.uptime() >= 300 then
+    computer.shutdown(true)
+end
+```
+- `computer.getBootAddress():string`
+  Get the address of the filesystem component from which to try to boot first. *New since OC 1.3*.
+- `computer.setBootAddress([address:string])`
+  Set the address of the filesystem component from which to try to boot first. Call with nil / no arguments to clear. *New since OC 1.3*.
+- `computer.runlevel(): string|number`
+  Returns the current [[https://en.wikipedia.org/wiki/Runlevel|runlevel]] the computer is in. Current Runlevels in OpenOS are:
+  - `S`: Single-User mode, no components or filesystems initialized yet
+  - `1`: Single-User mode, filesystems and components initialized - OpenOS finished booting
 - `computer.users(): string, ...`
   A list of all users registered on this computer, as a tuple. To iterate the result as a list, use `table.pack` on it, first.
   Please see [[:computer_users|the user rights documentation]].
 - `computer.addUser(name: string): boolean or nil, string`
   Registers a new user with this computer. Returns `true` if the user was successfully added. Returns `nil` and an error message otherwise.
-  The user must be currently in the game. The user will gain full access rights on the computer.
+  The user must be currently in the game. The user will gain full access rights on the computer. In the shell, `useradd USER` is a command line option to invoke this method.
 - `computer.removeUser(name: string): boolean`
   Unregisters a user from this computer. Returns `true` if the user was removed, `false` if they weren't registered in the first place.
-  The user will lose all access to this computer. When the last user is removed from the user list, the computer becomes accessible to all players.
+  The user will lose all access to this computer. When the last user is removed from the user list, the computer becomes accessible to all players. `userdel USER` is a command line option to invoke this method.
 - `computer.pushSignal(name: string[, ...])`
-  Pushes a new signal into the queue. Signals are processed in a FIFO order. The signal has to at least have a name. Arguments to pass along with it are optional. Note that the types supported as signal parameters are limited to the basic types nil, boolean, number and string, tables and functions are not supported.
+  Pushes a new signal into the queue. Signals are processed in a FIFO order. The signal has to at least have a name. Arguments to pass along with it are optional. Note that the types supported as signal parameters are limited to the basic types nil, boolean, number, string, and tables. Yes tables are supported (keep reading). Threads and functions are not supported.
+  Note that only tables of the supported types are supported. That is, tables must compose types supported, such as other strings and numbers, or even sub tables. But not of functions or threads.
 - `computer.pullSignal([timeout: number]): name, ...`
   Tries to pull a signal from the queue, waiting up to the specified amount of time before failing and returning `nil`. If no timeout is specified waits forever.
-  The first returned result is the signal name, following results correspond to what was pushed in `pushSignal`, for example. These vary based on the even type.
+  The first returned result is the signal name, following results correspond to what was pushed in `pushSignal`, for example. These vary based on the event type.
-  **Important**: it is generally advisable to use `event.pull` to wait for events, as opposed to calling this directly. Using `event.pull` will ensure that any other signals arriving in the meantime will be distributed as events, which is required by some libraries to work correctly (e.g. the [[api:term|term]] API). It also provides more advanced filtering.
+  Generally it is more convenient to use `event.pull` from the [[api:event|event]] library. The return value is the very same, but the `event` library provides some more options.
+- `computer.beep([frequency:string or number[, duration: number])`
+  if `frequency` is a number it value must be between 20 and 2000.
+  Causes the computer to produce a beep sound at `frequency` Hz for `duration` seconds. This method is overloaded taking a single string parameter as a pattern of dots `.` and dashes `-` for short and long beeps respectively.
+- `computer.getDeviceInfo(): table`
+  Returns a table of information about installed devices in the computer.
-This example will reboot the computer if it has been running for at least 300 seconds(5 minutes)
-```lua
-local computer = require("computer")
-if computer.uptime() >= 300 then
-    computer.shutdown(true)
-end
-```
 Contents
 -----------
 {{page>api:contents&noheader&noeditbutton&nouser&nofooter}}