# hs.caffeinate

Control system power states (sleeping, preventing sleep, screen locking, etc)

NOTE: Any sleep preventions will be removed when hs.reload() is called. A future version of the module will save/restore state across reloads.

# Submodules

hs.caffeinate.watcher

# API Overview

Functions - API calls offered directly by the extension

currentAssertions
declareUserActivity
fastUserSwitch
get
lockScreen
logOut
restartSystem
sessionProperties
set
shutdownSystem
startScreensaver
systemSleep
toggle

# API Documentation

# Functions

# currentAssertions


Signature	`hs.caffeinate.currentAssertions()`
Type	Function
Description	Fetches information about processes which are currently asserting display/power sleep restrictions
Parameters	None
Returns	A table containing information about current power assertions, with process IDs (PID) as the keys, each of which may contain multiple assertions
Notes	None
Examples	None
Source	extensions/caffeinate/libcaffeinate.m line 296

# declareUserActivity


Signature	`hs.caffeinate.declareUserActivity([id])`
Type	Function
Description	Informs the OS that the user performed some activity
Parameters	id - An option number containing the assertion ID returned by a previous call of this function
Returns	A number containing the ID of the assertion generated by this function
Notes	This is intended to simulate user activity, for example to prevent displays from sleeping, or to wake them up It is not mandatory to re-use assertion IDs if you are calling this function multiple times, but it is recommended that you do so if the calls are related
Examples	None
Source	extensions/caffeinate/libcaffeinate.m line 209

# fastUserSwitch


Signature	`hs.caffeinate.fastUserSwitch()`
Type	Function
Description	Show the Fast User Switch screen (ie a login screen without logging out first)
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 109

# get


Signature	`hs.caffeinate.get(sleepType) -> bool or nil`
Type	Function
Description	Queries whether a particular sleep type is being prevented
Parameters	sleepType - A string containing the type of sleep to inspect (see hs.caffeinate.set() for information about the possible values)
Returns	True if the specified type of sleep is being prevented, false if not. nil if sleepType was an invalid value
Notes	None
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 55

# lockScreen


Signature	`hs.caffeinate.lockScreen()`
Type	Function
Description	Locks the displays
Parameters	None
Returns	None
Notes	This function uses private Apple APIs and could therefore stop working in any given release of macOS without warning.
Examples	None
Source	extensions/caffeinate/libcaffeinate.m line 237

# logOut


Signature	`hs.caffeinate.logOut()`
Type	Function
Description	Request the system log out the current user
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 135

# restartSystem


Signature	`hs.caffeinate.restartSystem()`
Type	Function
Description	Request the system reboot
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 148

# sessionProperties


Signature	`hs.caffeinate.sessionProperties()`
Type	Function
Description	Fetches information from the display server about the current session
Parameters	None
Returns	A table containing information about the current session, or nil if an error occurred
Notes	The keys in this dictionary will vary based on the current state of the system (e.g. local vs VNC login, screen locked vs unlocked).
Examples	None
Source	extensions/caffeinate/libcaffeinate.m line 271

# set

| | | | --------------------------------------------|-------------------------------------------------------------------------------------| | Signature | hs.caffeinate.set(sleepType, aValue, acAndBattery) | | Type | Function | | Description | Configures the sleep prevention settings | | Parameters |

sleepType - A string containing the type of sleep to be configured. The value should be one of: displayIdle - Controls whether the screen will be allowed to sleep (and also the system) if the user is idle. systemIdle - Controls whether the system will be allowed to sleep if the user is idle (display may still sleep). system - Controls whether the system will be allowed to sleep for any reason.
aValue - A boolean, true if the specified type of sleep should be prevented, false if it should be allowed
acAndBattery - A boolean, true if the sleep prevention should apply to both AC power and battery power, false if it should only apply to AC power.

| | Returns |

None

| | Notes |

These calls are not guaranteed to prevent the system sleep behaviours described above. The OS may override them if it feels it must (e.g. if your CPU temperature becomes dangerously high).
The acAndBattery argument only applies to the system sleep type.
You can toggle the acAndBattery state by calling hs.caffeinate.set() again and altering the acAndBattery value.
The acAndBattery option does not appear to work anymore - it is based on private API that is not allowed in macOS 10.15 when running with the Hardened Runtime (which Hammerspoon now uses).

# shutdownSystem


Signature	`hs.caffeinate.shutdownSystem()`
Type	Function
Description	Request the system log out and power down
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 161

# startScreensaver


Signature	`hs.caffeinate.startScreensaver()`
Type	Function
Description	Request the system start the screensaver (which may lock the screen if the OS is configured to do so)
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 122

# systemSleep


Signature	`hs.caffeinate.systemSleep()`
Type	Function
Description	Requests the system to sleep immediately
Parameters	None
Returns	None
Notes	None
Examples	None
Source	extensions/caffeinate/libcaffeinate.m line 193

# toggle


Signature	`hs.caffeinate.toggle(sleepType) -> bool or nil`
Type	Function
Description	Toggles the current state of the specified type of sleep
Parameters	sleepType - A string containing the type of sleep to toggle (see hs.caffeinate.set() for information about the possible values)
Returns	True if the specified type of sleep is being prevented, false if not. nil if sleepType was an invalid value
Notes	If systemIdle is toggled to on, it will apply to AC only
Examples	None
Source	extensions/caffeinate/caffeinate.lua line 82