pmset
CautionPower & sleep settings
pmset -g
Shows/sets power policy. -g assertions reveals what's blocking sleep — the classic no-sleep probe.
Examples
pmset -g assertionsFind what prevents sleep
Syntax
pmset -g [assertions] / pmset sleepnow
Before you run it
Changes affect battery behavior.
Used when you see
Mac won't sleep (or wakes up)
1
See the whole flow →Identify assertions blocking sleepThe holder of PreventUserIdleSystemSleep is your culprit.
Related commands
- caffeinateKeep the Mac awake
- powercfgPower & battery diagnostics
The same reference, with no signal at all
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