reboot

Requests an immediate system reboot, halt or panic from the kernel; restricted to the superuser.

Prototype

int reboot(int opt, char *command);

Returns: int

Arguments

Name	Type	Dir	Description
opt	int	-
command	char	-

Version history

XNU tag	macOS	#
xnu-1456.1.26	macOS 10.6 Snow Leopard	55
xnu-1699.24.8	macOS 10.7 Lion	55
xnu-2050.18.24	macOS 10.8 Mountain Lion	55
xnu-2422.115.4	macOS 10.9 Mavericks	55
xnu-2782.40.9	macOS 10.10 Yosemite	55
xnu-3247.1.106	macOS 10.11 El Capitan	55
xnu-3789.1.32	macOS 10.12 Sierra	55
xnu-4570.1.46	macOS 10.13 High Sierra	55
xnu-1486.2.11	—	55
xnu-1504.15.3	—	55
xnu-1504.3.12	—	55
xnu-1504.7.4	—	55
xnu-1504.9.17	—	55
xnu-1504.9.26	—	55
xnu-1504.9.37	—	55
xnu-1699.22.73	—	55
xnu-1699.22.81	—	55
xnu-1699.24.23	—	55
xnu-1699.26.8	—	55
xnu-1699.32.7	—	55
xnu-2050.22.13	—	55
xnu-2050.24.15	—	55
xnu-2050.48.11	—	55
xnu-2050.7.9	—	55
xnu-2050.9.2	—	55
xnu-2422.1.72	—	55
xnu-2422.100.13	—	55
xnu-2422.110.17	—	55
xnu-2422.90.20	—	55
xnu-2782.1.97	—	55
xnu-2782.10.72	—	55
xnu-2782.20.48	—	55
xnu-2782.30.5	—	55
xnu-3247.10.11	—	55
xnu-3248.20.55	—	55
xnu-3248.30.4	—	55
xnu-3248.40.184	—	55
xnu-3248.50.21	—	55
xnu-3248.60.10	—	55
xnu-3789.21.4	—	55
xnu-3789.31.2	—	55
xnu-3789.41.3	—	55
xnu-3789.51.2	—	55
xnu-3789.60.24	—	55
xnu-3789.70.16	—	55
xnu-4570.20.62	—	55

Notes

reboot(2) takes a flag word (RB_AUTOBOOT, RB_HALT, RB_PANIC, RB_QUICK, RB_UPSDELAY…) and is the primitive behind shutdown(8), halt(8) and reboot(8). On modern macOS userland actually goes through launchd → IOKit power-management paths in the normal case; the raw syscall is reserved for emergencies and for the kernel itself.

Related APIs

shutdownkillexitreboot3 (Mach)