Developer's Daily | Unix by Example |
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halt, reboot, poweroff ? stop the system. |
/sbin/halt [?n] [?w]
[?d] [?f] [?i]
[?p] |
Halt notes that the system is being brought down in the file /var/log/wtmp, and then either tells the kernel to halt, reboot or poweroff the system. If halt or reboot is called when the system is not in runlevel 0 or 6, shutdown(8) will be invoked instead (with the flag -h or -r). |
?n |
Don’t sync before reboot or halt. |
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?w |
Don’t actually reboot or halt but only write the wtmp record (in the /var/log/wtmp file). |
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?d |
Don’t write the wtmp record. The ?n flag implies ?d. |
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?f |
Force halt or reboot, don’t call shutdown(8). |
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?i |
Shut down all network interfaces just before halt or reboot. |
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?p |
When halting the system, do a poweroff. This is the default when halt is called as poweroff. |
If you’re not the superuser, you will get the message ‘must be superuser’. |
Under older sysvinit releases , reboot and halt should never be called directly. From release 2.74 on halt and reboot invoke shutdown(8) if the system is not in runlevel 0 or 6. This means that if halt or reboot cannot find out the current runlevel (for example, when /var/run/utmp hasn’t been initialized correctly) shutdown will be called, which might not be what you want. Use the -f flag if you want to do a hard halt or reboot. |
Miquel van Smoorenburg, miquels@cistron.nl |
shutdown(8), init(1) |