reboot(2) System Calls Manual reboot(2)
Name
reboot - reboot system or halt processor
Syntax
#include <sys/reboot.h>
reboot(howto)
int howto;
Arguments
howto The howto argument is a mask of options passed to the bootstrap program.
The bits of howto are:
RB_HALT
the processor is simply halted; no reboot takes place. RB_HALT should be used with caution.
RB_ASKNAME
Interpreted by the bootstrap program itself, causing it to inquire as to what file should be booted. Normally, the system
is booted from the file "xx(0,0)vmunix" without asking.
RB_SINGLE
Normally, the reboot procedure involves an automatic disk consistency check and then multi-user operations. RB_SINGLE pre-
vents the consistency check, rather simply booting the system with a single-user shell on the console. RB_SINGLE is inter-
preted by the init(8) program in the newly booted system. This switch is not available from the system call interface.
Only the superuser may a machine.
Description
The system call reboots the system, and is invoked automatically in the event of unrecoverable system failures. The system call interface
permits only RB_HALT or RB_AUTOBOOT to be passed to the reboot program; the other flags are used in scripts stored on the console storage
media or used in manual bootstrap procedures. When none of these options (for example, RB_AUTOBOOT) is given, the system is rebooted from
file in the root file system of unit 0 of a disk chosen in a processor-specific way. Normally, an automatic consistency check of the disks
is then performed.
Return Values
If successful, this call never returns. Otherwise, a -1 is returned, and an error is stored in the global variable errno.
Diagnostics
The call fails under the following condition:
[EPERM] The caller is not the superuser.
See Also
crash(8v), halt(8), init(8), reboot(8)
reboot(2)