reboot(2) [freebsd man page]

REBOOT(2)						      BSD System Calls Manual							 REBOOT(2)

NAME

     reboot -- reboot system or halt processor

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>
     #include <sys/reboot.h>

     int
     reboot(int howto);

DESCRIPTION

     The reboot() system call reboots the system.  Only the super-user may reboot a machine on demand.	However, a reboot is invoked automatically
     in the event of unrecoverable system failures.

     The howto argument is a mask of options; the system call interface allows the following options, defined in the include file <sys/reboot.h>,
     to be passed to the new kernel or the new bootstrap and init programs.

     RB_AUTOBOOT   The default, causing the system to reboot in its usual fashion.

     RB_ASKNAME    Interpreted by the bootstrap program itself, causing it to prompt on the console as to what file should be booted.  Normally,
		   the system is booted from the file ``xx(0,0)kernel'', where xx is the default disk name, without prompting for the file name.

     RB_DFLTROOT   Use the compiled in root device.  Normally, the system uses the device from which it was booted as the root device if possible.
		   (The default behavior is dependent on the ability of the bootstrap program to determine the drive from which it was loaded,
		   which is not possible on all systems.)

     RB_DUMP	   Dump kernel memory before rebooting; see savecore(8) for more information.

     RB_HALT	   the processor is simply halted; no reboot takes place.  This option should be used with caution.

     RB_POWEROFF   After halting, the shutdown code will do what it can to turn off the power.	This requires hardware support.

     RB_INITNAME   An option allowing the specification of an init program (see init(8)) other than /sbin/init to be run when the system reboots.
		   This switch is not currently available.

     RB_KDB	   Load the symbol table and enable a built-in debugger in the system.	This option will have no useful function if the kernel is
		   not configured for debugging.  Several other options have different meaning if combined with this option, although their use
		   may not be possible via the reboot() system call.  See ddb(4) for more information.

     RB_NOSYNC	   Normally, the disks are sync'd (see sync(8)) before the processor is halted or rebooted.  This option may be useful if file
		   system changes have been made manually or if the processor is on fire.

     RB_RDONLY	   Initially mount the root file system read-only.  This is currently the default, and this option has been deprecated.

     RB_SINGLE	   Normally, the reboot procedure involves an automatic disk consistency check and then multi-user operations.	RB_SINGLE prevents
		   this, booting the system with a single-user shell on the console.  RB_SINGLE is actually interpreted by the init(8) program in
		   the newly booted system.

     When no options are given (i.e., RB_AUTOBOOT is used), the system is rebooted from file ``kernel'' in the root file system of unit 0 of a
     disk chosen in a processor specific way.  An automatic consistency check of the disks is normally performed (see fsck(8)).

RETURN VALUES

     If successful, this call never returns.  Otherwise, a -1 is returned and an error is returned in the global variable errno.

ERRORS

     [EPERM]		The caller is not the super-user.

SEE ALSO

     crash(8), halt(8), init(8), reboot(8), savecore(8)

HISTORY

     The reboot() system call appeared in 4.0BSD.

BUGS

     The HP300 implementation supports neither RB_DFLTROOT nor RB_KDB.

BSD
								   June 4, 1993 							       BSD

Check Out this Related Man Page

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)

Linux and UNIX Man Pages

reboot(2) [freebsd man page]

Check Out this Related Man Page