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reboot(2) [osx man page]

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

NAME
reboot -- reboot system or halt processor SYNOPSIS
#include <unistd.h> #include <sys/reboot.h> int reboot(int howto); DESCRIPTION
Reboot() reboots the system. Only the super-user may reboot a machine on demand. However, a reboot may be invoked automatically in the event of unrecoverable system failures. Programs other than reboot(8) should not call reboot(). Shutdown(8) or a higher-level API will shut the system down cleanly. Howto 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)bsd'', 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_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() call. See kadb(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 ``bsd'' 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
shutdown(8), halt(8), launchd(8), reboot(8) BUGS
The HP300 implementation supports neither RB_DFLTROOT nor RB_KDB. HISTORY
The reboot() function call appeared in 4.0BSD. 4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution

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REBOOT(8)						      System Manager's Manual							 REBOOT(8)

NAME
reboot - stopping and restarting the system SYNOPSIS
/sbin/reboot [ -lqnhdarsfRD ] /sbin/halt [ -lqndars ] /sbin/fastboot [ -lqndarsRD ] DESCRIPTION
2.11BSD is started by placing it in memory at location zero and transferring to its entry point. Since the system is not reentrant, it is necessary to read it in from disk or tape each time it is to be boot strapped. Rebooting a running system: When the system is running and a reboot is desired, shutdown(8) is normally used to stop time sharing and put the system into single user mode. If there are no users then /sbin/reboot can be used without shutting the system down first. Reboot normally causes the disks to be synced and allows the system to perform other shutdown activities such as resynchronizing hardware time-of-day clocks. A multi-user reboot (as described below) is then initiated. This causes a system to be booted and an automatic disk check to be performed. If all this succeeds without incident, the system is then brought up for multi-user operation. Options to reboot are: -l Don't try to tell syslogd(8) what's about to happen. -q Reboot quickly and ungracefully, without shutting down running processes first. -n Don't sync before rebooting. This can be used if a disk or the processor is on fire. -h Don't reboot, simply halt the processor. -d Dump memory onto the dump device, usually part of swap, before rebooting. The dump is done in the same way as after a panic. -a Have the system booter ask for the name of the system to be booted, rather than immediately booting the default system (/unix). -r Mount the root file system as read only when the system reboots. This is not supported by the kernel in 2.11BSD. -s Don't enter multi-user mode after system has rebooted - stay in single user mode. -f Fast reboot. Omit the automatic file system consistency check when the system reboots and goes multi-user. This is accomplished by passing a fast reboot flag on to the rebooting kernel. This currently prevents the use of -f flag in conjunction with the -h (halt) flag. -D Set the autoconfig(8) debug flag. This is normally not used unless one is debugging the autoconfig program. -R Tells the kernel to use the compiled in root device. Normally the system uses the device from which it was booted as the root/swap/pipe/dump device. Reboot normally places a shutdown record in the login accounting file /usr/adm/wtmp. This is inhibited if the -q or -n options are present. Note that the -f (fast reboot) and -n (don't sync) options are contradictory; the request for a fast reboot is ignored in this case. Halt and fastboot are synonymous with ``reboot -h'' and ``reboot -f'', respectively. Power fail and crash recovery: Normally, the system will reboot itself at power-up or after crashes if the contents of low memory are intact. An automatic consistency check of the file systems will be performed, and unless this fails, the system will resume multi-user operations. SEE ALSO
autoconfig(8), sync(2), utmp(8), shutdown(8), syslogd(8) 3rd Berkeley Distribution May 24, 1996 REBOOT(8)

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