reboot - Reboots system or halts processor
int howto );
Specifies a mask of options.
The reboot() function restarts the system. The startup is automatic and brings up /vmunix in the normal, nonmaintenance mode. The calling process must have superuser privilege to run this function successfully. However, a reboot is invoked automatically in the event of unrecoverable system failures.
The following options, defined in the sys/reboot.h include file are passed to the new kernel or the new bootstrap and init programs. They are supplied as values to the howto parameter. The default, causing the system to reboot in its usual fashion. Dump kernel memory before rebooting; see the savecore command for more information. The processor is simply halted; no reboot takes place. The disks are not sync'd before the processor is halted or rebooted. Normally, the disks are sync'd (see the sync() command) before the processor is halted or rebooted. Because the disks are not sync'd with the RB_NOSYNC option, loss of data may result from using it.
When no options are given (that is, RB_AUTOBOOT is used), the system is rebooted from file vmunix in the root file system of unit 0 (zero) of a disk chosen in a processor-specific way. (see the fsck command).
If successful, this call does not return. Otherwise, a -1 is returned and errno is set to indicate the error.
If the reboot() function fails, errno may be set to the following value: The calling process does not have appropriate privilege.
halt(8), init(8), reboot(8), savecore(8) delim off