NAME

reboot − Reboot or halt the system

SYNOPSIS

#include <sys/reboot.h>
int reboot(
        int howto );

PARAMETERS

howto
Specifies a mask of options.

DESCRIPTION

The reboot() function restarts the system. The default startup is automatic and brings up /vmunix in the normal, nonmaintenance mode.  In an application, the calling process must have superuser privilege to use this function.  However, a reboot is invoked automatically in the event of unrecoverable system failures. 

The following flags, defined in the <sys/reboot.h> header file, may be passed to the kernel bootstrap process by applications. These flags are supplied as values to the howto parameter. 

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

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

RB_HALT
The processor is simply halted; no reboot takes place.

RB_NOSYNC
The disks are not sync’ed before the processor is halted or rebooted.  Normally, the disks are sync’ed before the processor is halted or rebooted. See sync(8) for more information. 

Caution

Because the disks are not sync’ed when you specify the RB_NOSYNC option, loss of data may result from using it. 

If no flags are specified (equivalent to RB_AUTOBOOT), the system is rebooted from file vmunix in the root file system. 

RB_∗ flags that are defined in the <sys/reboot.h> header file and not listed in this reference page are reserved for internal use only. 

RETURN VALUES

If successful, this call does not return.  Otherwise, −1 is returned and errno is set to indicate the error. 

ERRORS

If the reboot() function fails, errno may be set to the following value:

[EPERM]
The calling process does not have appropriate privilege.

SEE ALSO

Commands: crashdc(8), halt(8), reboot(8), savecore(8), sync(8)

Functions: sync(2)