Plan B User's Manual


Name

sys ­ Machine boxes.

Synopsis

/b/sys/debug
/b/sys/cmd
/b/sys/null
/b/sys/time
/b/sys/atime
/b/sys/random
/b/sys/ads

Description

Boxes under /b/sys provide system services that either affect the whole machine or do not fit well on other place.

/b/sys/debug

is used to toggle debug flags in the kernel. Its contents appear to be the set of active debug flags—each one is a character. An string copied into it would either set or clear (if started by "-") the debug flags found in the string. Use grep defdbg on the source to see which debug flags are defined.
/b/sys/cmd
is a placeholder used to send system-wide commands to the machine, such as halt. No commands are defined yet.
/b/sys/null
is the great bit bucket. It discards data copied into, and appears to be always empty when data is copied from it.
/b/sys/time
is the node time in binary format. It is four bytes with the number of seconds since epoch.
/b/sys/atime
is the node time printed as a string.
/b/sys/random
contains a random number in binary format (four bytes).
/b/sys/ads
contains the set of boxes advertised to the network by the kernel at this machine (other boxes may be advertised by user processes). Copy a string made of two names (box name, ad name) separated by white space to stablish a new ad. Ads are sent upon request and also every 30 seconds. Ads are requested every time import(2) is used to mount network ads.

Example

->
   /b/sys/ads
/b/mem      /mem
->    /b/sys/ads
/b/proc     /proc

To advertise /b/mem as /mem and /b/proc as /proc.

Source

/src/b/port/sysbox.c

See also

import(2) and ->(1).

Bugs

There are some boxes missing from /b/sys. The reason is that no program on top of Plan B needs them yet. They will be added.


Plan B User's Manual. First edition.