.TH CHDEV 1 
.SH NAME
chdev \- change kernel driver access
.SH SYNOPSIS
.B chdev
[ -nr ] \f2devmask\fP...
.SH DESCRIPTION
.I Chdev
modifies access to kernel drivers for the current
process and processes within the same name group
(see
.IR fork (2)).
Access is defined as the ability for a process
to walk files and directories served by the driver
through its location within '#'. Existing binds
of drivers are left unaffected.
.PP
Access may only be removed; after a specific
driver is ejected no further operations can
permit access again. Access is inherited by
all children of the name group, regardless if the
child has elected to receive a clean namespace.
.PP
.IR Devmask
is a string of driver characters. The default
behavior is to block access to all but the listed
drivers. Flags provide a way to modify this behavior:
.TP
.B -r
Retain access to all but the specified drivers.
.TP
.B -n
Remove access to all drivers.
.I Devmask
is ignored.
.PP
Access to some drivers is tied to other
related process capabilities:
.TP
\f2mnt\fP(3)
.IP
Ability to perform the
.IR mount (2)
system call, and
to post new services to
.IR shr (3).
.TP
\f2pipe\fP(3)
.IP
Ability to perform the
.IR pipe (2)
system call.
.SH EXAMPLES
Permit access to only
.IR draw (3),
.IR rtc (3),
.IR fs (3),
and
.IR srv (3):
.IP
.EX
chdev irks
.EE
.PP
Remove access to
.IR cons (3),
.IR rtc (3),
.IR audio (3),
and
.IR proc (3):
.IP
.EX
chdev -r crAp
.EE
.PP
Create a
.IR pipe (3)
then remove the ability to create more:
.IP
.EX
bind '#|' /n/pipe
chdev -r '|'
.EE
.SH DIAGNOSTICS
.I Chdev
is implemented through writes to
.BR /dev/drivers ,
served by
.IR cons (3).
.SH SOURCE
.B /rc/bin/chdev
.SH "SEE ALSO"
.B /dev/drivers
for a list of current drivers.
.PP
.IR intro (3),
.IR cons (3)
.SH HISTORY
Chdev first appeared in 9front (May, 2022).