plan9fox/sys/man/8/hjfs

.TH HJFS 8
.SH NAME
hjfs \- file server maintenance
.SH SYNOPSIS
.PD 0
.PP
.B allow
.PP
.B chatty
.PP
.B create
.I path uid gid perm
.RB [ lad ]
.PP
.B df
.PP
.B disallow
.PP
.B dump
.PP
.B echo
.RB [on | off]
.PP
.B halt
.PP
.B newuser
.I name
.RI [ options ]
.PP
.B sync
.PP
.B debug-chdeind
.I file
.RB [offset
.RB value]
.PP
.B debug-deind
.I file
.PP
.B debug-getblk
.I file
.RB [blk | start
.RB end]
.SH DESCRIPTION
The following commands should be written to the console of an
.IR hjfs (4)
file server.
.PP
.I Allow
disables permission checking and allows
.BR chown .
This may help in initializing a file system.
Use this with caution.
.PP
.I Chatty
enables chatty 9p.
.PP
.I Create
creates a file on the current file system.
.I Uid
and
.I gid
are names or numbers from
.BR /adm/users .
.I Perm
is the low 9 bits of the permission mode of the file, in octal.
An optional final
.BR l ,
.BR a ,
or
.BR d
creates a locked file, append-only file, or directory.
.PP
.I Df
prints the number of free, used and total blocks/megabytes.
It scans the block table and can be slow on large hard disks.
.PP
.I Disallow
restores permission checking back to normal after a file system
has been initialized.
.PP
.I Dump
immediately starts a dump.
.PP
.I Echo
expects an argument
.I on
or
.I off.
.I  On
causes all executed commands to be printed on the system console.
.I Off
reverses the effects of
.I on.
.PP
.I Halt
exits the program.
.PP
.I Newuser
requires a
.I name
argument.
With no options it adds user
.IR name ,
with group leader
.IR name ,
to
.B /adm/users
and makes the directory
.BI /usr/ name
owned by user and group
.IR name .
The options are
.TF =leaderxx
.TP
.B ?
Print the entry for
.IR name .
.TP
.B :
Add a group: add the name to
.B /adm/users
but don't create the directory.
By convention, groups are numbered starting from 10000, users from 0.
.TP
.I newname
Rename existing user
.I name
to
.IR newname .
.TP
.BI = leader
Change the leader of
.I name
to
.IR leader .
If
.I leader
is missing, remove the existing leader.
.TP
.BI + member
Add
.I member
to the member list of
.IR name .
.TP
.BI - member
Remove existing
.I member
from the member list of
.IR name .
.PD
.PP
After a successful
.I newuser
command the file server overwrites
.B /adm/users
to reflect the internal state of the user table.
.PP
.I Sync
writes dirty blocks in memory to the magnetic disk cache.
.PP
Note: Debug commands operate on internal data
structures; they are inherently dangerous and can cause
file system damage.
.PP
.I Debug-chdeind
changes the value of the byte at the specified
.I offset
in the in-memory directory entry and prints
the old
.I value.
Dangerous if used carelessly.
.PP
.I Debug-deind
requiers a
.I file
argument. It prints the directory entry of
.I file.
.PP
.I Debug-getblk
prints the physical blocks of
.I file
corresponding to the logical block
.I blk
or the logical blocks between
.I start
and
.I end. 
.SH EXAMPLES
Check disk usage (output appears on the system console).
.IP
.EX
% echo df >>/srv/hjfs.cmd
.EE
.SH SEE ALSO
.IR hjfs (4)
.SH SOURCE
.B /sys/src/hjfs
.SH BUGS
.B Debug-chdeind
should perhaps be less crazy and have a portable interface.