ref: 654935ba71201d7215d9fcd96181a330ec6ff617
dir: /man/3/srv/
.TH SRV 3
.SH NAME
srv \- server registry
.SH SYNOPSIS
.BI "bind #s"
[
.I spec
]
.B /chan
.PP
.EX
sys->bind("#s\fIspec\fP", "/chan", Sys->MREPL);
.EE
.SH DESCRIPTION
.I Srv
converts between file system operations by applications
and messages on channels, as described in
.IR sys-file2chan (2).
Each attach that does not include a
.I spec
produces a new instance: an empty directory owned
by the current user in which only files
may be created, and then only by
.IR sys-file2chan ,
using a special internal interface.
Each such file initially has the same owner as the
directory, and permissions
.B 8r600
(read-write for the owner only),
but the permissions can be changed by
.BR Sys->wstat
(see
.IR sys-stat (2))
and thus
.IR chmod (1).
If mode
.B Sys->DMEXCL
is thereby set, the file becomes exclusive-use and can be opened by
only one process at a time.
The file length and
mode bit
.B Sys->DMAPPEND
may also be set by
.B wstat
but are not interpreted by the system.
.PP
Files may be removed, directly using
.IR sys-remove (2)
(and thus
.IR rm (1)),
or indirectly by opening them with mode
.B Sys->ORCLOSE
(see
.IR sys-open (2)).
.I File2chan
also removes the corresponding file when the last references
to the server's read and write channels have gone
(eg, on server exit).
.PP
A
.I spec
may be given to name specific instances of
.IR srv ,
so that a new name space can bind in a service created in another.
Only the owner (original creator) of the instance may attach to it,
unless the mode of the service directory is changed
using
.B Sys->wstat
(see
.IR sys-stat (2))
to have general access.
.SH FILES
.TF /chan
.TP
.B /chan
directory to which
.I srv
is conventionally bound by various applications
.SH SOURCE
.B /emu/port/devsrv.c
.br
.B /os/port/devsrv.c
.SH SEE ALSO
.IR plumb (1),
.IR wm (1),
.IR sys-file2chan (2)