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.\" --(license Id: LICENSE.proto,v 1.1 2000/06/13 21:40:26 cgd Exp )--
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.Dd November 1, 2000
.Dt LINEDISC 9
.Os
.Sh NAME
.Nm ttyldisc_add ,
.Nm ttyldisc_lookup ,
.Nm ttyldisc_remove
.Nd extensible line discipline framework
.Sh SYNOPSIS
.In sys/conf.h
.Ft int
.Fn ttyldisc_add "struct linesw *disc" "int no"
.Ft struct linesw *
.Fn ttyldisc_remove "const char *name"
.Ft struct linesw *
.Fn ttyldisc_lookup "const char *name"
.Sh DESCRIPTION
The
.Nx
TTY line discipline framework allows extensibility.
Modules that need special line disciplines can add
them as convenient and do not need to modify tty_conf.c.
Line disciplines are now managed by a string, rather than
number.
.Pp
Once the framework has been initialized, a new line
discipline can be added by creating and initializing a
.Fa struct linesw
and calling
.Fn ttyldisc_add .
.Pp
The following is a brief description of each function in the framework:
.Bl -tag -width "ttyldisc_remove()"
.It Fn ttyldisc_add
Register a line discipline.
The
.Fa l_name
field of the
.Fa struct linesw
should point to a string which is to be the symbolic
name of that line discipline.
For compatibility purposes, a line discipline number can be passed in
.Fa no ,
but for new disciplines this should be set to
.Dv -1 .
.It Fn ttyldisc_lookup
Look up a line discipline by
.Fa name .
.Dv NULL
is returned if it can not be found.
.It Fn ttyldisc_remove
Remove a line discipline called
.Fa name
and return a pointer to it.
If the discipline cannot be found or removed
.Fn ttyldisc_remove
will return
.Dv NULL .
.El
.Sh SEE ALSO
.Xr tty 4
.Sh HISTORY
The
.Nm
functions were added in
.Nx 1.6 .
.Sh AUTHORS
The
.Nx
extensible line discipline framework was created by
.An Eduardo Horvath
.Aq eeh@NetBSD.org .