man/getnetpath.3t

.\" @(#)getnetpath.3n 1.26 93/05/07 SMI; from SVr4
.\" Copyright 1989 AT&T
.Dd April 22, 2000
.Dt GETNETPATH 3
.Os
.Sh NAME
.Nm getnetpath ,
.Nm setnetpath ,
.Nm endnetpath
.Nd get
.Pa /etc/netconfig
entry corresponding to
.Ev NETPATH
component
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In netconfig.h
.Ft "struct netconfig *"
.Fn getnetpath "void *handlep"
.Ft "void *"
.Fn setnetpath "void"
.Ft int
.Fn endnetpath "void *handlep"
.Sh DESCRIPTION
The routines described in this page provide the application access to the system
network configuration database,
.Pa /etc/netconfig ,
as it is
.Dq filtered
by the
.Ev NETPATH
environment variable (see
.Xr environ 7 ) .
See
.Xr getnetconfig 3
for other routines that also access the
network configuration database directly.
The
.Ev NETPATH
variable is a list of colon-separated network identifiers.
.Pp
The
.Fn getnetpath
function
returns a pointer to the
netconfig database entry corresponding to the first valid
.Ev NETPATH
component.
The netconfig entry is formatted as a
.Ft "struct netconfig" .
On each subsequent call,
.Fn getnetpath
returns a pointer to the netconfig entry that corresponds to the next
valid
.Ev NETPATH
component.
The
.Fn getnetpath
function
can thus be used to search the netconfig database for all networks
included in the
.Ev NETPATH
variable.
When
.Ev NETPATH
has been exhausted,
.Fn getnetpath
returns
.Dv NULL .
.Pp
A call to
.Fn setnetpath
.Dq binds
to or
.Dq rewinds
.Ev NETPATH .
The
.Fn setnetpath
function
must be called before the first call to
.Fn getnetpath
and may be called at any other time.
It returns a handle that is used by
.Fn getnetpath .
.Pp
The
.Fn getnetpath
function
silently ignores invalid
.Ev NETPATH
components.
A
.Ev NETPATH
component is invalid if there is no corresponding
entry in the netconfig database.
.Pp
If the
.Ev NETPATH
variable is unset,
.Fn getnetpath
behaves as if
.Ev NETPATH
were set to the sequence of
.Dq default
or
.Dq visible
networks in the netconfig database, in the
order in which they are listed.
.\"This proviso holds also for this
.\"whole manpage.
.Pp
The
.Fn endnetpath
function
may be called to
.Dq unbind
from
.Ev NETPATH
when processing is complete, releasing resources for reuse.
Programmers should be aware, however, that
.Fn endnetpath
frees all memory allocated by
.Fn getnetpath
for the struct netconfig data structure.
.Sh RETURN VALUES
The
.Fn setnetpath
function
returns a handle that is used by
.Fn getnetpath .
In case of an error,
.Fn setnetpath
returns
.Dv NULL .
.Pp
The
.Fn endnetpath
function
returns 0 on success and \-1 on failure
(for example, if
.Fn setnetpath
was not called previously).
The
.Fn nc_perror
or
.Fn nc_sperror
function
can be used to print out the reason for failure.
See
.Xr getnetconfig 3 .
.Pp
When first called,
.Fn getnetpath
returns a pointer to the netconfig database entry corresponding to the first
valid
.Ev NETPATH
component.
When
.Ev NETPATH
has been exhausted,
.Fn getnetpath
returns
.Dv NULL .
.Sh SEE ALSO
.Xr getnetconfig 3 ,
.Xr netconfig 5 ,
.Xr environ 7