.\" $Id: pvm_setsbuf.3,v 1.1 1996/09/23 22:06:20 pvmsrc Exp $
.TH SETSBUF 3PVM "30 August, 1993" "" "PVM Version 3.4"
.SH NAME
pvm_setsbuf \- Switches the active send buffer.

.SH SYNOPSIS
.nf
.ft B
C	int oldbuf = pvm_setsbuf( int bufid )
.br

Fortran	call pvmfsetsbuf( bufid, oldbuf )
.fi

.SH PARAMETERS
.IP bufid 0.8i
Integer the message buffer identifier for the new active send buffer.
A value of 0 indicates the default receive buffer.
.br
.IP oldbuf
Integer returning the message buffer identifier
for the previous active send buffer.

.SH DESCRIPTION
The routine
.I pvm_setsbuf
switches the active send buffer to
.I bufid
and saves the previous active send buffer
.I oldbuf.
If
.I bufid
is set to 0 then the present active send buffer
is saved and no active send buffer exists.
.PP
The routine is required when managing multiple message buffers.
For example switching back and forth between two buffers.
One buffer could be used to send information to a graphical interface
while a second buffer could be used send data to other tasks
in the application.

.SH EXAMPLES
.nf
C:
	sbuf1 = pvm_setsbuf( sbuf2 );
Fortran:
	CALL PVMFSETSBUF( NEWBUF, OLDBUF )
.fi

.SH ERRORS
These error conditions can be returned by
.I pvm_setsbuf
.IP PvmBadParam
giving an invalid bufid.
.IP PvmNoSuchBuf
switching to a non-existent message buffer.
.PP
.SH SEE ALSO
pvm_setrbuf(3PVM)