.\" $Id: pvm_bufinfo.3,v 1.1 1996/09/23 22:01:05 pvmsrc Exp $
.TH BUFINFO 3PVM "30 August, 1993" "" "PVM Version 3.4"
.SH NAME
pvm_bufinfo() \- Returns information about a message buffer.

.SH SYNOPSIS
.nf
.ft B
C	int info = pvm_bufinfo( int bufid, int *bytes, int *msgtag,
int *tid )
.br

Fortran	call pvmfbufinfo( bufid, bytes, msgtag, tid, info )
.fi

.SH PARAMETERS
.IP bufid 0.8i
Integer specifying a particular message buffer identifier.
.br
.IP bytes
Integer returning the length in bytes of the body of the message.
This will be equal to the actual size of the data packed,
if \fIPvmDataRaw\fR is used,
otherwise it may include pad bytes.
.br
.IP msgtag
Integer returning the message label.
Useful when the message was received with a wildcard msgtag.
.br
.IP tid
Integer returning the source of the message.
Useful when the message was received with a wildcard tid.
.br
.IP info
Integer status code returned by the routine.
Values less than zero indicate an error.

.SH DESCRIPTION
The routine
.I pvm_bufinfo
returns information about the
requested message buffer. Typically it is used to determine
facts about the last received message such as its size or source.
pvm_bufinfo is especially useful when an application
is able to receive any incoming message, and the action
taken depends on the source
.I tid
and the
.I msgtag
associated with the message that comes in first.
If pvm_bufinfo is successful,
.I info
will be 0.
If some error occurs then
.I info
will be < 0.

.SH EXAMPLES
.nf
C:
	bufid = pvm_recv( -1, -1 );
	info = pvm_bufinfo( bufid, &bytes, &type, &source );
.sp
Fortran:
	CALL PVMFRECV( -1, -1, BUFID )
	CALL PVMFBUFINFO( BUFID, BYTES, TYPE, SOURCE, INFO )

.SH ERRORS
This error condition can be returned by
.I pvm_bufinfo.
.IP PvmNoSuchBuf
specified buffer does not exist.
.IP PvmBadParam
invalid argument
.PP
.SH SEE ALSO
pvm_recv(3PVM)