.\" $Id: pvm_config.3,v 1.1 1996/09/23 22:01:08 pvmsrc Exp $
.TH CONFIG 3PVM "31 August, 1994" "" "PVM Version 3.4"
.SH NAME
pvm_config \- Returns information about the present virtual machine
configuration.

.SH SYNOPSIS
.nf
.ft B
C	int info = pvm_config( int *nhost, int *narch, struct pvmhostinfo **hostp )
.br
	struct pvmhostinfo {
.br
		int  hi_tid;
.br
		char *hi_name;
.br
		char *hi_arch;
.br
		int  hi_speed;
.br
	};
.br

Fortran	call pvmfconfig( nhost, narch, dtid, name, arch, speed, info )
.fi

.SH PARAMETERS
.IP nhost 0.8i
Integer returning the number of hosts (pvmds) in the virtual machine.
.br
.IP narch
Integer returning the number of different data formats being used.
.br
.IP hostp
Returns pointer to an array of structures which contain
information about each host including its pvmd task ID,
name, architecture, and relative speed.
.br
.IP dtid
Integer returning pvmd task ID for host
.br
.IP name
Character string returning name of host
.br
.IP arch
Character string returning architecture name of host
.br
.IP speed
Integer returning relative speed of host. Default value is 1000.
.br
.IP info
Integer status code returned by the routine.
Values less than zero indicate an error.

.SH DESCRIPTION
The routine
.I pvm_config
returns information about
the present virtual machine. The information returned is
similar to that available from the console command
.I conf.
.PP
The C function returns information about the entire virtual machine
in one call. The Fortran function returns information about one host
per call and cycles through all the hosts.  Thus, if
.I pvmfconfig
is called nhost times, the entire virtual machine will be represented.

Note that in C the hostp array is allocated and owned by libpvm.
It is automatically freed or reused on the next call to pvm_config.

Note that in Fortran the reported value of nhost and the  host configuration
do not change until the function resets at the end of a complete cycle.
The user can reset pvmfconfig() at any time by calling it with
.I nhost = -1.

If pvm_config is successful,
.I info
will be 0.
If some error occurs then
.I info
will be < 0.

.SH EXAMPLES
.nf
C:
	struct pvmhostinfo *hostp;
	int i, nhost, narch;

	info = pvm_config( &nhost, &narch, &hostp );
	for (i = 0; i < nhost; i++)
		printf("%s\\n", hostp[i].hi_name);
.sp
Fortran:
	Do i=1, NHOST
	  CALL PVMFCONFIG( NHOST,NARCH,DTID(i),HOST(i),ARCH(i),SPEED(i),INFO )
	Enddo
.fi

.SH ERRORS
The following error condition can be returned by
.I pvm_config
.IP PvmSysErr
pvmd not responding.
.PP
.SH SEE ALSO
pvm_tasks(3PVM)