# blacs_pinfo

Returns the number of processes available for use.

## Syntax

call blacs_pinfo( mypnum, nprocs )

## Output Parameters

mypnum | INTEGER. An integer between 0 and (nprocs - 1) that uniquely identifies each process.
nprocs | INTEGER.The number of processes available for BLACS use.

## Description

This routine is used when some initial system information is required before the BLACS are set up. On all platforms except PVM, nprocs is the actual number of processes available for use, that is, `nprows * npcols <= nprocs`. In PVM, the virtual machine may not have been set up before this call, and therefore no parallel machine exists. In this case, nprocs is returned as less than one. If a process has been spawned via the keyboard, it receives mypnum of 0, and all other processes get mypnum of -1. As a result, the user can distinguish between processes. Only after the virtual machine has been set up via a call to BLACS_SETUP, this routine returns the correct values for mypnum and nprocs.

## See Also

BLACS Routines Usage Example
Parent topic: Initialization Routines