Environment Variables<A NAME=1447> </A>

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Environment Variables 

Experience seems to indicate that inherited environment (Unix environ) is useful to an application. For example, environment variables can be used to distinguish a group of related tasks or to set debugging variables.

PVM makes increasing use of environment, and may eventually support it even on machines where the concept is not native. For now, it allows a task to export any part of environ to tasks spawned by it. Setting variable PVM_EXPORT to the names of other variables causes them to be exported through spawn. For example, setting

exports the variables DISPLAY and SHELL to children tasks (and PVM_EXPORT too).

The following environment variables are used by PVM. The user may set these:

PVM_ROOT        Root installation directory
PVM_EXPORT      Names of environment variables to inherit through spawn
PVM_DPATH       Default slave pvmd install path
PVM_DEBUGGER    Path of debugger script used by spawn

The following variables are set by PVM and should not be modified:

PVM_ARCH        PVM architecture name
PVMSOCK         Address of the pvmd local socket; see Section 7.4.2
PVMEPID         Expected PID of a spawned task
PVMTMASK        Libpvm Trace mask