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
PVM_EXPORT=DISPLAY:SHELLexports 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 -------------------------------------------------------------------