ENV(3)
NAME
env − environment device
SYNOPSIS
bind #e /env
/env/name
DESCRIPTION
The environment device serves a one-level directory giving access to environment variables and their values. It is conventionally bound to /env. The value of an environment variable name may be obtained by reading the file /env/name. If the file does not exist, the variable is unset and has the value nil. The maximum length of a variable name is 127 bytes.
New environment variables are set by creating the corresponding file in /env and writing the required value to that file. Similarly environment variables are destroyed (unset) by removing the corresponding file.
Processes sharing an ‘environment group’ see the same files and contents; changes made by one process are seen by the others. A process can insulate itself from further changes using the option to sys-pctl(2), which creates a new environment group that is a copy of the old, but further changes in each are independent. A new empty environment group is created by the option to sys-pctl(2).
SOURCE
/os/port/devenv.c
/emu/port/devenv.c