ref: 43de7b8419fa3582af6df803473ef1bde2ce5c23
dir: /man/3/env/
.TH ENV 3 .SH NAME env \- environment device .SH SYNOPSIS .nf .B bind #e /env .BI /env/ name .fi .SH DESCRIPTION The environment device serves a one-level directory giving access to environment variables and their values. It is conventionally bound to .BR /env . The value of an environment variable .I name may be obtained by reading the file .BI /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. .PP New environment variables are set by creating the corresponding file in .B /env and writing the required value to that file. Similarly environment variables are destroyed (unset) by removing the corresponding file. .PP 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 .L FORKENV option to .IR 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 .L NEWENV option to .IR sys-pctl (2). .SH SOURCE .B /os/port/devenv.c .br .B /emu/port/devenv.c .SH SEE ALSO .IR env (1), .IR sh (1), .IR env (2), .IR sys-pctl (2)