plan9 man page for env

ENV(3)							     Library Functions Manual							    ENV(3)

NAME
       env - environment variables

SYNOPSIS
       bind #e /env

       /env/var1
       /env/var2
	...

DESCRIPTION
       The env device serves a one-level directory containing files with arbitrary names and contents.	The intention is that the file name is the
       name of an environment variable (see rc(1)), and the content is the variable's current value.

       When a fork(2) system call creates a new process, both the parent and the child continue to see exactly the same files in the  env  device:
       changes made in either process can be noticed by the other.  In contrast, an rfork system call with the RFENVG bit set (see fork(2)) causes
       a split: initially both process groups see the same environment files, but any changes made in one process group cannot be noticed  by  the
       other.  An rfork with RFCENVG splits and then clears the environment.

SEE ALSO
       rc(1), fork(2)

SOURCE
       /sys/src/9/port/devenv.c

BUGS
       A write starting at an offset after the current extent of a file yields an error instead of zero filling.

																	    ENV(3)