How to permanently set environmental variables

Question

My variables are

LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
ORACLE_HOME=/usr/lib/oracle/11.2/client64

How to save these variables permanently ?

Answer 1

You can add it to the file .profile or your login shell profile file (located in your home directory).

To change the environmental variable "permanently" you'll need to consider at least these situations:

1. Login/Non-login shell
2. Interactive/Non-interactive shell

bash

1. Bash as login shell will load /etc/profile, ~/.bash_profile, ~/.bash_login, ~/.profile in the order
2. Bash as non-login interactive shell will load ~/.bashrc
3. Bash as non-login non-interactive shell will load the configuration specified in environment variable $BASH_ENV

$EDITOR ~/.profile
#add lines at the bottom of the file:  
     export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
     export ORACLE_HOME=/usr/lib/oracle/11.2/client64

zsh

$EDITOR ~/.zprofile
#add lines at the bottom of the file:  
     export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
     export ORACLE_HOME=/usr/lib/oracle/11.2/client64

fish

set -Ux LD_LIBRARY_PATH /usr/lib/oracle/11.2/client64/lib
set -Ux ORACLE_HOME /usr/lib/oracle/11.2/client64

ksh

$EDITOR ~/.profile
#add lines at the bottom of the file:  
     export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
     export ORACLE_HOME=/usr/lib/oracle/11.2/client64

bourne

$EDITOR ~/.profile
#add lines at the bottom of the file:  
     LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib     
     ORACLE_HOME=/usr/lib/oracle/11.2/client64
     export LD_LIBRARY_PATH ORACLE_HOME

csh or tcsh

$EDITOR ~/.login
#add lines at the bottom of the file:  
     setenv LD_LIBRARY_PATH /usr/lib/oracle/11.2/client64/lib
     setenv ORACLE_HOME /usr/lib/oracle/11.2/client64

If you want to make it permanent for all users, you can edit the corresponding files under /etc/, i.e. /etc/profile for Bourne-like shells, /etc/csh.login for (t)csh, and /etc/zsh/zprofile and /etc/zsh/zshrc for zsh.

Another option is to use /etc/environment, which on Linux systems is read by the PAM module pam_env and supports only simple assignments, not shell-style expansions. (See Debian's guide on this.)

These files are likely to already contain some assignments, so follow the syntax you see already present in your file.

Make sure to restart the shell and relogin the user, to apply the changes.

If you need to add system wide environment variable, there's now /etc/profile.d folder that contains sh script to initialize variable.
You could place your sh script with all you exported variables here.
Be carefull though this should not be use as a standard way of adding variable to env on Debian.

Answer 2

To do if for all users/shells, depending on distro you could use /etc/environment or /etc/profile. Creating a new file in /etc/profile.d may be preferable if it exists, as it will be less likely to conflict with updates made by the packaging system.

In /etc/environment, variables are usually set with name=value, eg:

ORACLE_HOME=/usr/lib/oracle/11.2/client64

In /etc/profile, you must use export since this is a script, eg:

export ORACLE_HOME=/usr/lib/oracle/11.2/client64

Same goes for a file under /etc/profile.d, there also may be naming restrictions which must be met for the file to work. On Debian, the file must have the extension .sh (although does not need a bang line or executable permissions since it is sourced). check your distro documentation or look at the /etc/profile script to see how these files are loaded.

Note also though that setting LD_LIBRARY_PATH permanently is potentially problematic, including being a security risk. As an alternative, I would suggest finding some way to prepend the LD_LIBRARY_PATH to the start of the command line for each program that needs it before running. Eg:

LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib myprog

One way to do this is to use a wrapper script to run the program. You could give this the same name as your program and put it in /usr/local/bin or anywhere that appears before the location of your program in PATH. Here is an example script (don't forget to chmod +x the script):

#!/bin/sh
LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib /real/location/of/myprog "$@"

Answer 3

You don't specify which flavour of UNIX you are using. On FreeBSD (and Net and Open BSD) you can use /etc/login.conf. Full details in the man page but you can add something like:

:setenv=ORACLE_HOME=/usr/lib/oracle/11.2/client64:

to the default class and it will be set for all users regardless of shell or lack thereof.

There are also PAM modules that can do something similar if you are using PAM. e.g pam_env which reads from /etc/environment.

Answer 4

I find "How to save these variables permanently ?" ambiguous.

All answers seem to suppose that it means permanence in the meaning of "after a reboot".
I stumbled here looking for a way to persist ENVs for a bash session so that a production app could be run with ENVs set in the same process.

I'll leave this answer here for the like-minded.
The solution is to put them in a script like so:

set-envs.sh:

#!/bin/sh
export ENV1="some value"
export ENV1="some value"

chmod +x set-envs.sh once to make it executable
and run it before the app with source (or it's shorthand . )

. ./set-envs.sh
./run-the-app.sh  # or such