How to set environment variable on Ubuntu

On Ubuntu, there are two system-wide environment variables, both files need admin or sudo to modify it.

/etc/environment – It is not a script file, purely assignment expressions, one per line.

/etc/environment

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
JAVA_HOME=/usr/lib/jvm/adoptopenjdk-11-hotspot-amd64
LD_LIBRARY_PATH=/usr/local/lib:/usr/lib/postgresql/8.3/lib

/etc/profile.d/*.sh – Files with .sh extension in the /etc/profile.d/ folder.

/etc/profile.d/myenv.sh

export JAVA_HOME=JAVA_HOME=/usr/lib/jvm/adoptopenjdk-11-hotspot-amd64
export LD_LIBRARY_PATH=/usr/local/lib:/usr/lib/postgresql/8.3/lib
export PATH=$PATH:$JAVA_HOME/bin

Further Reading: Ubuntu – EnvironmentVariables

1. /etc/environment

1.1 Add a new environment variable MY_HOME=/home/mkyong in the /etc/environment file and source it to reflect the changes.


$ sudo vim /etc/environment

1.2 Modify, save and exit.

/etc/environment

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
JAVA_HOME=/usr/lib/jvm/adoptopenjdk-11-hotspot-amd64
LD_LIBRARY_PATH=/usr/local/lib:/usr/lib/postgresql/8.3/lib
MY_HOME=/home/mkyong

1.3 Test.


$ source /etc/environment

$ echo $MY_HOME
/home/mkyong

Note
The new changes in /etc/environment will disappear if we close the current session or reopen a new terminal because a new shell does not trigger the /etc/environment. Try to restart the Ubuntu or login again; the new changes in /etc/environment will apply automatically.

2. /etc/profile.d/new-env.sh

2.1 Add a new environment variable MY_HOME=/home/mkyong in the /etc/profile.d/new-env.sh file and source it to reflect the changes.


$ sudo vim /etc/environment

2.2 Create, save and exit.

/etc/profile.d/new-env.sh

export MY_HOME=/home/mkyong

2.3 Test.


$ source /etc/profile

$ echo $MY_HOME
/home/mkyong

2.4 Why source /etc/profile? Read the source code, it will execute all files with .sh extension.

/etc/profile

# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

if [ "${PS1-}" ]; then
  if [ "${BASH-}" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "`id -u`" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi

References

11 comments on “How to set environment variable on Ubuntu

  1. Hi Dear young,
    Im win user and in a job install fedora and a program on it due to speed up run. I need to add a environmental variable to run that program like this:
    FLXDM
    this variable point a license file in Home directory or where there is:
    /HOME/license.dat
    can you help me how set this environment variable?

  2. Dear Editor, 
    I am not professional at neither linux nor Ubuntu, only a new ubuntu 20 LTS user. I saw your web page while surfing. I need help from someone expertised. My problem is that: I am a new UBUNTU user. I was using the VIM editor to prepare a bashrc file. I made a wrong path in that file. Here are the commands that I have used in the bashrc via the VIM editor:
     
    PATH=/home/user/NBO/NBO6
    export=$PATH/nbo6.exe
    export=$PATH/genbo6.exe
     
    after closing the bashrc, I can not reach to Neither the VIM nor some Ubuntu Linux commands any way: Let me give several examples:
     
    user@sedatg:~$ ls
    the ‘ls’ command can be used in the following places
    * /bin/ls
    * /usr /bin/ls
    The command can not be positioned because ‘/bin:/usr/bin’ PATH has not been included into enviroment variables.
    ls: the command can not be found.
    secondly,
    user@sedatg:~$ vim
    the system reply is the same as above.
     
     
    But,
     
    user@sedatg:~$ cd $PATH
    user@sedatg:~/NBO/NBO6$
     
    My request from you is that: I want my terminal of the UBUNTU linux sys. to come back and to remove the definition of the variable “PATH” .
     
    Could you help and explain to me the steps for the solution, with the command instruction ?
     
    I will be thankful if you can save me from this trouble.
     
    Dr. Sedat GUMUS
     

      1. I tested your this command. It didnt recover the previous case. I want to enter my bashrc file again and to come back the previous stiuation, to remove my definition in the basch file. What can i do?

  3. /etc/environment – This file is specifically meant for system-wide environment variable settings. It is not a script file, but rather consists of assignment expressions, one per line. Specifically, this file stores the system-wide locale and path settings.

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