ubuntu path

    * /etc/environment file
      The first file that the operating system uses at login time is the /etc/environment file. The /etc/environment file contains variables specifying the basic environment for all processes.
    * /etc/profile file
      The second file that the operating system uses at login time is the /etc/profile file.
    * .profile file
      The .profile file is present in your home ($HOME) directory and lets you customize your individual working environment.
    * .env file

      A fourth file that the operating system uses at login time is the .env file, if your .profile contains the following line: export ENV=$HOME/.env

 

  /etc/environment -> /etc/profile ->* .profile -> * .env

 

 

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