persist-env give more flexibility to set or unset system wide environment variable.
persist-env is a set of functions desgined to create, edit or remove any environment variables accessible all throughout the system, by each and every user, both locally and remotely.
source the persist-env.sh script at the beginning of any Bash program.
    #!/bin/bash
    source /path/to/persist-env.shset a variables
    env_set MYVAR "myvalue"get it
    env_get MYVAR
    # or
    printenv MYVARthen unset it
    env_unset MYVAR
