Ubuntu – How we can change linux environment variable in python

The way I do it is using a custom_command in ~/.config/terminator/config as follows:

...
[profiles]
  [[default]]
    ...
    custom_command = TERM=xterm-256color bash -l # Do not use 'terminator' here
    use_custom_command = True
    ...

This works like a charm i.e. for the 256-color skins for midnight commander. The -l option makes bash run as a login shell (which means that it will load settings from your .bash_profile). You can omit it if you prefer Terminator to launch bash as a non-login shell (so that it will load .bashrc instead).

The issue here is not really the difference between echo and export, but rather the difference between an environment variable and a simple shell variable (and also about how the /etc/environment file is normally used).

In particular, although /etc/environment happens to contain lines of the form name=value that are valid as POSIX shell variable assignments, its primary purpose (in a modern Linux system) is to be read by the pam_env module during initialization of a user's session - it is pam_env that exports them to the user's environment.

When you source /etc/environment into your shell, there's no special magic that tells the shell that the assignments are those of environment variables (which are exported to the environment, and hence inherited by sub-processes) rather than regular shell variables (which are just available in the current shell scope).

Next time you log in, pam_env will do its magic and JAVA_HOME will then appear in the output of export | grep JAVA_HOME.

See also

• Difference between shell variables which are exported and those which are not in bash

• What scopes can shell variables have?