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Sinoosh
Asked: 2016-09-26 04:02:05 +0800 CST

Is "export" only useful for temporary effects?

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I know that, Shell variables are not available to the parent or child shells and Shell environments are available for child shells.

When I want to permanently add current directory to PATH I can do it in 2 ways:

1-Normal way:

 [sinoosh@localhost ~]$ vi ~/.bash_profile

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2-without export command

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And then logout i see the same result as normal way

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there is not different between "1"&"2" . can we say the export command is useful for that time we do not want permanently add to environment variables?

What's happening here?

command-line

1 Answers

  1. The export (or declare -x) declaration makes the difference between a plain shell variable and an environment variable.

    Since PATH is almost certainly already part of your environment - having been set in /etc/environment for example - marking it for export a second time isn't strictly necessary[1] (although it does no harm - and make the intent clear).

    1 at least I think that's the case - I'd like to find a primary reference

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