Accesing environment variables with $ and ENV in ruby

Question

I am trying to acces an environment variable set in ~/.bashrc

In ~/.bashrc I have set

export testdata = <some path>

without the <> of course. I may add that I also tried adding

testdata=<some path>

to /etc/environment

When I am still in the shell I can do

echo $testdata

which gives as result When in my script I can do

puts ENV['testdata']

which will print So far so good. However I another script that was not written by me where there is a line like

if $testdata then
#some code
end

which is supposed to just execute the code when the environment varaible is set. However this code is not working for me. Only when I replace $ with ENV[] the code is correclty executed.

Variables prefixed with $ are not environment variables in Ruby, they're global variables. Do `$testdata = ENV['testdata']` if you need that. — Aldehir, Sep 14 '15 at 19:51

score 3 · Accepted Answer · edited May 23 '17 at 12:29

3

This is expected behavior. $var is a global variable in Ruby, and not an environment variable. To access environment variable, as you said, you need to use ENV['var'].

edited May 23 '17 at 12:29

Community

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answered Sep 14 '15 at 19:48

Alexey Shein

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and global variables would have to be set in the same script or could they possibly be set by an external script? – FlyingTeller Sep 14 '15 at 19:51
What do you mean by external script? – Alexey Shein Sep 14 '15 at 19:52
Assuming my script as described above is in test.rb. If I have a script do_test.rb that called test.rb. Could do_test.rb set global variables for use in test.rb? – FlyingTeller Sep 14 '15 at 19:56
If your program `require`s several ruby files, then global variables maybe set anywhere in those files and they will become available when ruby interpreter encounters them. – Alexey Shein Sep 14 '15 at 19:56
Absolutely. Just make sure to define variables first and then require your test.rb. – Alexey Shein Sep 14 '15 at 19:58
thx for the answer. I might just have to get back to the original author and see if he has anything of the sort that I am missing – FlyingTeller Sep 14 '15 at 19:59

Accesing environment variables with $ and ENV in ruby

1 Answers1