Passing environment variable to PHP on the command-line

Question

On CentOS, I'm trying to pass an environment variable to a PHP script.

I've created this file, test.php:

<?php print_r($_ENV);

When I run this command:

DB=mysql php test.php

I get the following output:

Array
(
)

What did I miss?

Something in PHP, because even without your extra DB environment variable, there should be plenty of them. — derobert
– derobert, Commented Sep 17, 2014 at 15:59
@derobert Did you vote to move this to Stackoverflow? I specifically chose to ask it here because I thought it would be closed on Stackoverflow as off-topic, because it's about environment variables on Linux! — BenMorel
– BenMorel, Commented Sep 17, 2014 at 16:01
Yes. Most likely, you need to fix your setting of variables_order and/or use getenv(). Accessing the Unix environment variables (from a particular programming language, i.e., PHP) should be on-topic on SO... Though I wouldn't be surprised if there is a duplicate there. — derobert
– derobert, Commented Sep 17, 2014 at 16:03
@derobert Thank you, I just checked variables_order and noticed that it does not populate $_ENV by default, I did not know that! I thought this config was only about populating the $_REQUEST variable (and global variables in previous versions of PHP). — BenMorel
– BenMorel, Commented Sep 17, 2014 at 16:08
Indeed, I would have noticed the dup if only I knew that $_ENV should not be empty by default! Thanks for your help anyway, much appreciated. — BenMorel
– BenMorel, Commented Sep 17, 2014 at 16:10

Stephane Chazelas · Accepted Answer · 2014-09-17 16:07:49Z

8

Check your variables_order php.ini variable. It has to contain E for $_ENV to be populated. You can also do:

$ DB=whatever php -d variables_order=E -r 'echo $_ENV["DB"];'
whatever

Alternatively, you can use getenv() which will work regardless of the value of variables_order.

answered Sep 17, 2014 at 16:07

Stephane Chazelas

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Comments

cuonglm · Accepted Answer · 2014-09-17 16:03:14Z

2

Use getenv function:

$ cat test.php
<?php
    print_r(getenv('DB'));
?>

$ DB=msql php test.php
mysql

answered Sep 17, 2014 at 16:03

cuonglm

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