Question

I’m trying to set a variable that should be accessible from outside PHP. Ideally this should be a local variable, but environment variables are also welcome.

First, I’ve tried putenv(), but this gives no result:

$ php -r “putenv(‘PHP_TEST=string’);” ; echo $PHP_TEST

$

When i call getenv() from the same script — it results in the right ‘string’ value.
Safe mode is off, but the manual says ‘PHP_’ prefix is vital with safe=on so I use it just in case 🙂

Then I try system() or shell_exec():

$ php -r “shell_exec(‘PHP_TEST=string’);” ; echo $PHP_TEST

$ php -r “shell_exec(‘export PHP_TEST=string’);” ; echo $PHP_TEST

$

Is there a workaround? what might be the reason?
I’m using Ubuntu Linux 9.10 “Karmic”, but FreeBSD server gives the same result.

Answer 1

If you’re trying to pass some output to a shell variable, you can do it like this:

$ testvar=$(php -r 'print "hello"')
$ echo $testvar
hello

Showing how export affects things:

$ php -r '$a=getenv("testvar"); print $a;'
$ export testvar
$ php -r '$a=getenv("testvar"); print $a;'
hello

In these examples, the interactive shell is the parent process and everything else shown is a child (and siblings of each other).