Export a variable from PHP to shell

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,

Answer 1

Environment variables that are exported are only available in child processes.

So you'll be able to set an environment variable and then spawn a child process. The environment variable will be visible in that child process. However setting it in php and then launching a successive process (echo, in your example above) won't work.

If you set the variable and then spawn/exec a new process, it should be visible in that new process.

Answer 2

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).