Enumerate or list all variables in a program of [your favorite language here]

Question

A friend asked me last week how to enumerate or list all variables within a program/function/etc. for the purposes of debugging (essentially getting a snapshot of everything so you can see what variables are set to, or if they are set at all). I looked around a bit and found a relatively good way for Python:

#!/usr/bin/python                                                                                                                                                                                                                           
foo1 = "Hello world"
foo2 = "bar"
foo3 = {"1":"a",
        "2":"b"}
foo4 = "1+1"

for name in dir():
    myvalue = eval(name)
    print name, "is", type(name), "and is equal to ", myvalue

which will output something like:

__builtins__ is <type 'str'> and is equal to  <module '__builtin__' (built-in)>
__doc__ is <type 'str'> and is equal to  None
__file__ is <type 'str'> and is equal to  ./foo.py
__name__ is <type 'str'> and is equal to  __main__
foo1 is <type 'str'> and is equal to  Hello world
foo2 is <type 'str'> and is equal to  bar
foo3 is <type 'str'> and is equal to  {'1': 'a', '2': 'b'}
foo4 is <type 'str'> and is equal to  1+1

I have so far found a partial way in PHP (courtesy of link text) but it only lists all variables and their types, not the contents:

<?php
// create a few variables
$bar = 'foo';
$foo ='bar';
// create a new array object
$arrayObj = new ArrayObject(get_defined_vars());
// loop over the array object and echo variables and values
for($iterator = $arrayObj->getIterator(); $iterator->valid(); $iterator->next())
        {
        echo $iterator->key() . ' => ' . $iterator->current() . '<br />';
        }
?>

So I put it to you: how do you list all variables and their contents in your favorite language?

---

Edit by VonC: I propose this question follows the spirit of a little "code-challenge".
If you do not agree, just edit and remove the tag and the link.

Answer 1

In python, using locals which returns a dictionary containing all the local bindings, thus, avoiding eval:

>>> foo1 = "Hello world"
>>> foo2 = "bar"
>>> foo3 = {"1":"a",
...         "2":"b"}
>>> foo4 = "1+1"

>>> import pprint
>>> pprint.pprint(locals())
{'__builtins__': <module '__builtin__' (built-in)>,
 '__doc__': None,
 '__name__': '__main__',
 'foo1': 'Hello world',
 'foo2': 'bar',
 'foo3': {'1': 'a', '2': 'b'},
 'foo4': '1+1',
 'pprint': <module 'pprint' from '/usr/lib/python2.5/pprint.pyc'>}