A completely different way to solve this is to use Aspect-Oriented Programming (AOP). Your problem is that you want to do something when foo is called, but before foo executes and only the first time foo executes.

Aspect would be the Perl way to do this, but I don't know how to remove advice with it, so I'll demonstrate using Dojo. This is a Javascript library.

function foo () { ... };
function call_only_once () {
    dojo.event.disconnect( 'before', foo, call_only_once );
    // Do stuff here
};

dojo.event.connect( 'before', foo, call_only_once );

foo();
[download]

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.