Drupal Hook Menu Stuff

mymod.php

<?php

function mymod_menu() {
  $items = array();

  // the 3rd arg is a %, meaning its dynamic - in page and access arguments its the '2' value, based on 0/1/2
  // url parts are separated by /'s
  // the first part is 0
  // the second is 1
  // the third is 2 (goes up from there)
  $items['foo/bar/%'] = array(
    'page callback' => 'mymod_foobar',
    'page arguments' => array('static', 2), // these are always arrays
    'access callback' => 'mymod_access',
    'access arguments' => array(2), // these are always arrays
  );

  return $items;
}

// based on the menu hook above...
// if the url "/foo/bar/z" is visited then user will be denied access (permission denied)
// if the url "/foo/bar/crew" is visited then the user will be allowed to view the page
function mymod_access($dynamic_value) {
  if ($dynamic_value == 'z') {
    return false;
  } else {
    return true;
  }
}

// this is called with the arguments as defined in the hook_menu function page arguments
//
// if the url "/foo/bar/crew" is visited, this page will print 'static crew'
// if the url "/foo/bar/zoo" is visited, this page will print 'static zoo'
function mymod_foobar($static, $arg2) {
  print $static; // based on the page callback, this always equals 'static'
  print $arg2; // depending on the url, this will equal the 3rd part of the url (parts separated by /'s)
}