drupal/modules/module.module

<?php

function module_help() {
 ?>
  The module administration page provide you a list of all available modules.  Moreover, it allows you to "rehash" modules.  Whenever you install a new module or when an existing module has been changed or updated, it requires "rehashing": when you rehash a module, the module is registered to the engine and properly initialized.
 <?php
}

function module_admin_rehash() {
  $result = db_query("SELECT * FROM modules");
  while ($module = db_fetch_object($result)) {
    module_rehash($module->name);
  }

  foreach (module_list() as $name) {
    module_rehash($name);
  }
}

function module_admin_overview() {
  $output .= "<FORM ACTION=\"admin.php?mod=module\" METHOD=\"post\">\n";
  $output .= "<TABLE BORDER=\"1\" CELLPADDING=\"2\" CELLSPACING=\"2\">\n";
  $output .= " <TR><TH>module</TH><TH COLSPAN=\"3\">operations</TH></TR>\n";

  foreach (module_list() as $name) {
    $output .= " <TR><TD>$name</TD><TD>". (module_hook($name, "page") ? "<A HREF=\"module.php?mod=$name\">view</A>" : "&nbsp;") ."</TD><TD>". (module_hook($name, "admin") ? "<A HREF=\"admin.php?mod=$name\">admin</A>" : "&nbsp;") ."</TD><TD><A HREF=\"admin.php?mod=module&op=rehash&name=$name\">rehash</A></TD></TR>\n";
  }

  $output .= "</TABLE>\n";
  $output .= "<INPUT NAME=\"op\" TYPE=\"submit\" VALUE=\"Rehash modules\">\n";
  $output .= "</FORM>\n";
  print $output;
}

function module_admin() {
  global $op, $name;

  print "<SMALL><A HREF=\"admin.php?mod=module\">overview</A> | <A HREF=\"admin.php?mod=module&op=help\">help</A></SMALL><HR>\n";

  switch ($op) {
    case "help":
      module_help();
      break;
    case "rehash":
      module_rehash($name);
      module_admin_overview();
      break;
    case "Rehash modules":
      module_admin_rehash();
      module_admin_overview();
      break;
    default:
      module_admin_overview();
  }
}

?>