17.0 Introduction

LDAP, or Lightweight Directory Access Protocol, is a protocol that enables you to access X500-compliant directory servers. So, what are directory servers? They work much like your hard drive, except that they store user information in a hierarchical tree structure rather than storing files in a hierarchical tree structure. The terms are slightly different as well: In your filesystem, the top-level directory is known as the root, but when we are discussing LDAP, the top-level directory is known as the world.

PHP offers almost full support for the LDAP C API; it enables you to add, delete, get, modify, and search LDAP servers. The process of connecting to an LDAP server is simple with PHP ”just open a connection, log on, do your voodoo, and then close the connection.