ldap_unbind kills the link descriptor. So, if you want to rebind as another user, just bind again; don't unbind. Otherwise, you'll have to open up a new connection.
ldap_unbind
Description
bool ldap_unbind ( resource link_identifier )如果成功则返回 TRUE，失败则返回 FALSE。
ldap_unbind() function unbinds from the LDAP directory.
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User Contributed Notes
kmenard at wpi dot edu
30-Nov-2001 03:47
30-Nov-2001 03:47