Net::LDAP::Control::PreRead - LDAPv3 Pre-Read control object


 use Net::LDAP;
 use Net::LDAP::Control::PreRead;

 $ldap = Net::LDAP->new( "" );

 $preread = Net::LDAP::Control::PreRead->new( attrs => [ qw/givenName/ ] );

 my $mesg = $ldap->modify( "cn=Barbara Jensen, o=University of Michigan, c=US",
                           replace => { givenName => "Babs" },
                           control => $preread );

 if ($mesg->code eq LDAP_SUCCESS) {
   my ($previous) = $mesg->control( LDAP_CONTROL_PREREAD );
   my $entry = $previous ? $previous->entry() : undef;

   if ($entry) {
     print "givenName changed from '" .
           join("', '", $entry->get_value(givenName") .
           "' to 'Babs'\n");


Net::LDAP::Control::PreRead provides an interface for the creation and manipulation of objects that represent the Pre-Read Controls as described by RFC 4527.

In modification operations, the Pre-Read request control indicates to the server that a copy of the original entry before the update is to be returned. After the successful completion of the operation, the accompanying Pre-Read response control allows one to retrieve the original value from the server's response.

One use case of this control may be to obtain replaced or deleted values of modified attributes or a copy of the entry being deleted.


In addition to the constructor arguments described in Net::LDAP::Control the following are provided.

attrs => [ ATTR, ... ]

A list of attributes to be returned in the entry returned in the response control.

If absent, all attributes are returned.

Operational attributes may be included in the list by explicitly asking for them or by using special "+" feature (provided the server supports this feature).


As with Net::LDAP::Control each constructor argument described above is also available as a method on the object which will return the current value for the attribute if called without an argument, and set a new value for the attribute if called with an argument.

In addition to these methods, the control also supports the following method:

entry ()

Returns the entry from the response control in the response message to the LDAP request that contained the request control.

The result is either a Net::LDAP::Entry object or undefined.


Net::LDAP, Net::LDAP::Control,


Peter Marschall <>

Please report any bugs, or post any suggestions, to the perl-ldap mailing list <>


Copyright (c) 2008,2011 Peter Marschall. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.