shelldap
author Mahlon E. Smith <mahlon@martini.nu>
Mon, 13 May 2019 10:44:41 -0700
changeset 122 d6a75d14db12
parent 121 6c14c49fe429
child 125 6530284a0ae4
permissions -rwxr-xr-x
Update CONTRIBUTORS and bump version.

#!/usr/bin/env perl
# vim: set nosta noet ts=4 sw=4:
#
# Copyright (c) 2006-2019, Mahlon E. Smith <mahlon@martini.nu>
# All rights reserved.
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#
#     * Neither the name of Mahlon E. Smith nor the names of his
#       contributors may be used to endorse or promote products derived
#       from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=head1 NAME

Shelldap - A program for interacting with an LDAP server via a shell-like interface

=head1 DESCRIPTION

Shelldap /LDAP::Shell is a program for interacting with an LDAP server via a shell-like
interface.

This is not meant to be an exhaustive LDAP editing and browsing
interface, but rather an intuitive shell for performing basic LDAP
tasks quickly and with minimal effort.

=head1 SYNPOSIS

 shelldap --server example.net [--help]

=head1 FEATURES

 - Upon successful authenticated binding, credential information is
   auto-cached to ~/.shelldap.rc -- future loads require no command line
   flags.

 - Custom 'description maps' for entry listings.  (See the 'list' command.)

 - History and autocomplete via readline, if installed.

 - Automatic reconnection attempts if the connection is lost with the
   LDAP server.

 - Basic schema introspection for quick reference.

 - It feels like a semi-crippled shell, making LDAP browsing and editing
   at least halfway pleasurable.

=head1 OPTIONS

All command line options follow getopts long conventions.

    shelldap --server example.net --basedn dc=your,o=company

You may also optionally create a ~/.shelldap.rc file with command line
defaults.  This file should be valid YAML.  (This file is generated
automatically on a successful bind auth.)

Example:

    server: ldap.example.net
    binddn: cn=Manager,dc=your,o=company
    bindpass: xxxxxxxxx
    basedn: dc=your,o=company
    tls: yes
    tls_cacert: /etc/ssl/certs/cacert.pem
    tls_cert:   ~/.ssl/client.cert.pem 
    tls_key:    ~/.ssl/private/client.key.pem

=over 4

=item B<configfile>

Optional.  Use an alternate configuration file, instead of the
default ~/.shelldap.rc.

    --configfile /tmp/alternate-config.yml
    -f /tmp/alternate-config.yml

This config file overrides values found in the default config, so
you can easily have separate config files for connecting to your
cn=monitor or cn=log overlays (for example.)

=back

=over 4

=item B<server>

Required. The LDAP server to connect to.  This can be a hostname, IP
address, or a URI.

    --server ldaps://ldap.example.net
    -H ldaps://ldap.example.net
    -h hostname_or_IP

=back

=over 4

=item B<binddn>

The full dn of a user to authenticate as.  If not specified, defaults to
an anonymous bind.  You will be prompted for a password.

    --binddn cn=Manager,dc=your,o=company
    -D cn=Manager,dc=your,o=company

=back

=over 4

=item B<basedn>

The directory 'root' of your LDAP server.  If omitted, shelldap will
try and ask the server for a sane default.

    --basedn dc=your,o=company
    -b dc=your,o=company

=back

=over 4

=item B<paginate>

Integer.  If enabled, shelldap will attempt to use server side
pagination to build listings.  Note: if you're using this to avoid
sizelimit errors, you'll likely need server configuration to raise the
limits for paginated results.

  --paginate 100

=back

=over 4

=item B<promptpass>

Force password prompting.  Useful to temporarily override cached
credentials.

=back

=over 4

=item B<sasl>

A space separated list of SASL mechanisms.  Requires the Authen::SASL
module.

    --sasl 'PLAIN CRAM-MD5 GSSAPI'

=back

=over 4

=item B<tls>

Enables TLS over what would normally be an insecure connection.
Requires server side support.

=item B<tls_cacert>

Specify CA Certificate to trust.

    --tls_cacert /etc/ssl/certs/cacert.pem

=item B<tls_cert>

The TLS client certificate.

    --tls_cert ~/.ssl/client.cert.pem

=item B<tls_key>

The TLS client key.  Not specifying a key will connect via TLS without
key verification.

    --tls_key ~/.ssl/private/client.key.pem

=back

=over 4

=item B<cacheage>

Set the time to cache directory lookups in seconds.

By default, directory lookups are cached for 300 seconds, to speed
autocomplete up when changing between different basedns.

Modifications to the directory automatically reset the cache.  Directory
listings are not cached.  (This is just used for autocomplete.)  Set it
to 0 to disable caching completely.

=back

=over 4

=item B<timeout>

Set the maximum time an LDAP operation can take before it is cancelled.

=back

=over 4

=item B<debug>

Print extra operational info out, and backtrace on fatal error.

=back

=over 4

=item B<version>

Display the version number.

=back

=head1 SHELL COMMANDS

=over 4

=head2 alias

Define or display aliases.

Without arguments, `alias' prints the list of aliases in the reusable
form `alias NAME=VALUE' on standard output.

Otherwise, an alias is defined for each NAME whose VALUE is given.
A trailing space in VALUE causes the next word to be checked for
alias substitution when the alias is expanded.

    alias
    alias ll=ls -al
    alias ll
    alias show=cat
    alias cmd1=command 'arg with spaces'
    alias cmd2='command '
    alias cmd2=command 'with_arg '

=head2 cat

Print contents of LDAP entry to STDOUT in LDIF format.

Globbing is supported. Specify either full DN, or a RDN.
RDNs are local to the current search base ('cwd' in shell terms). If RDN is '.' or missing,
it defaults to the current search base.
You may additionally add a list of attributes to display (e.g. use '+' for operational
attributes or provide a specific space-separated list). Default list of attributes is ['*']
and this default list can be changed using 'attributes' config key or --attributes cmdline
option.

    cat uid=mahlon
    cat ou=*
    cat uid=mahlon,ou=People,dc=example,o=company
    cat uid=mahlon + userPassword

=head2 configfile

Load or save config file.

If no config file is specified as argument to 'load', the default search list is:

    $HOME/.shelldap.rc
    /usr/local/etc/shelldap.conf
    /etc/shelldap.conf

If no config file is specified as argument to 'save', the default path is
$HOME/.shelldap.rc.

    configfile load
    configfile load /path/to/config
    configfile save
    configfile save /path/to/config

=head2 less

Like 'cat', but use configured pager to paginate output.

=head2 cd

Change the working directory (LDAP search base).

Translated to LDAP, this changes the current basedn.
All commands after a 'cd' operate within the new basedn.

    cd                  change to 'home' (binddn if any, or basedn)
    cd ~                change to 'home' (binddn if any, or basedn)
    cd -                change to previous node
    cd ou=People        change to explicit path below current node
    cd ..               change to parent node
    cd ../../ou=Groups  change to node ou=Groups, which is a sibling
                        to the current node's grandparent

Since LDAP doesn't limit what can be a container object, you can 'cd' into
any entry. Many commands then work on '.' or default to '.', meaning
"wherever I currently am."

    cd uid=mahlon
    cat .
    cat

=head2 clear

Clear the terminal screen.

Clears screen similar to 'clear' or Ctrl+l on the shell command line.

Ctrl+l alias is also supported.

=head2 copy

Copy an entry.

All copies are relative to the
current basedn unless a full DN is specified.  All attributes are
copied and then an LDAP moddn() is performed.

    copy uid=mahlon uid=bob
    copy uid=mahlon ou=Others,dc=example,o=company
    copy uid=mahlon,ou=People,dc=example,o=company uid=mahlon,ou=Others,dc=example,o=company

=head2 create

Create an entry.

Arguments are space separated objectClass
names.  Possible objectClasses are derived automatically from the
server, and will tab-complete.

After the classes are specified, an editor will launch.  Required
attributes are listed first, then optional attributes.  Optionals are
commented out.  After the editor exits, the resulting LDIF is validated
and added to the LDAP directory.

    create top person organizationalPerson inetOrgPerson posixAccount

=head2 delete

Remove an entry.

Globbing is supported.
All deletes are sanity-prompted.  The -v flag prints the entries out
for review before delete.

    delete uid=mahlon
    delete uid=ma*
    rm -v uid=mahlon,ou=People,dc=example,o=company l=office

=head2 edit

Edit an entry in an external editor.

After the editor exits, the
resulting LDIF is sanity checked, and changes are written to the LDAP
directory.

    edit uid=mahlon

=head2 env

Print values of configurable shelldap variables.

This is a subset of all variables configurable via shelldap config
file and/or its command line options.

=head2 grep

Search using LDAP filters and return matching DN results.

The search string must be a valid LDAP filter.

    grep uid=mahlon
    grep uid=mahlon ou=People
    grep -r (&(uid=mahlon)(objectClass=*))

=head2 inspect

View schema and flags for an entry or objectClass.

It also includes the most common flags for the objectClass
attributes.

    inspect uid=mahlon
    inspect posixAccount organizationalUnit
    inspect _schema

The output is a list of found objectClasses, their schema hierarchy
(up to 'top'), whether or not they are a structural class, and then
a merged list of all valid attributes for the given objectClasses.
Attributes are marked as either required or optional, and whether
they allow multiple values or not.

If you ask for the special "_schema" object, the raw server schema
is dumped to screen.

=head2 list

List directory contents.

Globbing is supported.

    ls -l
    ls -lR uid=mahlon
    list uid=m*

In 'long' mode, descriptions are listed as well, if they exist.
There are some default 'long listing' mappings for common objectClass
types.  You can additionally specify your own mappings in your
.shelldap.rc, like so:

    ...
    descmaps:
        objectClass: attributename
        posixAccount: gecos
        posixGroup: gidNumber
        ipHost: ipHostNumber

=head2 mkdir

Create a new 'organizationalUnit' LDAP entry.

  mkdir containername
  mkdir ou=whatever

=head2 move

Move (rename) entry.

Usage is identical to B<copy>.

=head2 passwd

Change user password.

If supported server side, change the password for a specified entry.
The entry must have a 'userPassword' attribute.

    passwd uid=mahlon

=head2 pwd

Print name of current/working LDAP search base.

=head2 setenv

Change or define shelldap variable.

    setenv debug 1
    export debug=1

=head2 unalias

Remove each NAME from the list of defined aliases.

    alias ll=ls -al
    alias
    unalias ll
    unalias ll ls
    alias

=head2 unsetenv

Remove each NAME from the list of defined shelldap variables.

    unset debug
    unset configfile
    unset myvar1 myvar2 myvar3

=head2 whoami

Print current bind DN.

Show current auth credentials.  Unless you specified a binddn, this
will just show an anonymous bind.

=back

=head1 TODO

Referral support.  Currently, if you try to write to a replicant slave,
you'll just get a referral.  It would be nice if shelldap automatically
tried to follow it.

For now, it only makes sense to connect to a master if you plan on doing
any writes.

Add ability for command definitions in cmd_map to contain default
arguments passed to functions.

Then add ability to define custom commands/aliases in config file.

Split 'inspect' into separate commands, one working on files/entries,
and one working on objectclasses. This way, autocompleter for both commands
will be reasonable, unlike now.

=head1 BUGS / LIMITATIONS

There is no support for editing binary data.  If you need to edit base64
stuff, just feed it to the regular ldapmodify/ldapadd/etc tools.

=head1 AUTHOR

Mahlon E. Smith <mahlon@martini.nu>

=cut

package LDAP::Shell;
use strict;
use warnings;
use Term::ReadKey qw//;
use Term::Shell qw//;
use Digest::MD5 qw//;
use Net::LDAP qw/
	LDAP_SUCCESS
	LDAP_SERVER_DOWN
	LDAP_OPERATIONS_ERROR
	LDAP_TIMELIMIT_EXCEEDED
	LDAP_BUSY
	LDAP_UNAVAILABLE
	LDAP_OTHER
	LDAP_TIMEOUT
	LDAP_NO_MEMORY
	LDAP_EXTENSION_PASSWORD_MODIFY
	LDAP_CONNECT_ERROR
	LDAP_CONTROL_PAGED /;
use Net::LDAP::Util qw/ canonical_dn ldap_explode_dn /;
use Net::LDAP::LDIF qw//;
use Net::LDAP::Extension::SetPassword qw//;
use Net::LDAP::Control::Paged qw//;
use Data::Dumper qw//;
use File::Temp qw//;
use Algorithm::Diff qw//;
use Carp 'confess';
use POSIX qw//;
use Tie::IxHash qw//;
use Fatal qw/open/;
use base 'Term::Shell';

my $conf = $main::conf;

# make 'die' backtrace in debug mode
$SIG{'__DIE__'} = \&Carp::confess if $conf->{'debug'};



########################################################################
### Term::Shell Fixes
########################################################################

# Term::Shell function add_handlers() is implemented in an incorrect way.
# We reimplement the method here to fix its problems.

# In add_handlers, we split searching for aliases in a separate loop,
# because otherwise not all aliases are registered before we look them
# up.
sub add_handlers
{
    my $o = shift;
    for my $hnd (@_)
    {
        next unless $hnd =~ /^(run|help|smry|comp|catch|alias)_/o;
        my $t = $1;
        my $a = substr( $hnd, length($t) + 1 );
 
        # Add on the prefix and suffix if the command is defined
        if ( length $a )
        {
            substr( $a, 0, 0 ) = $o->cmd_prefix;
            $a .= $o->cmd_suffix;
        }
        $o->{handlers}{$a}{$t} = $hnd;
    }
    for my $hnd (@_)
    {
        next unless $hnd =~ /^(run|help|smry|comp|catch|alias)_/o;
        my $t = $1;
        my $a = substr( $hnd, length($t) + 1 );
 
        # Add on the prefix and suffix if the command is defined
        if ( length $a )
        {
            substr( $a, 0, 0 ) = $o->cmd_prefix;
            $a .= $o->cmd_suffix;
        }

        if ( $o->has_aliases($a) )
        {
            my @a = $o->get_aliases($a);
            for my $alias (@a)
            {
                substr( $alias, 0, 0 ) = $o->cmd_prefix;
                $alias .= $o->cmd_suffix;
                $o->{handlers}{$alias}{$t} = $hnd;
            }
        }
    }
}



########################################################################
### U T I L I T Y   F U N C T I O N S
########################################################################

### Initial shell behaviors.
### 
sub init
{
	my $self = shift;
	$self->{'API'}->{'match_uniq'} = 0;

	$self->{'editor'} = $conf->{'editor'} || $ENV{'EDITOR'} || 'vi';
	$self->{'pager'}  = $conf->{'pager'}  || $ENV{'PAGER'}  || 'less';
	$self->{'env'}	  = [ qw/ debug cacheage timeout attributes configfile / ];

	# let autocomplete work with the '=' character
	my $term = $self->term();
	$term->Attribs->{'basic_word_break_characters'}	 =~ s/=//m;
	$term->Attribs->{'completer_word_break_characters'} =~ s/=//m;

	# read in history
	eval {
		$term->history_truncate_file("$ENV{'HOME'}/.shelldap_history", 50);
		$term->ReadHistory("$ENV{'HOME'}/.shelldap_history");
	};

	# gather metadata from the LDAP server
	$self->{'root_dse'} = $self->ldap->root_dse() or
		die "Unable to retrieve LDAP server information.  (Doublecheck connection arguments.)\n";
	$self->{'schema'} = $self->ldap->schema();

	# get an initial list of all objectClasses
	$self->{'objectclasses'} = [];
	foreach my $o ( $self->{'schema'}->all_objectclasses() ) {
		push @{ $self->{'objectclasses'} }, $o->{'name'};
	}

	if ( $conf->{'debug'} ) {
		my @versions = $self->{'root_dse'}->get_value('supportedLDAPVersion');
		print "Connected to $conf->{'server'}\n";
		print "Supported LDAP version: ", ( join ', ', @versions ), "\n";
		print "Cipher in use: ", $self->ldap()->cipher() || '', "\n";
	}

	# check for the pagination extension on the server early, and bail
	# if necessary.
	if ( $conf->{'paginate'} && $conf->{'paginate'} =~ /^\d+$/ && $conf->{'paginate'} > 0 ) {
		unless ( $self->{'root_dse'}->supported_control(LDAP_CONTROL_PAGED) ) {
			die "Server pagination is enabled, but the server doesn't seem to support it.\n";
		}
	}
	else {
		$conf->{'paginate'} = undef;
	}

	# try an initial search and bail early if it doesn't work. (bad baseDN?)
	my $s = $self->search();
	die "LDAP baseDN error: ", $s->{'message'}, "\n" if $s->{'code'};

	# okay, now do an initial population of 'cwd' for autocomplete.
	$self->update_entries();

	# whew, okay.  Update prompt, wait for input!
	$self->update_prompt();

	return;
}


### Return an LDAP connection handle, creating it if necessary.
###
sub ldap
{
	my $self = shift;
	my $rv;

	# use cached connection object if it exists
	return $self->{'ldap'} if $self->{'ldap'};
	
	# fill in potentially missing info
	die "No server specified.\n" unless $conf->{'server'};

	# Emit a nicer error message if IO::Socket::SSL is
	# not installed and Net::LDAP decides it is required.
	#
	if ( $conf->{'tls'} || $conf->{'server'} =~ m|ldaps://| ) {
		eval { require IO::Socket::SSL; };
		die qq{IO::Socket::SSL not installed, but is required for SSL or TLS connections.
You may try connecting insecurely, or install the module and try again.\n} if $@;
	}

	if ($conf->{'binddn'}) {
		if($conf->{'promptpass'}) {
			# Prompt for a password after disabling local echo.
			#
			print "Bind password: ";
			Term::ReadKey::ReadMode 2;
			chomp( $conf->{'bindpass'} = <STDIN> );
			Term::ReadKey::ReadMode 0;
			print "\n";
		} elsif($conf->{'pass'}) {
			$conf->{'bindpass'} = $conf->{'pass'}
		} elsif($conf->{'passfile'}) {
			chomp( $conf->{'bindpass'} = slurp($conf->{'passfile'}));
		}
	}

	# make the connection
	my $ldap = Net::LDAP->new( $conf->{'server'}, $conf->{port} ? ('port' => $conf->{port}) : ())
		or die "Unable to connect to LDAP server '$conf->{'server'}' port ${\( $conf->{port} || 'default' )}: $!\n";

	# secure connection options
	#
	if ( $conf->{'tls'} )  {
		if ( $conf->{'tls_key'} ) {
			$ldap->start_tls( 
				verify     => 'require',
				cafile     => $conf->{'tls_cacert'},
				clientcert => $conf->{'tls_cert'},
				clientkey  => $conf->{'tls_key'},
				keydecrypt => sub {
					print "Key Passphrase: "; 
					Term::ReadKey::ReadMode 2;
					chomp( my $secret = <STDIN> );
					Term::ReadKey::ReadMode 0;
					print "\n";
					return $secret;
				});
		}
		else {
			$ldap->start_tls( verify => 'none' );
		}
	}

	undef $@; eval { require Authen::SASL; };
	my ( $sasl, $sasl_conn );
	my $has_sasl = ! $@;
	my $use_sasl = $has_sasl && $conf->{'sasl'};

	die "SASL requested, but library is not installed.  Please install Authen::SASL and try again.\n" if $conf->{'sasl'} && ! $has_sasl;

	if ( $use_sasl ) {
		my $serv = $conf->{'server'};
		$serv =~ s!^ldap[si]?://!!;
		$sasl = Authen::SASL->new( mechanism => $conf->{'sasl'} );
		$sasl_conn = $sasl->client_new( 'ldap', $serv );
	}

	# bind with sasl
	#
	if ( $sasl_conn ) {
		$rv = $ldap->bind( $conf->{'binddn'},
			password => $conf->{'bindpass'},
			sasl     => $sasl_conn
		);
	}

	# simple bind as an authenticated dn
	#
	elsif ( $conf->{'binddn'} ) {
		$rv = $ldap->bind( $conf->{'binddn'},
			password => $conf->{'bindpass'}
		);
	}

	# bind anonymously
	#
	else {
		$rv = $sasl_conn ? $ldap->bind( sasl => $sasl_conn ) : $ldap->bind();
	}

	my $err = $rv->error();
	$self->debug(
		"Bind as " .
			( $conf->{'binddn'} ? $conf->{'binddn'} : 'anonymous' ) .
			" to " . $conf->{'server'} . ": $err\n"
	);

	if ( $rv->code() ) {
		$err .= " (try the --tls flag?)" if $err =~ /confidentiality required/i;
		$err .= "\n" . $sasl->error if $sasl_conn && defined( $sasl->error );
		die "LDAP bind error: $err\n";
	}

	# Offer to cache authentication info.
	# If we enter this conditional, we have successfully authed with the server
	# (non anonymous), and we haven't cached anything in the past.
	#
	if ( $conf->{'binddn'} && ! -e $conf->{'configfile'} ) {
		print "Would you like to cache your connection information? [Yn]: ";
		chomp( my $response = <STDIN> );
		unless ( $response =~ /^n/i ) {
			main::save_config($conf->{configfile});
			print "Connection info cached to $conf->{'configfile'}.\n";
		}
	}

	$self->{'ldap'} = $ldap;
	return $ldap;
}


### Return a new LDIF object, suitable for populating with
### a Net::LDAP::Entry.
###
sub ldif 
{
	my $self	 = shift;
	my $use_temp = shift;

	my $raw = qr/(^jpegPhoto|;binary)/;

	# create tmpfile and link ldif object with it
	#
	if ( $use_temp ) {
		my ( undef, $fname ) =
		  File::Temp::tempfile( 'shelldap_XXXXXXXX', SUFFIX => '.ldif', TMPDIR => 1, UNLINK => 1 );
		$self->{'ldif'}	      = Net::LDAP::LDIF->new( $fname, 'w', sort => 1, wrap => 0, raw => $raw );
		$self->{'ldif_fname'} = $fname;
	}

	# ldif -> stdout
	#
	else {
		$self->{'ldif'} = Net::LDAP::LDIF->new( \*STDOUT, 'w', sort => 1, wrap => $self->wrapsize, raw => $raw );
	}

	return $self->{'ldif'};
}


### Return an Entry object from an LDIF filename, or undef if there was an error.
###
sub load_ldif
{
	my $self = shift;
	my $ldif = Net::LDAP::LDIF->new( shift(), 'r' );

	return unless $ldif;

	my $e;
	eval { $e = $ldif->read_entry(); };

	return if $@;
	return $e;
}


### Given a filename, return an md5 checksum.
###
sub chksum 
{
	my $self = shift;
	my $file = shift or return;

	my $md5 = Digest::MD5->new();
	open F, $file;
	my $hash = $md5->addfile( *F )->hexdigest();
	close F;

	return $hash;
}


### Find and return the current terminal width.
###
sub wrapsize
{
	my $self = shift;

	my $wrap = $conf->{'wrap'};
	eval {
		my $rows;
		my $term = Term::ReadLine->new( 1 );
		( $rows, $wrap ) = $term->get_screen_size() unless $wrap;
	};

	$wrap ||= 78;
	return $wrap;
}


### Used by Term::Shell to generate the prompt.
###
sub prompt_str
{
	my $self = shift;
	return $self->{'prompt'};
}


### Display the current working entry as the prompt,
### truncating if necessary.
###
sub update_prompt 
{
	my $self = shift;
	my $base = $self->base();

	if ( length $base > 50 ) {
		my $cwd_dn = $1 if $base =~ /^(.*?),/;
		$self->{'prompt'} = "... $cwd_dn > ";
	}
	else {
		my $prompt = $base;
		$prompt =~ s/$conf->{'basedn'}/~/;
		$self->{'prompt'} = "$prompt > ";
	}
	return;
}


### Prompt the user to re-edit their LDIF on error.
### Returns true if the user wants to do so.
###
sub prompt_edit_again
{
	my $self = shift;
	print "Edit again? [Yn]: ";
	chomp( my $ans = <STDIN> );
	return $ans !~ /^n/i;
}


### Return the basedn of the LDAP connection, being either explicitly
### configured or determined automatically from server metadata.
###
sub base 
{
	my $self = shift;
	$self->{'base'} ||= $conf->{'basedn'};

	# try and determine base automatically from rootDSE
	#
	unless ( $self->{'base'} ) {
		my @namingContexts = $self->{'root_dse'}->get_value('namingContexts');
		$conf->{'basedn'} = $namingContexts[0];
		$self->{'base'}   = $namingContexts[0];
	}
	if ( $_[0] ) {
		my $base = canonical_dn( $_[0], casefold => 'none' );
		$self->{'base'} = $base if $base;
	}
	return $self->{'base'};
}


### Returns true if the specified dn is valid on this LDAP server.
###
sub is_valid_dn 
{
	my $self = shift;
	my $dn   = shift or return 0;

	my $r = $self->search({ base => $dn });
	return $r->{'code'} == LDAP_SUCCESS ? 1 : 0;
}


### Emit LDIF to the terminal.
###
sub display
{
	my $self  = shift;
	my $dn    = shift;
	my @attrs = @{;shift};
	my $use_pager = shift;

	unless ( $dn ) {
		$dn = '.'
	}

	# support '.'
	$dn = $self->base() if $dn eq '.';

	# support globbing
	#
	my $s;
	if ( $dn eq '*' ) {
		$s = $self->search({
			scope  => 'one',
			vals   => 1,
			attrs  => \@attrs
		});
	}
	elsif ( $dn =~ /\*/ ) {
		$s = $self->search({
			scope  => 'one',
			vals   => 1,
			filter => $dn,
			attrs  => \@attrs
		});
	}

	# absolute/relative dn
	#
	else {
		$dn = $self->path_to_dn( $dn );
		$s = $self->search({
			base   => $dn,
			vals   => 1,
			attrs  => \@attrs
		});
	}

	# emit error, if any
	#
	if ( $s->{'code'} ) {
		print $s->{'message'} . "\n";
		return;
	}

	# display to stdout or pager
	#
	my $ldif = $self->ldif( $use_pager );
	foreach my $e ( @{ $s->{'entries'} } ) {
		$ldif->write_entry( $e );
	}
	if ( $use_pager ) {
		system( $self->{'pager'}, $self->{'ldif_fname'} );
		unlink $self->{'ldif_fname'};
	}	
	return;
}


### Perform an LDAP search, optionally with the server side pager
### control.
###
### Returns a hashref containing the return code and
### an arrayref of Net::LDAP::Entry objects.
###
sub search 
{
	my $self = shift;
	my $opts = shift || {};
	my $controls = [];

	$opts->{'base'}   ||= $self->base(),
	$opts->{'filter'} ||= '(objectClass=*)';
	$opts->{'scope'}  ||= 'base';

	my $pager;
	if ( $conf->{'paginate'} ) {
		$pager = Net::LDAP::Control::Paged->new( size => $conf->{'paginate'} );
		push( @$controls, $pager );
	}

	my $search = sub { 
		return $self->ldap->search(
			base	  => $opts->{'base'},
			filter	  => $opts->{'filter'},
			scope	  => $opts->{'scope'},
			timelimit => $conf->{'timeout'},
			typesonly => ! $opts->{'vals'},
			attrs	  => $opts->{'attrs'} || ['*'],
			control   => $controls
		);
	};

	my $s;
	my $entries = [];
   	my $token  = '-';

	if ( $conf->{'paginate'} ) {
		while( $token ) {
			$s = $self->with_retry( $search );
			push( @$entries, $s->entries() );

			my $page_response = $s->control( LDAP_CONTROL_PAGED ) or last;
			$token = $page_response->cookie;
			$pager->cookie( $token );
		}
	}
	else {
		$s = $self->with_retry( $search );
		$entries = [ $s->entries() ];
	}

	my $rv = {
		code	=> $s->code(),
		message => $s->error()
	};

	if ( $opts->{'scope'} eq 'base' ) {
		$rv->{'entries'} = [ $s->shift_entry() ]
	}
	else {
		$rv->{'entries'} = $entries;
	}

	return $rv;
}


### Maintain the cache of possible autocomplete values for
### the current DN.
###
sub update_entries 
{
	my $self = shift;
	my %opts = @_;
	my $base = lc( $self->base() );
	
	my $s = $opts{'search'} || $self->search({ scope => 'one', base => $base });

	$self->{'cwd_entries'} = [];
	return if $s->{'code'};

	# setup cache object
	$self->{'cache'} ||= {};
	$self->{'cache'}->{ $base } ||= {};
	$self->{'cache'}->{ $base } = {} if $opts{'clearcache'};
	my $cache = $self->{'cache'}->{ $base };

	my $now = time();
	if ( ! exists $cache->{'entries'}
		or $now - $cache->{'timestamp'} > $conf->{'cacheage'} )
	{
		$self->debug("Caching entries for $base\n");
		foreach my $e ( @{ $s->{'entries'} } ) {
			my $dn  = $e->dn();
			my $rdn = $dn;
			$rdn =~ s/,$base//i;  # remove base from display
			push @{ $self->{'cwd_entries'} }, $rdn;
		}
		$cache->{'timestamp'} = $now;
		$cache->{'entries'} = $self->{'cwd_entries'};
	}
	else {
		$self->debug("Using cached lookups for $base\n");
	}

	$self->{'cwd_entries'} = $cache->{'entries'};
	return;
}


### Roughly convert a given path to a DN.
###
### Additionally support:
###    parent  '..'
###    current '.'
###    last    '-'
###    home    '~'
###
### Synopsis: $dn = $self->path_to_dn( $path );
###
sub path_to_dn
{
	my $self    = shift;
	my $path    = shift;
	my %flags   = @_;
	my $curbase = $self->base();

	# support empty 'cd' or 'cd ~' going to root
	return $conf->{'basedn'} if ! $path || $path eq '~';

	# return current base DN
	return $curbase if $path eq '.';

	# support 'cd -'
	return $self->{'previous_base'} if $path eq '-';

	# relative path, upwards
	#
	if ( $path =~ /^\.\./o ) {
		# support '..' (possibly iterated and as prefix to a DN)
		my @base = @{ ldap_explode_dn($curbase, casefold => 'none') };

		# deal with leading ..,
		#
		while ( $path =~ /^\.\./ ) {
			shift( @base ) if @base;
			$path =~ s/^\.\.//;
			last if $path !~ /[,\/]\s*/;
			$path =~ s/[,\/]\s*//;
		}

		# append the new dn to the node if one was specified:
		#    cd ../../cn=somewhere  vs
		#    cd ../../
		#
		my $newbase_root = canonical_dn( \@base, casefold => 'none' );
		$path = $path ? $path . ',' . $newbase_root : $newbase_root;
	}

	# attach the base if it isn't already there (this takes care of
	# deeper relative nodes and absolutes)
	#
	else {
		$path = "$path," . $curbase unless $path =~ /$curbase/;
	}

	return $path;
}


### Given an array ref of shell-like globs, 
### create and return a Net::LDAP::Filter object.
###
sub make_filter 
{
	my $self  = shift;
	my $globs = shift or return;

	return unless ref $globs eq 'ARRAY';
	return unless scalar @$globs;

	my $filter;
	$filter = join('', map { (/^\(.*\)$/o) ? $_ : "($_)" } @$globs);
	$filter = '(|' . $filter . ')'  if (scalar(@$globs) > 1);
	$filter = Net::LDAP::Filter->new( $filter );

	if ( $filter ) {
		$self->debug( 'Filter parsed as: ' . $filter->as_string() . "\n" );
	}
	else {
		print "Error parsing filter.\n";
		return;
	}

	return $filter;
}


### Given an arrayref of objectClasses, pull a complete list of 
### required and optional attrbutes.  Returns two arrayrefs.
###
sub fetch_attributes
{
	my $self = shift;
	my $ocs  = shift or return [], [];

	my ( %seen, @must_attr, @may_attr );
	foreach my $oc ( sort @{$ocs} ) {

		# required
		my @must = $self->{'schema'}->must( $oc );
		foreach my $attr ( sort { $a->{'name'} cmp $b->{'name'} } @must ) {
			next if $attr->{'name'} =~ /^objectclass$/i;
			next if $seen{ $attr->{'name'} };
			push @must_attr, $attr->{'name'};
			$seen{ $attr->{'name'} }++;
		}

		# optional
		my @may  = $self->{'schema'}->may( $oc );
		foreach my $attr ( sort { $a->{'name'} cmp $b->{'name'} } @may ) {
			next if $attr->{'name'} =~ /^objectclass$/i;
			next if $seen{ $attr->{'name'} };
			push @may_attr, $attr->{'name'};
			$seen{ $attr->{'name'} }++;
		}
	}

	return \@must_attr, \@may_attr;
}


### Check whether a given string can be used directly as
### an LDAP search filter.
###
### Synopsis: $yesNo = $self->is_valid_filter($string);
###
sub is_valid_filter
{
	my $self   = shift;
	my $filter = shift or return;

	return Net::LDAP::Filter->new( $filter ) ? 1 : 0;
}


### Call code in subref $action, if there's any connection related errors,
### try it one additional time before giving up.  This should take care of
### most server disconnects due to timeout and other generic connection
### errors, and will attempt to transparently re-establish a connection.
###
sub with_retry
{
	my $self = shift;
	my $action = shift;

	my $rv = $action->();
	if ( $rv->code() == LDAP_OPERATIONS_ERROR   ||
		 $rv->code() == LDAP_TIMELIMIT_EXCEEDED ||
		 $rv->code() == LDAP_BUSY               ||
		 $rv->code() == LDAP_UNAVAILABLE        ||
		 $rv->code() == LDAP_OTHER              ||
		 $rv->code() == LDAP_SERVER_DOWN        ||
		 $rv->code() == LDAP_TIMEOUT            ||
		 $rv->code() == LDAP_NO_MEMORY          ||
		 $rv->code() == LDAP_CONNECT_ERROR ) {

		$self->debug( "Error ". $rv->code() . ", retrying.\n" );
		$self->{'ldap'} = undef;
		$rv = $action->();
	}

	return $rv;
}


### little. yellow. different. better.
###
sub debug 
{
	my $self = shift;
	return unless $conf->{'debug'};
	print "\e[33m";
	print shift();
	print "\e[0m";
	return;
}


### Autocomplete values: Returns cached children entries.
###
sub autocomplete_from_cwd
{
	my $self = shift;
	my $word = quotemeta shift;
	return grep {/^$word/} @{ $self->{'cwd_entries'} };
}


### Autocomplete values: Returns previously set shelldap environment values.
###
sub autocomplete_from_env
{ 
	my $self = shift;
	my $word = quotemeta shift;
	return grep {/^$word/} @{ $self->{'env'} };
}


### Autocomplete values: Returns all objectClasses as defined
### by the LDAP server.
###
sub autocomplete_from_objectclasses
{
	my $self = shift;
	my $word = quotemeta shift;
	return grep {/^$word/} @{ $self->{'objectclasses'} };
}


### Autocomplete values: Returns all objectClasses as defined
### by the LDAP server, along with current children DNs.
###
sub autocomplete_from_objectclasses_and_cwd
{
	my $self = shift;
	my $word = quotemeta shift;
	return grep {/^$word/} ('_schema', @{ $self->{'objectclasses'} }, @{ $self->{'cwd_entries'} });
}


### Given an $arrayref, remove LDIF continuation wrapping in place,
### effectively making each entry a single line for LCS comparisons.
### 
sub unwrap_line {
	my $self  = shift;
	my $array = shift;

	my $i = 1;
	while ( $i < scalar(@$array) ) {
		if ( $array->[$i] =~ /^\s/ ) {
			$array->[ $i - 1 ] =~ s/\n$//;
			$array->[ $i ] =~ s/^\s//;
			splice( @$array, $i - 1, 2, $array->[$i - 1] . $array->[$i] );
		}
		else {
			$i++;
		}
	}
}


### Given an LDAP Entry object $e, an array reference to it's LDIF original
### content, and another array reference to updated LDIF content, run an LCS
### comparison, modifying the Entry object in place.
### 
sub diff {
	my $self = shift;
	my $e    = shift;
	my $orig = shift;
	my $new  = shift;

	$self->unwrap_line( $orig );
	$self->unwrap_line( $new );

	# parser subref
	#
	my $parse = sub {
		my $line = shift || $_;
		return if $line	 =~ /^\#/; # ignore comments
		my ( $attr, $val ) = ( $1, $2 ) if $line =~ /^(.+?): (.*)$/;
		return unless $attr;
		return if index($attr, ':') != -1;  # ignore base64
		return ( $attr, $val );
	};

	my $diff = Algorithm::Diff->new( $orig, $new );
	HUNK:
	while ( $diff->Next() ) {
		next if $diff->Same();
		my $diff_bit = $diff->Diff();
		my %seen_attr;

		# attr removal hunk
		#
		if ( $diff_bit == 1 ) {
			foreach ( $diff->Items(1) ) {
				my ( $attr, $val ) = $parse->( $_ ) or next;
				$self->debug("DELETE: $_");
				$e->delete( $attr => [ $val ] );
			}
		}

		# attr insertion hunk
		#
		if ( $diff_bit == 2 ) {
			foreach ( $diff->Items(2) ) {
				my ( $attr, $val ) = $parse->( $_ ) or next;
				$self->debug("INSERT: $_");
				$e->add( $attr => $val );
			}
		}

		# attr change hunk
		#
		if ( $diff_bit == 3 ) {

			# modification to existing line
			#
			foreach ( $diff->Items(2) ) {
				my ( $attr, $val ) = $parse->( $_ ) or next;
				$self->debug("MODIFY: $_");

				my $cur_vals = $e->get_value( $attr, asref => 1 ) || [];
				my $cur_valcount = scalar @$cur_vals;
				next if $cur_valcount == 0; # should have been an 'add'

				# replace immediately 
				#
				if ( $cur_valcount == 1 ) {
					$e->replace( $attr => $val );
				}
				else {

					# retain attributes that allow multiples, so updating
					# one attribute doesn't inadvertently remove others with
					# the same name.
					#
					next if $seen_attr{ $attr };
					my @new_vals;
					foreach my $line ( @$new ) {
						my ( $new_attr, $new_val ) = $parse->( $line ) or next;
						next unless $new_attr eq $attr;
						$seen_attr{ $attr }++;
						push @new_vals, $new_val;
					}

					$e->replace( $attr => \@new_vals );
				}
			}

			# deletion within the same hunk
			#
			foreach ( $diff->Items(1) ) {
				my ( $attr, $val ) = $parse->( $_ ) or next;
				my $cur_vals = $e->get_value( $attr, asref => 1 ) || [];
				my $cur_valcount = scalar @$cur_vals;

				next if $cur_valcount == 1;
				next if $seen_attr{ $attr };
				$self->debug("DELETE: $_");
				$e->delete( $attr => [ $val ] );
			}
		}
	}
}



########################################################################
### S H E L L   M E T H O D S
########################################################################

# alias_or_command => [ real_command_name, completion_function ]
#
tie my %cmd_map, 'Tie::IxHash';
%cmd_map = (
	# Real commands:
	'alias'   => [ undef ],
	'configfile'=> [ undef ],
	'whoami'  => [ undef ],
	'pwd'     => [ undef ],
	'list'    => [ undef, 'autocomplete_from_cwd' ],
	'grep'    => [ undef, 'autocomplete_from_cwd' ],
	'edit'    => [ undef, 'autocomplete_from_cwd' ],
	'delete'  => [ undef, 'autocomplete_from_cwd' ],
	'copy'    => [ undef, 'autocomplete_from_cwd' ],
	'cat'     => [ undef, 'autocomplete_from_cwd' ],
	'move'    => [ undef, 'autocomplete_from_cwd' ],
	'less'    => [ undef, 'autocomplete_from_cwd' ],
	'cd'      => [ undef, 'autocomplete_from_cwd' ],
	'create'  => [ undef, 'autocomplete_from_objectclasses' ],
	'setenv'  => [ undef, 'autocomplete_from_env' ],
	'passwd'  => [ undef ],
	'clear'   => [ undef ],
	'env'     => [ undef, 'autocomplete_from_env' ],
	#'help'    => [ undef ],
	'mkdir'   => [ undef ],
	'inspect' => [ undef, 'autocomplete_from_objectclasses_and_cwd' ],
	'unalias' => [ undef ],
	'unsetenv'=> [ undef ],

	# Aliases:
	'id'      => [ 'whoami'  ],
	'ls'      => [ 'list'    ],
	'search'  => [ 'grep'    ],
	'vi'      => [ 'edit'    ],
	'rm'      => [ 'delete'  ],
	'cp'      => [ 'copy'    ],
	'read'    => [ 'read'    ],
	'mv'      => [ 'move'    ],
	'touch'   => [ 'create'  ],
	'export'  => [ 'setenv'  ],
	'set'     => [ 'setenv'  ],
	'?'       => [ 'help'    ],
	'man'     => [ 'help'    ],
	'unset'   => [ 'unsetenv'],
);


### Term::Shell hook.
### Write history for each command, print shell debug actions.
###
sub precmd
{
	my $self = shift;
	my ( $handler, $cmd, $args ) = @_;

	my $term = $self->term();
	eval { $term->WriteHistory("$ENV{'HOME'}/.shelldap_history"); };

	$self->debug( "$$cmd (" . ( join ' ', @$args ) . "), calling '$$handler'\n" );
	return;
} 


### Display or define aliases.
###
sub run_alias
{
	my $self  = shift;
	my $cmd_alias = shift;

	# If $cmd_alias is empty, user requested printing of known aliases
	unless($cmd_alias) {
		while(my($alias,$cmd_args) = each %{$conf->{alias}}) {
			print "alias $alias=${\( join ' ', map { $_=~ /\s/ ? \"'$_'\" : $_} @{$cmd_args})}\n";
		}
		return

	# If there is argument but without = or space, user wanted to print specific alias
	} elsif($cmd_alias !~ /[=\s]/ and !@_) {
		my $alias = $cmd_alias;
		my $cmd_args = $conf->{alias}{$alias};
		unless( $cmd_args) {
			print "alias: $alias: not found\n";
		} else {
			print "alias $alias=${\( join ' ', map { $_=~ /\s/ ? \"'$_'\" : $_} @{$cmd_args})}\n";
		}
		return

	# There is argument with =, so the line is a new alias definition
	} else {
		my($alias, $alias2, $command) = ($cmd_alias =~ m/^([a-zA-Z0-9_-]+)$|^(\S+?)[\=\s]+(.+)$/);
		$alias = $alias2 if $alias2;
		unless( $alias) {
			print "Invalid syntax.\n";
			return
		}
		$command = $cmd_map{$command}[0] if $command and $cmd_map{$command} and $cmd_map{$command}[0];
		$conf->{alias}{$alias} = [ $command ? $command : (), @_ ];
	}
}

# Remove alias
sub run_unalias
{
	my $self = shift;
	for my $alias(@_) {
		unless( $conf->{alias}{$alias}) {
			print "alias: $alias: not found\n";
		} else {
		delete $conf->{alias}{$alias};
		}
	}
	return
}

# Run aliased command when alias is entered
sub catch_run {
	my $self = shift;
	my @cmdline;

	unless( $conf->{alias}{$_[0]}) {
		print $self->msg_unknown_cmd($_[0]);
		return
	}

	my $done = 0;
	while(my $arg = $_[0]) {
		my @alias = @{$conf->{alias}{$arg} or last};

		if($alias[-1] !~ s/\s+$//) {
			$done++
		}
		push @cmdline, @alias;
		shift;
		last if $done;
	}

	push @cmdline, @_;

	$self->run(@cmdline);
}


### Display an entry as LDIF to the terminal.
###
sub run_cat 
{
	my $self  = shift;
	my $dn    = shift;
	my @attrs = (@_) ? @_ : @{$conf->{'attributes'}};

	$self->display( $dn, \@attrs, 0 );
}


### Load or save config
###
sub run_configfile
{
	my $self     = shift;
	my $action   = shift;
	my $filepath = shift;

	unless ( $action) {
		if( $conf->{configfile} ) {
			print qq{Current config file is '$conf->{configfile}'.\n}
		} else {
			print qq{Current config file is unset.\nDefault search locations:\n  ${\( join "\n  ", main::default_configfiles() )}\n}
		}
		return
	}

	unless( $action =~ /^(?:load|save)$/) {
		print "Invalid action specified; use 'load' or 'save'.\n";
		return;
	}

	# This too can result in $filepath being undef. In that case the defaults
	# from load_config() / save_config() will apply.
	$filepath ||= $conf->{configfile};

	if( $action eq 'load') {
		my($filepath, $more_conf) = main::load_config($filepath);
		if( $more_conf) {
			while ( my ($k, $v) = each %{$more_conf} ) { $conf->{ $k } = $v }
		}
		print "Config file '$filepath' loaded.\n";
	} elsif( $action eq 'save') {
		$filepath = main::save_config($filepath);
		print "Config file '$filepath' saved.\n";
	}
}


### Display an entry as LDIF to the terminal with external pagination.
###
sub run_less
{
	my $self  = shift;
	my $dn    = shift;
	my @attrs = (@_) ? @_ : ('*');

	$self->display( $dn, \@attrs, 1 );
}


### Change shelldap's idea of a current working 'directory',
### by adjusting the current default basedn for all searches.
###
sub run_cd 
{
	my $self	= shift;
	my $newbase = shift;

	# convert given path to a DN
	$newbase = $self->path_to_dn( $newbase );

	unless ( $self->is_valid_dn( $newbase ) ) {
		print "No such object\n";
		return;
	}

	# store old base
	$self->{'previous_base'} = $self->base();

	# update new base
	$self->base( $newbase );

	# get new 'cwd' listing
	my $s = $self->search({ scope => 'one', attrs => [ '1.1' ] });
	if ( $s->{'code'} ) {
		print "$s->{'message'}\n";
		return;
	}
	$self->update_entries( search => $s );

	# reflect cwd change in prompt
	$self->update_prompt();
	return;
}


### Simply clear the screen.
###
sub run_clear
{
	my $self = shift;
	system( 'clear' );
	return;
}


### Fetch the source DN entry, modify it's DN data
### and write it back to the directory.
###
sub run_copy
{
	my $self = shift;
	my ( $s_dn, $d_dn ) = @_;

	unless ( $s_dn ) {
		print "No source DN provided.\n";
		return;
	}
	unless ( $d_dn ) {
		print "No destination DN provided.\n";
		return;
	}

	# convert given source path to DN
	$s_dn = $self->path_to_dn( $s_dn );

	# sanity check source
	#
	my $s = $self->search({ base => $s_dn, vals => 1 });
	unless ( $s->{'code'} == LDAP_SUCCESS ) {
		print "No such object\n";
		return;
	}

	# see if we're copying the entry to a nonexistent path
	#
	my ( $new_dn, $old_dn );
	( $d_dn, $new_dn ) = ( $1, $2 ) if $d_dn =~ /^([\-\w=]+),(.*)$/;
	if ( $new_dn ) { # absolute
		unless ( $self->is_valid_dn( $new_dn ) ) {
			print "Invalid destination.\n";
			return;
		}
	}
	else { # relative
		$new_dn = $self->base();
	}
	$old_dn = $1 if $s_dn =~ /^[\-\w=]+,(.*)$/;

	# get the source entry object
	my $e = ${ $s->{'entries'} }[0];
	$e->dn( $s_dn );

	# add changes in new entry instead of modifying existing
	$e->changetype( 'add' ); 
	$e->dn( "$d_dn,$new_dn" );

	# get the unique attribute from the dn for modification
	# perhaps there is a better way to do this...?
	#
	my ( $uniqkey, $uniqval ) = ( $1, $2 )
	  if $d_dn =~ /^([\-\.\w]+)(?:\s+)?=(?:\s+)?([\-\.\s\w]+),?/;
	unless ( $uniqkey && $uniqval ) {
		print "Unable to parse unique values from RDN.\n";
		return;
	}
	$e->replace( $uniqkey => $uniqval );

	# update (which will actually create the new entry)
	#
	my $update = sub { return $e->update($self->ldap()) };
	my $rv = $self->with_retry( $update );
	print $rv->error(), "\n";

	# clear caches
	#
	$self->{'cache'}->{ $new_dn } = {} if $new_dn;
	$self->{'cache'}->{ $old_dn } = {} if $old_dn;
	$self->update_entries( clearcache => 1 );
	return;
}


### Create a new entry from scratch, using attributes from
### what the server's schema says is available from the specified
### (optional) objectClass list.  Populate a new LDIF file and
### present an editor to the user.
###
sub run_create
{
	my $self = shift;
	my @ocs  = @_;

	# manually generate some boilerplate LDIF.
	#
	unless ( $self->{'create_file'} ) {
		my $fh;

		( $fh, $self->{'create_file'} ) =
			File::Temp::tempfile( 'shelldap_XXXXXXXX', SUFFIX => '.ldif', DIR => '/tmp', UNLINK => 1 );

		# first print out the dn and object classes.
		#
		print $fh 'dn: ???,', $self->base(), "\n";
		foreach my $oc ( sort @ocs ) {
			print $fh "objectClass: $oc\n";
		}

		# gather and print attributes for requested objectClasses
		#
		my ( $must_attr, $may_attr ) = $self->fetch_attributes( \@ocs );
		print $fh "$_: \n"   foreach @{ $must_attr };
		print $fh "# $_: \n" foreach @{ $may_attr };
		close $fh;
	}

	# checksum the file.
	#
	my $hash_orig = $self->chksum( $self->{'create_file'} );
	system( $self->{'editor'}, $self->{'create_file'} ) && die "Unable to launch editor: $!\n";

	# detect a total lack of change
	#
	if ( $hash_orig eq $self->chksum($self->{'create_file'}) ) {
		print "Entry not modified.\n";
		unlink $self->{'create_file'};
		$self->{'create_file'} = undef;
		return;
	}

	# load in LDIF
	#
	my $ldif = Net::LDAP::LDIF->new( $self->{'create_file'}, 'r', onerror => 'warn' );
	my $e	 = $ldif->read_entry();
	unless ( $e ) {
		print "Unable to parse LDIF.\n";
		unlink $self->{'create_file'};
		$self->{'create_file'} = undef;
		return;
	}

	# create the new entry.
	#
	$e->changetype('add');
	my $create = sub { return $e->update($self->ldap()) };
	my $rv = $self->with_retry( $create );
	print $rv->error(), "\n";

	if ( $rv->code() != LDAP_SUCCESS && $self->prompt_edit_again() ) {
		return $self->run_create();
	}

	$self->update_entries( clearcache => 1 );
	unlink $self->{'create_file'};
	$self->{'create_file'} = undef;
	return;
}


### Remove an entry (or entries) from the LDAP directory.
###
sub run_delete
{
	my $self = shift;
	my @args  = @_;
	my @matches;
	my $s;
	my $verbose;

	unless ( scalar @args ) {
		print "No dn specified.\n";
		return;
	}

	# Flags.
	#
	if ( $args[0] =~ /^\-v/ ) {
		$verbose = 1;
		shift @args;
	}
	
	# Separate real args from filter arguments.
	#
	foreach my $dn ( @args ) {
		if ( $dn eq '*' ) {
			$s = $self->search({ scope => 'one' });
			map { push @matches, $_ } @{ $s->{'entries'} } if $s->{'code'} == LDAP_SUCCESS;
		}

		# Search by filter
		#
		else {

			my $filter = $self->make_filter( [$dn] ) or next;
			$s = $self->search({ scope => 'one', filter => $filter });
			if ( scalar @{$s->{'entries'}} != 0 ) {
				map { push @matches, $_ } @{ $s->{'entries'} } if $s->{'code'} == LDAP_SUCCESS;
			}

			# Search by exact DN.
			#
			else {
				$dn = $self->path_to_dn( $dn );
				$s = $self->search({ base => $dn, vals => 0 });
				my $e = ${ $s->{'entries'} }[0];
				push @matches, $e if $s->{'code'} == LDAP_SUCCESS;
			}
		}
	}

	# Unique the matchset for a consistent count, keyed by DN.
	#
	my @uniq_matches = keys %{{ map { $_->dn => 1 } @matches }};

	my $mcount = scalar @uniq_matches;
	if ( $mcount == 0 ) {
		print "Nothing matched.\n";
		return;
	}

	if ( $verbose ) {
		print "* $_\n" foreach @uniq_matches;
	}

	print "About to remove $mcount item(s).  Are you sure? [Ny]: ";
	chomp( my $resp = <STDIN> );
	return unless $resp =~ /^y/i;

	my %seen;
	foreach my $e ( @matches ) {
		my $dn = $e->dn();
		next if $seen{ $dn };
		my $rv = $self->ldap->delete( $dn );
		$seen{ $dn }++;
		print "$dn: ", $rv->error(), "\n";
	}
   
	$self->update_entries( clearcache => 1 );
	return;
}


### Fetch an entry from the directory, write it out to disk
### as LDIF, launch an editor, then compare changes and write
### it back to the directory.
###
sub run_edit
{
	my $self = shift;
	my $dn   = shift;

	unless ( $dn ) {
		print "No dn provided.\n";
		return;
	}

	# convert given path to DN
	$dn = $self->path_to_dn( $dn );

	# sanity check
	#
	my $s = $self->search({ base => $dn, vals => 1 });
	unless ( $s->{'code'} == LDAP_SUCCESS ) {
		print $s->{'message'} . "\n";
		return;
	}

	# fetch entry.
	my $e = ${ $s->{'entries'} }[0];
	$e->changetype( 'modify' );

	# write it out to disk.
	#
	unless( $self->{'edit_again'} )  {
		my $ldif = $self->ldif(1);
		$ldif->write_entry( $e );
		$ldif->done();  # force sync
	}

	# load it into an array for potential comparison
	open LDIF, "$self->{'ldif_fname'}";
	my @orig_ldif = <LDIF>;
	close LDIF;

	# append optional, unused attributes as comments for fast reference.
	#
	unless ( $self->{'edit_again'} )  {
		my %current_attrs = map { $_ => 1 } $e->attributes();
		my ( $must_attr, $may_attr ) = $self->fetch_attributes( $e->get_value('objectClass', asref => 1) );

		open LDIF, ">> $self->{'ldif_fname'}";
		foreach my $opt_attr ( sort { $a cmp $b } @{$may_attr} ) {
			next if $current_attrs{ $opt_attr };
			print LDIF "# " . $opt_attr . ":\n";
		}
		close LDIF;
	}

	# checksum it, then open it in an editor
	#
	my $hash_orig = $self->chksum( $self->{'ldif_fname'} );
	my @edit_args = split /\s+/, $self->{'editor'};
	push @edit_args, $self->{'ldif_fname'};
	system( @edit_args ) && die "Unable to launch editor: $!\n";

	# detect a total lack of change
	#
	if ( $hash_orig eq $self->chksum($self->{'ldif_fname'}) ) {
		print "Entry not modified.\n";
		unlink $self->{'ldif_fname'};
		$self->{'edit_again'} = undef;
		return;
	}

	# check changes for basic LDIF validity
	#
	while( ! $self->load_ldif($self->{'ldif_fname'}) ) {
		print "Unable to parse LDIF.\n";
		if ( $self->prompt_edit_again() ) {
			system( $self->{'editor'}, $self->{'ldif_fname'} );
		}
		else {
			unlink $self->{'ldif_fname'};
			$self->{'edit_again'} = undef;
			return;
		}
	}

	# load changes into a new array for comparison
	#
	open LDIF, "$self->{'ldif_fname'}";
	my @new_ldif = <LDIF>;
	close LDIF;

	$self->diff( $e, \@orig_ldif, \@new_ldif );

	my $update = sub { return $e->update( $self->ldap ); };
	my $rv = $self->with_retry( $update );
	print $rv->error(), "\n";

	if ( $rv->code() != LDAP_SUCCESS && $self->prompt_edit_again() ) {
		$self->{'edit_again'} = 1;
		return $self->run_edit( $dn );
	}

	unlink $self->{'ldif_fname'};
	$self->{'edit_again'} = undef;
	return;
}


### Display current tunable runtime settings.
###
sub run_env
{
	my $self = shift;

	print YAML::Syck::Dump( { map { $conf->{$_} ? ($_, $conf->{$_}) : ()} sort @{ $self->{'env'}} } );
	print "\n"
}


### Alter settings.
###
sub run_setenv
{
	my $self = shift;
	my ( $key, $val ) = @_;

	( $key, $val ) = split /=/, $key if $key && ! defined $val;
	return unless $key && defined $val;
	$key = lc $key;

	$conf->{$key} = $val;
	return;
}


### Alter settings.
###
sub run_unsetenv
{
	my $self = shift;

	for(@_) {
		delete $conf->{$_}
	}
	return;
}


### Search across the directory and display matching entries.
###
sub run_grep
{
	my $self = shift;
	my ( $recurse, $filter, $base ) = @_;

	# set 'recursion'
	unless ( $recurse && $recurse =~ /\-r|recurse/ ) {
		# shift args to the left
		( $recurse, $filter, $base ) = ( undef, $recurse, $filter );
	}

	$filter = Net::LDAP::Filter->new( $filter );
	unless ( $filter ) {
		print "Invalid search filter.\n";
		return;
	}

	# support '*'
	$base = $self->base() if ! $base or $base eq '*';

	unless ( $base ) {
		print "No search base specified.\n";
		return;
	}

	# convert base path to DN
	$base = $self->path_to_dn( $base );

	$self->debug("Filter parsed as: " . $filter->as_string() . "\n");

	my $s = $self->search({
		scope  => $recurse ? 'sub' : 'one',
		base   => $base,
		filter => $filter
	});

	foreach my $e ( @{ $s->{'entries'} } ) {
		my $dn = $e->dn();
		print "$dn\n";
	}

	return;
}


### Generate and display a list of LDAP entries, relative to the current
### location the command was run from.
###
sub run_list
{
	my $self  = shift;
	my @args  = @_;
	my @attrs = ();
	my $filter;

	# flag booleans
	my ( $recurse, $long, $all );

	# parse arguments: [ <option> ...] [<filter> ...] [<attribute> ...]
	#
	if ( scalar @args ) {
		# options: support '-l' or '-R' listings
		if ( $args[0] =~ /^\-(\w+)/o ) {
			my $flags = $1;
			$recurse  = $flags =~ /R/;
			$long	  = $flags =~ /l/;
			$all	  = $flags =~ /a/;
			shift( @args );
		}

		my @filters;

		# get filter elements from argument list
		#
		while ( @args && $self->is_valid_filter($args[0]) ) {
			push( @filters, shift(@args) );
		}

		# No filter for display?  Default to all entries.
		push( @filters, '(objectClass=*)' ) unless scalar @filters;
		
		# construct OR'ed filter from filter elements
		$filter = $self->make_filter( \@filters );

		# remaining arguments must be attributes
		push( @attrs, @args );
	}

	# Get all attributes if none are specified, and we're in long-list mode.
	push( @attrs, '*' )  if $long && ! scalar @attrs;

	my $s = $self->search({
		scope  => $recurse ? 'sub' : 'one',
		vals   => 1,
		filter => $filter,
		attrs  => [ @attrs, 'hasSubordinates' ]
	});
	if ( $s->{'code'} ) {
		print "$s->{'message'}\n";
		return;
	}

	# if an entry doesn't have a description field,
	# try and show some nice defaults for ls -l !
	# 
	# objectClass -> Attribute to show
	#
	my %descs = %{
		$conf->{'descmaps'}
		  || {
			posixAccount => 'gecos',
			posixGroup   => 'gidNumber',
			ipHost	     => 'ipHostNumber',
		  }
	  };

	# iterate and print
	#
	my $dn_count = 0;
	my $base = $self->base();
	foreach my $e ( sort { $a->dn() cmp $b->dn() } @{ $s->{'entries'} } ) {
		my $dn = $e->dn();

		# Later, turn this into '.' and '..' display
		unless($all) {
			next if lc( $dn ) eq lc( $base );
		}

		if ( ! $long ) {
			# strip the current base from the dn, if we're recursing and not in long mode
			if ( $recurse ) {
				$dn =~ s/,$base//oi;
			# only show RDN unless -l was given
			} else {
				$dn = canonical_dn( [shift(@{ldap_explode_dn($dn, casefold => 'none')})], casefold => 'none' )
			}
		}

		my $type = '-'; # Assume the entry is a leaf

		# if this entry is a container for other entries, append a
		# trailing slash.
		if( $e->get_value('hasSubordinates') && $e->get_value('hasSubordinates') eq 'TRUE') {
			$dn .= '/';
			$type = 'd'
		}

		# additional arguments/attributes were given; show their values
		#
		if ( scalar @args ) {
			my @line = ( $type, $dn );

			foreach my $attr ( @args ) {
				my @vals = $e->get_value( $attr );
				push( @line, join(',', @vals) );
			}

			print join( "\t", @line )."\n";

		}

		# show descriptions
		#
		else {
			my $line = "$type $dn";

			my $desc = $e->get_value( 'description' );
			if ( $desc ) {
				$desc =~ s/\n.*//s; # 1st line only
				$line .= " ($desc)";
			} else {
				# no desc?  Try and infer something useful
				# to display.
				#

				# pull objectClasses, hash for lookup speed
				my @oc = $e->get_value( 'objectClass' );
				my %ochash;
				map { $ochash{$_} = 1 } @oc;

				foreach my $d_listing ( sort keys %descs ) {
					if ( exists $ochash{ $d_listing } ) {
						my $str = $e->get_value( $descs{ $d_listing }, asref => 1 );
						$line .= ' (' . (join ', ', @$str) . ')' if $str && scalar @$str;
					}
					next;
				}
			}
			print "$line\n";
		}
		$dn_count++;
	}
	
	print "\n$dn_count " .
		( $dn_count == 1 ? 'object.' : 'objects.') .
		"\n" if $long;
	return;
}


### Create a new organizationalUnit entry.
###
sub run_mkdir
{
	my $self = shift;
	my $dir  = shift;

	unless ( $dir ) {
		print "No 'directory' provided.\n";
		return;
	}

	# normalize name, if it is not yet a legal DN
	$dir = 'ou=' . $dir unless canonical_dn( $dir );

	# convert given path to full DN
	$dir = $self->path_to_dn( $dir );

	# get RDN: naming attributes (lower-case) and their values
	my %rdn = %{ shift(@{ ldap_explode_dn($dir, casefold => 'lower') }) };

	# add
	my $mkdir = sub {
		return $self->ldap()->add( $dir, attr => [
			objectClass => [ 'top', 'organizationalUnit' ], %rdn
		]);
	};

	my $rv = $self->with_retry( $mkdir );

	print $rv->error(), "\n";
	$self->update_entries( clearcache => 1 );
	return;
}


### Alter an entry's DN.
###
sub run_move
{
	my $self = shift;
	my ( $s_dn, $d_dn ) = @_;

	unless ( $s_dn ) {
		print "No source dn provided.\n";
		return;
	}
	unless ( $d_dn ) {
		print "No destination dn provided.\n";
		return;
	}

	# convert given source path to DN
	$s_dn = $self->path_to_dn( $s_dn );

	unless ( $self->is_valid_dn( $s_dn ) ) {
		print "No such object\n";
		return;
	}

	# see if we're moving the entry to a totally new path
	my ( $new_dn, $old_dn );
	( $d_dn, $new_dn ) = ( $1, $2 ) if $d_dn =~ /^([\.\-\w=]+),(.*)$/;
	$old_dn = $1 if $s_dn =~ /^[\.\-\w=]+,(.*)$/;

	my $moddn = sub {
		return $self->ldap()->moddn(
			$s_dn,
			newrdn	     => $d_dn,
			deleteoldrdn => 1,
			newsuperior  => $new_dn
		);
	};
	my $rv = $self->with_retry( $moddn );
	print $rv->error(), "\n";

	# clear caches
	$self->{'cache'}->{ $new_dn } = {} if $new_dn;
	$self->{'cache'}->{ $old_dn } = {} if $old_dn;
	$self->update_entries( clearcache => 1 );
	return;
}


### Change the 'userPassword' attribute of an entry, if
### supported by the LDAP server.
###
sub run_passwd 
{
	my $self = shift;
	my $dn   = shift || $self->base();

	$self->{'root_dse'} ||= $self->ldap->root_dse();

	unless ( $self->{'root_dse'}->supported_extension(LDAP_EXTENSION_PASSWORD_MODIFY) ) {
		print "Sorry, password changes not supported by LDAP server.\n";
		return;
	}

	# convert given path to DN
	$dn = $self->path_to_dn( $dn );

	my $s = $self->search( { base => $dn, scope => 'base' } );
	if ( $s->{'code'} ) {
		print $s->{'message'}, "\n";
		return;
	}
	my $e = ${ $s->{'entries'} }[0];

	unless ( $e->exists('userPassword') ) {
		print "No userPassword attribute for $dn\n";
		return;
	}

	print "Changing password for $dn\n";
	Term::ReadKey::ReadMode 2;
	print "Enter new password: ";
	chomp( my $pw  = <STDIN> );
	print "\nRetype new password: ";
	chomp( my $pw2 = <STDIN> );
	print "\n";
	Term::ReadKey::ReadMode 0;

	if ( $pw ne $pw2 ) {
		print "Sorry, passwords do not match.\n";
		return;
	}

	my $setpw = sub { return $self->ldap->set_password( user => $dn, newpasswd => $pw ); };
	my $rv = $self->with_retry( $setpw );

	if ( $rv->code() == LDAP_SUCCESS ) {
		print "Password updated successfully.\n";
	}
	else {
		print "Password error: " . $rv->error() . "\n";
	}

	return;
}


### Display the current working "directory".
###
sub run_pwd 
{
	my $self = shift;
	print $self->base() . "\n";
	return;   
}


### Display the currently bound user.
###
sub run_whoami
{
	my $self = shift;
	my $msg = ( $conf->{'binddn'} || 'anonymous bind' ) . ' (' .  $conf->{'server'} . ')';
	print "$msg\n";
	return;
}


### Show basic information for an entry (DN) or list of objectClasses.
###
###   structural/auxillary classes
###   required attributes
###   optional attributes
###
sub run_inspect
{
	my $self = shift;
	my @ocs  = @_;
	my $dn   = $ocs[0];
	my ( $must_attr, $may_attr );

	unless ( $dn ) {
		print "No DN or objectClass(es) provided.\n";
		return;
	}

	# "Magic" argument that dumps all raw schema information.
	#
	if ( $dn eq '_schema' ) {
		$self->{'schema'}->dump();
		return;
	}

	# one argument -- if it successfully resolves to a valid DN, fetch
	# the objectClass list from it.
	#
	if ( scalar @ocs == 1 ) {
		$dn = $self->base() if $dn eq '.';
		$dn = $self->path_to_dn( $dn );

		my $s = $self->search({ base => $dn, vals => 1, attrs => ['objectClass'] });
		if ( $s->{'code'} == LDAP_SUCCESS ) {
			my $e = ${ $s->{'entries'} }[0];
			@ocs = $e->get_value('objectClass');
		}
	}

	# get the complete attributes list.
	#
	( $must_attr, $may_attr ) = $self->fetch_attributes( \@ocs );
	my %must = map { $_ => 1 } @{$must_attr};

	# Output objectClass chains and flags.
	#
	print "ObjectClasses:\n";
	foreach my $oc ( sort @ocs ) {
		my @sups = $self->findall_supers( $oc );

		my @oc_chain = ( $oc, @sups );
		my @oc_out;

		foreach my $oc ( @oc_chain ) {
			my $oc_obj = $self->{'schema'}->objectclass( $oc );
			next unless $oc_obj;

			$oc = $oc . ' (' . 'structural' . ')' if $oc_obj->{'structural'};
			push( @oc_out, $oc );
		}

		print "    " . join( ' --> ', @oc_out ) . "\n" if scalar @oc_out;
	}

	# Output attributes and flags.
	#
	print "\nAttributes:\n";
	foreach my $attr ( sort (@{$must_attr}, @{$may_attr}) ) {
		my @flaglist;

		push ( @flaglist, $must{$attr} ? 'required' : 'optional' );

		if ( $self->{'schema'}->attribute( $attr )->{'single-value'} ) {
			push ( @flaglist, 'single-value' );
		}
		else {
			push ( @flaglist, 'multivalue' );
		}

		my $flags = '';
		$flags = (' (' . join( ', ', @flaglist ) . ')') if scalar @flaglist > 0;

		printf( "    %s%s\n", $attr, $flags );
	}

	print "\n";
	return;
}


### Inject various autocomplete and alias routines into the symbol table.
###
{ no strict 'refs';
	local $| = 1;
	my %aliases;

	# In first pass, only identify aliases.
	while(my($cmd, $data) = each %cmd_map ) {
		# If command is an alias, it is enough to mark it as such.
		if( $$data[0]) {
			$aliases{$$data[0]} ||= [];
			push @{$aliases{$$data[0]}}, $cmd;

		# If it is a real command, let's do more work.
		}
	}

	# In second pass, deal with non-aliases.
	while(my($cmd, $data) = each %cmd_map ) {
		if( !$$data[0]) {
			# If completer is defined, set it.
			if( $$data[1]) {
				my $comp_sub = "comp_$cmd";
				*$comp_sub   = \&{$$data[1]}
			}

			# Define help and summary functions for the command:
			my $pod = ''; open my $io, '>', \$pod;
			Pod::Usage::pod2usage( -exitval  => 'NOEXIT', -verbose  => 99, -sections => "SHELL COMMANDS/${\( quotemeta $cmd )}", -output => \*$io );
			my @pod = split /\n/, $pod;
			my $summary = $pod[1];
			if($summary) {
				$summary =~ s/^\s+//s;
				$summary =~ s/\s+$//s;
				$summary =~ s/\s+/ /s;
			}
			my $help = join "\n", @pod;
			if( $aliases{$cmd}) {
				local $" = ', ';
				$help .= "\n\n    Aliases: @{$aliases{$cmd}}\n"
			}

			my $helpfunc = sub { "$help\n" };
			*{"help_$cmd"} = \&$helpfunc;

			my $summfunc = sub { $summary };
			*{"smry_$cmd"} = \&$summfunc;
		}
	}

	# In third pass, actually register found aliases.
	while(my($cmd,$aliases) = each %aliases) {
		my $aliasfunc = sub { @$aliases };
		*{"alias_$cmd"} = \&$aliasfunc;
	}
}


### Recursively walk an objectClass hierarchy, returning an array
### of inheritence.
###
sub findall_supers
{
	my $self = shift;
	my $oc   = shift or return;
	my @found;

	foreach my $sup ( $self->{'schema'}->superclass($oc) ) {
		push( @found, $sup );
		push( @found, $self->findall_supers( $sup ) );
	}

	return @found;
}



########################################################################
### M A I N
########################################################################

package main;
use strict;
use warnings;
use Fatal qw/open/;

$0 = 'shelldap';
my $VERSION = '1.5.0';

use Getopt::Long qw(:config no_ignore_case);
use YAML::Syck qw//;
use Pod::Usage qw//;
eval { require Term::ReadLine::Gnu; };
warn qq{Term::ReadLine::Gnu not installed.
Continuing, but shelldap is of limited usefulness without it.\n\n} if $@;

# get config - rc file first, command line overrides
use vars '$conf';
$conf = (load_config())[1];
$conf ||= {};
Getopt::Long::GetOptions(
	$conf, 
	'server|h|H=s',
	'port|p=s',
	'configfile|f=s',
	'binddn|D=s',
	'basedn|b=s',
	'cacheage=i',
	'cmdline_attributes|attributes=s@',
	'paginate=i',
	'promptpass|W!',
	'pass|w=s',
	'passfile|y=s',
	'timeout=i',
	'sasl|Y=s',
	'simple|x!' => sub {
		my($opt,$arg) = @_;
		$conf->{sasl} = $arg ? undef : 'PLAIN CRAM-MD5 GSSAPI'
	},
	'tls_cacert=s',
	'tls_cert=s',
	'tls_key=s',
	'tls|Z|ZZ!',
	'debug|v',
	'version',
	 help => sub {
	  Pod::Usage::pod2usage(
	  	-verbose => 1,
	  	-message => "\n$0 command line flags\n" . '-' x 65
	  );
	}
);

# show version
if ( $conf->{'version'} ) {
	print "$0 $VERSION\n";
	exit( 0 );
}

# additional/different config file?
#
if ( $conf->{'configfile'} ) {
	my( $filepath, $more_conf) = load_config( $conf->{'configfile'} );
	while ( my ($k, $v) = each %{$more_conf} ) { $conf->{ $k } = $v }
}


# defaults
$conf->{'configfile'} ||= "$ENV{'HOME'}/.shelldap.rc";
$conf->{'cacheage'}   ||= 300;
$conf->{'timeout'}    ||= 10;
$conf->{'attributes'} ||= ['*'];

# Allow command line option --attributes to override settings from
# config file.
if($conf->{'cmdline_attributes'}) {
	$conf->{'attributes'} = $conf->{'cmdline_attributes'}
}

# create and enter shell loop while also handling Ctrl+C correctly.
my $shell = LDAP::Shell->new;
my $sigset = POSIX::SigSet->new();
sub ctrl_c_handler {
	print "\n";
	$shell->term->on_new_line;
	$shell->term->replace_line('', 0);
	$shell->term->redisplay;
}
my $sigaction = POSIX::SigAction->new( \&ctrl_c_handler, $sigset, 0);
my $old_action = POSIX::SigAction->new;
POSIX::sigaction(&POSIX::SIGINT, $sigaction, $old_action); # save default one
$shell->cmdloop();
POSIX::sigaction(&POSIX::SIGINT, $old_action); # restore default one

### List of default config files
###
sub default_configfiles
{
	( "$ENV{'HOME'}/.shelldap.rc", '/usr/local/etc/shelldap.conf', '/etc/shelldap.conf' )
}

### load YAML config into global conf.
###
sub load_config
{
	my $confpath = shift;
	my ( $d, $data );

	unless ( $confpath ) {
		my @confs = default_configfiles();
		foreach ( @confs ) {
			if ( -e $_ ) {
				$confpath = $_;
				last;
			}
		}
	}
	$confpath or return undef;

	open(my($yaml) , "< $confpath");
	do {
		local $/ = undef;
		$data = <$yaml>;  # slurp!
	};
	close $yaml;

	my $conf2 = eval { YAML::Syck::Load( $data ) };
	die "Invalid YAML in $confpath\n" if $@;

	if( $conf2->{'configfile'} and ($confpath eq $conf2->{'configfile'})) {
		delete $conf2->{'configfile'}
	}

	$conf2->{alias} ||= {};

	return($confpath, $conf2);
}

### dump YAML config into conf file while making sure that
### name of configfile itself is not dumped if it is equal
### to the file being written.
###
sub save_config
{
	my $confpath = shift || $conf->{'configfile'} || (default_configfiles)[0];

	my %conf2 = %$conf;
	# This check is currently unnecessary because the comparison will always
	# be true, but is left here for effect of least surprise in the future.
	if( $conf->{configfile} and ($confpath eq $conf->{configfile})) {
	 			 delete $conf2{'configfile'}
	}
	YAML::Syck::DumpFile( $confpath, \%conf2 );
	chmod 0600, $confpath;

	return $confpath;
}

sub slurp
{
	open my $fh, '<:encoding(UTF-8)', $_[0];
	local $/;
	my $ret = <$fh>;
	close $fh;
	return $ret;
};

### EOF