ldapx(3tcl) LDAP extended object interface ldapx(3tcl)
______________________________________________________________________________
NAME
ldapx - LDAP extended object interface
SYNOPSIS
package require Tcl 8.4
package require ldapx ?1.1?
e reset
e dn ?newdn?
e rdn
e superior
e print
se isempty
se get attr
se get1 attr
se set attr values
se set1 attr value
se add attr values
se add1 attr value
se del attr ?values?
se del1 attr value
se getattr
se getall
se setall avpairs
se backup ?other?
se swap
se restore ?other?
se apply centry
ce change ?new?
ce diff new ?old?
la error ?newmsg?
la connect url ?binddn? ?bindpw?
la disconnect
la traverse base filter attrs entry body
la search base filter attrs
la read base filter entry ... entry
la commit entry ... entry
li channel chan
li error ?newmsg?
li read entry
li write entry
______________________________________________________________________________
DESCRIPTION
The ldapx package provides an extended Tcl interface to LDAP directores
and LDIF files. The ldapx package is built upon the ldap package in or-
der to get low level LDAP access.
LDAP access is compatible with RFC 2251 (http://www.rfc-edi-
tor.org/rfc/rfc2251.txt). LDIF access is compatible with RFC 2849
(http://www.rfc-editor.org/rfc/rfc2849.txt).
OVERVIEW
The ldapx package provides objects to interact with LDAP directories
and LDIF files with an easy to use programming interface. It imple-
ments three snit::type classes.
The first class, entry, is used to store individual entries. Two dif-
ferent formats are available: the first one is the standard format,
which represents an entry as read from the directory. The second format
is the change format, which stores differences between two standard en-
tries.
With these entries, an application which wants to modify an entry in a
directory needs to read a (standard) entry from the directory, create a
fresh copy into a new (standard) entry, modify the new copy, and then
compute the differences between the two entries into a new (change) en-
try, which may be commited to the directory.
Such kinds of modifications are so heavily used that standard entries
may contain their own copy of the original data. With such a copy, the
application described above reads a (standard) entry from the direc-
tory, backs-up the original data, modifies the entry, and computes the
differences between the entry and its backup. These differences are
then commited to the directory.
Methods are provided to compute differences between two entries, to ap-
ply differences to an entry in order to get a new entry, and to get or
set attributes in standard entries.
The second class is the ldap class. It provides a method to connect and
bind to the directory with a uniform access to LDAP and LDAPS through
an URL (ldap:// or ldaps://). The traverse control structure executes a
body for each entry found in the directory. The commit method applies
some changes (represented as entry objects) to the directory. Since
some attributes are represented as UTF-8 strings, the option -utf8 con-
trols which attributes must be converted and which attributes must not
be converted.
The last class is the ldif class. It provides a method to associate a
standard Tcl channel to an LDIF object. Then, methods read and write
read or write entries from or to this channel. This class can make use
of standard or change entries, according to the type of the LDIF file
which may contain either standard entries or change entries (but not
both at the same time). The option -utf8 works exactly as with the ldap
class.
ENTRY CLASS
ENTRY INSTANCE DATA
An instance of the entry class keeps the following data:
dn This is the DN of the entry, which includes (in LDAP terminol-
ogy) the RDN (relative DN) and the Superior parts.
format The format may be uninitialized (entry not yet used), standard
or change. Most methods check the format of the entry, which can
be reset with the reset method.
attrvals
In a standard entry, this is where the attributes and associated
values are stored. Many methods provide access to these informa-
tions. Attribute names are always converted into lower case.
backup In a standard entry, the backup may contain a copy of the dn and
all attributes and values. Methods backup and restore manipulate
these data, and method diff may use this backup.
change In a change entry, these data represent the modifications. Such
modifications are handled by specialized methods such as apply
or commit. Detailed format should not be used directly by pro-
grams.
Internally, modifications are represented as a list of elements,
each element has one of the following formats (which match the
corresponding LDAP operations):
[1] {add {attr1 {val1...valn} attr2 {...} ...}}
Addition of a new entry.
[2] {mod {modop {attr1 ?val1...valn?} attr2 ...} {modop ...}
...}
Modification of one or more attributes and/or values,
where <modop> can be modadd, moddel or modrepl (see the
LDAP modify operation).
[3] {del}
Deletion of an old entry.
[4] {modrdn newrdn deleteoldrdn ?newsuperior?}
Renaming of an entry.
ENTRY OPTIONS
No option is defined by this class.
METHODS FOR ALL KINDS OF ENTRIES
e reset
This method resets the entry to an uninitialized state.
e dn ?newdn?
This method returns the current DN of the entry. If the optional
newdn is specified, it replaces the current DN of the entry.
e rdn This method returns the RDN part of the DN of the entry.
e superior
This method returns the superior part of the DN of the entry.
e print
This method returns the entry as a string ready to be printed.
METHODS FOR STANDARD ENTRIES ONLY
In all methods, attribute names are converted in lower case.
se isempty
This method returns 1 if the entry is empty (i.e. without any
attribute).
se get attr
This method returns all values of the attribute attr, or the
empty list if the attribute is not fond.
se get1 attr
This method returns the first value of the attribute.
se set attr values
This method sets the values (list values) of the attribute attr.
If the list is empty, this method deletes all
se set1 attr value
This method sets the values of the attribute attr to be an
unique value value. Previous values, if any, are replaced by the
new value.
se add attr values
This method adds all elements the list values to the values of
the attribute attr.
se add1 attr value
This method adds a single value given by the parameter value to
the attribute attr.
se del attr ?values?
If the optional list values is specified, this method deletes
all specified values from the attribute attr. If the argument
values is not specified, this method deletes all values.
se del1 attr value
This method deletes a unique value from the attribute attr.
se getattr
This method returns all attributes names.
se getall
This method returns all attributes and values from the entry,
packed in a list of pairs <attribute, list of values>.
se setall avpairs
This method sets at once all attributes and values. The format
of the avpairs argument is the same as the one returned by
method getall.
se backup ?other?
This method stores in an other standard entry object a copy of
the current DN and attributes/values. If the optional other ar-
gument is not specified, copy is done in the current entry (in a
specific place, see section OVERVIEW).
se swap
This method swaps the current and backup contexts of the entry.
se restore ?other?
If the optional argument other is given, which must then be a
standard entry, this method restores the current entry into the
other entry. If the argument other argument is not specified,
this methods restores the current entry from its internal backup
(see section OVERVIEW).
se apply centry
This method applies changes defined in the centry argument,
which must be a change entry.
METHODS FOR CHANGE ENTRIES ONLY
ce change ?new?
If the optional argument new is specified, this method modifies
the change list (see subsection Entry Instance Data for the ex-
act format). In both cases, current change list is returned.
Warning: values returned by this method should only be used by
specialized methods such as apply or commit.
ce diff new ?old?
This method computes the differences between the new and old en-
tries under the form of a change list, and stores this list into
the current change entry. If the optional argument old is not
specified, difference is computed from the entry and its inter-
nal backup (see section OVERVIEW). Return value is the computed
change list.
ENTRY EXAMPLE
package require ldapx
#
# Create an entry and fill it as a standard entry with
# attributes and values
#
::ldapx::entry create e
e dn "uid=joe,ou=people,o=mycomp"
e set1 "uid" "joe"
e set "objectClass" {person anotherObjectClass}
e set1 "givenName" "Joe"
e set1 "sn" "User"
e set "telephoneNumber" {+31415926535 +2182818}
e set1 "anotherAttr" "This is a beautiful day, isn't it?"
puts stdout "e\n[e print]"
#
# Create a second entry as a backup of the first, and
# make some changes on it.
# Entry is named automatically by snit.
#
set b [::ldapx::entry create %AUTO%]
e backup $b
puts stdout "$b\n[$b print]"
$b del "anotherAttr"
$b del1 "objectClass" "anotherObjectClass"
#
# Create a change entry, a compute differences between first
# and second entry.
#
::ldapx::entry create c
c diff e $b
puts stdout "$c\n[$c print]"
#
# Apply changes to first entry. It should be the same as the
# second entry, now.
#
e apply c
::ldapx::entry create nc
nc diff e $b
puts stdout "nc\n[nc print]"
#
# Clean-up
#
e destroy
$b destroy
c destroy
nc destroy
LDAP CLASS
LDAP INSTANCE DATA
An instance of the ldap class keeps the following data:
channel
This is the channel used by the ldap package for communication
with the LDAP server.
lastError
This variable contains the error message which appeared in the
last method of the ldap class (this string is modified in nearly
all methods). The error method may be used to fetch this mes-
sage.
LDAP OPTIONS
A first set of options of the ldap class is used during search opera-
tions (methods traverse, search and read, see below).
-scope base|one|sub
Specify the scope of the LDAP search to be one of base, one or
sub to specify a base object, one-level or subtree search.
The default is sub.
-derefaliases never|seach|find|always
Specify how aliases dereferencing is handled: never is used to
specify that aliases are never derefenced, always that aliases
are always derefenced, search that aliases are dereferenced when
searching, or find that aliases are dereferenced only when lo-
cating the base object for the search.
The default is never.
-sizelimit integer
Specify the maximum number of entries to be retreived during a
search. A value of 0 means no limit.
Default is 0.
-timelimit integer
Specify the time limit for a search to complete. A value of 0
means no limit.
Default is 0.
-attrsonly 0|1
Specify if only attribute names are to be retrieved (value 1).
Normally (value 0), attribute values are also retrieved.
Default is 0.
The last option is used when getting entries or committing changes in
the directory:
-utf8 pattern-yes pattern-no
Specify which attribute values are encoded in UTF-8. This infor-
mation is specific to the LDAP schema in use by the application,
since some attributes such as jpegPhoto, for example, are not
encoded in UTF-8. This option takes the form of a list with two
regular expressions suitable for the regexp command (anchored by
^ and $). The first specifies which attribute names are to be
UTF-8 encoded, and the second selects, among those, the attri-
bute names which will not be UTF-8 encoded. It is thus possible
to say: convert all attributes, except jpegPhoto.
Default is {{.*} {}}, meaning: all attributes are converted,
without exception.
LDAP METHODS
la error ?newmsg?
This method returns the error message that occurred in the last
call to a ldap class method. If the optional argument newmsg is
supplied, it becomes the last error message.
la connect url ?binddn? ?bindpw?
This method connects to the LDAP server using given URL (which
can be of the form ldap://host:port or ldaps://host:port). If an
optional binddn argument is given together with the bindpw argu-
ment, the connect binds to the LDAP server using the specified
DN and password.
la disconnect
This method disconnects (and unbinds, if necessary) from the
LDAP server.
la traverse base filter attrs entry body
This method is a new control structure. It searches the LDAP di-
rectory from the specified base DN (given by the base argument)
and selects entries based on the argument filter. For each entry
found, this method fetches attributes specified by the attrs ar-
gument (or all attributes if it is an empty list), stores them
in the entry instance of class entry and executes the script de-
fined by the argument body. Options are used to refine the
search.
Caution: when this method is used, the script body cannot per-
form another LDAP search (methods traverse, search or read).
la search base filter attrs
This method searches the directory using the same way as method
traverse. All found entries are stored in newly created in-
stances of class entry, which are returned in a list. The newly
created instances should be destroyed when they are no longer
used.
la read base filter entry ... entry
This method reads one or more entries, using the same search
criteria as methods traverse and search. All attributes are
stored in the entries. This method provides a quick way to read
some entries. It returns the number of entries found in the di-
rectory (which may be more than the number of read entries). If
called without any entry argument, this method just returns the
number of entries found, without returning any data.
la commit entry ... entry
This method commits the changes stored in the entry arguments.
Each entry may be either a change entry, or a standard entry
with a backup.
Note: in the future, this method should use the LDAP transaction
extension provided by OpenLDAP 2.3 and later.
LDAP EXAMPLE
package require ldapx
#
# Connects to the LDAP directory
#
::ldapx::ldap create l
set url "ldap://server.mycomp.com"
if {! [l connect $url "cn=admin,o=mycomp" "mypasswd"]} then {
puts stderr "error: [l error]"
exit 1
}
#
# Search all entries matching some criterion
#
l configure -scope one
::ldapx::entry create e
set n 0
l traverse "ou=people,o=mycomp" "(sn=Joe*)" {sn givenName} e {
puts "dn: [e dn]"
puts " sn: [e get1 sn]"
puts " givenName: [e get1 givenName]"
incr n
}
puts "$n entries found"
e destroy
#
# Add a telephone number to some entries
# Note this modification cannot be done in the "traverse" operation.
#
set lent [l search "ou=people,o=mycomp" "(sn=Joe*)" {}]
::ldapx::entry create c
foreach e $lent {
$e backup
$e add1 "telephoneNumber" "+31415926535"
c diff $e
if {! [l commit c]} then {
puts stderr "error: [l error]"
exit 1
}
$e destroy
}
c destroy
l disconnect
l destroy
LDIF CLASS
LDIF INSTANCE DATA
An instance of the ldif class keeps the following data:
channel
This is the Tcl channel used to retrieve or store LDIF file con-
tents. The association between an instance and a channel is made
by the method channel. There is no need to disrupt this associa-
tion when the LDIF file operation has ended.
format LDIF files may contain standard entries or change entries, but
not both. This variable contains the detected format of the file
(when reading) or the format of entries written to the file
(when writing).
lastError
This variable contains the error message which appeared in the
last method of the ldif class (this string is modified in nearly
all methods). The error method may be used to fetch this mes-
sage.
version
This is the version of the LDIF file. Only version 1 is sup-
ported: the method read can only read from version 1 files, and
method write only creates version 1 files.
LDIF OPTIONS
This class defines two options:
-ignore list-of-attributes
This option is used to ignore certain attribute names on read-
ing. For example, to read OpenLDAP replica files (replog), one
must ignore replica and time attributes since they do not con-
form to the RFC 2849 standard for LDIF files.
Default is empty list: no attribute is ignored.
-utf8 pattern-yes pattern-no
Specify which attribute values are encoded in UTF-8. This infor-
mation is specific to the LDAP schema in use by the application,
since some attributes such as jpegPhoto, for example, are not
encoded in UTF-8. This option takes the form of a list with two
regular expressions suitable for the regexp command (anchored by
^ and $). The first specifies which attribute names are to be
UTF-8 encoded, and the second selects, among those, the attri-
bute names which will not be UTF-8 encoded. It is thus possible
to say: convert all attributes, except jpegPhoto.
Default is {{.*} {}}, meaning: all attributes are converted,
without exception.
LDIF METHODS
li channel chan
This method associates the Tcl channel named chan with the LDIF
instance. It resets the type of LDIF object to uninitialized.
li error ?newmsg?
This method returns the error message that occurred in the last
call to a ldif class method. If the optional argument newmsg is
supplied, it becomes the last error message.
li read entry
This method reads the next entry from the LDIF file and stores
it in the entry object of class entry. The entry may be a stan-
dard or change entry.
li write entry
This method writes the entry given in the argument entry to the
LDIF file.
LDIF EXAMPLE
package require ldapx
# This examples reads a LDIF file containing entries,
# compare them to a LDAP directory, and writes on standard
# output an LDIF file containing changes to apply to the
# LDAP directory to match exactly the LDIF file.
::ldapx::ldif create liin
liin channel stdin
::ldapx::ldif create liout
liout channel stdout
::ldapx::ldap create la
if {! [la connect "ldap://server.mycomp.com"]} then {
puts stderr "error: [la error]"
exit 1
}
la configure -scope one
# Reads LDIF file
::ldapx::entry create e1
::ldapx::entry create e2
::ldapx::entry create c
while {[liin read e1] != 0} {
set base [e1 superior]
set id [e1 rdn]
if {[la read $base "($id)" e2] == 0} then {
e2 reset
}
c diff e1 e2
if {[llength [c change]] != 0} then {
liout write c
}
}
la disconnect
la destroy
e1 destroy
e2 destroy
c destroy
liout destroy
liin destroy
REFERENCES
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category ldap of
the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
also report any ideas for enhancements you may have for either package
and/or documentation.
When proposing code changes, please provide unified diffs, i.e the out-
put of diff -u.
Note further that attachments are strongly preferred over inlined
patches. Attachments can be made by going to the Edit form of the
ticket immediately after its creation, and then using the left-most
button in the secondary navigation bar.
KEYWORDS
directory access, internet, ldap, ldap client, ldif, protocol, rfc
2251, rfc 2849
CATEGORY
Networking
COPYRIGHT
Copyright (c) 2006-2018 Pierre David <pdav@users.sourceforge.net>
tcllib 1.1 ldapx(3tcl)