This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2026 Paulo Moura <pmoura@logtalk.org> SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

`base32`

The base32 library provides predicates for encoding and decoding data in the Base32 format as per the specification found at:

https://www.rfc-editor.org/rfc/rfc4648

API documentation

Open the [../../apis/library_index.html#base32](../../apis/library_index.html#base32) link in a web browser.

Loading

To load all entities in this library, load the loader.lgt utility file:

| ?- logtalk_load(base32(loader)).

Testing

To test this library predicates, load the tester.lgt file:

| ?- logtalk_load(base32(tester)).

Encoding

Encoding a list of bytes in Base32 format is accomplished by the `base32::generate/2` predicate. For example:

| ?- atom_codes('Hello!', Bytes), base32::generate(atom(Base32), Bytes). Base32 = 'JBSWY3DPEE======' Bytes = [72,101,108,108,111,33] yes

| ?- atom_codes('Hello!', Bytes), base32::generate(codes(Base32), Bytes). Base32 = [74,66,83,87,89,51,68,80,69,69,61,61,61,61,61,61] Bytes = [72,101,108,108,111,33] yes

The Base32 result can also be represented using a list of chars, written to a file or to a stream. See the API documentation for details.

Decoding

Decoding of Base32 data is accomplished using the `base32::parse/2` predicate. For example:

| ?- base32::parse(atom('JBSWY3DPEE======'), Bytes), atom_codes(Atom, Bytes). Atom = 'Hello!' Bytes = [72,101,108,108,111,33] yes

| ?- base32::parse(chars(['J','B','S','W','Y','3','D','P','E','E','=','=','=','=','=','=']), Bytes), atom_codes(Atom, Bytes). Atom = 'Hello!' Bytes = [72,101,108,108,111,33] yes

The `base32::parse/2` predicate accepts other input sources such as a file or a stream. See the API documentation for details. Both uppercase and lowercase letters are accepted when decoding.