.. index:: os
.. _os/0:

**object**

``os``
======

Portable operating-system access predicates.

| **Author:** Paulo Moura
| **Version:** 1.49
| **Date:** 2018/3/15

| **Compilation flags:**
|    ``static, context_switching_calls``


| **Implements:**
|    ``public`` :ref:`osp <osp/0>`
| **Aliases:**
|    ``osp`` ``absolute_file_name/2`` aka ``expand_path/2``

Public interface
----------------

(see related entities)

Protected interface
-------------------

(see related entities)

Private predicates
------------------

(see related entities)

Operators
---------

(none)

Remarks
-------

* **File path expansion**: To ensure portability, all file paths are expanded before being handed to the backend Prolog system.

* **Missing implementations**: A few predicates (e.g. wall_time/1) cannot be implemented in some backend Prolog systems.

.. seealso::

   :ref:`os_types <os_types/0>`

