xotclsh(1) Tcl Shell containing object-oriented scripting language XOTcl


xotclsh ?filename arg arg ...?


xotclsh is a shell-like application that reads XOTcl commands from its standard input or from a file and evaluates them. Similarly as the relation between tclsh and wish, xowish provides all functionality of xotclsh and provides as well predefined support for TK widgets.

XOTcl (XOTcl, pronounced exotickle) is an object-oriented scripting language based on MIT's OTcl. It is intended as a value added replacement of OTcl.

Scripting languages, such as Tcl, are designed for glueing components together, provide features such as dynamic extensibility and dynamic typing with automatic conversion, that make them well suited for rapid application development.

The object system of XOTcl enables a user to to define objects, classes, and meta-classes. Classes are special objects with the purpose of managing other objects. ``Managing'' means that a class controls the creation and destruction of its instances and that it contains a repository of methods accessible for the instances. Every object may be enhanced with object-specific methods. XOTcl supports single and multiple inheritance. All object-class and class-class relationships in XOTcl are introspectable and can be dynamically changed at arbitrary times. Ambiguities in name resolution of methods are avoided through method chaining through "next", which does not require explicit method naming.

XOTcl combines the ideas of scripting and object-orientation in a way that preserves the benefits of both of them. It is equipped with several new language constructs that help building and managing complex systems. We added the following support:

Dynamic Object Aggregations, to provide dynamic aggregations through nested namespaces (objects).

Nested Classes, to reduce the interference of independently developed program structures.

Assertions, to reduce the interface and the reliability problems caused by dynamic typing and, therefore, to ease the combination of many components.

Meta-data, to enhance self-documentation of objects and classes.

Per-object mixins, as a means to give an object dynamically access to the methods of one or several supplemental classes.

Per-class mixins, as a means to give all instances of an class dynamically access to the methods of one or several supplemental classes.

Filters as a means of abstractions over method invocations to implement large program structures, like design patterns.

XOTcl provides a value-added replacement of Tcl package loading providing integration with object-oriented constructs and tracking/tracing of component loading.


xotclsh sets all variables that tclsh sets, and additionally the following variables:

::xotcl::version XOTcl version number.
::xotcl::confdir Directory for XOTcl configuration.
::xotcl::logdir Directory where logfiles are placed.


argument, interpreter, prompt, script file, shell