Scripting language

In computing, a script is a relatively short and simple set of instructions that typically automate an otherwise manual process.

[1] Originally, scripting was limited to automating an operating system shell and languages were relatively simple.

In this context, the term script refers to a small program in such a language; typically, contained in a single file, and no larger than a few thousand lines of code.

Generally, they are interpreted directly from source code or from bytecode or run as native after just-in-time compilation.

A codebase of multiple files, that performs sophisticated user or hardware interface or complicated algorithms or multiprogramming is probably not considered a script.

For example, Java is not script-like since an application starts at the function named main which need not be at the top of the code.

In contrast, the following Python code prints "Hello World" without the main function or other syntax such as a class definition required by Java.

[8] Louis Pouzin wrote an early processor for command scripts called RUNCOM for CTSS around 1964.

Other languages such as Visual Basic for Applications (VBA) provided strong integration with the automation facilities of an underlying system.

Pipelines and shell scripting are archetypal examples of glue languages, and Perl was initially developed to fill this same role.

But if a substantial amount of logic is written in script, it is better characterized as simply another software component, not "glue".

Other tools like AWK can also be considered glue languages, as can any language implemented by a Windows Script Host engine (VBScript, JScript and VBA by default in Windows and third-party engines including implementations of Rexx, Perl, Tcl, Python, XSLT, Ruby, Modern Pascal, Delphi, and C).

A majority of applications can access and use operating system components via the object models or its own functions.

Third-party implementations of more comprehensive Basic version that may be closer to variants listed as glue languages in this article are available—and attempts to implement Perl, Rexx, or various operating system shells on the TI and HP graphing calculators are also mentioned.

Sometimes text editors and edit macros are used under the covers to provide other applications, e.g., FILELIST and RDRLIST in CMS .

With the advent of graphical user interfaces, a specialized kind of scripting language emerged for controlling a computer.

Some GUI scripting languages are based on recognizing graphical objects from their display screen pixels.

Some other types of applications that need faster feature addition or tweak-and-run cycles (e.g. game engines) also use an embedded language.

The scripting languages used for this purpose range from the more common and more famous Lua and Python to lesser-known ones such as AngelScript and Squirrel.