Scripting language facts for kids

A scripting language is a special kind of programming language. It helps you create short programs called scripts. Think of scripts as a list of instructions for a computer to follow. They help automate tasks, making jobs easier and more reliable.

Scripting languages are often simpler to learn than other programming languages. They can still do many powerful things. Some scripts run inside other programs, like in a web browser or Microsoft Excel. Others act as a "shell," which lets you type commands directly to the computer's operating system (OS). This is like talking to your computer.

There's no strict rule for what counts as a scripting language. Some people say they must be for a specific job. Others include any language that is "interpreted" instead of "compiled." Interpreted means the computer runs the code line by line. Compiled means the code is fully translated before it runs.

What Are Scripting Languages Used For?

Scripting languages are used in many places. Here are some common examples:

• Controlling Computers: Languages like Bash are used to give commands to Unix-like operating systems. They help manage files and run programs.
• Inside Applications: Many programs have their own scripting languages. These are called "extension languages." For example, JavaScript helps make websites interactive, like the Google home page. Visual Basic for Applications (VBA) is used in Microsoft Office programs. Lua is another language often built into other applications.
• Video Games: Some games use scripts to create new levels or features. For example, in games like Second Life or Trainz, players can write scripts to customize their experience.
• Text Processing: Languages like sed and AWK are great for working with text files. They can quickly find and change words or patterns.
• General Use: Languages like Perl, Tcl, and Python are very flexible. They can be used for many different tasks, from building websites to analyzing data.

How Scripting Languages Work

Most scripting languages are designed to be easy to learn and use. You can often write a short script and run it right away. This is great for trying out new ideas quickly.

Quick Testing and Changes

Scripting languages often let you type commands one at a time. The computer then runs each command and shows you the result. This is called a "read-eval-print loop" (REPL). If something doesn't work, you can make a quick change and try again. This makes scripting languages perfect for creating a "rapid prototype." It helps you see if an idea works without spending a lot of time.

For example, in Python, you can just type: print ("Hello World") And the computer will immediately show "Hello World." You don't need a lot of extra code.

Interpreted Code

Scripting languages are usually "interpreted." This means another program, called an "interpreter," reads your script line by line and tells the computer what to do. This interpreter is often written in a "compiled language." Compiled languages are translated into a special code that the computer understands directly.

Easy to Use

Scripting languages often hide complex details from you. You don't always need to worry about things like how the computer stores data or manages its memory. This makes them easier for more people to use, even those who aren't professional programmers.

Sometimes, people who use a program (not just programmers) create or change scripts. This is called "end-user development." Scripts can also be shared or sold, especially when they make up big parts of games.

A Brief History

The idea of scripts goes back to early mainframe computers in the 1950s. These computers used "batch files" to run jobs one after another. IBM's Job Control Language (JCL) is a famous example of an early scripting language.

In the 1960s, "interactive shells" appeared. These let users type commands and get immediate responses. This was a big step forward. Languages like Tcl and Lua were later created to be general-purpose scripting languages. They could be easily added to many different applications. This made it simpler for both programmers and users.

Types of Scripting Languages

Glue Languages

Sometimes, scripting languages are used to connect different programs. This is called "glue code." A language made for this is a "glue language." They are useful for:

• Making custom commands for your computer's command line.
• Creating small programs that run before or after a main application.
• Writing scripts that might need to change often.

Examples of glue languages include Perl, AppleScript, and Windows PowerShell. Even programmable calculators sometimes have their own glue languages.

Job Control Languages

These languages help you start and control other programs on a computer system. They often work as "command-line interpreters." This means you type commands, and the language helps the computer understand them. The Unix shell is a good example.

GUI Scripting

"GUI" stands for Graphical User Interface. This is what you see on your screen, with windows, menus, and buttons. GUI scripting languages help test these interfaces. They can pretend to be a human user, moving the mouse, clicking, and typing. These recorded actions are often called "macros."

Application-Specific Languages

Many large programs, like games or business software, have their own scripting language built just for them. These languages are designed to control that one specific application. They might look like other programming languages but have special features for their program.

Extension Languages

These languages are similar to application-specific ones, but they can be used in many different applications. JavaScript is a great example. It started as a language for web browsers but is now used in many other programs, like those from Adobe.

Over time, some languages change and add more features. They might start as one type of scripting language and then become useful for many more things.

See also

In Spanish: Script para niños