A subset of the imperative programming languages is the collection of languages known as

scripting languages. These languages are typically used to perform administrative tasks rather than

to develop complex programs. The expression of such a task is known as a script,which explains the

term “scripting language.” For example, the administrator of a computer system might write a script

to describe a sequence of record-keeping activities that should be performed every evening, or the user of a

PC might write a script to direct the execution of a sequence of programs required to read pictures from a digital camera,

index the pictures by date, and store copies of them in an archival storage system. The origin of scripting languages can

be traced to the job control languages of the1960s that were used to direct an operating system

in the scheduling of batch processing jobs (see Section 3.1). Even today, many consider scripting languages to be

languages for directing the execution of other programs, which is a rather restrictive view of current scripting languages.

Examples of scripting languages include Perl and PHP, both of which are popular in controlling server-side Web

applications (see Section 4.3), as well as VBScript, which is a dialect of Visual Basic that was developed by Microsoft

and is used in Windows-specific situations.