The efforts for the search of new programming

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Unformatted text preview: "used in a variety of contexts. For an individual run of such an application, programmers must configure a setup to customize the application for its current run. This setup can be specified in the form of a script written in a scripting language. The script integrates individual commands into a single command that can be used to drive application execution. A scripting language is interpreted, rather than compiled. Hence a script can interact with a running program and change during the run. In addition to controlling a running program, scripts can preprocess and post process data. Scripting languages typically let programmers invoke individual application components directly. Application components are individual programs, such as data format converters and visualizers that carry out specific data processing tasks and can be used in different contexts . Some commonly known scripting languages are Unix Shell Script, Perl, Tel, and Python. A typical script looks like the one shown in Figure 12.27. users = 'who I we —1' if test $users -gt 10 then echo "More than 10 users logged on" fi Figure 12.27. A typical script. The first line of the script sets the variable 'users' equal to the value produced by the pipeline of commands 'who I we -F. This is in fact a count of the number of users currently logged on to the system. This value is then compared with the number 10, and if it is greater, then the message is displayed. Fourth-Generation Languages (4GLs) Some people in the computer field like to identify the major developments in programming language area by generations. According to them, machine languages, assembly languages, and high-level languages are identified as firstgeneration, second-generation, and third-generation languages respectively. Every new generation of language brought significant improvement in programmer productivity by making programming languages more and more user-friendly. Studies indicate that the move from first-generation machine langua...
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This document was uploaded on 04/07/2014.

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