A command in computation is a request to a software program to complete an assigned task. It can be delivered using a command-line interface(CLI), including a console, insight into a service provider as an element of an internet protocol, or as an occurrence in a graphical user interface (GUI) triggered by the user picking an item from a panel.
The concept of command is specifically used in impetuous programming languages. The term comes from the fact that sentences in these dialects are typically expressed urgently, which is common in many generative grammars. If one considers a declaration in an object-oriented language similar to a word in a linguistic form, a command is similar to a verb in such a syntax.
Several programs accept structured inputs defined as flags or alternatives that vary the system's configuration file, while additional parameters may offer entities to operate on those that include such configuration files. In terms of natural language, the flags are adjectives, while the other parameters are entities.
Definition of Command-line Interface
A command-line interface (CLI) is a computer application that executes instructions in the format of paragraphs. A command-line interpreter or command-line parser is the software that implements the interaction. Operating systems (OS) incorporate a command-line interface in a shell regarding interactive access to OS services and features. Beginning in the mid-1960s, such accessibility was generally supplied to consumers via client computers. It was used across the 1970s and 1980s on VAX/VMS, Virtual machines, portable communications systems, DOS (Disk operating system), CP/M, and Macintosh DOS.
Many consumers nowadays concentrate on GUI (graphical user interfaces) and menu-driven operations. On the other hand, many coding and administrative jobs may not have a graphical user interface (GUI) and must rely on a command prompt. Text-based user experience choices (for instance, IBM SMIT AIX), toolbar buttons, and several workstation paradigms focused on the cursor are options to the command line (usually managed with a mouse).
Windows XP, DOS Terminal, and Pointer Technologies Power panel are instances of CLI. In addition, Command-line interfaces (CLI) are usually used in connected devices, which are also susceptible to screen-oriented text-based user interface design that displays signals on a touchscreen displays via pointer referencing.
Power shell makes it easy to control applications with CLI (Command-line interfaces).
For planning and operation, many software applications use command-line terminals. It contains development platforms as well as distributed generation.
Here are a few examples of commands issued to a command-line interpreter (UNIX shell).
The below-mentioned command moves the client to the location /home/pete in the root folder. Cd (Compact disk) is the internetwork, and the parameter is /home/pete:
The below code writes the Hello Shell?s words on the output device, which publishes the information on the screen.
The title of the code is an echo, and the parameter is "Hello Shell." The quotation marks are required to prevent Hello and Shell from being considered as distinct items:
The default configuration is interchangeable. They display a list of entries in the /bin location. The application is ls, and the parameter is the path /bin:
ls -l -t -r /bin
ls -ltr /bin
The script shown below shows the information of the directories ch1.txt and ch2.txt. The system's identity is a cat, and it takes two directory name arguments:
ch1.txt cat ch2.txt
Here are several DOS, OS/2, and Windows Server command-line CPU commands. For example, the command below exposes the name of the file readme.txt. Here type is the application title, and readme.txt is the parameter.
The command below displays the information of the root folder. The project title is dir, and Q is a parameter that requests that the author of each folder will be shown as well.
Advantages of Command programming
Disadvantages of Command programming