Alsina González
Specialist journalist and researcher
Before there was Windows, the first MacOS, or any other computer environment that was controlled visually by using the mouse (or, now, playing with your fingers on the screen), computers were larger and rougher to deal with. human interaction, having to give them orders through words written on the keyboard that could be followed by various parameters to modify their operation.
In computing, a command is an instruction or order that is given to computers, through a keyboard or similar device.
Interaction through commands presupposes the existence of a command interpretera program that receives the instructions that we are giving it in the form of a written command, and executes them.
At this point, it is best to give an example of what I am talking about.
Old operating systems without a graphical environment, such as MS-DOS (and its variants such as DR-DOS or the current FreeDOS) interact with the user at the system level through a command interpreter and the corresponding commands that the latter is capable of. recognize.
Who already has an age will remember the time of MS-DOS. Thus, for example, the command to see the list of files and folders contained in a folder was DIR.
But let’s complicate things a bit…
The parameters They are command action modifiers, or data necessary for them to execute the entrusted task.
For example, in MS-DOS, to prepare a physical disk (like an old floppy disk) we had to use the FORMAT command. But this, entered dry, would show us an error because it would need to know which drive to format. FORMAT A: would be an example of the correct use of the FORMAT command, since we are telling it to format unit A:, and the latter would be the necessary parameter to carry out the action.
Confused? Let’s give it one more twist…
In any operating system the commands can be internal or external.
Earlier I explained that commands are processed by a shell. It may have been programmed to directly recognize various “key words” and perform actions when recognized. These are the internal commands, which do not need to be implemented separately, and which are directly recognized by the interpreter.
The external commands are nothing more than executable files that the interpreter will search for automatically in one of the folders that it has marked as system.
In this sense, if we delete the file that contains the command, we will be unable to use it.
Finally, a thought: have you noticed that in almost all operating systems with graphical environments we have the option of opening something called Command line? Its use is normally restricted to professionals and hobbyists who understand a lot about computers, but it is there for everyone who wants to dare. You just have to know… some commands!
Fotolia photos: Gorodenkoff/Superingo
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