The main objective of this article is to try to understand what happens behind our shell when we type ls -l. However, it is necessary to emphasize that before getting into the subject it is essential to clarify some very specific details that are part of this whole process. First, we must understand what the structure of the Linux file system is.

What is the structure of the file system?

In Linux, the file system is designed through a hierarchy in which the different directories and files are located and expressed in a tree form. Also, as it states [1] the basis of the file system is the…

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A few years ago, remote communication was complicated because you had to go to specific places to make international calls or you had to send a letter and wait for it to reach the recipient and for him or her to reply, which could take days or even weeks. …

What is an object? According to the Oxford dictionary [1] an object is a thing that can be seen and touched, but is not alive. You can look around you and you will realize that there are several types of objects surrounding you at the moment, and even, this type of interaction with objects can be experienced by the human being from his first years of life, identifying which is the functionality of each one of the objects with which he interacts. However, in the field of programming, when it refers to an object it is no different from the…

Many times, as programmers we are faced with great challenges that lead us to use different types of resources for which we must be prepared. One of those resources, without a doubt, are libraries.

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Let us explore a little the idea that libraries are in general. Let us imagine that we are in a bookstore with many books and that we have access to the content of each one of them immediately if we need them. But… What is the content of these books? These books contain the source code for many functions, with a special identifier known as the…

First of all it is important to define what we mean by libraries in the programming language C. The Standard C Library, also known as the ISO C Library, is a collection of macros, types and functions for tasks such as input/output processing, string handling, memory management, mathematical calculations and many other operating system services. It is specified in the C standard (e.g. C11). The content is distributed under different headings. Typically, a C library comes in two parts:

1) A header file that defines the functionality that the library is exposing (offering) to the programs that use it.

The creation of an executable C module from a source code is basically a three-stage process (see figure 1). In the first step, the processor prepares and modifies the source code for the compilation phase according to instructions specified in the pre-processing directives. One of its most important tasks is to copy the entire contents of all the headers, starting with the # (#include) symbol in each .c file.

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Fig 1. Resource: Beginning C++17, Ivor Horton and Peter Van Weert

It is important to note that in preprocessing, operations occur before the program is compiled. …

Linux is a fairly flexible operating system that can be reflected in the creation of the links. But what are links? It is simply a way to create a shortcut to an original directory, which can be used in different ways, for example if we want to access a path that is in a hierarchical order deep in the directories with a single command line can be accessed.

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However, it should be noted that there are two types of links. On the one hand, hard links can only link files (but not directories), a file cannot be referenced on a…

There are many commands for the Linux operating system, however, we will explain on this occasion how important it is to know how to use the “ls” command. Typing this command in our terminal helps us to list the contents of the directory we are referring to, as shown below:

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Using ‘ls’ command on linux terminal

As you can see, when typing the command “ls” the output is all the files that are in the directory called “command” (blue), whose files with their respective extensions are: code.c command.txt hello.html hello_world.c main.js programming.c style.css style.js.

Carlos Barros

Junior Data Scientist | Python | R programming | Tableau | AWS | Data Analytics | Data Visualization | Statistics

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