The dollar sign `$` shown in the figure is known as the *prompt*, and you are watching the typical *Ubuntu terminal* in version 18.04; other kind of prompts are `>`, `~`, `->`, among others.
The dollar sign `$` shown in the figure is known as the *prompt*, and you are watching the typical *Ubuntu terminal* in version 18.04; other kind of prompts are `>`, `~`, `->`, among others.
@ -122,11 +123,12 @@ The dollar sign `$` shown in the figure is known as the *prompt*, and you are wa
The *terminal* is some kind of front-end to observe the input/output of a command process task.
The *terminal* is some kind of front-end to observe the input/output of a command process task.
## Shell ##
## Shell ##
The third element is the shell. Once we have typed *a command-line tool* and pressed `<Enter>`, the terminal sends that command to the *shell*. The shell is a program that interprets the command. The image shows the Bash (Bourne Again Shell), but there are many others available like *Z shell*.
The third element is the shell. Once we have typed *a command-line tool* and pressed `<Enter>`, the terminal sends that command to the *shell*. The shell is a program that interprets the command. The image shows the Bash (Bourne Again Shell), but there are many others available like *Z shell*.
**aqui voy**
## Operating system ##
## Operating system ##
The last element is the operating system (OS), which is *GNU/Linux* in the Docker image. Linux is the name of the kernel, which is the heart of the operating system. The kernel has a direct contact with the CPU, disks, and other hardware. The kernel also executes the *command-line tools*. GNU, which stands for GNU’s not UNIX, refers to the set of basic tools. In this case the Docker image is based on Ubuntu Linux.
The last element is the operating system (OS), which is *GNU/Linux* in the Docker image. Linux is the name of the kernel, which is the heart of the operating system. The kernel has a direct contact with the CPU, disks, and other hardware. The kernel also executes the *command-line tools*. GNU, which stands for GNU’s not UNIX, refers to the set of basic tools. In this case the Docker image is based on Ubuntu Linux.
# Type of command-line tools #
# Type of command-line tools #
@ -142,9 +144,11 @@ The command-line tools are some kind of apps called by text and return text, str
The most common are the first two, while the others allow to build up a toolbox that will make us more efficient and productive.
The most common are the first two, while the others allow to build up a toolbox that will make us more efficient and productive.
## Binary executable ##
## Binary executable ##
Binary executables are programs in the classical sense. A binary executable is created by compiling source code to machine code. This means that when you open the file in a text editor you cannot read it[^2].
Binary executables are programs in the classical sense. A binary executable is created by compiling source code to machine code. This means that when you open the file in a text editor you cannot read it[^2].
## Shell builtin ##
## Shell builtin ##
Shell builtins are command-line tools provided by the shell, which is Bash in our case. Examples include cd and help. These cannot be changed. Shell builtins may differ between shells. Like binary executables, they cannot be easily inspected or changed.
Shell builtins are command-line tools provided by the shell, which is Bash in our case. Examples include cd and help. These cannot be changed. Shell builtins may differ between shells. Like binary executables, they cannot be easily inspected or changed.
## Interpreted Script ##
## Interpreted Script ##
@ -152,6 +156,7 @@ The most common are the first two, while the others allow to build up a toolbox
An interpreted script is a text file that is executed by a binary executable. Examples include: *Python*, *R*, and *Bash scripts*. One great advantage of an interpreted script is that you can read and change it. E.g. a script `fac.py`. This script is interpreted by Python not because of the file extension .py, but because the first line of the script defines the binary that should execute it.
An interpreted script is a text file that is executed by a binary executable. Examples include: *Python*, *R*, and *Bash scripts*. One great advantage of an interpreted script is that you can read and change it. E.g. a script `fac.py`. This script is interpreted by Python not because of the file extension .py, but because the first line of the script defines the binary that should execute it.
## Testing some tools ##
## Testing some tools ##
We employ the term command-line tool a lot, but so far, we have not yet explained what we actually mean by it. We use it as an umbrella term for anything that can be executed from the command line. Under the ho
We employ the term command-line tool a lot, but so far, we have not yet explained what we actually mean by it. We use it as an umbrella term for anything that can be executed from the command line. Under the ho
