VSCode supports region and endregion tags but not everywhere. These two special tags can be written differently depending on the language you're using but have, always, the same objective: allow you to fold part of the code.
Not everywhere means, for instance, VSCode didn't support code folding by default in Dockerfile. Let's see how to solve this.
When writing Bash scripts, I'm always putting some description block in front of any functions like I do in any language (think to PHP Docblock).
With PHP, there are a few tools like phpDocumentor for extracting these blocks and generate documentation but do such tools exist for Bash? I don't know, I haven't found any.
So I've written a small Bash script to accomplish this i.e. parse any .sh file present in a folder, extract doc blocks and create one markdown document for any retrieved script. Each function's documentation will then be copied in Markdown, then a table of contents will be appended and, finally, a generic readme.md file will display the list of markdown files retrieved.
Still faced with the problem of having to compare two versions of the same script (see the article Linux - Comparing two folders/files in the console), this time we're going to consider that the file we need to compare is a Bash script and that we have two versions of it.
And that we may have made the two files evolve in different ways, i.e. that one or other, or even both, of the files may have been modified.
The aim is therefore to compare the versions and highlight the differences.
In a previous article, we've seen a simple CLI command to display the list of functions present in a script but what about a Bash script that will scan an entire folder; retrieve any .sh scripts and check if functions are sorted in the files?
Natively, Linux has a command-line tool called diff for comparing two folders or files. Comparing two folders is quite simple: diff folder_1 folder2. And it's no more complicated for two files: diff file_1 file2.
However, when you want to do this in a slightly more industrialized way (launch a very large number of comparisons to compare two versions of the same project, for example), the use of a few flags and snippets comes in handy.
When faced with legacy code, it is often useful to reformat it to make it readable. And from there, the study of the code can begin.
There are plenty of reformatting tools for json, php, javascript and other languages, but far fewer for a query written in SQL.
Just copy/paste SELECT LAT_N, CITY, TEMP_F FROM STATS, STATION WHERE MONTH = 7 AND STATS.ID = STATION.ID ORDER BY TEMP_F in the tool and get
SELECT
LAT_N,
CITY,
TEMP_F
FROM
STATS,
STATION
WHERE
MONTH = 7
AND STATS.ID = STATION.ID
ORDER BY
TEMP_F
When I'm learning, I usually take notes. I find that it's one of the best ways of remembering what I've seen and being able to come back to it at any time.
Below is a note that I took and revised several times when I took the time to create my first .make files.
A concept of the clean code approach is to avoid too many function parameter (I would say that four parameters is already too many).
When you're programming in a language more advanced than Linux Bash, it's easy to get round the problem. For example, in PHP, if I need to call a function and pass it several parameters, I'll create an object that will be my only parameter and that object will then have several properties.
So, for instance, if I need to pass data such as a surname, first name, date of birth, gender, etc., I'll create a person object, define my properties and voil脿, I've only got one parameter to pass to my function. In most cases, it'll be a very nice solution.
But how do you do it in Linux Bash? It's impossible to pass an object... so I'm going to pass it an associative array.
Because you're an excellent developer, you deny anyone access to the properties of your class directly, but only via a getter or setter.
In other words, in your PHP class, you don't have public properties (they're devil) but exclusively protected ones or better private.
And using getter and setters you allow other objects to interact with your private methods by reading them (getters) or updating their values (setters).
Some people will say "Yes, but it's tedious to write these functions", but not at all.
Imagine you to have a very big docker-compose.yml file with a lot of services and dependencies.
You've too multiple exposed ports.
You'd like to have an at-a-glance view of services, dependencies and open ports. Is this possible? Yes! https://github.com/compose-viz/compose-viz do the magic for us.