Art_Code's questions

Good morning StackOverflow community!

My question is very theoretical this time, I am studying the methods readFile()and readFileSync()of the module fs.

Being the main advantage of nodejs the fact of executing asynchronous operations, I am left wondering why and what it exists for readFileSync()? Isn't it true that you could treat all cases with readFile()?

This approach leads me to my most important question: There are cases where it is more convenient to use readFileSync()instead of readFile()?

Thanks in advance for your collaboration!

Good morning StackOverflow community!

I'm learning to program in Kotlin and a doubt has arisen regarding its basic concepts, specifically regarding arrays and lists.

Lists based on what I've researched can be both mutable and immutable, however arrays can only be immutable. Taking into account that lists have a practically identical behavior to arrays, then:

1) Why do arrays exist in Kotlin?

2) Why not always use lists?

3) Are there specific cases in which an array is more convenient than a list?

I have a lot of these questions because trying to do a similarity in PHP, for example, there are arrays and objects. Both fulfill particular functions and even when both are naturally mutable, it is possible to differentiate according to the level of complexity of the issue being dealt with when to choose one and when to choose another.

In Kotlin I can't define any important difference that motivates me to ever use arrays instead of lists.

Thank you very much for the collaboration you can give me! All the best.

Good day StackOverflow community!

I have been researching on the internet about the official Arduino software to determine if it can emulate hardware or not, that is, I need to know if the Arduino software emulates in a virtual environment how any microcontroller would behave in reality (as the Proteus program does). for instance).

I have read in many forums in English and Spanish but I can't find the solution to my concern so I would like a member who has used it before to confirm if it can emulate software or not since the information I have read is very vague even on your page official.

Observation: I ask specifically about the Arduino software since I have read several "arduino's simulator" that are third-party programs in which I am not interested at the moment.

Thank you in advance for all the collaboration you can give me. All the best!

I managed to resize the /var directory with the Gparted live CD due to the urgency I had in executing the process, however, while I was waiting for the Gparted .iso it occurred to me to try to resize the partition "live". To complete this task I read that I should first unmount /var.

It so happens that I tried to unmount /var but the system gave me a message saying (words more, words less) that there was a process running in /var and being busy the unmount could not be performed.

I took it upon myself to do some research and didn't find a concrete and convincing explanation as to why /var can't be unmounted from the same OS it's currently running on so I decided to give it a try.

I rebooted the machine (so as not to have any additional processes preventing me from running the process) and forcefully unmounted /var through the terminal. The machine in response to my action generated a visible "blink" on the monitor, I clarify that it was not a system restart because when the screen turned on again it did not boot but instead asked for a username and password as if it had returned from a state of suspension or hibernation.

So I was left with doubts about everything mentioned above. These doubts are:

1) Is it possible to "live" or "hot" resize /var?

2) Why did my machine "blink" when forcefully unmounting /var?

3) Which processes does it run that are important enough that when trying to unmount /var the system I got the message I mentioned above?

4) Why being so important at the programming level (among other things) the /var folder of the system (Debian for example) in its installation process, when performing a "guided" partitioning, provides such a negligible space compared to the entire of the disk? Is there any special reason for this?

Observation: I know that /var is a reference for certain services associated with web development (Apache, docker, among others) but I don't think they are the ones that generate this problem since there is no system "resistance" when stopping these services by terminal.

Observation 2: I have read many technology forums and sites but they do not explain with certainty a convincing reason for each of the doubts raised and I am one of those who likes to understand each process, tool, etc. as best as possible.

I thank you in advance for any help provided.

Good morning StackOverflow community!

I have managed to install docker on a machine that is x64 and has Windows 7 Ultimate, however, as docker is a program that has official support for x64 bits and also uses virtual box, I was reading that it is necessary for the correct operation that the machine supports the virtualization at the hardware level and in fact when running docker it throws me a message saying that the machine does not have support for x64 bit systems. The problem is that the machine does not have this capacity (I have read its technical specifications, I also checked the Bios and if there were any doubts I confirmed that it does not have Hyper-V in the Windows characteristics).

Which leads me to ask if there is any other tool, "workaround" or alternative to be able to run docker on Windows 7 without using hardware virtualization in between.

Observation: I know that changing to Linux is a solution because it does not require virtualization technology at the hardware level, however, it is not an option since the host must be Windows due to the requirements that have been raised.

Update: At the request of the user @Alfabravo I have taken a screenshot with the error that docker shows due to the hardware virtualization problem.

Docker quick toolbox image:

Docker image "running" in virtual box:

It has happened to me many times that being with a system that has some distribution of Linux I find myself with an "unconfigured" keyboard or that does not have special characters such as "ñ" for example (those keyboards that come from the factory without the ñ key). To solve by "association" I automatically try alt+ código ASCII(as it is done in Windows) and I have realized that this combination is not valid to print special characters in Linux .

In view of this, I have asked myself the following question: is there any key combination to print ASCII characters in Linux?

I have been searching the internet and I know that MySQL for database connection as such is deprecated since Php 7.0.0 and MySQLi should be used as a replacement.

However, I have the big question: does this also cover the PDO part for MySQL?

I read on php.net about PDO MySQL and it doesn't mention that it is obsolete, but when dealing with the same connection to a database, the doubt remains.

If not obsolete, could it be discontinued in the near future? Is it advisable to continue using it or for new projects I use everything with MySQLi?