gir | generate rust bindings and user API | Wrapper library

You didn't close the brackets after 3rd $match stage. So, instead of this:

mark these two options in debug menu, you'll see a red screen on your device/emulator, that's what the problem is. Try to solve the issue.

if that's not working try to run app in release mode by running the following command:

flutter run --release -v and see the result in terminal in VS code

You are currently comparing the Student object with the name of the student, but theres an easy fix, suppose we had this code:

As @Someprogrammerdude said above, you need to specify the -l options after your program. Here is the relevant section from the gcc(1) man page:

-llibrary
...
It makes a difference where in the command you write this option; the linker searches and processes libraries and object files in the order they are specified. Thus, foo.o -lz bar.o searches library z after file foo.o but before bar.o. If bar.o refers to functions in z, those functions may not be loaded.

This turned out to be a problem caused by the way the build system I am using, Meson, was calling g-ir-scanner. I noticed that it was using --extra-library=GObject-2.0 while the few tutorials I could find on this subject was calling g-ir-scanner with --include=GObject-2.0.

I added includes: 'GObject-2.0' to the gnome.generate_gir section of my meson.build file and that fixed the problem:

The final meson.build file looks like this:

Remember that a word boundary meaning is context-dependent.

Here, you need to move the word boundary before optional . as \.\b (i.e. when there is a . after, say, etc) will only match if there is a letter, digit or _ right after ..

So, you can use

The question is not very clear in parts and the example files do not have much structure to them. See the code below as an example and do note that getting the Name looks a bit weak to me (though it does seem to work for the example files).

Apologies if there is something obviously wrong in the output. I cannot speak Portuguese so I did not look too hard at the exact words.

Maybe:

Hm....

I removed the brackets around the StartupWMClass and it works. So it should not be [xxx]. It can only be xxx.

When you say char d;, you tell the compiler to reserve exactly one byte of memory to hold one character.

Then when you say char e;, you tell the compiler to reserve exactly one byte of memory to hold another character.

Then you say scanf("%s", &d); which has the compiler read an entire string (including the string terminator) and try to store it in the one byte of memory reserved by char d;

The character you type when you run the program takes one byte of space and the string terminator takes another one so now you are storing two bytes of data in a spot only big enough for one byte.

And then you do it again for the second scanf call.

So now you have accessed memory you didn't reserve - you could have written over something really important. It is undefined behaviour and ANYTHING can happen (including making the program look as if it is working)

So, if you want to use char variables like you are now, the scanf("%s", &d); should be scanf(" %c", &d); and the other scanf call should be changed the same way.

The reason the scanf format string needs to start with a space is to tell the scanf function that it should ignore whitespace (like the newline that is created by pressing the enter key). Without that space, the second scanf will store a newline as its character because that is the second character that was input.

You might think that you could also change the variables to char d[2]; and char e[2]; so there is room to store the character and the string terminator. But this is a bad idea because, if the user enters more than one character before they press enter, you will still write past the end of the memory. So it has the exact same problem.

Another thing you could do (as suggested in the comments) is to not use scanf at all for reading single characters. If your variable is char d; then you could use d = getchar(); and that would work well - but you still need to do something to handle the newline character that comes in as the second character. That's why I think scanf(" %c", &d); is a good, simple way to make it work.

One other thing to note: you should always check the return value of the functions you call. If reading input doesn't work you should tell the user that the input is invalid and then not produce invalid output.