C Programming Language is an Interesting Experience
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by Blender Dumbass
Aka: J.Y. Amihud. A Jewish by blood, multifaceted artist with experience in film-making, visual effects, programming, game development, music and more. A philosopher at heart. An activist for freedom and privacy. Anti-Paternalist. A user of Libre Software. Speaking at least 3 human languages. The writer and director of the 2023 film "Moria's Race" and the lead developer of it's game sequel "Dani's Race".
I just wrote a functional program in C. It is not doing anything too fancy. But I'm so happy about it because of what it means. For the longest time I didn't know pretty much nothing except of Python. I can use Python for a lot of very interesting stuff. But I want to be able to look at code written in different languages and know what I'm looking at. I want to be able to make changes to the UPBGE game engine for my game Dani's Race and stuff. ↩ Reply
I know, I know, UPBGE is a fork of Blender and therefor is written in C++, not C. What am I wasting my time, learning C, for? Well... ↩ Reply
If C++ is a fork of C, with extensions on top of what C can do. I should understand the difference between the two, I suppose. And therefor I should, first of all, have some idea of what it is like to program in C. ↩ Reply
Here is a surprising thing about this whole endevour. I started looking into C today. And already while writing my first program
journal, which I will be talking more in depth about in this article, I already felt like I know the language enough to solve little annoyances and overall code rather quickly in it. It felt almost like writing python code.
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C has modules, kind of like python. In python you import modules using
import. Say you want to have access to the operating system functions. You can write something like this:
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import os
And it will give you the whole
os modules to do things with in the operating system.
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In C you
#include them instead.
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#include <stdio.h>
This
stdio.h file is a C code file ( as far as I understand ) that exists somewhere relative to the compiler. And the code of that file is injected into your code. So it is a bit different in practice.
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In python to call a function from
os I would be formatting it like this os.getcwd() or something. In C all the functions in the files you include are dumped straight into the same context as everything else.
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For example
stdio.h has a function called printf() useful to print stuff into the terminal. It is not stdio.printf() or anything stupid like that. You are just simply using printf() directly.
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I imagine what a pain in the ass this must be for large projects. You have to keep track of so many names. And not, by mistake, define a function with a name that already exist somewhere, in some library you want to use for some task. ↩ Reply
Another strange thing about C is that you must have a
main() function where the main execution thing of your code is done.
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In python you just type away. A "hello world" program in python is very simple: ↩ Reply
print("hello world")
In C
print does not exist and you have to define a main() function. So in C a "hello world" program is a bit more complicated:
c:0 ↩ Reply
#include <stdio.h> int main() { printf("hello world\n"); }
Funny, I wrote this example rather fast for this article. I'm still rather shocked how quickly I'm getting to the point where I can use C for things. And I did double-check myself. This code compiles and outputs an identical output to the python code above. ↩ Reply
Now you can spot a few differences of approach. First the inclusion of the
\n thingie in the C version. printf unlike python's print doesn't end every line with a new-line character. You have to specifically tell it to do so. Then there is the ; after each operation. This is because C is indentation agnostic. In python the white-space stuff, like indentation and new line characters, are used to separate stuff, not just visually, but functionally. In C you have visible marks that separate code. Like the ; sign after every operation. I needed time to get used to this.
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Variables are simple but not simple. In python you have so many types of data. You have
int for integers and float and floating point numbers and str for text and list and dict and tuple and other various interesting, useful things. In C you have almost none of it.
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You've got your
int and float and stuff. And you've got stuff like char which represents a single character of text.
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Now you can do something like this: ↩ Reply
char text[256];
which will be similar to doing something like: ↩ Reply
text = ""
in python, But notice a few things. First you have to specify that it is a
char type. Then you can do many char at once, kind of like a list in python, to store some characters-long strings of text. But you have to specify how many of those characters long, this object is. I think in the real world it literally allocates 256 bytes of RAM ( in this example ) for my text string. And running out of this space might cause all sorts of issues.
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Also comparing strings isn't simple either. ↩ Reply
When I was playing around with the language I wanted to make a simple if statement. I input some text and if the text I input is one thing, I do one thing, and if it is something else I do another thing. ↩ Reply
I tried doing this: ↩ Reply
if ( text1 == text2 ){ dosomething(); }
But even though it never errored out, it never worked either. ↩ Reply
Apparently I must do this instead: ↩ Reply
#include <string.h> if ( strcmp(text1, text2) == 0 ){ dosomething(); }c:1
The
string.h file has the strcmp() function I can use to compare texts. And if the texts are the same, it will return 0. So I need to compare the output of this function to 0. It is a bit annoying.
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In any-case, I decided to write something useful. Writing something useful is always a good stepping stone into learning a language. ↩ Reply
Just a few days ago I wrote a simple GTK program in Python to keep track of my weight. It basically records data I drop at it into a JSON and then shows it to me in a way that makes sense to the task. ↩ Reply
So I thought, okay... how hard would it be to read and write a JSON in C? Ah... I found this. And the size of this whole thing made me feel wrong. And then I found another something to do with C and JSON and the way they described doing it made me feel un-easy. ↩ Reply
See, because C doesn't have a
dict like python, making a JSON like structure of data inside of a C program becomes a pain in a butt.
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I decided, fuck it. What is the simplest shit I can do? Well maybe something like a journal writing program. Every entry is a line in a .txt file. All you need to do to present it, is just to
printf the whole file. And it is probably doable.
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I present to you
journal.c
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#include <stdio.h> #include <string.h> int help() { printf("\n\n"); printf(" HELP DIALOGUE of JOURNAL\n"); printf("\n"); printf(" help - Print this helps message.\n"); printf(" save - Saves a text into the journal.\n"); printf(" show - Prints out the entire journal.\n"); printf("\n\n"); } int save(char string[]) { FILE *data; data = fopen("journal.txt", "a"); fprintf(data, "\n%s", string); fclose(data); } int show() { FILE *data; data = fopen("journal.txt", "r"); char string[1024]; printf("\n\n"); while( fgets(string, 1024, data) ){ printf("%s", string); } printf("\n\n"); } int main(int argc, char *argv[]) { if (argc == 1 || strcmp(argv[1], "help") == 0) { help(); } else if (argc == 3 && strcmp(argv[1], "save") == 0) { save(argv[2]); } else if (argc > 1 && strcmp(argv[1], "show") == 0) { show(); } }
You can save it as
journal.c and run this command:
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gcc journal.c -o journal
to compile it into an executable. ↩ Reply
And then ↩ Reply
./journal help
to see the help of this program. ↩ Reply
Yes this program does system arguments. And you know what. Those are simple. ↩ Reply
int main(int argc, char *argv[]) {
This line defines the
main() function, but look what it also does, it gives it arguments. What? System arguments are built-in in C?
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The
argc variable contains the amount of arguments and the argv is a list of lists of characters. A list of text strings. A list of the arguments themselves.
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So from that point it becomes kind of simple. If there are no arguments or the second argument is
help ( because the first one is the name of the program ./journal ) we run the help() function. Or in code:
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if (argc == 1 || strcmp(argv[1], "help") == 0) { help(); }
And if you look into the
help() function. It is just a bunch of printf().
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Then if the argument is
show we open the file and dump its content into the terminal. Now that is not quite as simple as you think.
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The fun part was to realize that
fopen() is like either built-in or a part of the other stuff I already imported. So opening and saving files is actually not that big of a problem in C.
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But the code to dump a file into a terminal is strange: ↩ Reply
FILE *data; data = fopen("journal.txt", "r"); char string[1024]; printf("\n\n"); while( fgets(string, 1024, data) ){ printf("%s", string); } printf("\n\n");
There is a
FILE datatype apparently. Python has something similar. Not unlike python's read() C has fgets(). But because the string you are saving to has a certain pre-specified buffer size ( in the case of this code 1024 bytes ), you are reading the file one chunk at a time. And as I have noticed, one line at a time too.
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So while in python it would look like this: ↩ Reply
print("\n\n") data = open("journal.txt", "r") print(data.read()) print("\n\n")
in C we need to do a
while loop and read the data until there isn't any. Which is a bit weird.
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Also you can't
printf() a string directly. You need to append it like that printf("%s", string). What?
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On top of that it seems like C doesn't have much error handling at all. I can open a nonexistent file. And it will just have zero bytes in it. Instead in python it will error out. ↩ Reply
So yeah. It was fun. I know enough C to write pointless bullshit in it now. And to, hopefully, understand more complex code written in it. ↩ Reply
My next challenge. C++. Let's do it. Let's go! ↩ Reply
Happy Hacking!!! ↩ Reply
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Troler
c:0 August 04, 2026 In C print does not exist and you have to define a main() function. So in C a "hello world" program is a bit more complicated:
⤴ ViewAnd... your code is going to segfault, you did not provide a return statement.
... replies ( 1 )
Blender Dumbass
c:2 August 04, 2026@Troler I compiled it and tried it and it worked. So apparently it is not that needed.
Troler
c:1 August 04, 2026 if ( strcmp(text1, text2) == 0 ){ dosomething(); }
⤴ ViewI would write the code as
if ( !strcmp(text1, text2) ){ dosomething(); }
This is more in style of C, that is, less readable.
Blender Dumbass
c:2 August 04, 2026... c:0
@Troler I compiled it and tried it and it worked. So apparently it is not that needed.
... replies ( 1 )
Troler
c:4 August 04, 2026@blenderdumbass That's because the compiler adds it for you.
main() is an int function, it requires to return an whole number. Here, the number represents the return code.
Troler
c:4 August 04, 2026... c:2
Blender Dumbass c:2 August 04, 2026c:0
@Troler I compiled it and tried it and it worked. So apparently it is not that needed.
@blenderdumbass That's because the compiler adds it for you.
main() is an int function, it requires to return an whole number. Here, the number represents the return code.
... replies ( 1 )
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Robert Kist 🇦🇹🇩🇪
c:5@blenderdumbass the nice thing about both C and Python are that they are nice, concise languages, that yet have a great amount of depth. Now C++, well, there's also all that sprawl...
Blender Dumbass
c:6 August 04, 2026... c:4
Troler c:4 August 04, 2026c:2
@blenderdumbass That's because the compiler adds it for you.
main() is an int function, it requires to return an whole number. Here, the number represents the return code.@Troler Well I'm greatfull the GCC isn't stupid.
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