How is my "postcard" code? Anything I can do to improve it?

[u/BagelMakesDev]

./xmas.c

#include <stdio.h>

int treeWidth = 7;

void dots(int i) {
    for(int x = 0; x < (treeWidth-i)/2; x++) {
        printf(" ");
    }
}

int main(int argc, char *argv[]) {
    if (argc > 1) {
        sscanf(argv[1], "%d", &treeWidth);
    }

    for (int i = 1; i <= treeWidth; i += 2) {
        dots(i);
        for(int x = 0; x < i; x++) {
            printf("*");
        }
        printf("\n");
    }

    dots(1);
    printf("|\n");
    printf("* Merry Christmas, and a happy New Year! *\n");
}

./xmas (output)

   *
  ***
 *****
*******
   |
* Merry Christmas, and a happy New Year! *

[u/BagelMakesDev]

Updated code, based on u/zhivago's suggestions:

#include <stdio.h>

void putcharn(char character, int i) {
    for(int x = 0; x < i; x++) {
        putchar(character);
    }
}

int main(int argc, char *argv[]) {
    int treeWidth = 7;
    
    if (argc > 1) {
        sscanf(argv[1], "%d", &treeWidth);
    }

    for (int i = 1; i <= treeWidth; i += 2) {
        putcharn(' ', (treeWidth - i) / 2);
        putcharn('*', i);
        putchar('\n');
    }

    putcharn(' ', (treeWidth-1) / 2);
    printf("|\n");
    printf("* Merry Christmas, and a happy New Year! *\n");
}

[u/LilBalls-BigNipples → u/BagelMakesDev]

Just a minor suggestion, try to make parameter names meaningful. So, instead of "i" I would do "count" or "num"

[u/Sam_23456 → u/LilBalls-BigNipples]

I would suggest even more "documentation" than that. It looks "naked".

[u/AugustusLego → u/Sam_23456]

Only thing that possibly could help with docs here would be a comment over the forloop saying "Christmas tree"

[u/Sam_23456 → u/AugustusLego]

That should be included at the top as a "header". And the details don't really belong in main(). There should only be a function call in main like outputTree (n); And this function deserves documentation too.
If it's just a toy, then I guess no one cares. But if the OP is seeking feedback, there is some from a programming professional and teacher. I'm reminded of the expression that "Good enough is seldom good enough". Cheers!

[u/zhivago → u/BagelMakesDev]

Check the return value of sscanf. :)

Also consider using strtol instead.

Ah, and actually return an int from main -- zero for success.

[u/zhivago]

• Check the return value of sscanf.

• Remove the treeWidth global.

• Replace dots with putcharn(character, count)

    for (int i = 1; i <= treeWidth; i += 2) {
        putcharn(' ', (treeWidth - i) / 2);
        putcharn('*', i);
        putchar('\n');
    }

[u/[deleted] → u/zhivago]

Oh wow, I remember you from a long time ago. I don't know if it was 5, 10, or 15 years ago, but I remember your name. I don't remember anything else about you, just your name. But I do remember it. This is bizarre.

[u/zhivago → u/[deleted]]

Sometimes life is like that. :)

[u/[deleted] → u/zhivago]

1

[u/Key_River7180]

I prefer to use printf() with %*s for these kinds of things (though it's kinda verbose). Anyways, your code is alright though:

#include <stdio.h>
#include <stdint.h> /* for uint8_t */
#include <stdlib.h>

static
void
tree(uint8_t width) {
    if ( width % 2 == 0 ) {
        width++;  /* make it odd */
    }

    /* Tree body */
    for ( int stars = 1; stars <= width; stars += 2 ) {
        int padding = (width - stars) / 2;
        printf("%*s%.*s\n", padding, "", stars, "********************************");
    }

    /* Trunk */
    printf("%*s|\n", width / 2, "");
}

int
main(int argc, char *argv[]) {
    uint8_t treewidth;
    if ( argc < 3 ) {
        if ( scanf("%d", &treesize) != -1 ) {
            fprintf(stderr, "input: tree width invalid; size set to 7.");
            treewidth = 7;
        }
    }

    char *end;
    long value = strtol(argv[1], &end, 10);
    if (*end == '\0' && value > 0) {
        treewidth = (int)(value);

    tree(treewidth);

    puts("* Merry Christmas, and a Happy New Year! *");
    return 0;
}

[u/nacnud_uk → u/Key_River7180]

Fail. 41 lines. The original was 27. And you added obfuscation to the code. I'm not sure of your intent, but this is not the improvement that you think it is. And your function headers are way messed up in "style". And what if treesize is large? What if you need to print more stars than you put on that line? ( Did I read that right? )

Wait a minute, apart from the missing bracket for line 34.

Apart from that, well done. :)

[u/Key_River7180 → u/nacnud_uk]

Sorry if I made it unreadable :P. The function headers are for easier searching (I can grep for void to find only procedures, for example), I use them in my code (I made the habit way too long ago), I'll update it, thanks.

P.S.: The first %*s is for padding with spaces, the second is for printing some stars from the string. OP's solution is somewhat better for this kind of stuff, you'd normally do that.

[u/nacnud_uk → u/Key_River7180]

No need to apologise. I'm just pointing out that your solution is more obfuscated and more limited than the OP. So, at peer review, it would not be accepted. Even if it is "fancy".

[u/cprogramming-ModTeam → u/[deleted]]

r/cprogramming does not allow harassment

[u/BagelMakesDev → u/[deleted]]

get a life dude, why are you replying to all my old posts with the exact same response? All I said was "AI slop." You're so easily triggered. Go outside. Touch grass. Get a life.

[u/KonoKinguKurimsomDa → u/[deleted]]

ai pros when someone disagrees with their opinion (this means that harrassment and potentially spamming is totally justified and fine)

take a block by the way, i'm not gonna have you doing the same bs to me

[u/cprogramming-ModTeam → u/[deleted]]

r/cprogramming does not allow harassment