Box print

box.c

#include <unistd.h>

void ft_putchar(char c);
void box(int rows, int cols);

int main() {
    box(10, 20);
    return 0;
}

void ft_putchar(char c) {
    write(1, &c, 1);
}

void box(int rows, int cols) {
    int MAIN_DIAGONAL_CORNER = 0;
    int SECONDARY_DIAGONAL_CORNER = 1;
    int SIDE_BORDER = 2;
    int FILLER = 3;
    char glyphs[] = "ACB ";

    int x;
    int y;
    char c;
    for (y = 1; y <= rows; ++y) {
        for (x = 1; x <= cols; ++x) {
            if (y == 1 && x == 1 || y == rows && x == cols) {
                c = glyphs[MAIN_DIAGONAL_CORNER];
            } else if (y == 1 && x == cols || y == rows && x == 1) {
                c = glyphs[SECONDARY_DIAGONAL_CORNER];
            } else if (y == 1 || y == rows || x == 1 || x == cols) {
                c = glyphs[SIDE_BORDER];
            } else {
                c = glyphs[FILLER];
            }
            ft_putchar(c);
        }
        ft_putchar('\n');
    }
}