dotfiles/src/separator.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>

#define println() printf("\n")
#define printsep(sep) printf("%s\n", sep)

static char *separation_character_line(const char *separation_character, const unsigned short terminal_width) {
    const unsigned short line_length = terminal_width / 3;
    const size_t character_length = strlen(separation_character);

    char *line = malloc(line_length * sizeof(char));
    // Avoiding undefined behaviour with strlen if no null byte is
    // present at the end of line
    *line = 0;

    while (strlen(line) + character_length <= line_length) {
        strncat(line, separation_character, character_length);
    }

    return line;
}

static unsigned short terminal_width() {
    struct winsize w;
    ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
    return w.ws_col;
}

int main(int argc, char *argv[]) {
    // Parsing arguments
    char *name;
    char *separation_character;

    if (argc >= 2) {
        name = argv[1];
    } else {
        name = "";
    }

    if (argc >= 3 && *argv[2] != 0) {
        separation_character = argv[2];
    } else {
        separation_character = "=";
    }

    // Creating a /3 terminal size character line
    char *separation_line = separation_character_line(separation_character, terminal_width());

    // Printing the separator
    println();

    printsep(separation_line);

    if (name != NULL) {
        printf("\t%s\n", name);
    } else {
        println();
    }

    printsep(separation_line);

    // Freeing the created character line
    free(separation_line);

    // Returning with success
    return EXIT_SUCCESS;
}