#include "strutil.h"

size_t xstrncpy(char *dest, const char *src, size_t n) {
    size_t i;
    for (i = 0; i < n - 1 && src[i] != '\0'; ++i)
        dest[i] = src[i];
    if (n)
        dest[i] = '\0';
    return src[i] == '\0' ? i : n;
}

size_t xstrjoin(char *dst, const char *const tokens[], char sep, size_t n) {
    const char *const *remaining = tokens;
    const char *token = *remaining++;
    size_t i = 0;
    while (token) {
        if (i) {
            dst[i++] = sep;
            if (i == n)
                goto truncated;
        }
        size_t w = xstrncpy(dst + i, token, n - i);
        if (w >= n - i)
            goto truncated;
        i += w;
        token = *remaining++;
    }
    return i;

truncated:
    dst[n - 1] = '\0';
    return n;
}