Function to output all next permutations of a given string, part of my C exercices

permutations.c

void anagrammes(char *s) {
  /* Pask' trouver des algorithmes écrits en français c'est inefficace, 
   * voici la traduction en C du pseudocode donné par
   * https://en.wikipedia.org/wiki/Permutation#Generation_in_lexicographic_order */
  const int n = longueur(s);
  puts(s);
  while (1) {
    int i, k = -1, l;
    char c;
    /* Find the largest index k such that a[k] < a[k + 1].
     * If no such index exists, the permutation is the last permutation. */
    for (i = n-2; i >= 0; --i) {
      if (s[i] < s[i + 1]) {
        k = i;
        break;
      }
    }
    if (k == -1) {
      break;
    }
    /* Find the largest index l greater than k such that a[k] < a[l]. */
    for (l = n-1; s[k] >= s[l] && l > k; --l);
    /* Swap the value of a[k] with that of a[l]. */
    c = s[k];
    s[k] = s[l];
    s[l] = c;
    /* Reverse the sequence from a[k + 1] up to and including the final element a[n]. */
    l = (n - (++k)) / 2;
    for (i = n-1; k <= l; ++k, --i) {
      c = s[k];
      s[k] = s[i];
      s[i] = c;
    }
    puts(s);
  }
}