#include <stdio.h>

int     my_strlen(char *my_string)
{
  int   my_position = 0;

  while(my_string[my_position] != '\0')
    my_position++;

  return(my_position);
}

int     main(int ac, char **av)
{
  int my_nbr_char = 0;

  my_nbr_char = my_strlen(av[1]);
  printf("Nombre de lettre: %d\n", my_nbr_char);
}