#define NOARGC  /* no argument count passing */›#define FIXARGC /* don't expect arg counts passed in */›/*›** atoi(s) - convert s to integer.›*/›atoi(s) ›char *s; ›$(›  int sign, n;›  while(isspace(*s)) ++s;›  sign = 1;›  switch(*s) ›    $(›    case '-': sign = -1;›    case '+': ++s;›    $)›  n = 0;›  while(isdigit(*s)) ›  n = 10 * n + *s++ - '0';›  return (sign * n);›$)›