void li2a(long num, char *bf)
{
if (num < 0) {
num = -num;
*bf++ = '-';
}
uli2a(num, 10, 0, bf);
}
static void li2a(long num, struct param *p)
{
if(num < 0)
{
num = -num;
p->sign = '-';
}
uli2a(num, p);
}