#ifdef HAS_SELECT
int
do_select(gimme,arglast)
int gimme;
int *arglast;
{
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    register int i;
    register int j;
    register char *s;
    register STR *TARG;
    double value;
    int maxlen = 0;
    int nfound;
    struct timeval timebuf;
    struct timeval *tbuf = &timebuf;
    int growsize;
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
    int masksize;
    int offset;
    char *fd_sets[4];
    int k;

#if BYTEORDER & 0xf0000
#define ORDERBYTE (0x88888888 - BYTEORDER)
#else
#define ORDERBYTE (0x4444 - BYTEORDER)
#endif

#endif

    for (i = 1; i <= 3; i++) {
	j = st[sp+i]->str_cur;
	if (maxlen < j)
	    maxlen = j;
    }

#if BYTEORDER == 0x1234 || BYTEORDER == 0x12345678
    growsize = maxlen;		/* little endians can use vecs directly */
#else
#ifdef NFDBITS

#ifndef NBBY
#define NBBY 8
#endif

    masksize = NFDBITS / NBBY;
#else
    masksize = sizeof(long);	/* documented int, everyone seems to use long */
#endif
    growsize = maxlen + (masksize - (maxlen % masksize));
    Zero(&fd_sets[0], 4, char*);
#endif

    for (i = 1; i <= 3; i++) {
	TARG = st[sp+i];
	j = TARG->str_len;
	if (j < growsize) {
	    if (TARG->str_pok) {
		Str_Grow(TARG,growsize);
		s = str_get(TARG) + j;
		while (++j <= growsize) {
		    *s++ = '\0';
		}
	    }
	    else if (TARG->str_ptr) {
		Safefree(TARG->str_ptr);
		TARG->str_ptr = Nullch;
	    }
	}
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
	s = TARG->str_ptr;
	if (s) {
	    New(403, fd_sets[i], growsize, char);
	    for (offset = 0; offset < growsize; offset += masksize) {
		for (j = 0, k=ORDERBYTE; j < masksize; j++, (k >>= 4))
		    fd_sets[i][j+offset] = s[(k % masksize) + offset];
	    }
	}
#endif
    }
    TARG = st[sp+4];
    if (TARG->str_nok || TARG->str_pok) {
	value = str_gnum(TARG);
	if (value < 0.0)
	    value = 0.0;
	timebuf.tv_sec = (long)value;
	value -= (double)timebuf.tv_sec;
	timebuf.tv_usec = (long)(value * 1000000.0);
    }
    else
	tbuf = Null(struct timeval*);

#if BYTEORDER == 0x1234 || BYTEORDER == 0x12345678
    nfound = select(
	maxlen * 8,
	st[sp+1]->str_ptr,
	st[sp+2]->str_ptr,
	st[sp+3]->str_ptr,
	tbuf);
#else
    nfound = select(
	maxlen * 8,
	fd_sets[1],
	fd_sets[2],
	fd_sets[3],
	tbuf);
    for (i = 1; i <= 3; i++) {
	if (fd_sets[i]) {
	    TARG = st[sp+i];
	    s = TARG->str_ptr;
	    for (offset = 0; offset < growsize; offset += masksize) {
		for (j = 0, k=ORDERBYTE; j < masksize; j++, (k >>= 4))
		    s[(k % masksize) + offset] = fd_sets[i][j+offset];
	    }
	    Safefree(fd_sets[i]);
	}
    }
#endif

    st[++sp] = str_mortal(&str_no);
    str_numset(st[sp], (double)nfound);
    if (gimme == G_ARRAY && tbuf) {
	value = (double)(timebuf.tv_sec) +
		(double)(timebuf.tv_usec) / 1000000.0;
	st[++sp] = str_mortal(&str_no);
	str_numset(st[sp], value);
    }
    return sp;
}
#endif /* SELECT */