field.c

早期freebsd实现

}

/*
 * this is called both from get_field() and from do_split()
 * via (*parse_field)().  This variation is for when FS is a single character
 * other than space.
 */
static int
sc_parse_field(up_to, buf, len, fs, rp, set, n)
int up_to;	/* parse only up to this field number */
char **buf;	/* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
void (*set) ();	/* routine to set the value of the parsed field */
NODE *n;
{
	register char *scan = *buf;
	register char fschar;
	register int nf = parse_high_water;
	register char *field;
	register char *end = scan + len;
	char sav;

	if (up_to == HUGE)
		nf = 0;
	if (len == 0)
		return nf;

	if (*RS == 0 && fs->stlen == 0)
		fschar = '\n';
	else
		fschar = fs->stptr[0];

	/* before doing anything save the char at *end */
	sav = *end;
	/* because it will be destroyed now: */
	*end = fschar;	/* sentinel character */

	for (; nf < up_to; scan++) {
		field = scan;
		while (*scan++ != fschar)
			;
		scan--;
		(*set)(++nf, field, (int)(scan - field), n);
		if (scan == end)
			break;
	}

	/* everything done, restore original char at *end */
	*end = sav;

	*buf = scan;
	return nf;
}

/*
 * this is called both from get_field() and from do_split()
 * via (*parse_field)().  This variation is for fields are fixed widths.
 */
static int
fw_parse_field(up_to, buf, len, fs, rp, set, n)
int up_to;	/* parse only up to this field number */
char **buf;	/* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
void (*set) ();	/* routine to set the value of the parsed field */
NODE *n;
{
	register char *scan = *buf;
	register int nf = parse_high_water;
	register char *end = scan + len;

	if (up_to == HUGE)
		nf = 0;
	if (len == 0)
		return nf;
	for (; nf < up_to && (len = FIELDWIDTHS[nf+1]) != -1; ) {
		if (len > end - scan)
			len = end - scan;
		(*set)(++nf, scan, len, n);
		scan += len;
	}
	if (len == -1)
		*buf = end;
	else
		*buf = scan;
	return nf;
}

NODE **
get_field(requested, assign)
register int requested;
Func_ptr *assign;	/* this field is on the LHS of an assign */
{
	/*
	 * if requesting whole line but some other field has been altered,
	 * then the whole line must be rebuilt
	 */
	if (requested == 0) {
		if (!field0_valid) {
			/* first, parse remainder of input record */
			if (NF == -1) {
				NF = (*parse_field)(HUGE-1, &parse_extent,
		    			fields_arr[0]->stlen -
					(parse_extent - fields_arr[0]->stptr),
		    			save_FS, FS_regexp, set_field,
					(NODE *)NULL);
				parse_high_water = NF;
			}
			rebuild_record();
		}
		if (assign)
			*assign = reset_record;
		return &fields_arr[0];
	}

	/* assert(requested > 0); */

	if (assign)
		field0_valid = 0;		/* $0 needs reconstruction */

	if (requested <= parse_high_water)	/* already parsed this field */
		return &fields_arr[requested];

	if (NF == -1) {	/* have not yet parsed to end of record */
		/*
		 * parse up to requested fields, calling set_field() for each,
		 * saving in parse_extent the point where the parse left off
		 */
		if (parse_high_water == 0)	/* starting at the beginning */
			parse_extent = fields_arr[0]->stptr;
		parse_high_water = (*parse_field)(requested, &parse_extent,
		     fields_arr[0]->stlen - (parse_extent-fields_arr[0]->stptr),
		     save_FS, FS_regexp, set_field, (NODE *)NULL);

		/*
		 * if we reached the end of the record, set NF to the number of 
		 * fields so far.  Note that requested might actually refer to
		 * a field that is beyond the end of the record, but we won't
		 * set NF to that value at this point, since this is only a
		 * reference to the field and NF only gets set if the field
		 * is assigned to -- this case is handled below
		 */
		if (parse_extent == fields_arr[0]->stptr + fields_arr[0]->stlen)
			NF = parse_high_water;
		if (requested == HUGE-1)	/* HUGE-1 means set NF */
			requested = parse_high_water;
	}
	if (parse_high_water < requested) { /* requested beyond end of record */
		if (assign) {	/* expand record */
			register int i;

			if (requested > nf_high_water)
				grow_fields_arr(requested);

			/* fill in fields that don't exist */
			for (i = parse_high_water + 1; i <= requested; i++)
				fields_arr[i] = Nnull_string;

			NF = requested;
			parse_high_water = requested;
		} else
			return &Nnull_string;
	}

	return &fields_arr[requested];
}

static void
set_element(num, s, len, n)
int num;
char *s;
int len;
NODE *n;
{
	register NODE *it;

	it = make_string(s, len);
	it->flags |= MAYBE_NUM;
	*assoc_lookup(n, tmp_number((AWKNUM) (num))) = it;
}

NODE *
do_split(tree)
NODE *tree;
{
	NODE *t1, *t2, *t3, *tmp;
	NODE *fs;
	char *s;
	int (*parseit)P((int, char **, int, NODE *,
			 Regexp *, void (*)(), NODE *));
	Regexp *rp = NULL;

	t1 = tree_eval(tree->lnode);
	t2 = tree->rnode->lnode;
	t3 = tree->rnode->rnode->lnode;

	(void) force_string(t1);

	if (t2->type == Node_param_list)
		t2 = stack_ptr[t2->param_cnt];
	if (t2->type != Node_var && t2->type != Node_var_array)
		fatal("second argument of split is not a variable");
	assoc_clear(t2);

	if (t3->re_flags & FS_DFLT) {
		parseit = parse_field;
		fs = force_string(FS_node->var_value);
		rp = FS_regexp;
	} else {
		tmp = force_string(tree_eval(t3->re_exp));
		if (tmp->stlen == 1) {
			if (tmp->stptr[0] == ' ')
				parseit = def_parse_field;
			else
				parseit = sc_parse_field;
		} else {
			parseit = re_parse_field;
			rp = re_update(t3);
		}
		fs = tmp;
	}

	s = t1->stptr;
	tmp = tmp_number((AWKNUM) (*parseit)(HUGE, &s, (int)t1->stlen,
					     fs, rp, set_element, t2));
	free_temp(t1);
	free_temp(t3);
	return tmp;
}

void
set_FS()
{
	NODE *tmp = NULL;
	char buf[10];
	NODE *fs;

	buf[0] = '\0';
	default_FS = 0;
	if (FS_regexp) {
		refree(FS_regexp);
		FS_regexp = NULL;
	}
	fs = force_string(FS_node->var_value);
	if (fs->stlen > 1)
		parse_field = re_parse_field;
	else if (*RS == 0) {
		parse_field = sc_parse_field;
		if (fs->stlen == 1) {
			if (fs->stptr[0] == ' ') {
				default_FS = 1;
				strcpy(buf, "[ \t\n]+");
			} else if (fs->stptr[0] != '\n')
				sprintf(buf, "[%c\n]", fs->stptr[0]);
		}
	} else {
		parse_field = def_parse_field;
		if (fs->stptr[0] == ' ' && fs->stlen == 1)
			default_FS = 1;
		else if (fs->stptr[0] != ' ' && fs->stlen == 1) {
			if (IGNORECASE == 0)
				parse_field = sc_parse_field;
			else
				sprintf(buf, "[%c]", fs->stptr[0]);
		}
	}
	if (buf[0]) {
		FS_regexp = make_regexp(buf, strlen(buf), IGNORECASE, 1);
		parse_field = re_parse_field;
	} else if (parse_field == re_parse_field) {
		FS_regexp = make_regexp(fs->stptr, fs->stlen, IGNORECASE, 1);
	} else
		FS_regexp = NULL;
	resave_fs = 1;
}

void
set_RS()
{
	(void) force_string(RS_node->var_value);
	RS = RS_node->var_value->stptr;
	set_FS();
}

void
set_FIELDWIDTHS()
{
	register char *scan;
	char *end;
	register int i;
	static int fw_alloc = 1;
	static int warned = 0;
	extern double strtod();

	if (do_lint && ! warned) {
		warned = 1;
		warning("use of FIELDWIDTHS is a gawk extension");
	}
	if (do_unix)	/* quick and dirty, does the trick */
		return;

	parse_field = fw_parse_field;
	scan = force_string(FIELDWIDTHS_node->var_value)->stptr;
	end = scan + 1;
	if (FIELDWIDTHS == NULL)
		emalloc(FIELDWIDTHS, int *, fw_alloc * sizeof(int), "set_FIELDWIDTHS");
	FIELDWIDTHS[0] = 0;
	for (i = 1; ; i++) {
		if (i >= fw_alloc) {
			fw_alloc *= 2;
			erealloc(FIELDWIDTHS, int *, fw_alloc * sizeof(int), "set_FIELDWIDTHS");
		}
		FIELDWIDTHS[i] = (int) strtod(scan, &end);
		if (end == scan)
			break;
		scan = end;
	}
	FIELDWIDTHS[i] = -1;
}