xref: /minix/lib/libedit/keymacro.c (revision 3e1db26a)
1 /*	$NetBSD: keymacro.c,v 1.7 2011/08/16 16:25:15 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Christos Zoulas of Cornell University.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include "config.h"
36 #if !defined(lint) && !defined(SCCSID)
37 #if 0
38 static char sccsid[] = "@(#)key.c	8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: keymacro.c,v 1.7 2011/08/16 16:25:15 christos Exp $");
41 #endif
42 #endif /* not lint && not SCCSID */
43 
44 /*
45  * keymacro.c: This module contains the procedures for maintaining
46  *	       the extended-key map.
47  *
48  *      An extended-key (key) is a sequence of keystrokes introduced
49  *	with a sequence introducer and consisting of an arbitrary
50  *	number of characters.  This module maintains a map (the
51  *	el->el_keymacro.map)
52  *	to convert these extended-key sequences into input strs
53  *	(XK_STR), editor functions (XK_CMD), or unix commands (XK_EXE).
54  *
55  *      Warning:
56  *	  If key is a substr of some other keys, then the longer
57  *	  keys are lost!!  That is, if the keys "abcd" and "abcef"
58  *	  are in el->el_keymacro.map, adding the key "abc" will cause
59  *	  the first two definitions to be lost.
60  *
61  *      Restrictions:
62  *      -------------
63  *      1) It is not possible to have one key that is a
64  *	   substr of another.
65  */
66 #include <string.h>
67 #include <stdlib.h>
68 
69 #include "el.h"
70 
71 /*
72  * The Nodes of the el->el_keymacro.map.  The el->el_keymacro.map is a
73  * linked list of these node elements
74  */
75 struct keymacro_node_t {
76 	Char		 ch;		/* single character of key 	 */
77 	int		 type;		/* node type			 */
78 	keymacro_value_t val;		/* command code or pointer to str,  */
79 					/* if this is a leaf 		 */
80 	struct keymacro_node_t *next;	/* ptr to next char of this key  */
81 	struct keymacro_node_t *sibling;/* ptr to another key with same prefix*/
82 };
83 
84 private int		 node_trav(EditLine *, keymacro_node_t *, Char *,
85     keymacro_value_t *);
86 private int		 node__try(EditLine *, keymacro_node_t *, const Char *,
87     keymacro_value_t *, int);
88 private keymacro_node_t	*node__get(Int);
89 private void		 node__free(keymacro_node_t *);
90 private void		 node__put(EditLine *, keymacro_node_t *);
91 private int		 node__delete(EditLine *, keymacro_node_t **,
92     const Char *);
93 private int		 node_lookup(EditLine *, const Char *,
94     keymacro_node_t *, size_t);
95 private int		 node_enum(EditLine *, keymacro_node_t *, size_t);
96 
97 #define	KEY_BUFSIZ	EL_BUFSIZ
98 
99 
100 /* keymacro_init():
101  *	Initialize the key maps
102  */
103 protected int
keymacro_init(EditLine * el)104 keymacro_init(EditLine *el)
105 {
106 
107 	el->el_keymacro.buf = el_malloc(KEY_BUFSIZ *
108 	    sizeof(*el->el_keymacro.buf));
109 	if (el->el_keymacro.buf == NULL)
110 		return -1;
111 	el->el_keymacro.map = NULL;
112 	keymacro_reset(el);
113 	return 0;
114 }
115 
116 /* keymacro_end():
117  *	Free the key maps
118  */
119 protected void
keymacro_end(EditLine * el)120 keymacro_end(EditLine *el)
121 {
122 
123 	el_free(el->el_keymacro.buf);
124 	el->el_keymacro.buf = NULL;
125 	node__free(el->el_keymacro.map);
126 }
127 
128 
129 /* keymacro_map_cmd():
130  *	Associate cmd with a key value
131  */
132 protected keymacro_value_t *
keymacro_map_cmd(EditLine * el,int cmd)133 keymacro_map_cmd(EditLine *el, int cmd)
134 {
135 
136 	el->el_keymacro.val.cmd = (el_action_t) cmd;
137 	return &el->el_keymacro.val;
138 }
139 
140 
141 /* keymacro_map_str():
142  *	Associate str with a key value
143  */
144 protected keymacro_value_t *
keymacro_map_str(EditLine * el,Char * str)145 keymacro_map_str(EditLine *el, Char *str)
146 {
147 
148 	el->el_keymacro.val.str = str;
149 	return &el->el_keymacro.val;
150 }
151 
152 
153 /* keymacro_reset():
154  *	Takes all nodes on el->el_keymacro.map and puts them on free list.
155  *	Then initializes el->el_keymacro.map with arrow keys
156  *	[Always bind the ansi arrow keys?]
157  */
158 protected void
keymacro_reset(EditLine * el)159 keymacro_reset(EditLine *el)
160 {
161 
162 	node__put(el, el->el_keymacro.map);
163 	el->el_keymacro.map = NULL;
164 	return;
165 }
166 
167 
168 /* keymacro_get():
169  *	Calls the recursive function with entry point el->el_keymacro.map
170  *      Looks up *ch in map and then reads characters until a
171  *      complete match is found or a mismatch occurs. Returns the
172  *      type of the match found (XK_STR, XK_CMD, or XK_EXE).
173  *      Returns NULL in val.str and XK_STR for no match.
174  *      The last character read is returned in *ch.
175  */
176 protected int
keymacro_get(EditLine * el,Char * ch,keymacro_value_t * val)177 keymacro_get(EditLine *el, Char *ch, keymacro_value_t *val)
178 {
179 
180 	return node_trav(el, el->el_keymacro.map, ch, val);
181 }
182 
183 
184 /* keymacro_add():
185  *      Adds key to the el->el_keymacro.map and associates the value in
186  *	val with it. If key is already is in el->el_keymacro.map, the new
187  *	code is applied to the existing key. Ntype specifies if code is a
188  *	command, an out str or a unix command.
189  */
190 protected void
keymacro_add(EditLine * el,const Char * key,keymacro_value_t * val,int ntype)191 keymacro_add(EditLine *el, const Char *key, keymacro_value_t *val, int ntype)
192 {
193 
194 	if (key[0] == '\0') {
195 		(void) fprintf(el->el_errfile,
196 		    "keymacro_add: Null extended-key not allowed.\n");
197 		return;
198 	}
199 	if (ntype == XK_CMD && val->cmd == ED_SEQUENCE_LEAD_IN) {
200 		(void) fprintf(el->el_errfile,
201 		    "keymacro_add: sequence-lead-in command not allowed\n");
202 		return;
203 	}
204 	if (el->el_keymacro.map == NULL)
205 		/* tree is initially empty.  Set up new node to match key[0] */
206 		el->el_keymacro.map = node__get(key[0]);
207 			/* it is properly initialized */
208 
209 	/* Now recurse through el->el_keymacro.map */
210 	(void) node__try(el, el->el_keymacro.map, key, val, ntype);
211 	return;
212 }
213 
214 
215 /* keymacro_clear():
216  *
217  */
218 protected void
keymacro_clear(EditLine * el,el_action_t * map,const Char * in)219 keymacro_clear(EditLine *el, el_action_t *map, const Char *in)
220 {
221 #ifdef WIDECHAR
222         if (*in > N_KEYS) /* can't be in the map */
223                 return;
224 #endif
225 	if ((map[(unsigned char)*in] == ED_SEQUENCE_LEAD_IN) &&
226 	    ((map == el->el_map.key &&
227 	    el->el_map.alt[(unsigned char)*in] != ED_SEQUENCE_LEAD_IN) ||
228 	    (map == el->el_map.alt &&
229 	    el->el_map.key[(unsigned char)*in] != ED_SEQUENCE_LEAD_IN)))
230 		(void) keymacro_delete(el, in);
231 }
232 
233 
234 /* keymacro_delete():
235  *      Delete the key and all longer keys staring with key, if
236  *      they exists.
237  */
238 protected int
keymacro_delete(EditLine * el,const Char * key)239 keymacro_delete(EditLine *el, const Char *key)
240 {
241 
242 	if (key[0] == '\0') {
243 		(void) fprintf(el->el_errfile,
244 		    "keymacro_delete: Null extended-key not allowed.\n");
245 		return -1;
246 	}
247 	if (el->el_keymacro.map == NULL)
248 		return 0;
249 
250 	(void) node__delete(el, &el->el_keymacro.map, key);
251 	return 0;
252 }
253 
254 
255 /* keymacro_print():
256  *	Print the binding associated with key key.
257  *	Print entire el->el_keymacro.map if null
258  */
259 protected void
keymacro_print(EditLine * el,const Char * key)260 keymacro_print(EditLine *el, const Char *key)
261 {
262 
263 	/* do nothing if el->el_keymacro.map is empty and null key specified */
264 	if (el->el_keymacro.map == NULL && *key == 0)
265 		return;
266 
267 	el->el_keymacro.buf[0] = '"';
268 	if (node_lookup(el, key, el->el_keymacro.map, (size_t)1) <= -1)
269 		/* key is not bound */
270 		(void) fprintf(el->el_errfile, "Unbound extended key \"" FSTR
271 		    "\"\n", key);
272 	return;
273 }
274 
275 
276 /* node_trav():
277  *	recursively traverses node in tree until match or mismatch is
278  * 	found.  May read in more characters.
279  */
280 private int
node_trav(EditLine * el,keymacro_node_t * ptr,Char * ch,keymacro_value_t * val)281 node_trav(EditLine *el, keymacro_node_t *ptr, Char *ch, keymacro_value_t *val)
282 {
283 
284 	if (ptr->ch == *ch) {
285 		/* match found */
286 		if (ptr->next) {
287 			/* key not complete so get next char */
288 			if (FUN(el,getc)(el, ch) != 1) {/* if EOF or error */
289 				val->cmd = ED_END_OF_FILE;
290 				return XK_CMD;
291 				/* PWP: Pretend we just read an end-of-file */
292 			}
293 			return node_trav(el, ptr->next, ch, val);
294 		} else {
295 			*val = ptr->val;
296 			if (ptr->type != XK_CMD)
297 				*ch = '\0';
298 			return ptr->type;
299 		}
300 	} else {
301 		/* no match found here */
302 		if (ptr->sibling) {
303 			/* try next sibling */
304 			return node_trav(el, ptr->sibling, ch, val);
305 		} else {
306 			/* no next sibling -- mismatch */
307 			val->str = NULL;
308 			return XK_STR;
309 		}
310 	}
311 }
312 
313 
314 /* node__try():
315  * 	Find a node that matches *str or allocate a new one
316  */
317 private int
node__try(EditLine * el,keymacro_node_t * ptr,const Char * str,keymacro_value_t * val,int ntype)318 node__try(EditLine *el, keymacro_node_t *ptr, const Char *str,
319     keymacro_value_t *val, int ntype)
320 {
321 
322 	if (ptr->ch != *str) {
323 		keymacro_node_t *xm;
324 
325 		for (xm = ptr; xm->sibling != NULL; xm = xm->sibling)
326 			if (xm->sibling->ch == *str)
327 				break;
328 		if (xm->sibling == NULL)
329 			xm->sibling = node__get(*str);	/* setup new node */
330 		ptr = xm->sibling;
331 	}
332 	if (*++str == '\0') {
333 		/* we're there */
334 		if (ptr->next != NULL) {
335 			node__put(el, ptr->next);
336 				/* lose longer keys with this prefix */
337 			ptr->next = NULL;
338 		}
339 		switch (ptr->type) {
340 		case XK_CMD:
341 		case XK_NOD:
342 			break;
343 		case XK_STR:
344 		case XK_EXE:
345 			if (ptr->val.str)
346 				el_free(ptr->val.str);
347 			break;
348 		default:
349 			EL_ABORT((el->el_errfile, "Bad XK_ type %d\n",
350 			    ptr->type));
351 			break;
352 		}
353 
354 		switch (ptr->type = ntype) {
355 		case XK_CMD:
356 			ptr->val = *val;
357 			break;
358 		case XK_STR:
359 		case XK_EXE:
360 			if ((ptr->val.str = Strdup(val->str)) == NULL)
361 				return -1;
362 			break;
363 		default:
364 			EL_ABORT((el->el_errfile, "Bad XK_ type %d\n", ntype));
365 			break;
366 		}
367 	} else {
368 		/* still more chars to go */
369 		if (ptr->next == NULL)
370 			ptr->next = node__get(*str);	/* setup new node */
371 		(void) node__try(el, ptr->next, str, val, ntype);
372 	}
373 	return 0;
374 }
375 
376 
377 /* node__delete():
378  *	Delete node that matches str
379  */
380 private int
node__delete(EditLine * el,keymacro_node_t ** inptr,const Char * str)381 node__delete(EditLine *el, keymacro_node_t **inptr, const Char *str)
382 {
383 	keymacro_node_t *ptr;
384 	keymacro_node_t *prev_ptr = NULL;
385 
386 	ptr = *inptr;
387 
388 	if (ptr->ch != *str) {
389 		keymacro_node_t *xm;
390 
391 		for (xm = ptr; xm->sibling != NULL; xm = xm->sibling)
392 			if (xm->sibling->ch == *str)
393 				break;
394 		if (xm->sibling == NULL)
395 			return 0;
396 		prev_ptr = xm;
397 		ptr = xm->sibling;
398 	}
399 	if (*++str == '\0') {
400 		/* we're there */
401 		if (prev_ptr == NULL)
402 			*inptr = ptr->sibling;
403 		else
404 			prev_ptr->sibling = ptr->sibling;
405 		ptr->sibling = NULL;
406 		node__put(el, ptr);
407 		return 1;
408 	} else if (ptr->next != NULL &&
409 	    node__delete(el, &ptr->next, str) == 1) {
410 		if (ptr->next != NULL)
411 			return 0;
412 		if (prev_ptr == NULL)
413 			*inptr = ptr->sibling;
414 		else
415 			prev_ptr->sibling = ptr->sibling;
416 		ptr->sibling = NULL;
417 		node__put(el, ptr);
418 		return 1;
419 	} else {
420 		return 0;
421 	}
422 }
423 
424 
425 /* node__put():
426  *	Puts a tree of nodes onto free list using free(3).
427  */
428 private void
node__put(EditLine * el,keymacro_node_t * ptr)429 node__put(EditLine *el, keymacro_node_t *ptr)
430 {
431 	if (ptr == NULL)
432 		return;
433 
434 	if (ptr->next != NULL) {
435 		node__put(el, ptr->next);
436 		ptr->next = NULL;
437 	}
438 	node__put(el, ptr->sibling);
439 
440 	switch (ptr->type) {
441 	case XK_CMD:
442 	case XK_NOD:
443 		break;
444 	case XK_EXE:
445 	case XK_STR:
446 		if (ptr->val.str != NULL)
447 			el_free(ptr->val.str);
448 		break;
449 	default:
450 		EL_ABORT((el->el_errfile, "Bad XK_ type %d\n", ptr->type));
451 		break;
452 	}
453 	el_free(ptr);
454 }
455 
456 
457 /* node__get():
458  *	Returns pointer to a keymacro_node_t for ch.
459  */
460 private keymacro_node_t *
node__get(Int ch)461 node__get(Int ch)
462 {
463 	keymacro_node_t *ptr;
464 
465 	ptr = el_malloc(sizeof(*ptr));
466 	if (ptr == NULL)
467 		return NULL;
468 	ptr->ch = ch;
469 	ptr->type = XK_NOD;
470 	ptr->val.str = NULL;
471 	ptr->next = NULL;
472 	ptr->sibling = NULL;
473 	return ptr;
474 }
475 
476 private void
node__free(keymacro_node_t * k)477 node__free(keymacro_node_t *k)
478 {
479 	if (k == NULL)
480 		return;
481 	node__free(k->sibling);
482 	node__free(k->next);
483 	el_free(k);
484 }
485 
486 /* node_lookup():
487  *	look for the str starting at node ptr.
488  *	Print if last node
489  */
490 private int
node_lookup(EditLine * el,const Char * str,keymacro_node_t * ptr,size_t cnt)491 node_lookup(EditLine *el, const Char *str, keymacro_node_t *ptr, size_t cnt)
492 {
493 	ssize_t used;
494 
495 	if (ptr == NULL)
496 		return -1;	/* cannot have null ptr */
497 
498 	if (!str || *str == 0) {
499 		/* no more chars in str.  node_enum from here. */
500 		(void) node_enum(el, ptr, cnt);
501 		return 0;
502 	} else {
503 		/* If match put this char into el->el_keymacro.buf.  Recurse */
504 		if (ptr->ch == *str) {
505 			/* match found */
506 			used = ct_visual_char(el->el_keymacro.buf + cnt,
507 			    KEY_BUFSIZ - cnt, ptr->ch);
508 			if (used == -1)
509 				return -1; /* ran out of buffer space */
510 			if (ptr->next != NULL)
511 				/* not yet at leaf */
512 				return (node_lookup(el, str + 1, ptr->next,
513 				    (size_t)used + cnt));
514 			else {
515 			    /* next node is null so key should be complete */
516 				if (str[1] == 0) {
517 					size_t px = cnt + (size_t)used;
518 					el->el_keymacro.buf[px] = '"';
519 					el->el_keymacro.buf[px + 1] = '\0';
520 					keymacro_kprint(el, el->el_keymacro.buf,
521 					    &ptr->val, ptr->type);
522 					return 0;
523 				} else
524 					return -1;
525 					/* mismatch -- str still has chars */
526 			}
527 		} else {
528 			/* no match found try sibling */
529 			if (ptr->sibling)
530 				return (node_lookup(el, str, ptr->sibling,
531 				    cnt));
532 			else
533 				return -1;
534 		}
535 	}
536 }
537 
538 
539 /* node_enum():
540  *	Traverse the node printing the characters it is bound in buffer
541  */
542 private int
node_enum(EditLine * el,keymacro_node_t * ptr,size_t cnt)543 node_enum(EditLine *el, keymacro_node_t *ptr, size_t cnt)
544 {
545         ssize_t used;
546 
547 	if (cnt >= KEY_BUFSIZ - 5) {	/* buffer too small */
548 		el->el_keymacro.buf[++cnt] = '"';
549 		el->el_keymacro.buf[++cnt] = '\0';
550 		(void) fprintf(el->el_errfile,
551 		    "Some extended keys too long for internal print buffer");
552 		(void) fprintf(el->el_errfile, " \"" FSTR "...\"\n",
553 		    el->el_keymacro.buf);
554 		return 0;
555 	}
556 	if (ptr == NULL) {
557 #ifdef DEBUG_EDIT
558 		(void) fprintf(el->el_errfile,
559 		    "node_enum: BUG!! Null ptr passed\n!");
560 #endif
561 		return -1;
562 	}
563 	/* put this char at end of str */
564         used = ct_visual_char(el->el_keymacro.buf + cnt, KEY_BUFSIZ - cnt,
565 	    ptr->ch);
566 	if (ptr->next == NULL) {
567 		/* print this key and function */
568 		el->el_keymacro.buf[cnt + (size_t)used   ] = '"';
569 		el->el_keymacro.buf[cnt + (size_t)used + 1] = '\0';
570 		keymacro_kprint(el, el->el_keymacro.buf, &ptr->val, ptr->type);
571 	} else
572 		(void) node_enum(el, ptr->next, cnt + (size_t)used);
573 
574 	/* go to sibling if there is one */
575 	if (ptr->sibling)
576 		(void) node_enum(el, ptr->sibling, cnt);
577 	return 0;
578 }
579 
580 
581 /* keymacro_kprint():
582  *	Print the specified key and its associated
583  *	function specified by val
584  */
585 protected void
keymacro_kprint(EditLine * el,const Char * key,keymacro_value_t * val,int ntype)586 keymacro_kprint(EditLine *el, const Char *key, keymacro_value_t *val, int ntype)
587 {
588 	el_bindings_t *fp;
589 	char unparsbuf[EL_BUFSIZ];
590 	static const char fmt[] = "%-15s->  %s\n";
591 
592 	if (val != NULL)
593 		switch (ntype) {
594 		case XK_STR:
595 		case XK_EXE:
596 			(void) keymacro__decode_str(val->str, unparsbuf,
597 			    sizeof(unparsbuf),
598 			    ntype == XK_STR ? "\"\"" : "[]");
599 			(void) fprintf(el->el_outfile, fmt,
600 			    ct_encode_string(key, &el->el_scratch), unparsbuf);
601 			break;
602 		case XK_CMD:
603 			for (fp = el->el_map.help; fp->name; fp++)
604 				if (val->cmd == fp->func) {
605                     ct_wcstombs(unparsbuf, fp->name, sizeof(unparsbuf));
606                     unparsbuf[sizeof(unparsbuf) -1] = '\0';
607 					(void) fprintf(el->el_outfile, fmt,
608                         ct_encode_string(key, &el->el_scratch), unparsbuf);
609 					break;
610 				}
611 #ifdef DEBUG_KEY
612 			if (fp->name == NULL)
613 				(void) fprintf(el->el_outfile,
614 				    "BUG! Command not found.\n");
615 #endif
616 
617 			break;
618 		default:
619 			EL_ABORT((el->el_errfile, "Bad XK_ type %d\n", ntype));
620 			break;
621 		}
622 	else
623 		(void) fprintf(el->el_outfile, fmt, ct_encode_string(key,
624 		    &el->el_scratch), "no input");
625 }
626 
627 
628 #define ADDC(c) \
629 	if (b < eb) \
630 		*b++ = c; \
631 	else \
632 		b++
633 /* keymacro__decode_str():
634  *	Make a printable version of the ey
635  */
636 protected size_t
keymacro__decode_str(const Char * str,char * buf,size_t len,const char * sep)637 keymacro__decode_str(const Char *str, char *buf, size_t len, const char *sep)
638 {
639 	char *b = buf, *eb = b + len;
640 	const Char *p;
641 
642 	b = buf;
643 	if (sep[0] != '\0') {
644 		ADDC(sep[0]);
645 	}
646 	if (*str == '\0') {
647 		ADDC('^');
648 		ADDC('@');
649 		goto add_endsep;
650 	}
651 	for (p = str; *p != 0; p++) {
652 		Char dbuf[VISUAL_WIDTH_MAX];
653 		Char *p2 = dbuf;
654 		ssize_t l = ct_visual_char(dbuf, VISUAL_WIDTH_MAX, *p);
655 		while (l-- > 0) {
656 			ssize_t n = ct_encode_char(b, (size_t)(eb - b), *p2++);
657 			if (n == -1) /* ran out of space */
658 				goto add_endsep;
659 			else
660 				b += n;
661 		}
662 	}
663 add_endsep:
664 	if (sep[0] != '\0' && sep[1] != '\0') {
665 		ADDC(sep[1]);
666 	}
667 	ADDC('\0');
668 	if ((size_t)(b - buf) >= len)
669 	    buf[len - 1] = '\0';
670 	return (size_t)(b - buf);
671 }
672