1 /* $Id: read.c,v 1.220 2021/06/27 17:57:54 schwarze Exp $ */
2 /*
3 * Copyright (c) 2010-2020 Ingo Schwarze <schwarze@openbsd.org>
4 * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
5 * Copyright (c) 2010, 2012 Joerg Sonnenberger <joerg@netbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 *
19 * Top-level functions of the mandoc(3) parser:
20 * Parser and input encoding selection, decompression,
21 * handling of input bytes, characters, lines, and files,
22 * handling of roff(7) loops and file inclusion,
23 * and steering of the various parsers.
24 */
25 #include "config.h"
26
27 #include <sys/types.h>
28 #include <sys/mman.h>
29 #include <sys/stat.h>
30
31 #include <assert.h>
32 #include <ctype.h>
33 #include <errno.h>
34 #include <fcntl.h>
35 #include <stdarg.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <zlib.h>
41
42 #include "mandoc_aux.h"
43 #include "mandoc.h"
44 #include "roff.h"
45 #include "mdoc.h"
46 #include "man.h"
47 #include "mandoc_parse.h"
48 #include "libmandoc.h"
49 #include "roff_int.h"
50 #include "tag.h"
51
52 #define REPARSE_LIMIT 1000
53
54 struct mparse {
55 struct roff *roff; /* roff parser (!NULL) */
56 struct roff_man *man; /* man parser */
57 struct buf *primary; /* buffer currently being parsed */
58 struct buf *secondary; /* copy of top level input */
59 struct buf *loop; /* open .while request line */
60 const char *os_s; /* default operating system */
61 int options; /* parser options */
62 int gzip; /* current input file is gzipped */
63 int filenc; /* encoding of the current file */
64 int reparse_count; /* finite interp. stack */
65 int line; /* line number in the file */
66 };
67
68 static void choose_parser(struct mparse *);
69 static void free_buf_list(struct buf *);
70 static void resize_buf(struct buf *, size_t);
71 static int mparse_buf_r(struct mparse *, struct buf, size_t, int);
72 static int read_whole_file(struct mparse *, int, struct buf *, int *);
73 static void mparse_end(struct mparse *);
74
75
76 static void
resize_buf(struct buf * buf,size_t initial)77 resize_buf(struct buf *buf, size_t initial)
78 {
79
80 buf->sz = buf->sz > initial/2 ? 2 * buf->sz : initial;
81 buf->buf = mandoc_realloc(buf->buf, buf->sz);
82 }
83
84 static void
free_buf_list(struct buf * buf)85 free_buf_list(struct buf *buf)
86 {
87 struct buf *tmp;
88
89 while (buf != NULL) {
90 tmp = buf;
91 buf = tmp->next;
92 free(tmp->buf);
93 free(tmp);
94 }
95 }
96
97 static void
choose_parser(struct mparse * curp)98 choose_parser(struct mparse *curp)
99 {
100 char *cp, *ep;
101 int format;
102
103 /*
104 * If neither command line arguments -mdoc or -man select
105 * a parser nor the roff parser found a .Dd or .TH macro
106 * yet, look ahead in the main input buffer.
107 */
108
109 if ((format = roff_getformat(curp->roff)) == 0) {
110 cp = curp->primary->buf;
111 ep = cp + curp->primary->sz;
112 while (cp < ep) {
113 if (*cp == '.' || *cp == '\'') {
114 cp++;
115 if (cp[0] == 'D' && cp[1] == 'd') {
116 format = MPARSE_MDOC;
117 break;
118 }
119 if (cp[0] == 'T' && cp[1] == 'H') {
120 format = MPARSE_MAN;
121 break;
122 }
123 }
124 cp = memchr(cp, '\n', ep - cp);
125 if (cp == NULL)
126 break;
127 cp++;
128 }
129 }
130
131 if (format == MPARSE_MDOC) {
132 curp->man->meta.macroset = MACROSET_MDOC;
133 if (curp->man->mdocmac == NULL)
134 curp->man->mdocmac = roffhash_alloc(MDOC_Dd, MDOC_MAX);
135 } else {
136 curp->man->meta.macroset = MACROSET_MAN;
137 if (curp->man->manmac == NULL)
138 curp->man->manmac = roffhash_alloc(MAN_TH, MAN_MAX);
139 }
140 curp->man->meta.first->tok = TOKEN_NONE;
141 }
142
143 /*
144 * Main parse routine for a buffer.
145 * It assumes encoding and line numbering are already set up.
146 * It can recurse directly (for invocations of user-defined
147 * macros, inline equations, and input line traps)
148 * and indirectly (for .so file inclusion).
149 */
150 static int
mparse_buf_r(struct mparse * curp,struct buf blk,size_t i,int start)151 mparse_buf_r(struct mparse *curp, struct buf blk, size_t i, int start)
152 {
153 struct buf ln;
154 struct buf *firstln, *lastln, *thisln, *loop;
155 char *cp;
156 size_t pos; /* byte number in the ln buffer */
157 size_t spos; /* at the start of the current line parse */
158 int line_result, result;
159 int of;
160 int lnn; /* line number in the real file */
161 int fd;
162 int inloop; /* Saw .while on this level. */
163 unsigned char c;
164
165 ln.sz = 256;
166 ln.buf = mandoc_malloc(ln.sz);
167 ln.next = NULL;
168 firstln = lastln = loop = NULL;
169 lnn = curp->line;
170 pos = 0;
171 inloop = 0;
172 result = ROFF_CONT;
173
174 while (i < blk.sz && (blk.buf[i] != '\0' || pos != 0)) {
175 if (start) {
176 curp->line = lnn;
177 curp->reparse_count = 0;
178
179 if (lnn < 3 &&
180 curp->filenc & MPARSE_UTF8 &&
181 curp->filenc & MPARSE_LATIN1)
182 curp->filenc = preconv_cue(&blk, i);
183 }
184 spos = pos;
185
186 while (i < blk.sz && (start || blk.buf[i] != '\0')) {
187
188 /*
189 * When finding an unescaped newline character,
190 * leave the character loop to process the line.
191 * Skip a preceding carriage return, if any.
192 */
193
194 if ('\r' == blk.buf[i] && i + 1 < blk.sz &&
195 '\n' == blk.buf[i + 1])
196 ++i;
197 if ('\n' == blk.buf[i]) {
198 ++i;
199 ++lnn;
200 break;
201 }
202
203 /*
204 * Make sure we have space for the worst
205 * case of 12 bytes: "\\[u10ffff]\n\0"
206 */
207
208 if (pos + 12 > ln.sz)
209 resize_buf(&ln, 256);
210
211 /*
212 * Encode 8-bit input.
213 */
214
215 c = blk.buf[i];
216 if (c & 0x80) {
217 if ( ! (curp->filenc && preconv_encode(
218 &blk, &i, &ln, &pos, &curp->filenc))) {
219 mandoc_msg(MANDOCERR_CHAR_BAD,
220 curp->line, pos, "0x%x", c);
221 ln.buf[pos++] = '?';
222 i++;
223 }
224 continue;
225 }
226
227 /*
228 * Exclude control characters.
229 */
230
231 if (c == 0x7f || (c < 0x20 && c != 0x09)) {
232 mandoc_msg(c == 0x00 || c == 0x04 ||
233 c > 0x0a ? MANDOCERR_CHAR_BAD :
234 MANDOCERR_CHAR_UNSUPP,
235 curp->line, pos, "0x%x", c);
236 i++;
237 if (c != '\r')
238 ln.buf[pos++] = '?';
239 continue;
240 }
241
242 ln.buf[pos++] = blk.buf[i++];
243 }
244 ln.buf[pos] = '\0';
245
246 /*
247 * Maintain a lookaside buffer of all lines.
248 * parsed from this input source.
249 */
250
251 thisln = mandoc_malloc(sizeof(*thisln));
252 thisln->buf = mandoc_strdup(ln.buf);
253 thisln->sz = strlen(ln.buf) + 1;
254 thisln->next = NULL;
255 if (firstln == NULL) {
256 firstln = lastln = thisln;
257 if (curp->secondary == NULL)
258 curp->secondary = firstln;
259 } else {
260 lastln->next = thisln;
261 lastln = thisln;
262 }
263
264 /* XXX Ugly hack to mark the end of the input. */
265
266 if (i == blk.sz || blk.buf[i] == '\0') {
267 if (pos + 2 > ln.sz)
268 resize_buf(&ln, 256);
269 ln.buf[pos++] = '\n';
270 ln.buf[pos] = '\0';
271 }
272
273 /*
274 * A significant amount of complexity is contained by
275 * the roff preprocessor. It's line-oriented but can be
276 * expressed on one line, so we need at times to
277 * readjust our starting point and re-run it. The roff
278 * preprocessor can also readjust the buffers with new
279 * data, so we pass them in wholesale.
280 */
281
282 of = 0;
283 rerun:
284 line_result = roff_parseln(curp->roff, curp->line,
285 &ln, &of, start && spos == 0 ? pos : 0);
286
287 /* Process options. */
288
289 if (line_result & ROFF_APPEND)
290 assert(line_result == (ROFF_IGN | ROFF_APPEND));
291
292 if (line_result & ROFF_USERCALL)
293 assert((line_result & ROFF_MASK) == ROFF_REPARSE);
294
295 if (line_result & ROFF_USERRET) {
296 assert(line_result == (ROFF_IGN | ROFF_USERRET));
297 if (start == 0) {
298 /* Return from the current macro. */
299 result = ROFF_USERRET;
300 goto out;
301 }
302 }
303
304 switch (line_result & ROFF_LOOPMASK) {
305 case ROFF_IGN:
306 break;
307 case ROFF_WHILE:
308 if (curp->loop != NULL) {
309 if (loop == curp->loop)
310 break;
311 mandoc_msg(MANDOCERR_WHILE_NEST,
312 curp->line, pos, NULL);
313 }
314 curp->loop = thisln;
315 loop = NULL;
316 inloop = 1;
317 break;
318 case ROFF_LOOPCONT:
319 case ROFF_LOOPEXIT:
320 if (curp->loop == NULL) {
321 mandoc_msg(MANDOCERR_WHILE_FAIL,
322 curp->line, pos, NULL);
323 break;
324 }
325 if (inloop == 0) {
326 mandoc_msg(MANDOCERR_WHILE_INTO,
327 curp->line, pos, NULL);
328 curp->loop = loop = NULL;
329 break;
330 }
331 if (line_result & ROFF_LOOPCONT)
332 loop = curp->loop;
333 else {
334 curp->loop = loop = NULL;
335 inloop = 0;
336 }
337 break;
338 default:
339 abort();
340 }
341
342 /* Process the main instruction from the roff parser. */
343
344 switch (line_result & ROFF_MASK) {
345 case ROFF_IGN:
346 break;
347 case ROFF_CONT:
348 if (curp->man->meta.macroset == MACROSET_NONE)
349 choose_parser(curp);
350 if ((curp->man->meta.macroset == MACROSET_MDOC ?
351 mdoc_parseln(curp->man, curp->line, ln.buf, of) :
352 man_parseln(curp->man, curp->line, ln.buf, of)
353 ) == 2)
354 goto out;
355 break;
356 case ROFF_RERUN:
357 goto rerun;
358 case ROFF_REPARSE:
359 if (++curp->reparse_count > REPARSE_LIMIT) {
360 /* Abort and return to the top level. */
361 result = ROFF_IGN;
362 mandoc_msg(MANDOCERR_ROFFLOOP,
363 curp->line, pos, NULL);
364 goto out;
365 }
366 result = mparse_buf_r(curp, ln, of, 0);
367 if (line_result & ROFF_USERCALL) {
368 roff_userret(curp->roff);
369 /* Continue normally. */
370 if (result & ROFF_USERRET)
371 result = ROFF_CONT;
372 }
373 if (start == 0 && result != ROFF_CONT)
374 goto out;
375 break;
376 case ROFF_SO:
377 if ( ! (curp->options & MPARSE_SO) &&
378 (i >= blk.sz || blk.buf[i] == '\0')) {
379 curp->man->meta.sodest =
380 mandoc_strdup(ln.buf + of);
381 goto out;
382 }
383 if ((fd = mparse_open(curp, ln.buf + of)) != -1) {
384 mparse_readfd(curp, fd, ln.buf + of);
385 close(fd);
386 } else {
387 mandoc_msg(MANDOCERR_SO_FAIL,
388 curp->line, of, ".so %s: %s",
389 ln.buf + of, strerror(errno));
390 ln.sz = mandoc_asprintf(&cp,
391 ".sp\nSee the file %s.\n.sp",
392 ln.buf + of);
393 free(ln.buf);
394 ln.buf = cp;
395 of = 0;
396 mparse_buf_r(curp, ln, of, 0);
397 }
398 break;
399 default:
400 abort();
401 }
402
403 /* Start the next input line. */
404
405 if (loop != NULL &&
406 (line_result & ROFF_LOOPMASK) == ROFF_IGN)
407 loop = loop->next;
408
409 if (loop != NULL) {
410 if ((line_result & ROFF_APPEND) == 0)
411 *ln.buf = '\0';
412 if (ln.sz < loop->sz)
413 resize_buf(&ln, loop->sz);
414 (void)strlcat(ln.buf, loop->buf, ln.sz);
415 of = 0;
416 goto rerun;
417 }
418
419 pos = (line_result & ROFF_APPEND) ? strlen(ln.buf) : 0;
420 }
421 out:
422 if (inloop) {
423 if (result != ROFF_USERRET)
424 mandoc_msg(MANDOCERR_WHILE_OUTOF,
425 curp->line, pos, NULL);
426 curp->loop = NULL;
427 }
428 free(ln.buf);
429 if (firstln != curp->secondary)
430 free_buf_list(firstln);
431 return result;
432 }
433
434 static int
read_whole_file(struct mparse * curp,int fd,struct buf * fb,int * with_mmap)435 read_whole_file(struct mparse *curp, int fd, struct buf *fb, int *with_mmap)
436 {
437 struct stat st;
438 gzFile gz;
439 size_t off;
440 ssize_t ssz;
441 int gzerrnum, retval;
442
443 if (fstat(fd, &st) == -1) {
444 mandoc_msg(MANDOCERR_FSTAT, 0, 0, "%s", strerror(errno));
445 return -1;
446 }
447
448 /*
449 * If we're a regular file, try just reading in the whole entry
450 * via mmap(). This is faster than reading it into blocks, and
451 * since each file is only a few bytes to begin with, I'm not
452 * concerned that this is going to tank any machines.
453 */
454
455 if (curp->gzip == 0 && S_ISREG(st.st_mode)) {
456 if (st.st_size > 0x7fffffff) {
457 mandoc_msg(MANDOCERR_TOOLARGE, 0, 0, NULL);
458 return -1;
459 }
460 *with_mmap = 1;
461 fb->sz = (size_t)st.st_size;
462 fb->buf = mmap(NULL, fb->sz, PROT_READ, MAP_SHARED, fd, 0);
463 if (fb->buf != MAP_FAILED)
464 return 0;
465 }
466
467 if (curp->gzip) {
468 /*
469 * Duplicating the file descriptor is required
470 * because we will have to call gzclose(3)
471 * to free memory used internally by zlib,
472 * but that will also close the file descriptor,
473 * which this function must not do.
474 */
475 if ((fd = dup(fd)) == -1) {
476 mandoc_msg(MANDOCERR_DUP, 0, 0,
477 "%s", strerror(errno));
478 return -1;
479 }
480 if ((gz = gzdopen(fd, "rb")) == NULL) {
481 mandoc_msg(MANDOCERR_GZDOPEN, 0, 0,
482 "%s", strerror(errno));
483 close(fd);
484 return -1;
485 }
486 } else
487 gz = NULL;
488
489 /*
490 * If this isn't a regular file (like, say, stdin), then we must
491 * go the old way and just read things in bit by bit.
492 */
493
494 *with_mmap = 0;
495 off = 0;
496 retval = -1;
497 fb->sz = 0;
498 fb->buf = NULL;
499 for (;;) {
500 if (off == fb->sz) {
501 if (fb->sz == (1U << 31)) {
502 mandoc_msg(MANDOCERR_TOOLARGE, 0, 0, NULL);
503 break;
504 }
505 resize_buf(fb, 65536);
506 }
507 ssz = curp->gzip ?
508 gzread(gz, fb->buf + (int)off, fb->sz - off) :
509 read(fd, fb->buf + (int)off, fb->sz - off);
510 if (ssz == 0) {
511 fb->sz = off;
512 retval = 0;
513 break;
514 }
515 if (ssz == -1) {
516 if (curp->gzip)
517 (void)gzerror(gz, &gzerrnum);
518 mandoc_msg(MANDOCERR_READ, 0, 0, "%s",
519 curp->gzip && gzerrnum != Z_ERRNO ?
520 zError(gzerrnum) : strerror(errno));
521 break;
522 }
523 off += (size_t)ssz;
524 }
525
526 if (curp->gzip && (gzerrnum = gzclose(gz)) != Z_OK)
527 mandoc_msg(MANDOCERR_GZCLOSE, 0, 0, "%s",
528 gzerrnum == Z_ERRNO ? strerror(errno) :
529 zError(gzerrnum));
530 if (retval == -1) {
531 free(fb->buf);
532 fb->buf = NULL;
533 }
534 return retval;
535 }
536
537 static void
mparse_end(struct mparse * curp)538 mparse_end(struct mparse *curp)
539 {
540 if (curp->man->meta.macroset == MACROSET_NONE)
541 curp->man->meta.macroset = MACROSET_MAN;
542 if (curp->man->meta.macroset == MACROSET_MDOC)
543 mdoc_endparse(curp->man);
544 else
545 man_endparse(curp->man);
546 roff_endparse(curp->roff);
547 }
548
549 /*
550 * Read the whole file into memory and call the parsers.
551 * Called recursively when an .so request is encountered.
552 */
553 void
mparse_readfd(struct mparse * curp,int fd,const char * filename)554 mparse_readfd(struct mparse *curp, int fd, const char *filename)
555 {
556 static int recursion_depth;
557
558 struct buf blk;
559 struct buf *save_primary;
560 const char *save_filename, *cp;
561 size_t offset;
562 int save_filenc, save_lineno;
563 int with_mmap;
564
565 if (recursion_depth > 64) {
566 mandoc_msg(MANDOCERR_ROFFLOOP, curp->line, 0, NULL);
567 return;
568 } else if (recursion_depth == 0 &&
569 (cp = strrchr(filename, '.')) != NULL &&
570 cp[1] >= '1' && cp[1] <= '9')
571 curp->man->filesec = cp[1];
572 else
573 curp->man->filesec = '\0';
574
575 if (read_whole_file(curp, fd, &blk, &with_mmap) == -1)
576 return;
577
578 /*
579 * Save some properties of the parent file.
580 */
581
582 save_primary = curp->primary;
583 save_filenc = curp->filenc;
584 save_lineno = curp->line;
585 save_filename = mandoc_msg_getinfilename();
586
587 curp->primary = &blk;
588 curp->filenc = curp->options & (MPARSE_UTF8 | MPARSE_LATIN1);
589 curp->line = 1;
590 mandoc_msg_setinfilename(filename);
591
592 /* Skip an UTF-8 byte order mark. */
593 if (curp->filenc & MPARSE_UTF8 && blk.sz > 2 &&
594 (unsigned char)blk.buf[0] == 0xef &&
595 (unsigned char)blk.buf[1] == 0xbb &&
596 (unsigned char)blk.buf[2] == 0xbf) {
597 offset = 3;
598 curp->filenc &= ~MPARSE_LATIN1;
599 } else
600 offset = 0;
601
602 recursion_depth++;
603 mparse_buf_r(curp, blk, offset, 1);
604 if (--recursion_depth == 0)
605 mparse_end(curp);
606
607 /*
608 * Clean up and restore saved parent properties.
609 */
610
611 if (with_mmap)
612 munmap(blk.buf, blk.sz);
613 else
614 free(blk.buf);
615
616 curp->primary = save_primary;
617 curp->filenc = save_filenc;
618 curp->line = save_lineno;
619 if (save_filename != NULL)
620 mandoc_msg_setinfilename(save_filename);
621 }
622
623 int
mparse_open(struct mparse * curp,const char * file)624 mparse_open(struct mparse *curp, const char *file)
625 {
626 char *cp;
627 int fd, save_errno;
628
629 cp = strrchr(file, '.');
630 curp->gzip = (cp != NULL && ! strcmp(cp + 1, "gz"));
631
632 /* First try to use the filename as it is. */
633
634 if ((fd = open(file, O_RDONLY)) != -1)
635 return fd;
636
637 /*
638 * If that doesn't work and the filename doesn't
639 * already end in .gz, try appending .gz.
640 */
641
642 if ( ! curp->gzip) {
643 save_errno = errno;
644 mandoc_asprintf(&cp, "%s.gz", file);
645 fd = open(cp, O_RDONLY);
646 free(cp);
647 errno = save_errno;
648 if (fd != -1) {
649 curp->gzip = 1;
650 return fd;
651 }
652 }
653
654 /* Neither worked, give up. */
655
656 return -1;
657 }
658
659 struct mparse *
mparse_alloc(int options,enum mandoc_os os_e,const char * os_s)660 mparse_alloc(int options, enum mandoc_os os_e, const char *os_s)
661 {
662 struct mparse *curp;
663
664 curp = mandoc_calloc(1, sizeof(struct mparse));
665
666 curp->options = options;
667 curp->os_s = os_s;
668
669 curp->roff = roff_alloc(options);
670 curp->man = roff_man_alloc(curp->roff, curp->os_s,
671 curp->options & MPARSE_QUICK ? 1 : 0);
672 if (curp->options & MPARSE_MDOC) {
673 curp->man->meta.macroset = MACROSET_MDOC;
674 if (curp->man->mdocmac == NULL)
675 curp->man->mdocmac = roffhash_alloc(MDOC_Dd, MDOC_MAX);
676 } else if (curp->options & MPARSE_MAN) {
677 curp->man->meta.macroset = MACROSET_MAN;
678 if (curp->man->manmac == NULL)
679 curp->man->manmac = roffhash_alloc(MAN_TH, MAN_MAX);
680 }
681 curp->man->meta.first->tok = TOKEN_NONE;
682 curp->man->meta.os_e = os_e;
683 tag_alloc();
684 return curp;
685 }
686
687 void
mparse_reset(struct mparse * curp)688 mparse_reset(struct mparse *curp)
689 {
690 tag_free();
691 roff_reset(curp->roff);
692 roff_man_reset(curp->man);
693 free_buf_list(curp->secondary);
694 curp->secondary = NULL;
695 curp->gzip = 0;
696 tag_alloc();
697 }
698
699 void
mparse_free(struct mparse * curp)700 mparse_free(struct mparse *curp)
701 {
702 tag_free();
703 roffhash_free(curp->man->mdocmac);
704 roffhash_free(curp->man->manmac);
705 roff_man_free(curp->man);
706 roff_free(curp->roff);
707 free_buf_list(curp->secondary);
708 free(curp);
709 }
710
711 struct roff_meta *
mparse_result(struct mparse * curp)712 mparse_result(struct mparse *curp)
713 {
714 roff_state_reset(curp->man);
715 if (curp->options & MPARSE_VALIDATE) {
716 if (curp->man->meta.macroset == MACROSET_MDOC)
717 mdoc_validate(curp->man);
718 else
719 man_validate(curp->man);
720 tag_postprocess(curp->man, curp->man->meta.first);
721 }
722 return &curp->man->meta;
723 }
724
725 void
mparse_copy(const struct mparse * p)726 mparse_copy(const struct mparse *p)
727 {
728 struct buf *buf;
729
730 for (buf = p->secondary; buf != NULL; buf = buf->next)
731 puts(buf->buf);
732 }
733