1 /* Handling of recursive HTTP retrieving.
2 Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
4 This file is part of GNU Wget.
6 GNU Wget is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 GNU Wget is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with Wget; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
28 #endif /* HAVE_STRING_H */
31 #endif /* HAVE_UNISTD_H */
34 #include <sys/types.h>
51 extern char *version_string;
53 static struct hash_table *dl_file_url_map;
54 static struct hash_table *dl_url_file_map;
56 /* List of HTML files downloaded in this Wget run. Used for link
57 conversion after Wget is done. */
58 static slist *downloaded_html_files;
60 /* List of undesirable-to-load URLs. */
61 static struct hash_table *undesirable_urls;
63 /* Current recursion depth. */
66 /* Base directory we're recursing from (used by no_parent). */
67 static char *base_dir;
69 static int first_time = 1;
72 /* Cleanup the data structures associated with recursive retrieving
73 (the variables above). */
75 recursive_cleanup (void)
79 string_set_free (undesirable_urls);
80 undesirable_urls = NULL;
84 free_keys_and_values (dl_file_url_map);
85 hash_table_destroy (dl_file_url_map);
86 dl_file_url_map = NULL;
90 free_keys_and_values (dl_url_file_map);
91 hash_table_destroy (dl_url_file_map);
92 dl_url_file_map = NULL;
94 undesirable_urls = NULL;
95 slist_free (downloaded_html_files);
96 downloaded_html_files = NULL;
97 FREE_MAYBE (base_dir);
101 /* Reset FIRST_TIME to 1, so that some action can be taken in
102 recursive_retrieve(). */
104 recursive_reset (void)
109 /* The core of recursive retrieving. Endless recursion is avoided by
110 having all URLs stored to a linked list of URLs, which is checked
111 before loading any URL. That way no URL can get loaded twice.
113 The function also supports specification of maximum recursion depth
114 and a number of other goodies. */
116 recursive_retrieve (const char *file, const char *this_url)
118 char *constr, *filename, *newloc;
119 char *canon_this_url = NULL;
120 int dt, inl, dash_p_leaf_HTML = FALSE;
121 int meta_disallow_follow;
122 int this_url_ftp; /* See below the explanation */
124 urlpos *url_list, *cur_url;
127 assert (this_url != NULL);
128 assert (file != NULL);
129 /* If quota was exceeded earlier, bail out. */
130 if (downloaded_exceeds_quota ())
132 /* Cache the current URL in the list. */
135 /* These three operations need to be done only once per Wget
136 run. They should probably be at a different location. */
137 if (!undesirable_urls)
138 undesirable_urls = make_string_hash_table (0);
140 hash_table_clear (undesirable_urls);
141 string_set_add (undesirable_urls, this_url);
142 /* Enter this_url to the hash table, in original and "enhanced" form. */
144 err = parseurl (this_url, u, 0);
147 string_set_add (undesirable_urls, u->url);
149 base_dir = xstrdup (u->dir); /* Set the base dir. */
150 /* Set the canonical this_url to be sent as referer. This
151 problem exists only when running the first time. */
152 canon_this_url = xstrdup (u->url);
156 DEBUGP (("Double yuck! The *base* URL is broken.\n"));
166 if (opt.reclevel != INFINITE_RECURSION && depth > opt.reclevel)
167 /* We've exceeded the maximum recursion depth specified by the user. */
169 if (opt.page_requisites && depth <= opt.reclevel + 1)
170 /* When -p is specified, we can do one more partial recursion from the
171 "leaf nodes" on the HTML document tree. The recursion is partial in
172 that we won't traverse any <A> or <AREA> tags, nor any <LINK> tags
173 except for <LINK REL="stylesheet">. */
174 dash_p_leaf_HTML = TRUE;
176 /* Either -p wasn't specified or it was and we've already gone the one
177 extra (pseudo-)level that it affords us, so we need to bail out. */
179 DEBUGP (("Recursion depth %d exceeded max. depth %d.\n",
180 depth, opt.reclevel));
186 /* Determine whether this_url is an FTP URL. If it is, it means
187 that the retrieval is done through proxy. In that case, FTP
188 links will be followed by default and recursion will not be
189 turned off when following them. */
190 this_url_ftp = (url_scheme (this_url) == SCHEME_FTP);
192 /* Get the URL-s from an HTML file: */
193 url_list = get_urls_html (file, canon_this_url ? canon_this_url : this_url,
194 dash_p_leaf_HTML, &meta_disallow_follow);
196 if (opt.use_robots && meta_disallow_follow)
198 /* The META tag says we are not to follow this file. Respect
200 free_urlpos (url_list);
204 /* Decide what to do with each of the URLs. A URL will be loaded if
205 it meets several requirements, discussed later. */
206 for (cur_url = url_list; cur_url; cur_url = cur_url->next)
208 /* If quota was exceeded earlier, bail out. */
209 if (downloaded_exceeds_quota ())
211 /* Parse the URL for convenient use in other functions, as well
212 as to get the optimized form. It also checks URL integrity. */
214 if (parseurl (cur_url->url, u, 0) != URLOK)
216 DEBUGP (("Yuck! A bad URL.\n"));
220 assert (u->url != NULL);
221 constr = xstrdup (u->url);
223 /* Several checkings whether a file is acceptable to load:
224 1. check if URL is ftp, and we don't load it
225 2. check for relative links (if relative_only is set)
227 4. check for no-parent
228 5. check for excludes && includes
230 7. check for same host (if spanhost is unset), with possible
231 gethostbyname baggage
232 8. check for robots.txt
234 Addendum: If the URL is FTP, and it is to be loaded, only the
235 domain and suffix settings are "stronger".
237 Note that .html and (yuck) .htm will get loaded regardless of
238 suffix rules (but that is remedied later with unlink) unless
239 the depth equals the maximum depth.
241 More time- and memory- consuming tests should be put later on
244 /* inl is set if the URL we are working on (constr) is stored in
245 undesirable_urls. Using it is crucial to avoid unnecessary
246 repeated continuous hits to the hash table. */
247 inl = string_set_contains (undesirable_urls, constr);
249 /* If it is FTP, and FTP is not followed, chuck it out. */
251 if (u->scheme == SCHEME_FTP && !opt.follow_ftp && !this_url_ftp)
253 DEBUGP (("Uh, it is FTP but i'm not in the mood to follow FTP.\n"));
254 string_set_add (undesirable_urls, constr);
257 /* If it is absolute link and they are not followed, chuck it
259 if (!inl && u->scheme != SCHEME_FTP)
260 if (opt.relative_only && !cur_url->link_relative_p)
262 DEBUGP (("It doesn't really look like a relative link.\n"));
263 string_set_add (undesirable_urls, constr);
266 /* If its domain is not to be accepted/looked-up, chuck it out. */
268 if (!accept_domain (u))
270 DEBUGP (("I don't like the smell of that domain.\n"));
271 string_set_add (undesirable_urls, constr);
274 /* Check for parent directory. */
275 if (!inl && opt.no_parent
276 /* If the new URL is FTP and the old was not, ignore
278 && !(!this_url_ftp && u->scheme == SCHEME_FTP))
280 /* Check for base_dir first. */
281 if (!(base_dir && frontcmp (base_dir, u->dir)))
283 /* Failing that, check for parent dir. */
284 struct urlinfo *ut = newurl ();
285 if (parseurl (this_url, ut, 0) != URLOK)
286 DEBUGP (("Double yuck! The *base* URL is broken.\n"));
287 else if (!frontcmp (ut->dir, u->dir))
289 /* Failing that too, kill the URL. */
290 DEBUGP (("Trying to escape parental guidance with no_parent on.\n"));
291 string_set_add (undesirable_urls, constr);
297 /* If the file does not match the acceptance list, or is on the
298 rejection list, chuck it out. The same goes for the
299 directory exclude- and include- lists. */
300 if (!inl && (opt.includes || opt.excludes))
302 if (!accdir (u->dir, ALLABS))
304 DEBUGP (("%s (%s) is excluded/not-included.\n", constr, u->dir));
305 string_set_add (undesirable_urls, constr);
312 /* We check for acceptance/rejection rules only for non-HTML
313 documents. Since we don't know whether they really are
314 HTML, it will be deduced from (an OR-ed list):
316 1) u->file is "" (meaning it is a directory)
317 2) suffix exists, AND:
321 If the file *is* supposed to be HTML, it will *not* be
322 subject to acc/rej rules, unless a finite maximum depth has
323 been specified and the current depth is the maximum depth. */
326 || (((suf = suffix (constr)) != NULL)
327 && ((!strcmp (suf, "html") || !strcmp (suf, "htm"))
328 && ((opt.reclevel != INFINITE_RECURSION) &&
329 (depth != opt.reclevel))))))
331 if (!acceptable (u->file))
333 DEBUGP (("%s (%s) does not match acc/rej rules.\n",
335 string_set_add (undesirable_urls, constr);
341 /* Optimize the URL (which includes possible DNS lookup) only
342 after all other possibilities have been exhausted. */
345 if (!opt.simple_check)
350 /* Just lowercase the hostname. */
351 for (p = u->host; *p; p++)
354 u->url = str_url (u, 0);
357 constr = xstrdup (u->url);
358 /* After we have canonicalized the URL, check if we have it
359 on the black list. */
360 if (string_set_contains (undesirable_urls, constr))
362 /* This line is bogus. */
363 /*string_set_add (undesirable_urls, constr);*/
365 if (!inl && !((u->scheme == SCHEME_FTP) && !this_url_ftp))
366 if (!opt.spanhost && this_url && !same_host (this_url, constr))
368 DEBUGP (("This is not the same hostname as the parent's.\n"));
369 string_set_add (undesirable_urls, constr);
373 /* What about robots.txt? */
374 if (!inl && opt.use_robots && u->scheme == SCHEME_FTP)
376 struct robot_specs *specs = res_get_specs (u->host, u->port);
380 if (res_retrieve_file (constr, &rfile))
382 specs = res_parse_from_file (rfile);
387 /* If we cannot get real specs, at least produce
388 dummy ones so that we can register them and stop
389 trying to retrieve them. */
390 specs = res_parse ("", 0);
392 res_register_specs (u->host, u->port, specs);
395 /* Now that we have (or don't have) robots.txt specs, we can
396 check what they say. */
397 if (!res_match_path (specs, u->path))
399 DEBUGP (("Not following %s because robots.txt forbids it.\n",
401 string_set_add (undesirable_urls, constr);
407 /* If it wasn't chucked out, do something with it. */
410 DEBUGP (("I've decided to load it -> "));
411 /* Add it to the list of already-loaded URL-s. */
412 string_set_add (undesirable_urls, constr);
413 /* Automatically followed FTPs will *not* be downloaded
415 if (u->scheme == SCHEME_FTP)
417 /* Don't you adore side-effects? */
420 /* Reset its type. */
423 retrieve_url (constr, &filename, &newloc,
424 canon_this_url ? canon_this_url : this_url, &dt);
425 if (u->scheme == SCHEME_FTP)
435 /* If there was no error, and the type is text/html, parse
440 recursive_retrieve (filename, constr);
443 DEBUGP (("%s is not text/html so we don't chase.\n",
444 filename ? filename: "(null)"));
446 if (opt.delete_after || (filename && !acceptable (filename)))
447 /* Either --delete-after was specified, or we loaded this otherwise
448 rejected (e.g. by -R) HTML file just so we could harvest its
449 hyperlinks -- in either case, delete the local file. */
451 DEBUGP (("Removing file due to %s in recursive_retrieve():\n",
452 opt.delete_after ? "--delete-after" :
453 "recursive rejection criteria"));
454 logprintf (LOG_VERBOSE,
455 (opt.delete_after ? _("Removing %s.\n")
456 : _("Removing %s since it should be rejected.\n")),
458 if (unlink (filename))
459 logprintf (LOG_NOTQUIET, "unlink: %s\n", strerror (errno));
463 /* If everything was OK, and links are to be converted, let's
464 store the local filename. */
465 if (opt.convert_links && (dt & RETROKF) && (filename != NULL))
467 cur_url->convert = CO_CONVERT_TO_RELATIVE;
468 cur_url->local_name = xstrdup (filename);
472 DEBUGP (("%s already in list, so we don't load.\n", constr));
473 /* Free filename and constr. */
474 FREE_MAYBE (filename);
477 /* Increment the pbuf for the appropriate size. */
479 if (opt.convert_links && !opt.delete_after)
480 /* This is merely the first pass: the links that have been
481 successfully downloaded are converted. In the second pass,
482 convert_all_links() will also convert those links that have NOT
483 been downloaded to their canonical form. */
484 convert_links (file, url_list);
485 /* Free the linked list of URL-s. */
486 free_urlpos (url_list);
487 /* Free the canonical this_url. */
488 FREE_MAYBE (canon_this_url);
489 /* Decrement the recursion depth. */
491 if (downloaded_exceeds_quota ())
498 register_download (const char *url, const char *file)
500 if (!opt.convert_links)
502 if (!dl_file_url_map)
503 dl_file_url_map = make_string_hash_table (0);
504 hash_table_put (dl_file_url_map, xstrdup (file), xstrdup (url));
505 if (!dl_url_file_map)
506 dl_url_file_map = make_string_hash_table (0);
507 hash_table_put (dl_url_file_map, xstrdup (url), xstrdup (file));
511 register_html (const char *url, const char *file)
513 if (!opt.convert_links)
515 downloaded_html_files = slist_prepend (downloaded_html_files, file);
518 /* convert_links() is called from recursive_retrieve() after we're
519 done with an HTML file. This call to convert_links is not complete
520 because it converts only the downloaded files, and Wget cannot know
521 which files will be downloaded afterwards. So, if we have file
524 <a href="/c/something.gif">
526 and /c/something.gif was not downloaded because it exceeded the
527 recursion depth, the reference will *not* be changed.
529 However, later we can encounter /c/something.gif from an "upper"
530 level HTML (let's call it filetwo.html), and it gets downloaded.
532 But now we have a problem because /c/something.gif will be
533 correctly transformed in filetwo.html, but not in fileone.html,
534 since Wget could not have known that /c/something.gif will be
535 downloaded in the future.
537 This is why Wget must, after the whole retrieval, call
538 convert_all_links to go once more through the entire list of
539 retrieved HTMLs, and re-convert them.
541 All the downloaded HTMLs are kept in downloaded_html_files, and downloaded URLs
542 in urls_downloaded. From these two lists information is
545 convert_all_links (void)
549 /* Destructively reverse downloaded_html_files to get it in the right order.
550 recursive_retrieve() used slist_prepend() consistently. */
551 downloaded_html_files = slist_nreverse (downloaded_html_files);
553 for (html = downloaded_html_files; html; html = html->next)
555 urlpos *urls, *cur_url;
558 DEBUGP (("Rescanning %s\n", html->string));
559 /* Determine the URL of the HTML file. get_urls_html will need
561 url = hash_table_get (dl_file_url_map, html->string);
563 DEBUGP (("It should correspond to %s.\n", url));
565 DEBUGP (("I cannot find the corresponding URL.\n"));
566 /* Parse the HTML file... */
567 urls = get_urls_html (html->string, url, FALSE, NULL);
568 /* We don't respect meta_disallow_follow here because, even if
569 the file is not followed, we might still want to convert the
570 links that have been followed from other files. */
571 for (cur_url = urls; cur_url; cur_url = cur_url->next)
575 /* The URL must be in canonical form to be compared. */
576 struct urlinfo *u = newurl ();
577 uerr_t res = parseurl (cur_url->url, u, 0);
583 /* We decide the direction of conversion according to whether
584 a URL was downloaded. Downloaded URLs will be converted
585 ABS2REL, whereas non-downloaded will be converted REL2ABS. */
586 local_name = hash_table_get (dl_url_file_map, u->url);
588 DEBUGP (("%s marked for conversion, local %s\n",
589 u->url, local_name));
590 /* Decide on the conversion direction. */
593 /* We've downloaded this URL. Convert it to relative
594 form. We do this even if the URL already is in
595 relative form, because our directory structure may
596 not be identical to that on the server (think `-nd',
597 `--cut-dirs', etc.) */
598 cur_url->convert = CO_CONVERT_TO_RELATIVE;
599 cur_url->local_name = xstrdup (local_name);
603 /* We haven't downloaded this URL. If it's not already
604 complete (including a full host name), convert it to
605 that form, so it can be reached while browsing this
607 if (!cur_url->link_complete_p)
608 cur_url->convert = CO_CONVERT_TO_COMPLETE;
609 cur_url->local_name = NULL;
613 /* Convert the links in the file. */
614 convert_links (html->string, urls);