1 This is Info file wget.info, produced by Makeinfo version 1.68 from the
2 input file ./wget.texi.
4 INFO-DIR-SECTION Net Utilities
5 INFO-DIR-SECTION World Wide Web
7 * Wget: (wget). The non-interactive network downloader.
10 This file documents the the GNU Wget utility for downloading network
13 Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
15 Permission is granted to make and distribute verbatim copies of this
16 manual provided the copyright notice and this permission notice are
17 preserved on all copies.
19 Permission is granted to copy and distribute modified versions of
20 this manual under the conditions for verbatim copying, provided also
21 that the sections entitled "Copying" and "GNU General Public License"
22 are included exactly as in the original, and provided that the entire
23 resulting derived work is distributed under the terms of a permission
24 notice identical to this one.
27 File: wget.info, Node: Top, Next: Overview, Prev: (dir), Up: (dir)
32 This manual documents version 1.5.3+dev of GNU Wget, the freely
33 available utility for network download.
35 Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
39 * Overview:: Features of Wget.
40 * Invoking:: Wget command-line arguments.
41 * Recursive Retrieval:: Description of recursive retrieval.
42 * Following Links:: The available methods of chasing links.
43 * Time-Stamping:: Mirroring according to time-stamps.
44 * Startup File:: Wget's initialization file.
45 * Examples:: Examples of usage.
46 * Various:: The stuff that doesn't fit anywhere else.
47 * Appendices:: Some useful references.
48 * Copying:: You may give out copies of Wget.
49 * Concept Index:: Topics covered by this manual.
52 File: wget.info, Node: Overview, Next: Invoking, Prev: Top, Up: Top
57 GNU Wget is a freely available network utility to retrieve files from
58 the World Wide Web, using HTTP (Hyper Text Transfer Protocol) and FTP
59 (File Transfer Protocol), the two most widely used Internet protocols.
60 It has many useful features to make downloading easier, some of them
63 * Wget is non-interactive, meaning that it can work in the
64 background, while the user is not logged on. This allows you to
65 start a retrieval and disconnect from the system, letting Wget
66 finish the work. By contrast, most of the Web browsers require
67 constant user's presence, which can be a great hindrance when
68 transferring a lot of data.
70 * Wget is capable of descending recursively through the structure of
71 HTML documents and FTP directory trees, making a local copy of the
72 directory hierarchy similar to the one on the remote server. This
73 feature can be used to mirror archives and home pages, or traverse
74 the web in search of data, like a WWW robot (*Note Robots::). In
75 that spirit, Wget understands the `norobots' convention.
77 * File name wildcard matching and recursive mirroring of directories
78 are available when retrieving via FTP. Wget can read the
79 time-stamp information given by both HTTP and FTP servers, and
80 store it locally. Thus Wget can see if the remote file has
81 changed since last retrieval, and automatically retrieve the new
82 version if it has. This makes Wget suitable for mirroring of FTP
83 sites, as well as home pages.
85 * Wget works exceedingly well on slow or unstable connections,
86 retrying the document until it is fully retrieved, or until a
87 user-specified retry count is surpassed. It will try to resume the
88 download from the point of interruption, using `REST' with FTP and
89 `Range' with HTTP servers that support them.
91 * By default, Wget supports proxy servers, which can lighten the
92 network load, speed up retrieval and provide access behind
93 firewalls. However, if you are behind a firewall that requires
94 that you use a socks style gateway, you can get the socks library
95 and build wget with support for socks. Wget also supports the
96 passive FTP downloading as an option.
98 * Builtin features offer mechanisms to tune which links you wish to
99 follow (*Note Following Links::).
101 * The retrieval is conveniently traced with printing dots, each dot
102 representing a fixed amount of data received (1KB by default).
103 These representations can be customized to your preferences.
105 * Most of the features are fully configurable, either through
106 command line options, or via the initialization file `.wgetrc'
107 (*Note Startup File::). Wget allows you to define "global"
108 startup files (`/usr/local/etc/wgetrc' by default) for site
111 * Finally, GNU Wget is free software. This means that everyone may
112 use it, redistribute it and/or modify it under the terms of the
113 GNU General Public License, as published by the Free Software
114 Foundation (*Note Copying::).
117 File: wget.info, Node: Invoking, Next: Recursive Retrieval, Prev: Overview, Up: Top
122 By default, Wget is very simple to invoke. The basic syntax is:
124 wget [OPTION]... [URL]...
126 Wget will simply download all the URLs specified on the command
127 line. URL is a "Uniform Resource Locator", as defined below.
129 However, you may wish to change some of the default parameters of
130 Wget. You can do it two ways: permanently, adding the appropriate
131 command to `.wgetrc' (*Note Startup File::), or specifying it on the
138 * Basic Startup Options::
139 * Logging and Input File Options::
141 * Directory Options::
144 * Recursive Retrieval Options::
145 * Recursive Accept/Reject Options::
148 File: wget.info, Node: URL Format, Next: Option Syntax, Prev: Invoking, Up: Invoking
153 "URL" is an acronym for Uniform Resource Locator. A uniform
154 resource locator is a compact string representation for a resource
155 available via the Internet. Wget recognizes the URL syntax as per
156 RFC1738. This is the most widely used form (square brackets denote
159 http://host[:port]/directory/file
160 ftp://host[:port]/directory/file
162 You can also encode your username and password within a URL:
164 ftp://user:password@host/path
165 http://user:password@host/path
167 Either USER or PASSWORD, or both, may be left out. If you leave out
168 either the HTTP username or password, no authentication will be sent.
169 If you leave out the FTP username, `anonymous' will be used. If you
170 leave out the FTP password, your email address will be supplied as a
173 You can encode unsafe characters in a URL as `%xy', `xy' being the
174 hexadecimal representation of the character's ASCII value. Some common
175 unsafe characters include `%' (quoted as `%25'), `:' (quoted as `%3A'),
176 and `@' (quoted as `%40'). Refer to RFC1738 for a comprehensive list
177 of unsafe characters.
179 Wget also supports the `type' feature for FTP URLs. By default, FTP
180 documents are retrieved in the binary mode (type `i'), which means that
181 they are downloaded unchanged. Another useful mode is the `a'
182 ("ASCII") mode, which converts the line delimiters between the
183 different operating systems, and is thus useful for text files. Here
186 ftp://host/directory/file;type=a
188 Two alternative variants of URL specification are also supported,
189 because of historical (hysterical?) reasons and their widespreaded use.
191 FTP-only syntax (supported by `NcFTP'):
194 HTTP-only syntax (introduced by `Netscape'):
197 These two alternative forms are deprecated, and may cease being
198 supported in the future.
200 If you do not understand the difference between these notations, or
201 do not know which one to use, just use the plain ordinary format you use
202 with your favorite browser, like `Lynx' or `Netscape'.
204 ---------- Footnotes ----------
206 (1) If you have a `.netrc' file in your home directory, password
207 will also be searched for there.
210 File: wget.info, Node: Option Syntax, Next: Basic Startup Options, Prev: URL Format, Up: Invoking
215 Since Wget uses GNU getopts to process its arguments, every option
216 has a short form and a long form. Long options are more convenient to
217 remember, but take time to type. You may freely mix different option
218 styles, or specify options after the command-line arguments. Thus you
221 wget -r --tries=10 http://fly.cc.fer.hr/ -o log
223 The space between the option accepting an argument and the argument
224 may be omitted. Instead `-o log' you can write `-olog'.
226 You may put several options that do not require arguments together,
231 This is a complete equivalent of:
235 Since the options can be specified after the arguments, you may
236 terminate them with `--'. So the following will try to download URL
237 `-x', reporting failure to `log':
241 The options that accept comma-separated lists all respect the
242 convention that specifying an empty list clears its value. This can be
243 useful to clear the `.wgetrc' settings. For instance, if your `.wgetrc'
244 sets `exclude_directories' to `/cgi-bin', the following example will
245 first reset it, and then set it to exclude `/~nobody' and `/~somebody'.
246 You can also clear the lists in `.wgetrc' (*Note Wgetrc Syntax::).
248 wget -X '' -X /~nobody,/~somebody
251 File: wget.info, Node: Basic Startup Options, Next: Logging and Input File Options, Prev: Option Syntax, Up: Invoking
253 Basic Startup Options
254 =====================
258 Display the version of Wget.
262 Print a help message describing all of Wget's command-line options.
266 Go to background immediately after startup. If no output file is
267 specified via the `-o', output is redirected to `wget-log'.
271 Execute COMMAND as if it were a part of `.wgetrc' (*Note Startup
272 File::). A command thus invoked will be executed *after* the
273 commands in `.wgetrc', thus taking precedence over them.
276 File: wget.info, Node: Logging and Input File Options, Next: Download Options, Prev: Basic Startup Options, Up: Invoking
278 Logging and Input File Options
279 ==============================
282 `--output-file=LOGFILE'
283 Log all messages to LOGFILE. The messages are normally reported
287 `--append-output=LOGFILE'
288 Append to LOGFILE. This is the same as `-o', only it appends to
289 LOGFILE instead of overwriting the old log file. If LOGFILE does
290 not exist, a new file is created.
294 Turn on debug output, meaning various information important to the
295 developers of Wget if it does not work properly. Your system
296 administrator may have chosen to compile Wget without debug
297 support, in which case `-d' will not work. Please note that
298 compiling with debug support is always safe--Wget compiled with
299 the debug support will *not* print any debug info unless requested
300 with `-d'. *Note Reporting Bugs:: for more information on how to
301 use `-d' for sending bug reports.
305 Turn off Wget's output.
309 Turn on verbose output, with all the available data. The default
314 Non-verbose output--turn off verbose without being completely quiet
315 (use `-q' for that), which means that error messages and basic
316 information still get printed.
320 Read URLs from FILE, in which case no URLs need to be on the
321 command line. If there are URLs both on the command line and in
322 an input file, those on the command lines will be the first ones to
323 be retrieved. The FILE need not be an HTML document (but no harm
324 if it is)--it is enough if the URLs are just listed sequentially.
326 However, if you specify `--force-html', the document will be
327 regarded as `html'. In that case you may have problems with
328 relative links, which you can solve either by adding `<base
329 href="URL">' to the documents or by specifying `--base=URL' on the
334 When input is read from a file, force it to be treated as an HTML
335 file. This enables you to retrieve relative links from existing
336 HTML files on your local disk, by adding `<base href="URL">' to
337 HTML, or using the `--base' command-line option.
340 File: wget.info, Node: Download Options, Next: Directory Options, Prev: Logging and Input File Options, Up: Invoking
347 Set number of retries to NUMBER. Specify 0 or `inf' for infinite
351 `--output-document=FILE'
352 The documents will not be written to the appropriate files, but
353 all will be concatenated together and written to FILE. If FILE
354 already exists, it will be overwritten. If the FILE is `-', the
355 documents will be written to standard output. Including this
356 option automatically sets the number of tries to 1.
360 Do not clobber existing files when saving to directory hierarchy
361 within recursive retrieval of several files. This option is
362 *extremely* useful when you wish to continue where you left off
363 with retrieval of many files. If the files have the `.html' or
364 (yuck) `.htm' suffix, they will be loaded from the local disk, and
365 parsed as if they have been retrieved from the Web.
369 Continue getting an existing file. This is useful when you want to
370 finish up the download started by another program, or a previous
371 instance of Wget. Thus you can write:
373 wget -c ftp://sunsite.doc.ic.ac.uk/ls-lR.Z
375 If there is a file name `ls-lR.Z' in the current directory, Wget
376 will assume that it is the first portion of the remote file, and
377 will require the server to continue the retrieval from an offset
378 equal to the length of the local file.
380 Note that you need not specify this option if all you want is Wget
381 to continue retrieving where it left off when the connection is
382 lost--Wget does this by default. You need this option only when
383 you want to continue retrieval of a file already halfway
384 retrieved, saved by another FTP client, or left by Wget being
387 Without `-c', the previous example would just begin to download the
388 remote file to `ls-lR.Z.1'. The `-c' option is also applicable
389 for HTTP servers that support the `Range' header.
392 Set the retrieval style to STYLE. Wget traces the retrieval of
393 each document by printing dots on the screen, each dot
394 representing a fixed amount of retrieved data. Any number of dots
395 may be separated in a "cluster", to make counting easier. This
396 option allows you to choose one of the pre-defined styles,
397 determining the number of bytes represented by a dot, the number
398 of dots in a cluster, and the number of dots on the line.
400 With the `default' style each dot represents 1K, there are ten dots
401 in a cluster and 50 dots in a line. The `binary' style has a more
402 "computer"-like orientation--8K dots, 16-dots clusters and 48 dots
403 per line (which makes for 384K lines). The `mega' style is
404 suitable for downloading very large files--each dot represents 64K
405 retrieved, there are eight dots in a cluster, and 48 dots on each
406 line (so each line contains 3M). The `micro' style is exactly the
407 reverse; it is suitable for downloading small files, with 128-byte
408 dots, 8 dots per cluster, and 48 dots (6K) per line.
412 Turn on time-stamping. *Note Time-Stamping:: for details.
416 Print the headers sent by HTTP servers and responses sent by FTP
420 When invoked with this option, Wget will behave as a Web "spider",
421 which means that it will not download the pages, just check that
422 they are there. You can use it to check your bookmarks, e.g. with:
424 wget --spider --force-html -i bookmarks.html
426 This feature needs much more work for Wget to get close to the
427 functionality of real WWW spiders.
431 Set the read timeout to SECONDS seconds. Whenever a network read
432 is issued, the file descriptor is checked for a timeout, which
433 could otherwise leave a pending connection (uninterrupted read).
434 The default timeout is 900 seconds (fifteen minutes). Setting
435 timeout to 0 will disable checking for timeouts.
437 Please do not lower the default timeout value with this option
438 unless you know what you are doing.
442 Wait the specified number of seconds between the retrievals. Use
443 of this option is recommended, as it lightens the server load by
444 making the requests less frequent. Instead of in seconds, the
445 time can be specified in minutes using the `m' suffix, in hours
446 using `h' suffix, or in days using `d' suffix.
448 Specifying a large value for this option is useful if the network
449 or the destination host is down, so that Wget can wait long enough
450 to reasonably expect the network error to be fixed before the
453 `--waitretry=SECONDS'
454 If you don't want Wget to wait between *every* retrieval, but only
455 between retries of failed downloads, you can use this option.
456 Wget will use "linear backoff", waiting 1 second after the first
457 failure on a given file, then waiting 2 seconds after the second
458 failure on that file, up to the maximum number of SECONDS you
459 specify. Therefore, a value of 10 will actually make Wget wait up
460 to (1 + 2 + ... + 10) = 55 seconds per file.
462 Note that this option is turned on by default in the global
467 Turn proxy support on or off. The proxy is on by default if the
468 appropriate environmental variable is defined.
472 Specify download quota for automatic retrievals. The value can be
473 specified in bytes (default), kilobytes (with `k' suffix), or
474 megabytes (with `m' suffix).
476 Note that quota will never affect downloading a single file. So
477 if you specify `wget -Q10k ftp://wuarchive.wustl.edu/ls-lR.gz',
478 all of the `ls-lR.gz' will be downloaded. The same goes even when
479 several URLs are specified on the command-line. However, quota is
480 respected when retrieving either recursively, or from an input
481 file. Thus you may safely type `wget -Q2m -i sites'--download
482 will be aborted when the quota is exceeded.
484 Setting quota to 0 or to `inf' unlimits the download quota.
487 File: wget.info, Node: Directory Options, Next: HTTP Options, Prev: Download Options, Up: Invoking
494 Do not create a hierarchy of directories when retrieving
495 recursively. With this option turned on, all files will get saved
496 to the current directory, without clobbering (if a name shows up
497 more than once, the filenames will get extensions `.n').
500 `--force-directories'
501 The opposite of `-nd'--create a hierarchy of directories, even if
502 one would not have been created otherwise. E.g. `wget -x
503 http://fly.cc.fer.hr/robots.txt' will save the downloaded file to
504 `fly.cc.fer.hr/robots.txt'.
507 `--no-host-directories'
508 Disable generation of host-prefixed directories. By default,
509 invoking Wget with `-r http://fly.cc.fer.hr/' will create a
510 structure of directories beginning with `fly.cc.fer.hr/'. This
511 option disables such behavior.
514 Ignore NUMBER directory components. This is useful for getting a
515 fine-grained control over the directory where recursive retrieval
518 Take, for example, the directory at
519 `ftp://ftp.xemacs.org/pub/xemacs/'. If you retrieve it with `-r',
520 it will be saved locally under `ftp.xemacs.org/pub/xemacs/'.
521 While the `-nH' option can remove the `ftp.xemacs.org/' part, you
522 are still stuck with `pub/xemacs'. This is where `--cut-dirs'
523 comes in handy; it makes Wget not "see" NUMBER remote directory
524 components. Here are several examples of how `--cut-dirs' option
527 No options -> ftp.xemacs.org/pub/xemacs/
529 -nH --cut-dirs=1 -> xemacs/
530 -nH --cut-dirs=2 -> .
532 --cut-dirs=1 -> ftp.xemacs.org/xemacs/
535 If you just want to get rid of the directory structure, this
536 option is similar to a combination of `-nd' and `-P'. However,
537 unlike `-nd', `--cut-dirs' does not lose with subdirectories--for
538 instance, with `-nH --cut-dirs=1', a `beta/' subdirectory will be
539 placed to `xemacs/beta', as one would expect.
542 `--directory-prefix=PREFIX'
543 Set directory prefix to PREFIX. The "directory prefix" is the
544 directory where all other files and subdirectories will be saved
545 to, i.e. the top of the retrieval tree. The default is `.' (the
549 File: wget.info, Node: HTTP Options, Next: FTP Options, Prev: Directory Options, Up: Invoking
555 `--http-passwd=PASSWORD'
556 Specify the username USER and password PASSWORD on an HTTP server.
557 According to the type of the challenge, Wget will encode them
558 using either the `basic' (insecure) or the `digest' authentication
561 Another way to specify username and password is in the URL itself
562 (*Note URL Format::). For more information about security issues
563 with Wget, *Note Security Considerations::.
567 When set to off, disable server-side cache. In this case, Wget
568 will send the remote server an appropriate directive (`Pragma:
569 no-cache') to get the file from the remote service, rather than
570 returning the cached version. This is especially useful for
571 retrieving and flushing out-of-date documents on proxy servers.
573 Caching is allowed by default.
576 Unfortunately, some HTTP servers (CGI programs, to be more
577 precise) send out bogus `Content-Length' headers, which makes Wget
578 go wild, as it thinks not all the document was retrieved. You can
579 spot this syndrome if Wget retries getting the same document again
580 and again, each time claiming that the (otherwise normal)
581 connection has closed on the very same byte.
583 With this option, Wget will ignore the `Content-Length' header--as
586 `--header=ADDITIONAL-HEADER'
587 Define an ADDITIONAL-HEADER to be passed to the HTTP servers.
588 Headers must contain a `:' preceded by one or more non-blank
589 characters, and must not contain newlines.
591 You may define more than one additional header by specifying
592 `--header' more than once.
594 wget --header='Accept-Charset: iso-8859-2' \
595 --header='Accept-Language: hr' \
596 http://fly.cc.fer.hr/
598 Specification of an empty string as the header value will clear all
599 previous user-defined headers.
602 `--proxy-passwd=PASSWORD'
603 Specify the username USER and password PASSWORD for authentication
604 on a proxy server. Wget will encode them using the `basic'
605 authentication scheme.
609 Save the headers sent by the HTTP server to the file, preceding the
610 actual contents, with an empty line as the separator.
613 `--user-agent=AGENT-STRING'
614 Identify as AGENT-STRING to the HTTP server.
616 The HTTP protocol allows the clients to identify themselves using a
617 `User-Agent' header field. This enables distinguishing the WWW
618 software, usually for statistical purposes or for tracing of
619 protocol violations. Wget normally identifies as `Wget/VERSION',
620 VERSION being the current version number of Wget.
622 However, some sites have been known to impose the policy of
623 tailoring the output according to the `User-Agent'-supplied
624 information. While conceptually this is not such a bad idea, it
625 has been abused by servers denying information to clients other
626 than `Mozilla' or Microsoft `Internet Explorer'. This option
627 allows you to change the `User-Agent' line issued by Wget. Use of
628 this option is discouraged, unless you really know what you are
631 *NOTE* that Netscape Communications Corp. has claimed that false
632 transmissions of `Mozilla' as the `User-Agent' are a copyright
633 infringement, which will be prosecuted. *DO NOT* misrepresent
637 File: wget.info, Node: FTP Options, Next: Recursive Retrieval Options, Prev: HTTP Options, Up: Invoking
643 Retrieve symbolic links on FTP sites as if they were plain files,
644 i.e. don't just create links locally.
648 Turn FTP globbing on or off. Globbing means you may use the
649 shell-like special characters ("wildcards"), like `*', `?', `['
650 and `]' to retrieve more than one file from the same directory at
653 wget ftp://gnjilux.cc.fer.hr/*.msg
655 By default, globbing will be turned on if the URL contains a
656 globbing character. This option may be used to turn globbing on
659 You may have to quote the URL to protect it from being expanded by
660 your shell. Globbing makes Wget look for a directory listing,
661 which is system-specific. This is why it currently works only
662 with Unix FTP servers (and the ones emulating Unix `ls' output).
665 Use the "passive" FTP retrieval scheme, in which the client
666 initiates the data connection. This is sometimes required for FTP
667 to work behind firewalls.
670 File: wget.info, Node: Recursive Retrieval Options, Next: Recursive Accept/Reject Options, Prev: FTP Options, Up: Invoking
672 Recursive Retrieval Options
673 ===========================
677 Turn on recursive retrieving. *Note Recursive Retrieval:: for more
682 Specify recursion maximum depth level DEPTH (*Note Recursive
683 Retrieval::). The default maximum depth is 5.
686 This option tells Wget to delete every single file it downloads,
687 *after* having done so. It is useful for pre-fetching popular
688 pages through proxy, e.g.:
690 wget -r -nd --delete-after http://whatever.com/~popular/page/
692 The `-r' option is to retrieve recursively, and `-nd' not to
697 Convert the non-relative links to relative ones locally. Only the
698 references to the documents actually downloaded will be converted;
699 the rest will be left unchanged.
701 Note that only at the end of the download can Wget know which
702 links have been downloaded. Because of that, much of the work
703 done by `-k' will be performed at the end of the downloads.
707 When converting a file, back up the original version with a `.orig'
708 suffix. Affects the behavior of `-N' (*Note HTTP Time-Stamping
713 Turn on options suitable for mirroring. This option turns on
714 recursion and time-stamping, sets infinite recursion depth and
715 keeps FTP directory listings. It is currently equivalent to `-r
719 `--dont-remove-listing'
720 Don't remove the temporary `.listing' files generated by FTP
721 retrievals. Normally, these files contain the raw directory
722 listings received from FTP servers. Not removing them can be
723 useful to access the full remote file list when running a mirror,
724 or for debugging purposes.
727 File: wget.info, Node: Recursive Accept/Reject Options, Prev: Recursive Retrieval Options, Up: Invoking
729 Recursive Accept/Reject Options
730 ===============================
732 `-A ACCLIST --accept ACCLIST'
733 `-R REJLIST --reject REJLIST'
734 Specify comma-separated lists of file name suffixes or patterns to
735 accept or reject (*Note Types of Files:: for more details).
738 `--domains=DOMAIN-LIST'
739 Set domains to be accepted and DNS looked-up, where DOMAIN-LIST is
740 a comma-separated list. Note that it does *not* turn on `-H'.
741 This option speeds things up, even if only one host is spanned
742 (*Note Domain Acceptance::).
744 `--exclude-domains DOMAIN-LIST'
745 Exclude the domains given in a comma-separated DOMAIN-LIST from
746 DNS-lookup (*Note Domain Acceptance::).
749 Follow FTP links from HTML documents. Without this option, Wget
750 will ignore all the FTP links.
753 Wget has an internal table of HTML tag / attribute pairs that it
754 considers when looking for linked documents during a recursive
755 retrieval. If a user wants only a subset of those tags to be
756 considered, however, he or she should be specify such tags in a
757 comma-separated LIST with this option.
761 This is the opposite of the `--follow-tags' option. To skip
762 certain HTML tags when recursively looking for documents to
763 download, specify them in a comma-separated LIST. The author of
764 this option likes to use the following command to download a
765 single HTML page and all documents necessary to display it
768 wget -Ga,area -H -k -K -nh -r http://SITE/DOCUMENT
772 Enable spanning across hosts when doing recursive retrieving
777 Follow relative links only. Useful for retrieving a specific home
778 page without any distractions, not even those from the same hosts
779 (*Note Relative Links::).
782 `--include-directories=LIST'
783 Specify a comma-separated list of directories you wish to follow
784 when downloading (*Note Directory-Based Limits:: for more
785 details.) Elements of LIST may contain wildcards.
788 `--exclude-directories=LIST'
789 Specify a comma-separated list of directories you wish to exclude
790 from download (*Note Directory-Based Limits:: for more details.)
791 Elements of LIST may contain wildcards.
795 Disable the time-consuming DNS lookup of almost all hosts (*Note
801 Do not ever ascend to the parent directory when retrieving
802 recursively. This is a useful option, since it guarantees that
803 only the files *below* a certain hierarchy will be downloaded.
804 *Note Directory-Based Limits:: for more details.
807 File: wget.info, Node: Recursive Retrieval, Next: Following Links, Prev: Invoking, Up: Top
812 GNU Wget is capable of traversing parts of the Web (or a single HTTP
813 or FTP server), depth-first following links and directory structure.
814 This is called "recursive" retrieving, or "recursion".
816 With HTTP URLs, Wget retrieves and parses the HTML from the given
817 URL, documents, retrieving the files the HTML document was referring
818 to, through markups like `href', or `src'. If the freshly downloaded
819 file is also of type `text/html', it will be parsed and followed
822 The maximum "depth" to which the retrieval may descend is specified
823 with the `-l' option (the default maximum depth is five layers). *Note
824 Recursive Retrieval::.
826 When retrieving an FTP URL recursively, Wget will retrieve all the
827 data from the given directory tree (including the subdirectories up to
828 the specified depth) on the remote server, creating its mirror image
829 locally. FTP retrieval is also limited by the `depth' parameter.
831 By default, Wget will create a local directory tree, corresponding to
832 the one found on the remote server.
834 Recursive retrieving can find a number of applications, the most
835 important of which is mirroring. It is also useful for WWW
836 presentations, and any other opportunities where slow network
837 connections should be bypassed by storing the files locally.
839 You should be warned that invoking recursion may cause grave
840 overloading on your system, because of the fast exchange of data
841 through the network; all of this may hamper other users' work. The
842 same stands for the foreign server you are mirroring--the more requests
843 it gets in a rows, the greater is its load.
845 Careless retrieving can also fill your file system uncontrollably,
846 which can grind the machine to a halt.
848 The load can be minimized by lowering the maximum recursion level
849 (`-l') and/or by lowering the number of retries (`-t'). You may also
850 consider using the `-w' option to slow down your requests to the remote
851 servers, as well as the numerous options to narrow the number of
852 followed links (*Note Following Links::).
854 Recursive retrieval is a good thing when used properly. Please take
855 all precautions not to wreak havoc through carelessness.
858 File: wget.info, Node: Following Links, Next: Time-Stamping, Prev: Recursive Retrieval, Up: Top
863 When retrieving recursively, one does not wish to retrieve loads of
864 unnecessary data. Most of the time the users bear in mind exactly what
865 they want to download, and want Wget to follow only specific links.
867 For example, if you wish to download the music archive from
868 `fly.cc.fer.hr', you will not want to download all the home pages that
869 happen to be referenced by an obscure part of the archive.
871 Wget possesses several mechanisms that allows you to fine-tune which
872 links it will follow.
876 * Relative Links:: Follow relative links only.
877 * Host Checking:: Follow links on the same host.
878 * Domain Acceptance:: Check on a list of domains.
879 * All Hosts:: No host restrictions.
880 * Types of Files:: Getting only certain files.
881 * Directory-Based Limits:: Getting only certain directories.
882 * FTP Links:: Following FTP links.
885 File: wget.info, Node: Relative Links, Next: Host Checking, Prev: Following Links, Up: Following Links
890 When only relative links are followed (option `-L'), recursive
891 retrieving will never span hosts. No time-expensive DNS-lookups will
892 be performed, and the process will be very fast, with the minimum
893 strain of the network. This will suit your needs often, especially when
894 mirroring the output of various `x2html' converters, since they
895 generally output relative links.
898 File: wget.info, Node: Host Checking, Next: Domain Acceptance, Prev: Relative Links, Up: Following Links
903 The drawback of following the relative links solely is that humans
904 often tend to mix them with absolute links to the very same host, and
905 the very same page. In this mode (which is the default mode for
906 following links) all URLs that refer to the same host will be retrieved.
908 The problem with this option are the aliases of the hosts and
909 domains. Thus there is no way for Wget to know that `regoc.srce.hr' and
910 `www.srce.hr' are the same host, or that `fly.cc.fer.hr' is the same as
911 `fly.cc.etf.hr'. Whenever an absolute link is encountered, the host is
912 DNS-looked-up with `gethostbyname' to check whether we are maybe
913 dealing with the same hosts. Although the results of `gethostbyname'
914 are cached, it is still a great slowdown, e.g. when dealing with large
915 indices of home pages on different hosts (because each of the hosts
916 must be DNS-resolved to see whether it just *might* be an alias of the
919 To avoid the overhead you may use `-nh', which will turn off
920 DNS-resolving and make Wget compare hosts literally. This will make
921 things run much faster, but also much less reliable (e.g. `www.srce.hr'
922 and `regoc.srce.hr' will be flagged as different hosts).
924 Note that modern HTTP servers allow one IP address to host several
925 "virtual servers", each having its own directory hierarchy. Such
926 "servers" are distinguished by their hostnames (all of which point to
927 the same IP address); for this to work, a client must send a `Host'
928 header, which is what Wget does. However, in that case Wget *must not*
929 try to divine a host's "real" address, nor try to use the same hostname
930 for each access, i.e. `-nh' must be turned on.
932 In other words, the `-nh' option must be used to enable the
933 retrieval from virtual servers distinguished by their hostnames. As the
934 number of such server setups grow, the behavior of `-nh' may become the
935 default in the future.
938 File: wget.info, Node: Domain Acceptance, Next: All Hosts, Prev: Host Checking, Up: Following Links
943 With the `-D' option you may specify the domains that will be
944 followed. The hosts the domain of which is not in this list will not be
945 DNS-resolved. Thus you can specify `-Dmit.edu' just to make sure that
946 *nothing outside of MIT gets looked up*. This is very important and
947 useful. It also means that `-D' does *not* imply `-H' (span all
948 hosts), which must be specified explicitly. Feel free to use this
949 options since it will speed things up, with almost all the reliability
950 of checking for all hosts. Thus you could invoke
952 wget -r -D.hr http://fly.cc.fer.hr/
954 to make sure that only the hosts in `.hr' domain get DNS-looked-up
955 for being equal to `fly.cc.fer.hr'. So `fly.cc.etf.hr' will be checked
956 (only once!) and found equal, but `www.gnu.ai.mit.edu' will not even be
959 Of course, domain acceptance can be used to limit the retrieval to
960 particular domains with spanning of hosts in them, but then you must
961 specify `-H' explicitly. E.g.:
963 wget -r -H -Dmit.edu,stanford.edu http://www.mit.edu/
965 will start with `http://www.mit.edu/', following links across MIT
968 If there are domains you want to exclude specifically, you can do it
969 with `--exclude-domains', which accepts the same type of arguments of
970 `-D', but will *exclude* all the listed domains. For example, if you
971 want to download all the hosts from `foo.edu' domain, with the
972 exception of `sunsite.foo.edu', you can do it like this:
974 wget -rH -Dfoo.edu --exclude-domains sunsite.foo.edu http://www.foo.edu/
977 File: wget.info, Node: All Hosts, Next: Types of Files, Prev: Domain Acceptance, Up: Following Links
982 When `-H' is specified without `-D', all hosts are freely spanned.
983 There are no restrictions whatsoever as to what part of the net Wget
984 will go to fetch documents, other than maximum retrieval depth. If a
985 page references `www.yahoo.com', so be it. Such an option is rarely
989 File: wget.info, Node: Types of Files, Next: Directory-Based Limits, Prev: All Hosts, Up: Following Links
994 When downloading material from the web, you will often want to
995 restrict the retrieval to only certain file types. For example, if you
996 are interested in downloading GIFs, you will not be overjoyed to get
997 loads of PostScript documents, and vice versa.
999 Wget offers two options to deal with this problem. Each option
1000 description lists a short name, a long name, and the equivalent command
1006 The argument to `--accept' option is a list of file suffixes or
1007 patterns that Wget will download during recursive retrieval. A
1008 suffix is the ending part of a file, and consists of "normal"
1009 letters, e.g. `gif' or `.jpg'. A matching pattern contains
1010 shell-like wildcards, e.g. `books*' or `zelazny*196[0-9]*'.
1012 So, specifying `wget -A gif,jpg' will make Wget download only the
1013 files ending with `gif' or `jpg', i.e. GIFs and JPEGs. On the
1014 other hand, `wget -A "zelazny*196[0-9]*"' will download only files
1015 beginning with `zelazny' and containing numbers from 1960 to 1969
1016 anywhere within. Look up the manual of your shell for a
1017 description of how pattern matching works.
1019 Of course, any number of suffixes and patterns can be combined
1020 into a comma-separated list, and given as an argument to `-A'.
1025 The `--reject' option works the same way as `--accept', only its
1026 logic is the reverse; Wget will download all files *except* the
1027 ones matching the suffixes (or patterns) in the list.
1029 So, if you want to download a whole page except for the cumbersome
1030 MPEGs and .AU files, you can use `wget -R mpg,mpeg,au'.
1031 Analogously, to download all files except the ones beginning with
1032 `bjork', use `wget -R "bjork*"'. The quotes are to prevent
1033 expansion by the shell.
1035 The `-A' and `-R' options may be combined to achieve even better
1036 fine-tuning of which files to retrieve. E.g. `wget -A "*zelazny*" -R
1037 .ps' will download all the files having `zelazny' as a part of their
1038 name, but *not* the PostScript files.
1040 Note that these two options do not affect the downloading of HTML
1041 files; Wget must load all the HTMLs to know where to go at
1042 all--recursive retrieval would make no sense otherwise.
1045 File: wget.info, Node: Directory-Based Limits, Next: FTP Links, Prev: Types of Files, Up: Following Links
1047 Directory-Based Limits
1048 ======================
1050 Regardless of other link-following facilities, it is often useful to
1051 place the restriction of what files to retrieve based on the directories
1052 those files are placed in. There can be many reasons for this--the
1053 home pages may be organized in a reasonable directory structure; or some
1054 directories may contain useless information, e.g. `/cgi-bin' or `/dev'
1057 Wget offers three different options to deal with this requirement.
1058 Each option description lists a short name, a long name, and the
1059 equivalent command in `.wgetrc'.
1063 `include_directories = LIST'
1064 `-I' option accepts a comma-separated list of directories included
1065 in the retrieval. Any other directories will simply be ignored.
1066 The directories are absolute paths.
1068 So, if you wish to download from `http://host/people/bozo/'
1069 following only links to bozo's colleagues in the `/people'
1070 directory and the bogus scripts in `/cgi-bin', you can specify:
1072 wget -I /people,/cgi-bin http://host/people/bozo/
1076 `exclude_directories = LIST'
1077 `-X' option is exactly the reverse of `-I'--this is a list of
1078 directories *excluded* from the download. E.g. if you do not want
1079 Wget to download things from `/cgi-bin' directory, specify `-X
1080 /cgi-bin' on the command line.
1082 The same as with `-A'/`-R', these two options can be combined to
1083 get a better fine-tuning of downloading subdirectories. E.g. if
1084 you want to load all the files from `/pub' hierarchy except for
1085 `/pub/worthless', specify `-I/pub -X/pub/worthless'.
1090 The simplest, and often very useful way of limiting directories is
1091 disallowing retrieval of the links that refer to the hierarchy
1092 "above" than the beginning directory, i.e. disallowing ascent to
1093 the parent directory/directories.
1095 The `--no-parent' option (short `-np') is useful in this case.
1096 Using it guarantees that you will never leave the existing
1097 hierarchy. Supposing you issue Wget with:
1099 wget -r --no-parent http://somehost/~luzer/my-archive/
1101 You may rest assured that none of the references to
1102 `/~his-girls-homepage/' or `/~luzer/all-my-mpegs/' will be
1103 followed. Only the archive you are interested in will be
1104 downloaded. Essentially, `--no-parent' is similar to
1105 `-I/~luzer/my-archive', only it handles redirections in a more
1106 intelligent fashion.
1109 File: wget.info, Node: FTP Links, Prev: Directory-Based Limits, Up: Following Links
1114 The rules for FTP are somewhat specific, as it is necessary for them
1115 to be. FTP links in HTML documents are often included for purposes of
1116 reference, and it is often inconvenient to download them by default.
1118 To have FTP links followed from HTML documents, you need to specify
1119 the `--follow-ftp' option. Having done that, FTP links will span hosts
1120 regardless of `-H' setting. This is logical, as FTP links rarely point
1121 to the same host where the HTTP server resides. For similar reasons,
1122 the `-L' options has no effect on such downloads. On the other hand,
1123 domain acceptance (`-D') and suffix rules (`-A' and `-R') apply
1126 Also note that followed links to FTP directories will not be
1127 retrieved recursively further.
1130 File: wget.info, Node: Time-Stamping, Next: Startup File, Prev: Following Links, Up: Top
1135 One of the most important aspects of mirroring information from the
1136 Internet is updating your archives.
1138 Downloading the whole archive again and again, just to replace a few
1139 changed files is expensive, both in terms of wasted bandwidth and money,
1140 and the time to do the update. This is why all the mirroring tools
1141 offer the option of incremental updating.
1143 Such an updating mechanism means that the remote server is scanned in
1144 search of "new" files. Only those new files will be downloaded in the
1145 place of the old ones.
1147 A file is considered new if one of these two conditions are met:
1149 1. A file of that name does not already exist locally.
1151 2. A file of that name does exist, but the remote file was modified
1152 more recently than the local file.
1154 To implement this, the program needs to be aware of the time of last
1155 modification of both remote and local files. Such information are
1156 called the "time-stamps".
1158 The time-stamping in GNU Wget is turned on using `--timestamping'
1159 (`-N') option, or through `timestamping = on' directive in `.wgetrc'.
1160 With this option, for each file it intends to download, Wget will check
1161 whether a local file of the same name exists. If it does, and the
1162 remote file is older, Wget will not download it.
1164 If the local file does not exist, or the sizes of the files do not
1165 match, Wget will download the remote file no matter what the time-stamps
1170 * Time-Stamping Usage::
1171 * HTTP Time-Stamping Internals::
1172 * FTP Time-Stamping Internals::
1175 File: wget.info, Node: Time-Stamping Usage, Next: HTTP Time-Stamping Internals, Prev: Time-Stamping, Up: Time-Stamping
1180 The usage of time-stamping is simple. Say you would like to
1181 download a file so that it keeps its date of modification.
1183 wget -S http://www.gnu.ai.mit.edu/
1185 A simple `ls -l' shows that the time stamp on the local file equals
1186 the state of the `Last-Modified' header, as returned by the server. As
1187 you can see, the time-stamping info is preserved locally, even without
1190 Several days later, you would like Wget to check if the remote file
1191 has changed, and download it if it has.
1193 wget -N http://www.gnu.ai.mit.edu/
1195 Wget will ask the server for the last-modified date. If the local
1196 file is newer, the remote file will not be re-fetched. However, if the
1197 remote file is more recent, Wget will proceed fetching it normally.
1199 The same goes for FTP. For example:
1201 wget ftp://ftp.ifi.uio.no/pub/emacs/gnus/*
1203 `ls' will show that the timestamps are set according to the state on
1204 the remote server. Reissuing the command with `-N' will make Wget
1205 re-fetch *only* the files that have been modified.
1207 In both HTTP and FTP retrieval Wget will time-stamp the local file
1208 correctly (with or without `-N') if it gets the stamps, i.e. gets the
1209 directory listing for FTP or the `Last-Modified' header for HTTP.
1211 If you wished to mirror the GNU archive every week, you would use the
1212 following command every week:
1214 wget --timestamping -r ftp://prep.ai.mit.edu/pub/gnu/
1217 File: wget.info, Node: HTTP Time-Stamping Internals, Next: FTP Time-Stamping Internals, Prev: Time-Stamping Usage, Up: Time-Stamping
1219 HTTP Time-Stamping Internals
1220 ============================
1222 Time-stamping in HTTP is implemented by checking of the
1223 `Last-Modified' header. If you wish to retrieve the file `foo.html'
1224 through HTTP, Wget will check whether `foo.html' exists locally. If it
1225 doesn't, `foo.html' will be retrieved unconditionally.
1227 If the file does exist locally, Wget will first check its local
1228 time-stamp (similar to the way `ls -l' checks it), and then send a
1229 `HEAD' request to the remote server, demanding the information on the
1232 The `Last-Modified' header is examined to find which file was
1233 modified more recently (which makes it "newer"). If the remote file is
1234 newer, it will be downloaded; if it is older, Wget will give up.(1)
1236 When `--backup-converted' (`-K') is specified in conjunction with
1237 `-N', server file `X' is compared to local file `X.orig', if extant,
1238 rather than being compared to local file `X', which will always differ
1239 if it's been converted by `--convert-links' (`-k').
1241 Arguably, HTTP time-stamping should be implemented using the
1242 `If-Modified-Since' request.
1244 ---------- Footnotes ----------
1246 (1) As an additional check, Wget will look at the `Content-Length'
1247 header, and compare the sizes; if they are not the same, the remote
1248 file will be downloaded no matter what the time-stamp says.
1251 File: wget.info, Node: FTP Time-Stamping Internals, Prev: HTTP Time-Stamping Internals, Up: Time-Stamping
1253 FTP Time-Stamping Internals
1254 ===========================
1256 In theory, FTP time-stamping works much the same as HTTP, only FTP
1257 has no headers--time-stamps must be received from the directory
1260 For each directory files must be retrieved from, Wget will use the
1261 `LIST' command to get the listing. It will try to analyze the listing,
1262 assuming that it is a Unix `ls -l' listing, and extract the
1263 time-stamps. The rest is exactly the same as for HTTP.
1265 Assumption that every directory listing is a Unix-style listing may
1266 sound extremely constraining, but in practice it is not, as many
1267 non-Unix FTP servers use the Unixoid listing format because most (all?)
1268 of the clients understand it. Bear in mind that RFC959 defines no
1269 standard way to get a file list, let alone the time-stamps. We can
1270 only hope that a future standard will define this.
1272 Another non-standard solution includes the use of `MDTM' command
1273 that is supported by some FTP servers (including the popular
1274 `wu-ftpd'), which returns the exact time of the specified file. Wget
1275 may support this command in the future.