1 GNU Wget NEWS -- history of user-visible changes.
3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 2006, 2007, 2008 Free Software Foundation, Inc.
5 See the end for copying conditions.
7 Please send GNU Wget bug reports to <bug-wget@gnu.org>.
9 * Changes in Wget 1.12 (MAINLINE)
11 ** Added support for CSS. This includes:
12 - Parsing links from CSS files, and from CSS content found in HTML
13 style tags and attributes.
14 - Supporting conversion of links found within CSS content, when
15 --convert-links is specified.
16 - Ensuring that CSS files end in the ".css" filename extension,
17 when --convert-links is specified.
19 CSS support in Wget is thanks to Ted Mielczarek
20 <ted.mielczarek@gmail.com>.
22 ** --ask-password option (and associated wgetrc command) added to
23 support password prompts at the console.
25 * Changes in Wget 1.11.4
27 ** Fixed an issue (apparently a regression) where -O would refuse to
28 download when -nc was given, even though the file didn't exist.
30 ** Fixed a situation where Wget could abort with --continue if the
31 remote server gives a content-length of zero when the file exists
34 ** Fixed a crash on some systems, due to Wget casting a pointer-to-long
35 to a pointer-to-time_t.
37 ** Translation updates for Catalan.
39 * Changes in Wget 1.11.3
41 ** Downgraded -N with -O to a warning, rather than an error.
43 ** Translation updates
45 * Changes in Wget 1.11.2
47 ** Fixed a problem in authenticating over HTTPS through a proxy.
48 (Regression in 1.11 over 1.10.2.)
50 ** The combination of -r or -p with -O, which was disallowed in 1.11,
51 has been downgraded to a warning in 1.11.2. (-O and -N, which was never
52 meaningful, is still an error.)
54 ** Further improvements to progress bar displays in non-English locales
55 (too many spaces could be inserted, causing the display to scroll).
57 ** Successive invocations of Wget on FTP URLS, with --no-remove-listing
58 and --continue, was causing Wget to append, rather than replace,
59 information in the .listing file, and thereby download the same files
60 multiple times. This has been fixed in 1.11.2.
62 ** Wget 1.11 no longer allowed ".." to persist at the beginning of URLs,
63 for improved conformance with RFC 3986. However, this behavior presents
64 problems for some FTP setups, and so they are now preserved again, for
67 * Changes in Wget 1.11.1.
69 ** Interrupted downloads no longer result in renaming the file
70 (regression in 1.11 over 1.10.2).
72 ** Progress bar now displays correctly in non-English locales (and a
73 related assertion failure was fixed).
75 ** Wget no longer issues a GET request over HTTP for files it should
76 know it's not going to download (regression in 1.11 over 1.10.2).
78 ** Added option --auth-no-challenge, to support broken pre-1.11
79 authentication-before-server-challenge, which turns out to still be
80 useful for some limited cases.
82 ** Documentation of accept/reject lists in the manual's "Types of
83 Files" section now explains various aspects of their behavior that may
84 be surprising, and notes that they may change in the future.
86 ** Documentation of --no-parents now explains how a trailing slash, or
87 lack thereof, in the specified URL, will affect behavior.
89 * Changes in Wget 1.11.
91 ** Timestamping now uses the value from the most recent HTTP response,
92 rather than the first one it got.
94 ** Authentication information is no longer sent as part of the Referer
95 header in recursive fetches.
97 ** No authentication credentials are sent until a challenge is issued,
98 for improved security. Authentication handling is still not
99 RFC-compliant, as once a Basic challenge has been received, it will
100 assume it can send credentials to any URL at that same host, and not
101 just the ones at or below the original authenticated location.
102 Credentials for Digest authentication are still never saved or issued
103 automatically, and continue to require a challenge for each resource.
105 ** Added --max-redirect option, allowing the user to specify what should
106 be the maximum number of HTTP redirects to follow.
108 ** Wget now supports saving HTTP downloads using file names specified by
109 the `Content-Disposition' header. This is a standard way of specifying
110 the file name used by many web dynamically generated pages. However, the
111 current implementation is inefficient, and known to have bugs. It is
112 EXPERIMENTAL only, and not enabled by default. Use --content-disposition
115 ** The new option `--ignore-case' makes Wget ignore case when
116 matching files, directories, and wildcards. This affects the -X, -I,
117 -A, and -R options, as well as globbing in FTP URLs.
119 ** ETA projection is now displayed in "dot" progress output as well as
120 in the default progress bar. (The dot progress is used by default when
121 logging Wget's output to file using the `-o' option.)
123 ** The "lockable boolean" argument type is no longer supported. It
124 was only used by the passive_ftp .wgetrc setting. If you're running
125 broken scripts or Perl modules that unconditionally specify
126 `--passive-ftp' and your firewall disallows it, you can override them
127 by replacing wget with a script that execs wget "$@" --no-passive-ftp.
129 ** The source code has been migrated to Mercurial. The repositories are
130 available at http://hg.addictivecode.org/. Prior to this, the source
131 code was hosted on Subversion (migrated from the original CVS); you can
132 still get access to older tags and branches for Wget in the Subversion
133 repository at http://addictivecode.org/svn/wget/.
135 * Changes in Wget 1.10.
137 ** Downloading files larger than 2GB, sometimes referred to as "large
138 files", now works on systems that support them. This includes the
139 majority of modern Unixes, as well as MS Windows.
141 ** IPv6 is now supported by Wget. Unlike the experimental code in
142 1.9, this version supports dual-family systems. The new flags
143 `--inet4' and `--inet6' (or `-4' and `-6' for short) force the use of
144 IPv4 and IPv6 respectively. Note that IPv6 support has not yet been
147 ** Microsoft's proprietary "NTLM" method of HTTP authentication is now
148 supported. This authentication method is undocumented and only used
149 by IIS. Note that *proxy* authentication is not supported in this
150 release; you can only authenticate to the target web site.
152 ** Wget no longer truncates partially downloaded files when download
153 has to start over because the server doesn't support Range. Instead,
154 with such servers Wget now simply ignores the data up to the byte
155 where the last attempt left off, and only then continues appending to
156 the file. That way the downloaded file never shrinks, and download
157 retries from servers without support for partial downloads work even
158 when downloading to stdout.
162 *** SSL/TLS downloads now attempt to verify the server's certificate
163 against the recognized certificate authorities. This requires CA
164 certificates to have been installed in a location visible to the
165 OpenSSL library. If this is not the case, you can get the bundle
166 yourself from a source you trust (for example, the bundle extracted
167 from Mozilla available at http://curl.haxx.se/docs/caextract.html),
168 and point Wget to the PEM file using the `--ca-certificate'
169 command-line option or the corresponding `.wgetrc' command.
171 *** Secure downloads now verify that the host name in the URL matches
172 the "common name" in the certificate presented by the server.
174 *** Although the above checks provide more secure downloads, they
175 unavoidably break interoperability with some sites that worked with
176 previous versions, particularly those using self-signed, expired, or
177 otherwise invalid certificates. If you encounter "certificate
178 verification" errors or complaints that "common name doesn't match
179 requested host name" and are convinced of the site's authenticity, you
180 can use `--no-check-certificate' to bypass both checks.
182 *** Talking to SSL/TLS servers over proxies now actually works.
183 Previous versions of Wget erroneously sent GET requests for https
184 URLs. Wget 1.10 utilizes the CONNECT method designed for this
187 *** The SSL/TLS-related options have been redesigned and, for the
188 first time, documented in the manual. The old, undocumented, options
189 are no longer supported.
191 ** Passive FTP is now the default FTP transfer mode. Use
192 `--no-passive-ftp' or specify `passive_ftp = off' in your init file to
193 revert to the old behavior.
195 ** The `--header' option can now be used to override generated
196 headers. For example, `wget --header="Host: foo.bar"
197 http://127.0.0.1' tells Wget to connect to localhost, but to specify
198 "foo.bar" in the `Host' header. In previous versions such use of
199 `--header' lead to duplicate headers in HTTP requests.
201 ** The responses without headers, aka "HTTP 0.9" responses, are
202 detected and handled. Although HTTP 0.9 has long been obsolete, it is
203 still occasionally used, sometimes by accident.
205 ** The progress bar is now updated regularly even when the data does
206 not arrive from the network.
208 ** Wget no longer preserves permissions of files retrieved by FTP by
209 default. Anonymous FTP servers frequently use permissions like "664",
210 which might not be what the user wants. The new option
211 `--preserve-permissions' and the corresponding `.wgetrc' variable can
212 be used to revert to the old behavior.
214 ** The new option `--protocol-directories' instructs Wget to also use
215 the protocol name as a directory component of local file names.
217 ** Options that previously unconditionally set or unset various flags
218 are now boolean options that can be invoked as either `--OPTION' or
219 `--no-OPTION'. Options that required an argument "on" or "off" have
220 also been changed this way, but they still accept the old syntax for
221 backward compatibility. For example, instead of `--glob=off' you can
224 Allowing `--no-OPTION' for every `--OPTION' and the other way around
225 is useful because it allows the user to override non-default behavior
226 specified via `.wgetrc'.
228 ** The new option `--keep-session-cookies' causes `--save-cookies' to
229 save session cookies (normally only kept in memory) along with the
230 permanent ones. This is useful because many sites track important
231 information, such as whether the user has authenticated, in session
232 cookies. With this option multiple Wget runs are treated as a single
235 ** Wget now supports the --ftp-user and --ftp-password command
236 switches to set username and password for FTP, and the --user and
237 --password command switches to set username and password for both FTP
238 and HTTP. The --http-passwd and --proxy-passwd command switches have
239 been renamed to --http-password and --proxy-password respectively, and
240 the related http_passwd and proxy_passwd .wgetrc commands to
241 http_password and proxy_password respectively. The login and passwd
242 .wgetrc commands have been deprecated.
244 * `wget -b' now works correctly under Windows.
246 * Wget 1.9.1 is a bugfix release with no user-visible changes.
248 * Changes in Wget 1.9.
250 ** It is now possible to specify that POST method be used for HTTP
251 requests. For example, `wget --post-data="id=foo&data=bar" URL' will
252 send a POST request with the specified contents.
254 ** IPv6 support is available, although it's still experimental.
256 ** The `--timeout' option now also affects DNS lookup and establishing
257 the TCP connection. Previously it only affected reading and writing
258 data. Those three timeouts can be set separately using
259 `--dns-timeout', `--connection-timeout', and `--read-timeout',
262 ** Download speed shown by the progress bar is based on the data
263 recently read, rather than the average speed of the entire download.
264 The ETA projection is still based on the overall average.
266 ** It is now possible to connect to FTP servers through FWTK
267 firewalls. Set ftp_proxy to an FTP URL, and Wget will automatically
268 log on to the proxy as "username@host".
270 ** The new option `--retry-connrefused' makes Wget retry downloads
271 even in the face of refused connections, which are otherwise
272 considered a fatal error.
274 ** The new option `--no-dns-cache' may be used to prevent Wget from
277 ** Wget no longer escapes characters in local file names based on
278 whether they're appropriate in URLs. Escaping can still occur for
279 nonprintable characters or for '/', but no longer for frequent
280 characters such as space. You can use the new option
281 --restrict-file-names to relax or strengthen these rules, which can be
282 useful if you dislike the default or if you're downloading to
283 non-native partitions.
285 ** Handling of HTML comments has been dumbed down to conform to what
286 users expect and other browsers do: instead of being treated as SGML
287 declaration, a comment is terminated at the first occurrence of "-->".
288 Use `--strict-comments' to revert to the old behavior.
290 ** Wget now correctly handles relative URIs that begin with "//", such
291 as "//img.foo.com/foo.jpg".
293 ** Boolean options in `.wgetrc' and on the command line now accept
294 values "yes" and "no" along with the traditional "on" and "off".
296 ** It is now possible to specify decimal values for timeouts, waiting
297 periods, and download rate. For instance, `--wait=0.5' now works as
298 expected, as does `--dns-timeout=0.5' and even `--limit-rate=2.5k'.
300 * Wget 1.8.2 is a bugfix release with no user-visible changes.
302 * Wget 1.8.1 is a bugfix release with no user-visible changes.
304 * Changes in Wget 1.8.
306 ** A new progress indicator is now available and used by default.
307 You can choose the progress bar type with `--progress=TYPE'. Two
308 types are available, "bar" (the new default), and "dot" (the old
309 dotted indicator). You can permanently revert to the old progress
310 indicator by putting `progress = dot' in your `.wgetrc'.
312 ** You can limit the download rate of the retrieval using the
313 `--limit-rate' option. For example, `wget --limit-rate=15k URL' will
314 tell Wget not to download the body of the URL faster than 15 kilobytes
317 ** Recursive retrieval and link conversion have been revamped:
319 *** Wget now traverses links breadth-first. This makes the
320 calculation of depth much more reliable than before. Also, recursive
321 downloads are faster and consume *significantly* less memory than
324 *** Links are converted only when the entire retrieval is complete.
325 This is the only safe thing to do, as only then is it known what URLs
326 have been downloaded.
328 *** BASE tags are handled correctly when converting links. Since Wget
329 already resolves <base href="..."> when resolving handling URLs, link
330 conversion now makes the BASE tags point to an empty string.
332 *** HTML anchors are now handled correctly. Links to an anchor in the
333 same document (<a href="#anchorname">), which used to confuse Wget,
334 are now converted correctly.
336 *** When in page-requisites (-p) mode, no-parent (-np) is ignored when
337 retrieving for inline images, stylesheets, and other documents needed
340 *** Page-requisites (-p) mode now works with frames. In other words,
341 `wget -p URL-THAT-USES-FRAMES' will now download the frame HTML files,
342 and all the files that they need to be displayed properly.
344 ** `--base' now works conjunction with `--input-file', providing a
345 base for each URL and thereby allowing the URLs in the file to be
348 ** If a host has more than one IP address, Wget uses the other
349 addresses when accessing the first one fails.
351 ** Host directories now contain port information if the URL is at a
354 ** Wget now supports the robots.txt directives specified in
355 <http://www.robotstxt.org/wc/norobots-rfc.txt>.
357 ** URL parser has been fixed, especially the infamous overzealous
358 quoting. Wget no longer dequotes reserved characters, e.g. `%3F' is
359 no longer translated to `?', nor `%2B' to `+'. Unsafe characters
360 which are not reserved are still escaped, of course.
362 ** No more than 20 successive redirections are allowed.
364 * Wget 1.7.1 is a bugfix release with no user-visible changes.
366 * Changes in Wget 1.7.
368 ** SSL (`https') pages now work if you compile Wget with SSL support;
369 use the `--with-ssl' configure flag. You need to have OpenSSL
372 ** Cookies are now supported. Wget will accept cookies sent by the
373 server and return them in later requests. Additionally, it can load
374 and save cookies to disk, in the same format that Netscape uses.
376 ** "Keep-alive" (persistent) HTTP connections are now supported.
377 Using keep-alive allows Wget to share one TCP/IP connection for
378 many retrievals, making multiple-file downloads faster and less
379 stressing for the server and the network.
381 ** Wget now recognizes FTP directory listings generated by NT and VMS
384 ** It is now possible to recurse through FTP sites where logging in
385 puts you in some directory other than '/'.
387 ** You may now use `~' to mean home directory in `.wgetrc'. For
388 example, `load_cookies = ~/.netscape/cookies.txt' works as you would
391 ** The HTML parser has been rewritten. The new one works more
392 reliably, allows finer-grained control over which tags and attributes
393 are detected, and has better support for some features like correctly
394 skipping comments and declarations, decoding entities, etc. It is
397 ** <meta name="robots"> tags are now respected.
399 ** Wget's internal tables now use hash tables instead of linked lists
400 where appropriate. This results in huge speedups when retrieving
401 large sites (thousands of documents).
403 ** Wget now has a man page, automatically generated from the Texinfo
404 documentation. (The last version that shipped with a man page was
405 1.4.5). To get this, you need to have pod2man from the Perl
406 distribution installed on your system.
408 * Changes in Wget 1.6
410 ** Administrative changes.
412 *** Maintainership. Due to Hrvoje being plagued with a "real job",
413 Dan Harkless is the most active maintainer (not that he doesn't have a
414 real job as well). Hrvoje still participates occasionally, and both
415 are being helped by many other people.
417 *** Web page. Thanks to Jan Prikryl, Wget has an "official" web page.
420 http://sunsite.dk/wget/
422 *** Anonymous CVS. Thanks to ever-helpful Karsten Thygesen, Wget
423 sources are now available at an anonymous CVS server. Take a look at
424 the web page for downloading instructions.
426 ** New -K / --backup-converted / backup_converted = on option causes files
427 modified due to -k to be saved with a .orig prefix before being changed. When
428 using -N as well, it is these .orig files that are compared against the server.
430 ** New --follow-tags / follow_tags = ... option allows you to restrict
431 Wget to following only certain HTML tags when doing a recursive
432 retrieval. -G / --ignore-tags / ignore_tags = ... is just the
433 opposite -- all tags but the ones you specify will be followed.
435 ** New --waitretry / waitretry = SECONDS option allows waiting between retries
436 of failed downloads. Wget will use "linear" backoff, waiting 1 second after the
437 first failure, 2 after the second, up to SECONDS. waitretry is set to 10 by
438 default in the system wgetrc.
440 ** New -p / --page-requisites / page_requisites = on option causes
441 Wget to download all ancillary files necessary to display a given HTML
442 page properly (e.g. inlined images).
444 ** New -E / --html-extension / html_extension = on option causes Wget
445 to append ".html" to text/html filenames not ending in regexp
446 "\.[Hh][Tt][Mm][Ll]?".
448 ** New type of .wgetrc command -- "lockable Boolean". Can be set to on, off,
449 always, or never. This allows the .wgetrc to override the commandline. So far,
450 passive_ftp is the only .wgetrc command which takes a lockable Boolean.
452 ** A number of new translation files have been added.
454 ** New --bind-address / bind_address = <address> option for people on hosts
455 bound to multiple IP addresses.
457 ** wget now accepts (illegal per HTTP spec) relative URLs in HTTP redirects.
459 * Wget 1.5.3 is a bugfix release with no user-visible changes.
461 * Wget 1.5.2 is a bugfix release with no user-visible changes.
463 * Wget 1.5.1 is a bugfix release with no user-visible changes.
465 * Changes in Wget 1.5.0
467 ** Wget speaks many languages!
469 On systems with gettext(), Wget will output messages in the language
470 set by the current locale, if available. At this time we support
471 Czech, German, Croatian, Italian, Norwegian and Portuguese.
473 ** Opie (Skey) is now supported with FTP.
475 ** HTTP Digest Access Authentication (RFC2069) is now supported.
477 ** The new `-b' option makes Wget go to background automatically.
479 ** The `-I' and `-X' options now accept wildcard arguments.
481 ** The `-w' option now accepts suffixes `s' for seconds, `m' for
482 minutes, `h' for hours, `d' for days and `w' for weeks.
484 ** Upon getting SIGHUP, the whole previous log is now copied to
487 ** Wget now understands proxy settings with explicit usernames and
488 passwords, e.g. `http://user:password@proxy.foo.com/'.
490 ** You can use the new `--cut-dirs' option to make Wget create less
493 ** The `;type=a' appendix to FTP URLs is now recognized. For
494 instance, the following command will retrieve the welcoming message in
497 wget "ftp://ftp.somewhere.com/welcome.msg;type=a"
499 ** `--help' and `--version' options have been redone to to conform to
500 standards set by other GNU utilities.
502 ** Wget should now be compilable under MS Windows environment. MS
503 Visual C++ and Watcom C have been used successfully.
505 ** If the file length is known, percentages are displayed during
508 ** The manual page, now hopelessly out of date, is no longer
509 distributed with Wget.
511 * Wget 1.4.5 is a bugfix release with no user-visible changes.
513 * Wget 1.4.4 is a bugfix release with no user-visible changes.
515 * Changes in Wget 1.4.3
517 ** Wget is now a GNU utility.
519 ** Can do passive FTP.
523 ** Info documentation expanded.
525 ** Compiles on pre-ANSI compilers.
527 ** Global wgetrc now goes to /usr/local/etc (i.e. $sysconfdir).
531 * Changes in Wget 1.4.2
533 ** New mirror site at ftp://sunsite.auc.dk/pub/infosystems/wget/,
534 thanks to Karsten Thygesen.
536 ** Mailing list! Mail to wget-request@sunsite.auc.dk to subscribe.
538 ** New option --delete-after for proxy prefetching.
540 ** New option --retr-symlinks to retrieve symbolic links like plain
543 ** rmold.pl -- script to remove files deleted on the remote server
545 ** --convert-links should work now.
549 * Changes in Wget 1.4.1
553 ** Added -I (the opposite of -X).
555 ** Dot tracing is now customizable; try wget --dot-style=binary
557 * Changes in Wget 1.4.0
559 ** Wget 1.4.0 [formerly known as Geturl] is an extensive rewrite of
560 Geturl. Although many things look suspiciously similar, most of the
561 stuff was rewritten, like recursive retrieval, HTTP, FTP and mostly
562 everything else. Wget should be now easier to debug, maintain and,
563 most importantly, use.
565 ** Recursive HTTP should now work without glitches, even with Location
566 changes, server-generated directory listings and other naughty stuff.
568 ** HTTP regetting is supported on servers that support Range
569 specification. WWW authorization is supported -- try
570 wget http://user:password@hostname/
572 ** FTP support was rewritten and widely enhanced. Globbing should now
573 work flawlessly. Symbolic links are created locally. All the
574 information the Unix-style ls listing can give is now recognized.
576 ** Recursive FTP is supported, e.g.
577 wget -r ftp://gnjilux.cc.fer.hr/pub/unix/util/
579 ** You can specify "rejected" directories, to which you do not want to
580 enter, e.g. with wget -X /pub
582 ** Time-stamping is supported, with both HTTP and FTP. Try wget -N URL.
584 ** A new texinfo reference manual is provided. It can be read with
585 Emacs, standalone info, or converted to HTML, dvi or postscript.
587 ** Fixed a long-standing bug, so that Wget now works over SLIP
590 ** You can have a system-wide wgetrc (/usr/local/lib/wgetrc by
591 default). Settings in $HOME/.wgetrc override the global ones, of
594 ** You can set up quota in .wgetrc to prevent sucking too much
595 data. Try `quota = 5M' in .wgetrc (or quota = 100K if you want your
596 sysadmin to like you).
598 ** Download rate is printed after retrieval.
600 ** Wget now sends the `Referer' header when retrieving
603 ** With the new --no-parent option Wget can retrieve FTP recursively
604 through a proxy server.
606 ** HTML parser, as well as the whole of Wget was rewritten to be much
607 faster and less memory-consuming (yes, both).
609 ** Absolute links can be converted to relative links locally. Check
612 ** Wget catches hangup, filtering the output to a log file and
613 resuming work. Try kill -HUP %?wget.
615 ** User-defined headers can be sent. Try
617 wget http://fly.cc.her.hr/ --header='Accept-Charset: iso-8859-2'
619 ** Acceptance/Rejection lists may contain wildcards.
621 ** Wget can display HTTP headers and/or FTP server response with the
622 new `-S' option. It can save the original HTTP headers with `-s'.
624 ** socks library is now supported (thanks to Antonio Rosella
625 <Antonio.Rosella@agip.it>). Configure with --with-socks.
627 ** There is a nicer display of REST-ed output.
629 ** Many new options (like -x to force directory hierarchy, or -m to
630 turn on mirroring options).
632 ** Wget is now distributed under GNU General Public License (GPL).
634 ** Lots of small features I can't remember. :-)
636 ** A host of bugfixes.
638 * Changes in Geturl 1.3
640 ** Added FTP globbing support (ftp://fly.cc.fer.hr/*)
642 ** Added support for no_proxy
644 ** Added support for ftp://user:password@host/
646 ** Added support for %xx in URL syntax
648 ** More natural command-line options
650 ** Added -e switch to execute .geturlrc commands from the command-line
652 ** Added support for robots.txt
654 ** Fixed some minor bugs
656 * Geturl 1.2 is a bugfix release with no user-visible changes.
658 * Changes in Geturl 1.1
660 ** REST supported in FTP
662 ** Proxy servers supported
664 ** GNU getopt used, which enables command-line arguments to be ordered
665 as you wish, e.g. geturl http://fly.cc.fer.hr/ -vo log is the same as
666 geturl -vo log http://fly.cc.fer.hr/
668 ** Netscape-compatible URL syntax for HTTP supported: host[:port]/dir/file
670 ** NcFTP-compatible colon URL syntax for FTP supported: host:/dir/file
672 ** <base href="xxx"> supported
674 ** autoconf supported
676 ----------------------------------------------------------------------
677 Copyright information:
679 Copyright (C) 1997-2005 Free Software Foundation, Inc.
681 Permission is granted to anyone to make or distribute verbatim
682 copies of this document as received, in any medium, provided that
683 the copyright notice and this permission notice are preserved, thus
684 giving the recipient permission to redistribute in turn.
686 Permission is granted to distribute modified versions of this
687 document, or of portions of it, under the above conditions,
688 provided also that they carry prominent notices stating who last