This is Info file wget.info, produced by Makeinfo version 1.68 from the input file ./wget.texi. INFO-DIR-SECTION Net Utilities INFO-DIR-SECTION World Wide Web START-INFO-DIR-ENTRY * Wget: (wget). The non-interactive network downloader. END-INFO-DIR-ENTRY This file documents the the GNU Wget utility for downloading network data. Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the sections entitled "Copying" and "GNU General Public License" are included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.  File: wget.info, Node: Startup File, Next: Examples, Prev: Time-Stamping, Up: Top Startup File ************ Once you know how to change default settings of Wget through command line arguments, you may wish to make some of those settings permanent. You can do that in a convenient way by creating the Wget startup file--`.wgetrc'. Besides `.wgetrc' is the "main" initialization file, it is convenient to have a special facility for storing passwords. Thus Wget reads and interprets the contents of `$HOME/.netrc', if it finds it. You can find `.netrc' format in your system manuals. Wget reads `.wgetrc' upon startup, recognizing a limited set of commands. * Menu: * Wgetrc Location:: Location of various wgetrc files. * Wgetrc Syntax:: Syntax of wgetrc. * Wgetrc Commands:: List of available commands. * Sample Wgetrc:: A wgetrc example.  File: wget.info, Node: Wgetrc Location, Next: Wgetrc Syntax, Prev: Startup File, Up: Startup File Wgetrc Location =============== When initializing, Wget will look for a "global" startup file, `/usr/local/etc/wgetrc' by default (or some prefix other than `/usr/local', if Wget was not installed there) and read commands from there, if it exists. Then it will look for the user's file. If the environmental variable `WGETRC' is set, Wget will try to load that file. Failing that, no further attempts will be made. If `WGETRC' is not set, Wget will try to load `$HOME/.wgetrc'. The fact that user's settings are loaded after the system-wide ones means that in case of collision user's wgetrc *overrides* the system-wide wgetrc (in `/usr/local/etc/wgetrc' by default). Fascist admins, away!  File: wget.info, Node: Wgetrc Syntax, Next: Wgetrc Commands, Prev: Wgetrc Location, Up: Startup File Wgetrc Syntax ============= The syntax of a wgetrc command is simple: variable = value The "variable" will also be called "command". Valid "values" are different for different commands. The commands are case-insensitive and underscore-insensitive. Thus `DIr__PrefiX' is the same as `dirprefix'. Empty lines, lines beginning with `#' and lines containing white-space only are discarded. Commands that expect a comma-separated list will clear the list on an empty command. So, if you wish to reset the rejection list specified in global `wgetrc', you can do it with: reject =  File: wget.info, Node: Wgetrc Commands, Next: Sample Wgetrc, Prev: Wgetrc Syntax, Up: Startup File Wgetrc Commands =============== The complete set of commands is listed below, the letter after `=' denoting the value the command takes. It is `on/off' for `on' or `off' (which can also be `1' or `0'), STRING for any non-empty string or N for a positive integer. For example, you may specify `use_proxy = off' to disable use of proxy servers by default. You may use `inf' for infinite values, where appropriate. Most of the commands have their equivalent command-line option (*Note Invoking::), except some more obscure or rarely used ones. accept/reject = STRING Same as `-A'/`-R' (*Note Types of Files::). add_hostdir = on/off Enable/disable host-prefixed file names. `-nH' disables it. continue = on/off Enable/disable continuation of the retrieval, the same as `-c' (which enables it). background = on/off Enable/disable going to background, the same as `-b' (which enables it). backup_converted = on/off Enable/disable saving pre-converted files with the suffix `.orig' - the same as `-K' (which enables it). base = STRING Set base for relative URLs, the same as `-B'. cache = on/off When set to off, disallow server-caching. See the `-C' option. convert links = on/off Convert non-relative links locally. The same as `-k'. cut_dirs = N Ignore N remote directory components. debug = on/off Debug mode, same as `-d'. delete_after = on/off Delete after download, the same as `--delete-after'. dir_prefix = STRING Top of directory tree, the same as `-P'. dirstruct = on/off Turning dirstruct on or off, the same as `-x' or `-nd', respectively. domains = STRING Same as `-D' (*Note Domain Acceptance::). dot_bytes = N Specify the number of bytes "contained" in a dot, as seen throughout the retrieval (1024 by default). You can postfix the value with `k' or `m', representing kilobytes and megabytes, respectively. With dot settings you can tailor the dot retrieval to suit your needs, or you can use the predefined "styles" (*Note Download Options::). dots_in_line = N Specify the number of dots that will be printed in each line throughout the retrieval (50 by default). dot_spacing = N Specify the number of dots in a single cluster (10 by default). dot_style = STRING Specify the dot retrieval "style", as with `--dot-style'. exclude_directories = STRING Specify a comma-separated list of directories you wish to exclude from download, the same as `-X' (*Note Directory-Based Limits::). exclude_domains = STRING Same as `--exclude-domains' (*Note Domain Acceptance::). follow_ftp = on/off Follow FTP links from HTML documents, the same as `-f'. follow_tags = STRING Only follow certain HTML tags when doing a recursive retrieval, just like `--follow-tags'. force_html = on/off If set to on, force the input filename to be regarded as an HTML document, the same as `-F'. ftp_proxy = STRING Use STRING as FTP proxy, instead of the one specified in environment. glob = on/off Turn globbing on/off, the same as `-g'. header = STRING Define an additional header, like `--header'. http_passwd = STRING Set HTTP password. http_proxy = STRING Use STRING as HTTP proxy, instead of the one specified in environment. http_user = STRING Set HTTP user to STRING. ignore_length = on/off When set to on, ignore `Content-Length' header; the same as `--ignore-length'. ignore_tags = STRING Ignore certain HTML tags when doing a recursive retrieval, just like `-G' / `--ignore-tags'. include_directories = STRING Specify a comma-separated list of directories you wish to follow when downloading, the same as `-I'. input = STRING Read the URLs from STRING, like `-i'. kill_longer = on/off Consider data longer than specified in content-length header as invalid (and retry getting it). The default behaviour is to save as much data as there is, provided there is more than or equal to the value in `Content-Length'. logfile = STRING Set logfile, the same as `-o'. login = STRING Your user name on the remote machine, for FTP. Defaults to `anonymous'. mirror = on/off Turn mirroring on/off. The same as `-m'. netrc = on/off Turn reading netrc on or off. noclobber = on/off Same as `-nc'. no_parent = on/off Disallow retrieving outside the directory hierarchy, like `--no-parent' (*Note Directory-Based Limits::). no_proxy = STRING Use STRING as the comma-separated list of domains to avoid in proxy loading, instead of the one specified in environment. output_document = STRING Set the output filename, the same as `-O'. passive_ftp = on/off Set passive FTP, the same as `--passive-ftp'. passwd = STRING Set your FTP password to PASSWORD. Without this setting, the password defaults to `username@hostname.domainname'. proxy_user = STRING Set proxy authentication user name to STRING, like `--proxy-user'. proxy_passwd = STRING Set proxy authentication password to STRING, like `--proxy-passwd'. quiet = on/off Quiet mode, the same as `-q'. quota = QUOTA Specify the download quota, which is useful to put in global wgetrc. When download quota is specified, Wget will stop retrieving after the download sum has become greater than quota. The quota can be specified in bytes (default), kbytes `k' appended) or mbytes (`m' appended). Thus `quota = 5m' will set the quota to 5 mbytes. Note that the user's startup file overrides system settings. reclevel = N Recursion level, the same as `-l'. recursive = on/off Recursive on/off, the same as `-r'. relative_only = on/off Follow only relative links, the same as `-L' (*Note Relative Links::). remove_listing = on/off If set to on, remove FTP listings downloaded by Wget. Setting it to off is the same as `-nr'. retr_symlinks = on/off When set to on, retrieve symbolic links as if they were plain files; the same as `--retr-symlinks'. robots = on/off Use (or not) `/robots.txt' file (*Note Robots::). Be sure to know what you are doing before changing the default (which is `on'). server_response = on/off Choose whether or not to print the HTTP and FTP server responses, the same as `-S'. simple_host_check = on/off Same as `-nh' (*Note Host Checking::). span_hosts = on/off Same as `-H'. timeout = N Set timeout value, the same as `-T'. timestamping = on/off Turn timestamping on/off. The same as `-N' (*Note Time-Stamping::). tries = N Set number of retries per URL, the same as `-t'. use_proxy = on/off Turn proxy support on/off. The same as `-Y'. verbose = on/off Turn verbose on/off, the same as `-v'/`-nv'. wait = N Wait N seconds between retrievals, the same as `-w'.  File: wget.info, Node: Sample Wgetrc, Prev: Wgetrc Commands, Up: Startup File Sample Wgetrc ============= This is the sample initialization file, as given in the distribution. It is divided in two section--one for global usage (suitable for global startup file), and one for local usage (suitable for `$HOME/.wgetrc'). Be careful about the things you change. Note that all the lines are commented out. For any line to have effect, you must remove the `#' prefix at the beginning of line. ### ### Sample Wget initialization file .wgetrc ### ## You can use this file to change the default behaviour of wget or to ## avoid having to type many many command-line options. This file does ## not contain a comprehensive list of commands -- look at the manual ## to find out what you can put into this file. ## ## Wget initialization file can reside in /usr/local/etc/wgetrc ## (global, for all users) or $HOME/.wgetrc (for a single user). ## ## To use any of the settings in this file, you will have to uncomment ## them (and probably change them). ## ## Global settings (useful for setting up in /usr/local/etc/wgetrc). ## Think well before you change them, since they may reduce wget's ## functionality, and make it behave contrary to the documentation: ## # You can set retrieve quota for beginners by specifying a value # optionally followed by 'K' (kilobytes) or 'M' (megabytes). The # default quota is unlimited. #quota = inf # You can lower (or raise) the default number of retries when # downloading a file (default is 20). #tries = 20 # Lowering the maximum depth of the recursive retrieval is handy to # prevent newbies from going too "deep" when they unwittingly start # the recursive retrieval. The default is 5. #reclevel = 5 # Many sites are behind firewalls that do not allow initiation of # connections from the outside. On these sites you have to use the # `passive' feature of FTP. If you are behind such a firewall, you # can turn this on to make Wget use passive FTP by default. #passive_ftp = off ## ## Local settings (for a user to set in his $HOME/.wgetrc). It is ## *highly* undesirable to put these settings in the global file, since ## they are potentially dangerous to "normal" users. ## ## Even when setting up your own ~/.wgetrc, you should know what you ## are doing before doing so. ## # Set this to on to use timestamping by default: #timestamping = off # It is a good idea to make Wget send your email address in a `From:' # header with your request (so that server administrators can contact # you in case of errors). Wget does *not* send `From:' by default. #header = From: Your Name # You can set up other headers, like Accept-Language. Accept-Language # is *not* sent by default. #header = Accept-Language: en # You can set the default proxy for Wget to use. It will override the # value in the environment. #http_proxy = http://proxy.yoyodyne.com:18023/ # If you do not want to use proxy at all, set this to off. #use_proxy = on # You can customize the retrieval outlook. Valid options are default, # binary, mega and micro. #dot_style = default # Setting this to off makes Wget not download /robots.txt. Be sure to # know *exactly* what /robots.txt is and how it is used before changing # the default! #robots = on # It can be useful to make Wget wait between connections. Set this to # the number of seconds you want Wget to wait. #wait = 0 # You can force creating directory structure, even if a single is being # retrieved, by setting this to on. #dirstruct = off # You can turn on recursive retrieving by default (don't do this if # you are not sure you know what it means) by setting this to on. #recursive = off # To have Wget follow FTP links from HTML files by default, set this # to on: #follow_ftp = off  File: wget.info, Node: Examples, Next: Various, Prev: Startup File, Up: Top Examples ******** The examples are classified into three sections, because of clarity. The first section is a tutorial for beginners. The second section explains some of the more complex program features. The third section contains advice for mirror administrators, as well as even more complex features (that some would call perverted). * Menu: * Simple Usage:: Simple, basic usage of the program. * Advanced Usage:: Advanced techniques of usage. * Guru Usage:: Mirroring and the hairy stuff.  File: wget.info, Node: Simple Usage, Next: Advanced Usage, Prev: Examples, Up: Examples Simple Usage ============ * Say you want to download a URL. Just type: wget http://fly.cc.fer.hr/ The response will be something like: --13:30:45-- http://fly.cc.fer.hr:80/en/ => `index.html' Connecting to fly.cc.fer.hr:80... connected! HTTP request sent, awaiting response... 200 OK Length: 4,694 [text/html] 0K -> .... [100%] 13:30:46 (23.75 KB/s) - `index.html' saved [4694/4694] * But what will happen if the connection is slow, and the file is lengthy? The connection will probably fail before the whole file is retrieved, more than once. In this case, Wget will try getting the file until it either gets the whole of it, or exceeds the default number of retries (this being 20). It is easy to change the number of tries to 45, to insure that the whole file will arrive safely: wget --tries=45 http://fly.cc.fer.hr/jpg/flyweb.jpg * Now let's leave Wget to work in the background, and write its progress to log file `log'. It is tiring to type `--tries', so we shall use `-t'. wget -t 45 -o log http://fly.cc.fer.hr/jpg/flyweb.jpg & The ampersand at the end of the line makes sure that Wget works in the background. To unlimit the number of retries, use `-t inf'. * The usage of FTP is as simple. Wget will take care of login and password. $ wget ftp://gnjilux.cc.fer.hr/welcome.msg --10:08:47-- ftp://gnjilux.cc.fer.hr:21/welcome.msg => `welcome.msg' Connecting to gnjilux.cc.fer.hr:21... connected! Logging in as anonymous ... Logged in! ==> TYPE I ... done. ==> CWD not needed. ==> PORT ... done. ==> RETR welcome.msg ... done. Length: 1,340 (unauthoritative) 0K -> . [100%] 10:08:48 (1.28 MB/s) - `welcome.msg' saved [1340] * If you specify a directory, Wget will retrieve the directory listing, parse it and convert it to HTML. Try: wget ftp://prep.ai.mit.edu/pub/gnu/ lynx index.html  File: wget.info, Node: Advanced Usage, Next: Guru Usage, Prev: Simple Usage, Up: Examples Advanced Usage ============== * You would like to read the list of URLs from a file? Not a problem with that: wget -i file If you specify `-' as file name, the URLs will be read from standard input. * Create a mirror image of GNU WWW site (with the same directory structure the original has) with only one try per document, saving the log of the activities to `gnulog': wget -r -t1 http://www.gnu.ai.mit.edu/ -o gnulog * Retrieve the first layer of yahoo links: wget -r -l1 http://www.yahoo.com/ * Retrieve the index.html of `www.lycos.com', showing the original server headers: wget -S http://www.lycos.com/ * Save the server headers with the file: wget -s http://www.lycos.com/ more index.html * Retrieve the first two levels of `wuarchive.wustl.edu', saving them to /tmp. wget -P/tmp -l2 ftp://wuarchive.wustl.edu/ * You want to download all the GIFs from an HTTP directory. `wget http://host/dir/*.gif' doesn't work, since HTTP retrieval does not support globbing. In that case, use: wget -r -l1 --no-parent -A.gif http://host/dir/ It is a bit of a kludge, but it works. `-r -l1' means to retrieve recursively (*Note Recursive Retrieval::), with maximum depth of 1. `--no-parent' means that references to the parent directory are ignored (*Note Directory-Based Limits::), and `-A.gif' means to download only the GIF files. `-A "*.gif"' would have worked too. * Suppose you were in the middle of downloading, when Wget was interrupted. Now you do not want to clobber the files already present. It would be: wget -nc -r http://www.gnu.ai.mit.edu/ * If you want to encode your own username and password to HTTP or FTP, use the appropriate URL syntax (*Note URL Format::). wget ftp://hniksic:mypassword@jagor.srce.hr/.emacs * If you do not like the default retrieval visualization (1K dots with 10 dots per cluster and 50 dots per line), you can customize it through dot settings (*Note Wgetrc Commands::). For example, many people like the "binary" style of retrieval, with 8K dots and 512K lines: wget --dot-style=binary ftp://prep.ai.mit.edu/pub/gnu/README You can experiment with other styles, like: wget --dot-style=mega ftp://ftp.xemacs.org/pub/xemacs/xemacs-20.4/xemacs-20.4.tar.gz wget --dot-style=micro http://fly.cc.fer.hr/ To make these settings permanent, put them in your `.wgetrc', as described before (*Note Sample Wgetrc::).  File: wget.info, Node: Guru Usage, Prev: Advanced Usage, Up: Examples Guru Usage ========== * If you wish Wget to keep a mirror of a page (or FTP subdirectories), use `--mirror' (`-m'), which is the shorthand for `-r -N'. You can put Wget in the crontab file asking it to recheck a site each Sunday: crontab 0 0 * * 0 wget --mirror ftp://ftp.xemacs.org/pub/xemacs/ -o /home/me/weeklog * You may wish to do the same with someone's home page. But you do not want to download all those images--you're only interested in HTML. wget --mirror -A.html http://www.w3.org/ * But what about mirroring the hosts networkologically close to you? It seems so awfully slow because of all that DNS resolving. Just use `-D' (*Note Domain Acceptance::). wget -rN -Dsrce.hr http://www.srce.hr/ Now Wget will correctly find out that `regoc.srce.hr' is the same as `www.srce.hr', but will not even take into consideration the link to `www.mit.edu'. * You have a presentation and would like the dumb absolute links to be converted to relative? Use `-k': wget -k -r URL * You would like the output documents to go to standard output instead of to files? OK, but Wget will automatically shut up (turn on `--quiet') to prevent mixing of Wget output and the retrieved documents. wget -O - http://jagor.srce.hr/ http://www.srce.hr/ You can also combine the two options and make weird pipelines to retrieve the documents from remote hotlists: wget -O - http://cool.list.com/ | wget --force-html -i -  File: wget.info, Node: Various, Next: Appendices, Prev: Examples, Up: Top Various ******* This chapter contains all the stuff that could not fit anywhere else. * Menu: * Proxies:: Support for proxy servers * Distribution:: Getting the latest version. * Mailing List:: Wget mailing list for announcements and discussion. * Reporting Bugs:: How and where to report bugs. * Portability:: The systems Wget works on. * Signals:: Signal-handling performed by Wget.  File: wget.info, Node: Proxies, Next: Distribution, Prev: Various, Up: Various Proxies ======= "Proxies" are special-purpose HTTP servers designed to transfer data from remote servers to local clients. One typical use of proxies is lightening network load for users behind a slow connection. This is achieved by channeling all HTTP and FTP requests through the proxy which caches the transferred data. When a cached resource is requested again, proxy will return the data from cache. Another use for proxies is for companies that separate (for security reasons) their internal networks from the rest of Internet. In order to obtain information from the Web, their users connect and retrieve remote data using an authorized proxy. Wget supports proxies for both HTTP and FTP retrievals. The standard way to specify proxy location, which Wget recognizes, is using the following environment variables: `http_proxy' This variable should contain the URL of the proxy for HTTP connections. `ftp_proxy' This variable should contain the URL of the proxy for HTTP connections. It is quite common that HTTP_PROXY and FTP_PROXY are set to the same URL. `no_proxy' This variable should contain a comma-separated list of domain extensions proxy should *not* be used for. For instance, if the value of `no_proxy' is `.mit.edu', proxy will not be used to retrieve documents from MIT. In addition to the environment variables, proxy location and settings may be specified from within Wget itself. `-Y on/off' `--proxy=on/off' `proxy = on/off' This option may be used to turn the proxy support on or off. Proxy support is on by default, provided that the appropriate environment variables are set. `http_proxy = URL' `ftp_proxy = URL' `no_proxy = STRING' These startup file variables allow you to override the proxy settings specified by the environment. Some proxy servers require authorization to enable you to use them. The authorization consists of "username" and "password", which must be sent by Wget. As with HTTP authorization, several authentication schemes exist. For proxy authorization only the `Basic' authentication scheme is currently implemented. You may specify your username and password either through the proxy URL or through the command-line options. Assuming that the company's proxy is located at `proxy.srce.hr' at port 8001, a proxy URL location containing authorization data might look like this: http://hniksic:mypassword@proxy.company.com:8001/ Alternatively, you may use the `proxy-user' and `proxy-password' options, and the equivalent `.wgetrc' settings `proxy_user' and `proxy_passwd' to set the proxy username and password.  File: wget.info, Node: Distribution, Next: Mailing List, Prev: Proxies, Up: Various Distribution ============ Like all GNU utilities, the latest version of Wget can be found at the master GNU archive site prep.ai.mit.edu, and its mirrors. For example, Wget 1.5.3+dev can be found at `ftp://prep.ai.mit.edu/gnu/wget/wget-1.5.3+dev.tar.gz'  File: wget.info, Node: Mailing List, Next: Reporting Bugs, Prev: Distribution, Up: Various Mailing List ============ Wget has its own mailing list at , thanks to Karsten Thygesen. The mailing list is for discussion of Wget features and web, reporting Wget bugs (those that you think may be of interest to the public) and mailing announcements. You are welcome to subscribe. The more people on the list, the better! To subscribe, send mail to . the magic word `subscribe' in the subject line. Unsubscribe by mailing to . The mailing list is archived at `http://fly.cc.fer.hr/archive/wget'.  File: wget.info, Node: Reporting Bugs, Next: Portability, Prev: Mailing List, Up: Various Reporting Bugs ============== You are welcome to send bug reports about GNU Wget to . The bugs that you think are of the interest to the public (i.e. more people should be informed about them) can be Cc-ed to the mailing list at . Before actually submitting a bug report, please try to follow a few simple guidelines. 1. Please try to ascertain that the behaviour you see really is a bug. If Wget crashes, it's a bug. If Wget does not behave as documented, it's a bug. If things work strange, but you are not sure about the way they are supposed to work, it might well be a bug. 2. Try to repeat the bug in as simple circumstances as possible. E.g. if Wget crashes on `wget -rLl0 -t5 -Y0 http://yoyodyne.com -o /tmp/log', you should try to see if it will crash with a simpler set of options. Also, while I will probably be interested to know the contents of your `.wgetrc' file, just dumping it into the debug message is probably a bad idea. Instead, you should first try to see if the bug repeats with `.wgetrc' moved out of the way. Only if it turns out that `.wgetrc' settings affect the bug, should you mail me the relevant parts of the file. 3. Please start Wget with `-d' option and send the log (or the relevant parts of it). If Wget was compiled without debug support, recompile it. It is *much* easier to trace bugs with debug support on. 4. If Wget has crashed, try to run it in a debugger, e.g. `gdb `which wget` core' and type `where' to get the backtrace. 5. Find where the bug is, fix it and send me the patches. :-)  File: wget.info, Node: Portability, Next: Signals, Prev: Reporting Bugs, Up: Various Portability =========== Since Wget uses GNU Autoconf for building and configuring, and avoids using "special" ultra-mega-cool features of any particular Unix, it should compile (and work) on all common Unix flavors. Various Wget versions have been compiled and tested under many kinds of Unix systems, including Solaris, Linux, SunOS, OSF (aka Digital Unix), Ultrix, *BSD, IRIX, and others; refer to the file `MACHINES' in the distribution directory for a comprehensive list. If you compile it on an architecture not listed there, please let me know so I can update it. Wget should also compile on the other Unix systems, not listed in `MACHINES'. If it doesn't, please let me know. Thanks to kind contributors, this version of Wget compiles and works on Microsoft Windows 95 and Windows NT platforms. It has been compiled successfully using MS Visual C++ 4.0, Watcom, and Borland C compilers, with Winsock as networking software. Naturally, it is crippled of some features available on Unix, but it should work as a substitute for people stuck with Windows. Note that the Windows port is *neither tested nor maintained* by me--all questions and problems should be reported to Wget mailing list at where the maintainers will look at them.  File: wget.info, Node: Signals, Prev: Portability, Up: Various Signals ======= Since the purpose of Wget is background work, it catches the hangup signal (`SIGHUP') and ignores it. If the output was on standard output, it will be redirected to a file named `wget-log'. Otherwise, `SIGHUP' is ignored. This is convenient when you wish to redirect the output of Wget after having started it. $ wget http://www.ifi.uio.no/~larsi/gnus.tar.gz & $ kill -HUP %% # Redirect the output to wget-log Other than that, Wget will not try to interfere with signals in any way. `C-c', `kill -TERM' and `kill -KILL' should kill it alike.  File: wget.info, Node: Appendices, Next: Copying, Prev: Various, Up: Top Appendices ********** This chapter contains some references I consider useful, like the Robots Exclusion Standard specification, as well as a list of contributors to GNU Wget. * Menu: * Robots:: Wget as a WWW robot. * Security Considerations:: Security with Wget. * Contributors:: People who helped.  File: wget.info, Node: Robots, Next: Security Considerations, Prev: Appendices, Up: Appendices Robots ====== Since Wget is able to traverse the web, it counts as one of the Web "robots". Thus Wget understands "Robots Exclusion Standard" (RES)--contents of `/robots.txt', used by server administrators to shield parts of their systems from wanderings of Wget. Norobots support is turned on only when retrieving recursively, and *never* for the first page. Thus, you may issue: wget -r http://fly.cc.fer.hr/ First the index of fly.cc.fer.hr will be downloaded. If Wget finds anything worth downloading on the same host, only *then* will it load the robots, and decide whether or not to load the links after all. `/robots.txt' is loaded only once per host. Wget does not support the robots `META' tag. The description of the norobots standard was written, and is maintained by Martijn Koster . With his permission, I contribute a (slightly modified) TeXified version of the RES. * Menu: * Introduction to RES:: * RES Format:: * User-Agent Field:: * Disallow Field:: * Norobots Examples::  File: wget.info, Node: Introduction to RES, Next: RES Format, Prev: Robots, Up: Robots Introduction to RES ------------------- "WWW Robots" (also called "wanderers" or "spiders") are programs that traverse many pages in the World Wide Web by recursively retrieving linked pages. For more information see the robots page. In 1993 and 1994 there have been occasions where robots have visited WWW servers where they weren't welcome for various reasons. Sometimes these reasons were robot specific, e.g. certain robots swamped servers with rapid-fire requests, or retrieved the same files repeatedly. In other situations robots traversed parts of WWW servers that weren't suitable, e.g. very deep virtual trees, duplicated information, temporary information, or cgi-scripts with side-effects (such as voting). These incidents indicated the need for established mechanisms for WWW servers to indicate to robots which parts of their server should not be accessed. This standard addresses this need with an operational solution. This document represents a consensus on 30 June 1994 on the robots mailing list (`robots@webcrawler.com'), between the majority of robot authors and other people with an interest in robots. It has also been open for discussion on the Technical World Wide Web mailing list (`www-talk@info.cern.ch'). This document is based on a previous working draft under the same title. It is not an official standard backed by a standards body, or owned by any commercial organization. It is not enforced by anybody, and there no guarantee that all current and future robots will use it. Consider it a common facility the majority of robot authors offer the WWW community to protect WWW server against unwanted accesses by their robots. The latest version of this document can be found at `http://info.webcrawler.com/mak/projects/robots/norobots.html'.  File: wget.info, Node: RES Format, Next: User-Agent Field, Prev: Introduction to RES, Up: Robots RES Format ---------- The format and semantics of the `/robots.txt' file are as follows: The file consists of one or more records separated by one or more blank lines (terminated by `CR', `CR/NL', or `NL'). Each record contains lines of the form: : The field name is case insensitive. Comments can be included in file using UNIX Bourne shell conventions: the `#' character is used to indicate that preceding space (if any) and the remainder of the line up to the line termination is discarded. Lines containing only a comment are discarded completely, and therefore do not indicate a record boundary. The record starts with one or more User-agent lines, followed by one or more Disallow lines, as detailed below. Unrecognized headers are ignored. The presence of an empty `/robots.txt' file has no explicit associated semantics, it will be treated as if it was not present, i.e. all robots will consider themselves welcome.  File: wget.info, Node: User-Agent Field, Next: Disallow Field, Prev: RES Format, Up: Robots User-Agent Field ---------------- The value of this field is the name of the robot the record is describing access policy for. If more than one User-agent field is present the record describes an identical access policy for more than one robot. At least one field needs to be present per record. The robot should be liberal in interpreting this field. A case insensitive substring match of the name without version information is recommended. If the value is `*', the record describes the default access policy for any robot that has not matched any of the other records. It is not allowed to have multiple such records in the `/robots.txt' file.  File: wget.info, Node: Disallow Field, Next: Norobots Examples, Prev: User-Agent Field, Up: Robots Disallow Field -------------- The value of this field specifies a partial URL that is not to be visited. This can be a full path, or a partial path; any URL that starts with this value will not be retrieved. For example, `Disallow: /help' disallows both `/help.html' and `/help/index.html', whereas `Disallow: /help/' would disallow `/help/index.html' but allow `/help.html'. Any empty value, indicates that all URLs can be retrieved. At least one Disallow field needs to be present in a record.  File: wget.info, Node: Norobots Examples, Prev: Disallow Field, Up: Robots Norobots Examples ----------------- The following example `/robots.txt' file specifies that no robots should visit any URL starting with `/cyberworld/map/' or `/tmp/': # robots.txt for http://www.site.com/ User-agent: * Disallow: /cyberworld/map/ # This is an infinite virtual URL space Disallow: /tmp/ # these will soon disappear This example `/robots.txt' file specifies that no robots should visit any URL starting with `/cyberworld/map/', except the robot called `cybermapper': # robots.txt for http://www.site.com/ User-agent: * Disallow: /cyberworld/map/ # This is an infinite virtual URL space # Cybermapper knows where to go. User-agent: cybermapper Disallow: This example indicates that no robots should visit this site further: # go away User-agent: * Disallow: /  File: wget.info, Node: Security Considerations, Next: Contributors, Prev: Robots, Up: Appendices Security Considerations ======================= When using Wget, you must be aware that it sends unencrypted passwords through the network, which may present a security problem. Here are the main issues, and some solutions. 1. The passwords on the command line are visible using `ps'. If this is a problem, avoid putting passwords from the command line--e.g. you can use `.netrc' for this. 2. Using the insecure "basic" authentication scheme, unencrypted passwords are transmitted through the network routers and gateways. 3. The FTP passwords are also in no way encrypted. There is no good solution for this at the moment. 4. Although the "normal" output of Wget tries to hide the passwords, debugging logs show them, in all forms. This problem is avoided by being careful when you send debug logs (yes, even when you send them to me).  File: wget.info, Node: Contributors, Prev: Security Considerations, Up: Appendices Contributors ============ GNU Wget was written by Hrvoje Niksic . However, its development could never have gone as far as it has, were it not for the help of many people, either with bug reports, feature proposals, patches, or letters saying "Thanks!". Special thanks goes to the following people (no particular order): * Karsten Thygesen--donated the mailing list and the initial FTP space. * Shawn McHorse--bug reports and patches. * Kaveh R. Ghazi--on-the-fly `ansi2knr'-ization. * Gordon Matzigkeit--`.netrc' support. * Zlatko Calusic, Tomislav Vujec and Drazen Kacar--feature suggestions and "philosophical" discussions. * Darko Budor--initial port to Windows. * Antonio Rosella--help and suggestions, plus the Italian translation. * Tomislav Petrovic, Mario Mikocevic--many bug reports and suggestions. * Francois Pinard--many thorough bug reports and discussions. * Karl Eichwalder--lots of help with internationalization and other things. * Junio Hamano--donated support for Opie and HTTP `Digest' authentication. * Brian Gough--a generous donation. The following people have provided patches, bug/build reports, useful suggestions, beta testing services, fan mail and all the other things that make maintenance so much fun: Tim Adam, Martin Baehr, Dieter Baron, Roger Beeman and the Gurus at Cisco, Dan Berger, Mark Boyns, John Burden, Wanderlei Cavassin, Gilles Cedoc, Tim Charron, Noel Cragg, Kristijan Conkas, Andrew Deryabin, Damir Dzeko, Andrew Davison, Ulrich Drepper, Marc Duponcheel, Aleksandar Erkalovic, Andy Eskilsson, Masashi Fujita, Howard Gayle, Marcel Gerrits, Hans Grobler, Mathieu Guillaume, Dan Harkless, Heiko Herold, Karl Heuer, HIROSE Masaaki, Gregor Hoffleit, Erik Magnus Hulthen, Richard Huveneers, Simon Josefsson, Mario Juric, Goran Kezunovic, Robert Kleine, Fila Kolodny, Alexander Kourakos, Martin Kraemer, Simos KSenitellis, Hrvoje Lacko, Daniel S. Lewart, Dave Love, Jordan Mendelson, Lin Zhe Min, Charlie Negyesi, Andrew Pollock, Steve Pothier, Jan Prikryl, Marin Purgar, Keith Refson, Tobias Ringstrom, Juan Jose Rodrigues, Edward J. Sabol, Heinz Salzmann, Robert Schmidt, Toomas Soome, Tage Stabell-Kulo, Sven Sternberger, Markus Strasser, Szakacsits Szabolcs, Mike Thomas, Russell Vincent, Charles G Waldman, Douglas E. Wegscheid, Jasmin Zainul, Bojan Zdrnja, Kristijan Zimmer. Apologies to all who I accidentally left out, and many thanks to all the subscribers of the Wget mailing list.