9 Nisan 2010 Cuma

Linux / Unix Command: wget

wget - GNU Wget Manual

SYNOPSIS

wget [<I>option</I>]... [<I></I><I>URL</I><I></I>]...

DESCRIPTION

GNU Wget is a free utility for non-interactive download of files from the Web. It supports HTTP, HTTPS, and FTP protocols, as well as retrieval through HTTP proxies.

Wget is non-interactive, meaning that it can work in the background, while the user is not logged on. This allows you to start a retrieval and disconnect from the system, letting Wget finish the work. By contrast, most of the Web browsers require constant user's presence, which can be a great hindrance when transferring a lot of data.

Wget can follow links in HTML pages and create local versions of remote web sites, fully recreating the directory structure of the original site. This is sometimes referred to as ``recursive downloading.'' While doing that, Wget respects the Robot Exclusion Standard (<I>/robots.txt</I>). Wget can be instructed to convert the links in downloaded HTML files to the local files for offline viewing.

Wget has been designed for robustness over slow or unstable network connections; if a download fails due to a network problem, it will keep retrying until the whole file has been retrieved. If the server supports regetting, it will instruct the server to continue the download from where it left off.

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OPTIONS

Basic Startup Options

-V
--version
Display the version of Wget.
-h
--help
Print a help message describing all of Wget's command-line options.
-b
--background
Go to background immediately after startup. If no output file is specified via the -o, output is redirected to <I>wget-log</I>.
-e <I>command</I>
--execute <I>command</I>
Execute <I>command</I> as if it were a part of <I>.wgetrc</I>. A command thus invoked will be executed <I>after</I> the commands in <I>.wgetrc</I>, thus taking precedence over them.

Logging and Input File Options

-o <I>logfile</I>
--output-file=<I>logfile</I>
Log all messages to <I>logfile</I>. The messages are normally reported to standard error.
-a <I>logfile</I>
--append-output=<I>logfile</I>
Append to <I>logfile</I>. This is the same as -o, only it appends to <I>logfile</I> instead of overwriting the old log file. If <I>logfile</I> does not exist, a new file is created.
-d
--debug
Turn on debug output, meaning various information important to the developers of Wget if it does not work properly. Your system administrator may have chosen to compile Wget without debug support, in which case -d will not work. Please note that compiling with debug support is always safe---Wget compiled with the debug support will <I>not</I> print any debug info unless requested with -d.
-q
--quiet
Turn off Wget's output.
-v
--verbose
Turn on verbose output, with all the available data. The default output is verbose.
-nv
--non-verbose
Non-verbose output---turn off verbose without being completely quiet (use -q for that), which means that error messages and basic information still get printed.
-i <I>file</I>
--input-file=<I>file</I>
Read URLs from <I>file</I>, in which case no URLs need to be on the command line. If there are URLs both on the command line and in an input file, those on the command lines will be the first ones to be retrieved. The <I>file</I> need not be an HTML document (but no harm if it is)---it is enough if the URLs are just listed sequentially.

However, if you specify --force-html, the document will be regarded as html. In that case you may have problems with relative links, which you can solve either by adding "" to the documents or by specifying --base=<I>url</I> on the command line.

-F
--force-html
When input is read from a file, force it to be treated as an HTML file. This enables you to retrieve relative links from existing HTML files on your local disk, by adding "" to HTML, or using the --base command-line option.
-B <I></I><I>URL</I><I></I>
--base=<I></I><I>URL</I><I></I>
When used in conjunction with -F, prepends <I></I><I>URL</I><I></I> to relative links in the file specified by -i.

Download Options

--bind-address=<I></I><I>ADDRESS</I><I></I>
When making client TCP/IP connections, "bind()" to <I></I><I>ADDRESS</I><I></I> on the local machine. <I></I><I>ADDRESS</I><I></I> may be specified as a hostname or IP address. This option can be useful if your machine is bound to multiple IPs.
-t <I>number</I>
--tries=<I>number</I>
Set number of retries to <I>number</I>. Specify 0 or inf for infinite retrying.
-O <I>file</I>
--output-document=<I>file</I>
The documents will not be written to the appropriate files, but all will be concatenated together and written to <I>file</I>. If <I>file</I> already exists, it will be overwritten. If the <I>file</I> is -, the documents will be written to standard output. Including this option automatically sets the number of tries to 1.
-nc
--no-clobber
If a file is downloaded more than once in the same directory, Wget's behavior depends on a few options, including -nc. In certain cases, the local file will be <I>clobbered</I>, or overwritten, upon repeated download. In other cases it will be preserved.

When running Wget without -N, -nc, or -r, downloading the same file in the same directory will result in the original copy of <I>file</I> being preserved and the second copy being named <I>file</I>.1. If that file is downloaded yet again, the third copy will be named <I>file</I>.2, and so on. When -nc is specified, this behavior is suppressed, and Wget will refuse to download newer copies of <I>file</I>. Therefore, ``"no-clobber"'' is actually a misnomer in this mode---it's not clobbering that's prevented (as the numeric suffixes were already preventing clobbering), but rather the multiple version saving that's prevented.

When running Wget with -r, but without -N or -nc, re-downloading a file will result in the new copy simply overwriting the old. Adding -nc will prevent this behavior, instead causing the original version to be preserved and any newer copies on the server to be ignored.

When running Wget with -N, with or without -r, the decision as to whether or not to download a newer copy of a file depends on the local and remote timestamp and size of the file. -nc may not be specified at the same time as -N.

Note that when -nc is specified, files with the suffixes .html or (yuck) .htm will be loaded from the local disk and parsed as if they had been retrieved from the Web.

-c
--continue
Continue getting a partially-downloaded file. This is useful when you want to finish up a download started by a previous instance of Wget, or by another program. For instance:
        wget -c ftp://sunsite.doc.ic.ac.uk/ls-lR.Z


If there is a file named <I>ls-lR.Z</I> in the current directory, Wget will assume that it is the first portion of the remote file, and will ask the server to continue the retrieval from an offset equal to the length of the local file.

Note that you don't need to specify this option if you just want the current invocation of Wget to retry downloading a file should the connection be lost midway through. This is the default behavior. -c only affects resumption of downloads started <I>prior</I> to this invocation of Wget, and whose local files are still sitting around.

Without -c, the previous example would just download the remote file to <I>ls-lR.Z.1</I>, leaving the truncated <I>ls-lR.Z</I> file alone.

Beginning with Wget 1.7, if you use -c on a non-empty file, and it turns out that the server does not support continued downloading, Wget will refuse to start the download from scratch, which would effectively ruin existing contents. If you really want the download to start from scratch, remove the file.

Also beginning with Wget 1.7, if you use -c on a file which is of equal size as the one on the server, Wget will refuse to download the file and print an explanatory message. The same happens when the file is smaller on the server than locally (presumably because it was changed on the server since your last download attempt)---because ``continuing'' is not meaningful, no download occurs.

On the other side of the coin, while using -c, any file that's bigger on the server than locally will be considered an incomplete download and only "(length(remote) - length(local))" bytes will be downloaded and tacked onto the end of the local file. This behavior can be desirable in certain cases---for instance, you can use wget -c to download just the new portion that's been appended to a data collection or log file.

However, if the file is bigger on the server because it's been <I>changed</I>, as opposed to just <I>appended</I> to, you'll end up with a garbled file. Wget has no way of verifying that the local file is really a valid prefix of the remote file. You need to be especially careful of this when using -c in conjunction with -r, since every file will be considered as an ``incomplete download'' candidate.

Another instance where you'll get a garbled file if you try to use -c is if you have a lame HTTP proxy that inserts a ``transfer interrupted'' string into the local file. In the future a ``rollback'' option may be added to deal with this case.

Note that -c only works with FTP servers and with HTTP servers that support the "Range" header.


--progress=<I>type</I>
Select the type of the progress indicator you wish to use. Legal indicators are ``dot'' and ``bar''.

The ``bar'' indicator is used by default. It draws an ASCII progress bar graphics (a.k.a ``thermometer'' display) indicating the status of retrieval. If the output is not a TTY, the ``dot'' bar will be used by default.

Use --progress=dot to switch to the ``dot'' display. It traces the retrieval by printing dots on the screen, each dot representing a fixed amount of downloaded data.

When using the dotted retrieval, you may also set the <I>style</I> by specifying the type as dot:<I>style</I>. Different styles assign different meaning to one dot. With the "default" style each dot represents 1K, there are ten dots in a cluster and 50 dots in a line. The "binary" style has a more ``computer''-like orientation---8K dots, 16-dots clusters and 48 dots per line (which makes for 384K lines). The "mega" style is suitable for downloading very large files---each dot represents 64K retrieved, there are eight dots in a cluster, and 48 dots on each line (so each line contains 3M).

Note that you can set the default style using the "progress" command in <I>.wgetrc</I>. That setting may be overridden from the command line. The exception is that, when the output is not a TTY, the ``dot'' progress will be favored over ``bar''. To force the bar output, use --progress=bar:force.


-N

--timestamping
Turn on time-stamping.
-S

--server-response
Print the headers sent by HTTP servers and responses sent by FTP servers.
--spider
When invoked with this option, Wget will behave as a Web <I>spider</I>, which means that it will not download the pages, just check that they are there. You can use it to check your bookmarks, e.g. with:
        wget --spider --force-html -i bookmarks.html


This feature needs much more work for Wget to get close to the functionality of real WWW spiders.


-T seconds

--timeout=<I>seconds</I>
Set the read timeout to <I>seconds</I> seconds. Whenever a network read is issued, the file descriptor is checked for a timeout, which could otherwise leave a pending connection (uninterrupted read). The default timeout is 900 seconds (fifteen minutes). Setting timeout to 0 will disable checking for timeouts.

Please do not lower the default timeout value with this option unless you know what you are doing.


--limit-rate=<I>amount</I>
Limit the download speed to <I>amount</I> bytes per second. Amount may be expressed in bytes, kilobytes with the k suffix, or megabytes with the m suffix. For example, --limit-rate=20k will limit the retrieval rate to 20KB/s. This kind of thing is useful when, for whatever reason, you don't want Wget to consume the entire evailable bandwidth.

Note that Wget implementeds the limiting by sleeping the appropriate amount of time after a network read that took less time than specified by the rate. Eventually this strategy causes the TCP transfer to slow down to approximately the specified rate. However, it takes some time for this balance to be achieved, so don't be surprised if limiting the rate doesn't work with very small files. Also, the ``sleeping'' strategy will misfire when an extremely small bandwidth, say less than 1.5KB/s, is specified.


-w <I>seconds</I>

--wait=<I>seconds</I>
Wait the specified number of seconds between the retrievals. Use of this option is recommended, as it lightens the server load by making the requests less frequent. Instead of in seconds, the time can be specified in minutes using the "m" suffix, in hours using "h" suffix, or in days using "d" suffix.

Specifying a large value for this option is useful if the network or the destination host is down, so that Wget can wait long enough to reasonably expect the network error to be fixed before the retry.


--waitretry=<I>seconds</I>
If you don't want Wget to wait between <I>every</I> retrieval, but only between retries of failed downloads, you can use this option. Wget will use <I>linear backoff</I>, waiting 1 second after the first failure on a given file, then waiting 2 seconds after the second failure on that file, up to the maximum number of <I>seconds</I> you specify. Therefore, a value of 10 will actually make Wget wait up to (1 + 2 + ... + 10) = 55 seconds per file.

Note that this option is turned on by default in the global <I>wgetrc</I> file.


--random-wait
Some web sites may perform log analysis to identify retrieval programs such as Wget by looking for statistically significant similarities in the time between requests. This option causes the time between requests to vary between 0 and 2 * <I>wait</I> seconds, where <I>wait</I> was specified using the -w or --wait options, in order to mask Wget's presence from such analysis.

A recent article in a publication devoted to development on a popular consumer platform provided code to perform this analysis on the fly. Its author suggested blocking at the class C address level to ensure automated retrieval programs were blocked despite changing DHCP-supplied addresses.

The --random-wait option was inspired by this ill-advised recommendation to block many unrelated users from a web site due to the actions of one.


-Y on/off

--proxy=on/off
Turn proxy support on or off. The proxy is on by default if the appropriate environmental variable is defined.
-Q <I>quota</I>

--quota=<I>quota</I>
Specify download quota for automatic retrievals. The value can be specified in bytes (default), kilobytes (with k suffix), or megabytes (with m suffix).

Note that quota will never affect downloading a single file. So if you specify wget -Q10k ftp://wuarchive.wustl.edu/ls-lR.gz, all of the <I>ls-lR.gz</I> will be downloaded. The same goes even when several URLs are specified on the command-line. However, quota is respected when retrieving either recursively, or from an input file. Thus you may safely type wget -Q2m -i sites---download will be aborted when the quota is exceeded.

Setting quota to 0 or to inf unlimits the download quota.


Directory Options



-nd

--no-directories
Do not create a hierarchy of directories when retrieving recursively. With this option turned on, all files will get saved to the current directory, without clobbering (if a name shows up more than once, the filenames will get extensions .n).
-x

--force-directories
The opposite of -nd---create a hierarchy of directories, even if one would not have been created otherwise. E.g. wget -x http://fly.srk.fer.hr/robots.txt will save the downloaded file to <I>fly.srk.fer.hr/robots.txt</I>.
-nH

--no-host-directories
Disable generation of host-prefixed directories. By default, invoking Wget with -r http://fly.srk.fer.hr/ will create a structure of directories beginning with <I>fly.srk.fer.hr/</I>. This option disables such behavior.
--cut-dirs=<I>number</I>
Ignore <I>number</I> directory components. This is useful for getting a fine-grained control over the directory where recursive retrieval will be saved.

Take, for example, the directory at ftp://ftp.xemacs.org/pub/xemacs/. If you retrieve it with -r, it will be saved locally under <I>ftp.xemacs.org/pub/xemacs/</I>. While the -nH option can remove the <I>ftp.xemacs.org/</I> part, you are still stuck with <I>pub/xemacs</I>. This is where --cut-dirs comes in handy; it makes Wget not ``see'' <I>number</I> remote directory components. Here are several examples of how --cut-dirs option works.

        No options        -> ftp.xemacs.org/pub/xemacs/
-nH -> pub/xemacs/
-nH --cut-dirs=1 -> xemacs/
-nH --cut-dirs=2 -> .

        --cut-dirs=1      -> ftp.xemacs.org/xemacs/
...


If you just want to get rid of the directory structure, this option is similar to a combination of -nd and -P. However, unlike -nd, --cut-dirs does not lose with subdirectories---for instance, with -nH --cut-dirs=1, a <I>beta/</I> subdirectory will be placed to <I>xemacs/beta</I>, as one would expect.


-P <I>prefix</I>

--directory-prefix=<I>prefix</I>
Set directory prefix to <I>prefix</I>. The <I>directory prefix</I> is the directory where all other files and subdirectories will be saved to, i.e. the top of the retrieval tree. The default is . (the current directory).

HTTP Options



-E

--html-extension
If a file of type text/html is downloaded and the URL does not end with the regexp \.[Hh][Tt][Mm][Ll]?, this option will cause the suffix .html to be appended to the local filename. This is useful, for instance, when you're mirroring a remote site that uses .asp pages, but you want the mirrored pages to be viewable on your stock Apache server. Another good use for this is when you're downloading the output of CGIs. A URL like http://site.com/article.cgi?25 will be saved as <I>article.cgi?25.html</I>.

Note that filenames changed in this way will be re-downloaded every time you re-mirror a site, because Wget can't tell that the local <I>X.html</I> file corresponds to remote URL <I>X</I> (since it doesn't yet know that the URL produces output of type text/html. To prevent this re-downloading, you must use -k and -K so that the original version of the file will be saved as <I>X.orig</I>.


--http-user=<I>user</I>

--http-passwd=<I>password</I>
Specify the username <I>user</I> and password <I>password</I> on an HTTP server. According to the type of the challenge, Wget will encode them using either the "basic" (insecure) or the "digest" authentication scheme.

Another way to specify username and password is in the URL itself. Either method reveals your password to anyone who bothers to run "ps". To prevent the passwords from being seen, store them in <I>.wgetrc</I> or <I>.netrc</I>, and make sure to protect those files from other users with "chmod". If the passwords are really important, do not leave them lying in those files either---edit the files and delete them after Wget has started the download.

For more information about security issues with Wget,


-C on/off

--cache=on/off
When set to off, disable server-side cache. In this case, Wget will send the remote server an appropriate directive (Pragma: no-cache) to get the file from the remote service, rather than returning the cached version. This is especially useful for retrieving and flushing out-of-date documents on proxy servers.

Caching is allowed by default.


--cookies=on/off
When set to off, disable the use of cookies. Cookies are a mechanism for maintaining server-side state. The server sends the client a cookie using the "Set-Cookie" header, and the client responds with the same cookie upon further requests. Since cookies allow the server owners to keep track of visitors and for sites to exchange this information, some consider them a breach of privacy. The default is to use cookies; however, <I>storing</I> cookies is not on by default.
--load-cookies <I>file</I>
Load cookies from <I>file</I> before the first HTTP retrieval. <I>file</I> is a textual file in the format originally used by Netscape's <I>cookies.txt</I> file.

You will typically use this option when mirroring sites that require that you be logged in to access some or all of their content. The login process typically works by the web server issuing an HTTP cookie upon receiving and verifying your credentials. The cookie is then resent by the browser when accessing that part of the site, and so proves your identity.

Mirroring such a site requires Wget to send the same cookies your browser sends when communicating with the site. This is achieved by --load-cookies---simply point Wget to the location of the <I>cookies.txt</I> file, and it will send the same cookies your browser would send in the same situation. Different browsers keep textual cookie files in different locations:





Netscape 4.x.
The cookies are in <I>~/.netscape/cookies.txt</I>.
Mozilla and Netscape 6.x.
Mozilla's cookie file is also named <I>cookies.txt</I>, located somewhere under <I>~/.mozilla</I>, in the directory of your profile. The full path usually ends up looking somewhat like <I>~/.mozilla/default/some-weird-string/cookies.txt</I>.
Internet Explorer.
You can produce a cookie file Wget can use by using the File menu, Import and Export, Export Cookies. This has been tested with Internet Explorer 5; it is not guaranteed to work with earlier versions.
Other browsers.
If you are using a different browser to create your cookies, --load-cookies will only work if you can locate or produce a cookie file in the Netscape format that Wget expects.




If you cannot use --load-cookies, there might still be an alternative. If your browser supports a ``cookie manager'', you can use it to view the cookies used when accessing the site you're mirroring. Write down the name and value of the cookie, and manually instruct Wget to send those cookies, bypassing the ``official'' cookie support:

        wget --cookies=off --header "Cookie: I=I"


--save-cookies <I>file</I>
Save cookies from <I>file</I> at the end of session. Cookies whose expiry time is not specified, or those that have already expired, are not saved.
--ignore-length
Unfortunately, some HTTP servers (CGI programs, to be more precise) send out bogus "Content-Length" headers, which makes Wget go wild, as it thinks not all the document was retrieved. You can spot this syndrome if Wget retries getting the same document again and again, each time claiming that the (otherwise normal) connection has closed on the very same byte.

With this option, Wget will ignore the "Content-Length" header---as if it never existed.


--header=<I>additional-header</I>
Define an <I>additional-header</I> to be passed to the HTTP servers. Headers must contain a : preceded by one or more non-blank characters, and must not contain newlines.

You may define more than one additional header by specifying --header more than once.

        wget --header='Accept-Charset: iso-8859-2' \
--header='Accept-Language: hr' \
http://fly.srk.fer.hr/


Specification of an empty string as the header value will clear all previous user-defined headers.


--proxy-user=<I>user</I>

--proxy-passwd=<I>password</I>
Specify the username <I>user</I> and password <I>password</I> for authentication on a proxy server. Wget will encode them using the "basic" authentication scheme.

Security considerations similar to those with --http-passwd pertain here as well.


--referer=<I>url</I>
Include `Referer: <I>url</I>' header in HTTP request. Useful for retrieving documents with server-side processing that assume they are always being retrieved by interactive web browsers and only come out properly when Referer is set to one of the pages that point to them.
-s

--save-headers
Save the headers sent by the HTTP server to the file, preceding the actual contents, with an empty line as the separator.
-U <I>agent-string</I>

--user-agent=<I>agent-string</I>
Identify as <I>agent-string</I> to the HTTP server.

The HTTP protocol allows the clients to identify themselves using a "User-Agent" header field. This enables distinguishing the WWW software, usually for statistical purposes or for tracing of protocol violations. Wget normally identifies as Wget/<I>version</I>, <I>version</I> being the current version number of Wget.

However, some sites have been known to impose the policy of tailoring the output according to the "User-Agent"-supplied information. While conceptually this is not such a bad idea, it has been abused by servers denying information to clients other than "Mozilla" or Microsoft "Internet Explorer". This option allows you to change the "User-Agent" line issued by Wget. Use of this option is discouraged, unless you really know what you are doing.


FTP Options



-nr

--dont-remove-listing
Don't remove the temporary <I>.listing</I> files generated by FTP retrievals. Normally, these files contain the raw directory listings received from FTP servers. Not removing them can be useful for debugging purposes, or when you want to be able to easily check on the contents of remote server directories (e.g. to verify that a mirror you're running is complete).

Note that even though Wget writes to a known filename for this file, this is not a security hole in the scenario of a user making <I>.listing</I> a symbolic link to <I>/etc/passwd</I> or something and asking "root" to run Wget in his or her directory. Depending on the options used, either Wget will refuse to write to <I>.listing</I>, making the globbing/recursion/time-stamping operation fail, or the symbolic link will be deleted and replaced with the actual <I>.listing</I> file, or the listing will be written to a <I>.listing.number</I> file.

Even though this situation isn't a problem, though, "root" should never run Wget in a non-trusted user's directory. A user could do something as simple as linking <I>index.html</I> to <I>/etc/passwd</I> and asking "root" to run Wget with -N or -r so the file will be overwritten.


-g on/off

--glob=on/off
Turn FTP globbing on or off. Globbing means you may use the shell-like special characters (<I>wildcards</I>), like *, ?, [ and ] to retrieve more than one file from the same directory at once, like:
        wget ftp://gnjilux.srk.fer.hr/*.msg


By default, globbing will be turned on if the URL contains a globbing character. This option may be used to turn globbing on or off permanently.

You may have to quote the URL to protect it from being expanded by your shell. Globbing makes Wget look for a directory listing, which is system-specific. This is why it currently works only with Unix FTP servers (and the ones emulating Unix "ls" output).


--passive-ftp
Use the <I>passive</I> FTP retrieval scheme, in which the client initiates the data connection. This is sometimes required for FTP to work behind firewalls.
--retr-symlinks
Usually, when retrieving FTP directories recursively and a symbolic link is encountered, the linked-to file is not downloaded. Instead, a matching symbolic link is created on the local filesystem. The pointed-to file will not be downloaded unless this recursive retrieval would have encountered it separately and downloaded it anyway.

When --retr-symlinks is specified, however, symbolic links are traversed and the pointed-to files are retrieved. At this time, this option does not cause Wget to traverse symlinks to directories and recurse through them, but in the future it should be enhanced to do this.

Note that when retrieving a file (not a directory) because it was specified on the commandline, rather than because it was recursed to, this option has no effect. Symbolic links are always traversed in this case.

Recursive Retrieval Options



-r

--recursive
Turn on recursive retrieving.
-l <I>depth</I>

--level=<I>depth</I>
Specify recursion maximum depth level <I>depth</I>. The default maximum depth is 5.
--delete-after
This option tells Wget to delete every single file it downloads, <I>after</I> having done so. It is useful for pre-fetching popular pages through a proxy, e.g.:
        wget -r -nd --delete-after http://whatever.com/~popular/page/


The -r option is to retrieve recursively, and -nd to not create directories.

Note that --delete-after deletes files on the local machine. It does not issue the DELE command to remote FTP sites, for instance. Also note that when --delete-after is specified, --convert-links is ignored, so .orig files are simply not created in the first place.


-k

--convert-links
After the download is complete, convert the links in the document to make them suitable for local viewing. This affects not only the visible hyperlinks, but any part of the document that links to external content, such as embedded images, links to style sheets, hyperlinks to non-HTML content, etc.

Each link will be changed in one of the two ways:





*
The links to files that have been downloaded by Wget will be changed to refer to the file they point to as a relative link.

Example: if the downloaded file <I>/foo/doc.html</I> links to <I>/bar/img.gif</I>, also downloaded, then the link in <I>doc.html</I> will be modified to point to ../bar/img.gif. This kind of transformation works reliably for arbitrary combinations of directories.


*
The links to files that have not been downloaded by Wget will be changed to include host name and absolute path of the location they point to.

Example: if the downloaded file <I>/foo/doc.html</I> links to <I>/bar/img.gif</I> (or to <I>../bar/img.gif</I>), then the link in <I>doc.html</I> will be modified to point to <I>http://hostname/bar/img.gif</I>.





Because of this, local browsing works reliably: if a linked file was downloaded, the link will refer to its local name; if it was not downloaded, the link will refer to its full Internet address rather than presenting a broken link. The fact that the former links are converted to relative links ensures that you can move the downloaded hierarchy to another directory.

Note that only at the end of the download can Wget know which links have been downloaded. Because of that, the work done by -k will be performed at the end of all the downloads.


-K

--backup-converted
When converting a file, back up the original version with a .orig suffix. Affects the behavior of -N.
-m

--mirror
Turn on options suitable for mirroring. This option turns on recursion and time-stamping, sets infinite recursion depth and keeps FTP directory listings. It is currently equivalent to -r -N -l inf -nr.
-p

--page-requisites
This option causes Wget to download all the files that are necessary to properly display a given HTML page. This includes such things as inlined images, sounds, and referenced stylesheets.

Ordinarily, when downloading a single HTML page, any requisite documents that may be needed to display it properly are not downloaded. Using -r together with -l can help, but since Wget does not ordinarily distinguish between external and inlined documents, one is generally left with ``leaf documents'' that are missing their requisites.

For instance, say document <I>1.html</I> contains an "< IMG >" tag referencing <I>1.gif</I> and an "< A >" tag pointing to external document <I>2.html</I>. Say that <I>2.html</I> is similar but that its image is <I>2.gif</I> and it links to <I>3.html</I>. Say this continues up to some arbitrarily high number.

If one executes the command:

        wget -r -l 2 http://I/1.html

</SITE>

then <I>1.html</I>, <I>1.gif</I>, <I>2.html</I>, <I>2.gif</I>, and <I>3.html</I> will be downloaded. As you can see, <I>3.html</I> is without its requisite <I>3.gif</I> because Wget is simply counting the number of hops (up to 2) away from <I>1.html</I> in order to determine where to stop the recursion. However, with this command:

        wget -r -l 2 -p http://I/1.html

</SITE>

all the above files <I>and</I> <I>3.html</I>'s requisite <I>3.gif</I> will be downloaded. Similarly,

        wget -r -l 1 -p http://I/1.html

</SITE>

will cause <I>1.html</I>, <I>1.gif</I>, <I>2.html</I>, and <I>2.gif</I> to be downloaded. One might think that:

        wget -r -l 0 -p http://I/1.html

</SITE>

would download just <I>1.html</I> and <I>1.gif</I>, but unfortunately this is not the case, because -l 0 is equivalent to -l inf---that is, infinite recursion. To download a single HTML page (or a handful of them, all specified on the commandline or in a -i URL input file) and its (or their) requisites, simply leave off -r and -l:

        wget -p http://I/1.html

</SITE>

Note that Wget will behave as if -r had been specified, but only that single page and its requisites will be downloaded. Links from that page to external documents will not be followed. Actually, to download a single page and all its requisites (even if they exist on separate websites), and make sure the lot displays properly locally, this author likes to use a few options in addition to -p:

        wget -E -H -k -K -p http://I/I

</SITE>

To finish off this topic, it's worth knowing that Wget's idea of an external document link is any URL specified in an "< A >" tag, an "" tag, or a "" tag other than "".

Recursive Accept/Reject Options

-A <I>acclist</I> --accept <I>acclist</I>
-R <I>rejlist</I> --reject <I>rejlist</I>
Specify comma-separated lists of file name suffixes or patterns to accept or reject.
-D <I>domain-list</I>
--domains=<I>domain-list</I>
Set domains to be followed. <I>domain-list</I> is a comma-separated list of domains. Note that it does <I>not</I> turn on -H.
--exclude-domains <I>domain-list</I>
Specify the domains that are <I>not</I> to be followed..
--follow-ftp
Follow FTP links from HTML documents. Without this option, Wget will ignore all the FTP links.
--follow-tags=<I>list</I>
Wget has an internal table of HTML tag / attribute pairs that it considers when looking for linked documents during a recursive retrieval. If a user wants only a subset of those tags to be considered, however, he or she should be specify such tags in a comma-separated <I>list</I> with this option.
-G <I>list</I>
--ignore-tags=<I>list</I>
This is the opposite of the --follow-tags option. To skip certain HTML tags when recursively looking for documents to download, specify them in a comma-separated <I>list</I>.

In the past, the -G option was the best bet for downloading a single page and its requisites, using a commandline like:

        wget -Ga,area -H -k -K -r http://I/I

</SITE>

However, the author of this option came across a page with tags like "" and came to the realization that -G was not enough. One can't just tell Wget to ignore "", because then stylesheets will not be downloaded. Now the best bet for downloading a single page and its requisites is the dedicated --page-requisites option.

-H
--span-hosts
Enable spanning across hosts when doing recursive retrieving.
-L
--relative
Follow relative links only. Useful for retrieving a specific home page without any distractions, not even those from the same hosts.
-I <I>list</I>
--include-directories=<I>list</I>
Specify a comma-separated list of directories you wish to follow when downloading Elements of <I>list</I> may contain wildcards.
-X <I>list</I>
--exclude-directories=<I>list</I>
Specify a comma-separated list of directories you wish to exclude from download Elements of <I>list</I> may contain wildcards.
-np
--no-parent
Do not ever ascend to the parent directory when retrieving recursively. This is a useful option, since it guarantees that only the files <I>below</I> a certain hierarchy will be downloaded.

EXAMPLES

The examples are divided into three sections loosely based on their complexity.

Simple Usage

*
Say you want to download a URL. Just type:
        wget http://fly.srk.fer.hr/

*
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.srk.fer.hr/jpg/flyweb.jpg

*
Now let's leave Wget to work in the background, and write its progress to log file <I>log</I>. It is tiring to type --tries, so we shall use -t.
        wget -t 45 -o log http://fly.srk.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.srk.fer.hr/welcome.msg

*
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/
links index.html

Advanced Usage

*
You have a file that contains the URLs you want to download? Use the -i switch:
        wget -i I

</FILE>

If you specify - as file name, the URLs will be read from standard input.

*
Create a five levels deep mirror image of the GNU web site, with the same directory structure the original has, with only one try per document, saving the log of the activities to <I>gnulog</I>:
        wget -r http://www.gnu.org/ -o gnulog

*
The same as the above, but convert the links in the HTML files to point to local files, so you can view the documents off-line:
        wget --convert-links -r http://www.gnu.org/ -o gnulog

*
Retrieve only one HTML page, but make sure that all the elements needed for the page to be displayed, such as inline images and external style sheets, are also downloaded. Also make sure the downloaded page references the downloaded links.
        wget -p --convert-links http://www.server.com/dir/page.html

The HTML page will be saved to <I>www.server.com/dir/page.html</I>, and the images, stylesheets, etc., somewhere under <I>www.server.com/</I>, depending on where they were on the remote server.

*
The same as the above, but without the <I>www.server.com/</I> directory. In fact, I don't want to have all those random server directories anyway---just save <I>all</I> those files under a <I>download/</I> subdirectory of the current directory.
        wget -p --convert-links -nH -nd -Pdownload \
http://www.server.com/dir/page.html

*
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, perhaps for post-processing.
        wget -s http://www.lycos.com/
more index.html

*
Retrieve the first two levels of wuarchive.wustl.edu, saving them to <I>/tmp</I>.
        wget -r -l2 -P/tmp ftp://wuarchive.wustl.edu/

*
You want to download all the GIFs from a directory on an HTTP server. You tried wget http://www.server.com/dir/*.gif, but that didn't work because HTTP retrieval does not support globbing. In that case, use:
        wget -r -l1 --no-parent -A.gif http://www.server.com/dir/

More verbose, but the effect is the same. -r -l1 means to retrieve recursively, with maximum depth of 1. --no-parent means that references to the parent directory are ignored, 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.org/

*
If you want to encode your own username and password to HTTP or FTP, use the appropriate URL syntax.
        wget ftp://hniksic:mypassword@unix.server.com/.emacs

Note, however, that this usage is not advisable on multi-user systems because it reveals your password to anyone who looks at the output of "ps".

*
You would like the output documents to go to standard output instead of to files?
        wget -O - http://jagor.srce.hr/ http://www.srce.hr/

You can also combine the two options and make pipelines to retrieve the documents from remote hotlists:

        wget -O - http://cool.list.com/ | wget --force-html -i -

Very Advanced Usage

*
If you wish Wget to keep a mirror of a page (or FTP subdirectories), use --mirror (-m), which is the shorthand for -r -l inf -N. You can put Wget in the crontab file asking it to recheck a site each Sunday:
        crontab
0 0 * * 0 wget --mirror http://www.gnu.org/ -o /home/me/weeklog

*
In addition to the above, you want the links to be converted for local viewing. But, after having read this manual, you know that link conversion doesn't play well with timestamping, so you also want Wget to back up the original HTML files before the conversion. Wget invocation would look like this:
        wget --mirror --convert-links --backup-converted  \
http://www.gnu.org/ -o /home/me/weeklog

*
But you've also noticed that local viewing doesn't work all that well when HTML files are saved under extensions other than .html, perhaps because they were served as <I>index.cgi</I>. So you'd like Wget to rename all the files served with content-type text/html to <I>name.html</I>.
        wget --mirror --convert-links --backup-converted \
--html-extension -o /home/me/weeklog \
http://www.gnu.org/

Or, with less typing:

        wget -m -k -K -E http://www.gnu.org/ -o /home/me/weeklog

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