‘-E’
‘--adjust-extension’
If a file of type ‘application/xhtml+xml’ or ‘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 CGI-generated materials. A URL like ‘http://site.com/article.cgi?25’ will be saved as article.cgi?25.html.
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 X.html file corresponds to remote URL ‘X’ (since it doesn't yet know that the URL produces output of type ‘text/html’ or ‘application/xhtml+xml’. To prevent this re-downloading, you must use ‘-k’ and ‘-K’ so that the original version of the file will be saved as X.orig (see Recursive Retrieval Options).

As of version 1.12, Wget will also ensure that any downloaded files of type ‘text/css’ end in the suffix ‘.css’, and the option was renamed from ‘--html-extension’, to better reflect its new behavior. The old option name is still acceptable, but should now be considered deprecated.

At some point in the future, this option may well be expanded to include suffixes for other types of content, including content types that are not parsed by Wget.




‘-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 /foo/doc.html links to /bar/img.gif, also downloaded, then the link in doc.html 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 /foo/doc.html links to /bar/img.gif (or to ../bar/img.gif), then the link in doc.html will be modified to point to http://hostname/bar/img.gif.

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.


‘-H’
‘--span-hosts’
Enable spanning across hosts when doing recursive retrieving (see Spanning Hosts). 


4.1 Spanning Hosts

Wget's recursive retrieval normally refuses to visit hosts different than the one you specified on the command line. This is a reasonable default; without it, every retrieval would have the potential to turn your Wget into a small version of google.

However, visiting different hosts, or host spanning, is sometimes a useful option. Maybe the images are served from a different server. Maybe you're mirroring a site that consists of pages interlinked between three servers. Maybe the server has two equivalent names, and the html pages refer to both interchangeably.

Span to any host—‘-H’
The ‘-H’ option turns on host spanning, thus allowing Wget's recursive run to visit any host referenced by a link. Unless sufficient recursion-limiting criteria are applied depth, these foreign hosts will typically link to yet more hosts, and so on until Wget ends up sucking up much more data than you have intended. 
Limit spanning to certain domains—‘-D’
The ‘-D’ option allows you to specify the domains that will be followed, thus limiting the recursion only to the hosts that belong to these domains. Obviously, this makes sense only in conjunction with ‘-H’. A typical example would be downloading the contents of ‘www.server.com’, but allowing downloads from ‘images.server.com’, etc.:
          wget -rH -Dserver.com http://www.server.com/
You can specify more than one address by separating them with a comma, e.g. ‘-Ddomain1.com,domain2.com’. 

Keep download off certain domains—‘--exclude-domains’
If there are domains you want to exclude specifically, you can do it with ‘--exclude-domains’, which accepts the same type of arguments of ‘-D’, but will exclude all the listed domains. For example, if you want to download all the hosts from ‘foo.edu’ domain, with the exception of ‘sunsite.foo.edu’, you can do it like this:
          wget -rH -Dfoo.edu --exclude-domains sunsite.foo.edu \
              http://www.foo.edu/



‘-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 /foo/doc.html links to /bar/img.gif, also downloaded, then the link in doc.html 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 /foo/doc.html links to /bar/img.gif (or to ../bar/img.gif), then the link in doc.html will be modified to point to http://hostname/bar/img.gif.

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.


‘-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 1.html contains an <IMG> tag referencing 1.gif and an <A> tag pointing to external document 2.html. Say that 2.html is similar but that its image is 2.gif and it links to 3.html. Say this continues up to some arbitrarily high number.

If one executes the command:

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

          wget -r -l 2 -p http://site/1.html
all the above files and 3.html's requisite 3.gif will be downloaded. Similarly,

          wget -r -l 1 -p http://site/1.html
will cause 1.html, 1.gif, 2.html, and 2.gif to be downloaded. One might think that:

          wget -r -l 0 -p http://site/1.html
would download just 1.html and 1.gif, 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 command-line or in a ‘-i’ url input file) and its (or their) requisites, simply leave off ‘-r’ and ‘-l’:

          wget -p http://site/1.html
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://site/document
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 <AREA> tag, or a <LINK> tag other than <LINK REL="stylesheet">.


‘-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’). 



‘-P prefix’
‘--directory-prefix=prefix’
Set directory prefix to prefix. The directory prefix 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).



‘-R rejlist’
‘--reject rejlist’
‘reject = rejlist’
The ‘--reject’ option works the same way as ‘--accept’, only its logic is the reverse; Wget will download all files except the ones matching the suffixes (or patterns) in the list.
So, if you want to download a whole page except for the cumbersome mpegs and .au files, you can use ‘wget -R mpg,mpeg,au’. Analogously, to download all files except the ones beginning with ‘bjork’, use ‘wget -R "bjork*"’. The quotes are to prevent expansion by the shell.

The ‘-A’ and ‘-R’ options may be combined to achieve even better fine-tuning of which files to retrieve. E.g. ‘wget -A "*zelazny*" -R .ps’ will download all the files having ‘zelazny’ as a part of their name, but not the PostScript files.

Note that these two options do not affect the downloading of html files (as determined by a ‘.htm’ or ‘.html’ filename prefix). This behavior may not be desirable for all users, and may be changed for future versions of Wget.

Note, too, that query strings (strings at the end of a URL beginning with a question mark (‘?’) are not included as part of the filename for accept/reject rules, even though these will actually contribute to the name chosen for the local file. It is expected that a future version of Wget will provide an option to allow matching against query strings.

Finally, it's worth noting that the accept/reject lists are matched twice against downloaded files: once against the URL's filename portion, to determine if the file should be downloaded in the first place; then, after it has been accepted and successfully downloaded, the local file's name is also checked against the accept/reject lists to see if it should be removed. The rationale was that, since ‘.htm’ and ‘.html’ files are always downloaded regardless of accept/reject rules, they should be removed after being downloaded and scanned for links, if they did match the accept/reject lists. However, this can lead to unexpected results, since the local filenames can differ from the original URL filenames in the following ways, all of which can change whether an accept/reject rule matches:

If the local file already exists and ‘--no-directories’ was specified, a numeric suffix will be appended to the original name.
If ‘--adjust-extension’ was specified, the local filename might have ‘.html’ appended to it. If Wget is invoked with ‘-E -A.php’, a filename such as ‘index.php’ will match be accepted, but upon download will be named ‘index.php.html’, which no longer matches, and so the file will be deleted.
Query strings do not contribute to URL matching, but are included in local filenames, and so do contribute to filename matching.
This behavior, too, is considered less-than-desirable, and may change in a future version of Wget.



‘-D domain-list’
‘--domains=domain-list’
Set domains to be followed. domain-list is a comma-separated list of domains. Note that it does not turn on ‘-H’. 
‘--exclude-domains domain-list’
Specify the domains that are not to be followed. (see Spanning Hosts).










