wget(1)


NAME

   Wget - The non-interactive network downloader.

SYNOPSIS

   wget [option]... [URL]...

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, XHTML, and CSS pages, to 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 (/robots.txt).  Wget can be instructed to convert the links in
   downloaded files to point at 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.

   Wget does not support Client Revocation Lists (CRLs) so the HTTPS
   certificate you are connecting to might be revoked by the siteowner.

OPTIONS

   Option Syntax
   Since Wget uses GNU getopt to process command-line arguments, every
   option has a long form along with the short one.  Long options are more
   convenient to remember, but take time to type.  You may freely mix
   different option styles, or specify options after the command-line
   arguments.  Thus you may write:

           wget -r --tries=10 http://fly.srk.fer.hr/ -o log

   The space between the option accepting an argument and the argument may
   be omitted.  Instead of -o log you can write -olog.

   You may put several options that do not require arguments together,
   like:

           wget -drc <URL>

   This is completely equivalent to:

           wget -d -r -c <URL>

   Since the options can be specified after the arguments, you may
   terminate them with --.  So the following will try to download URL -x,
   reporting failure to log:

           wget -o log -- -x

   The options that accept comma-separated lists all respect the
   convention that specifying an empty list clears its value.  This can be
   useful to clear the .wgetrc settings.  For instance, if your .wgetrc
   sets "exclude_directories" to /cgi-bin, the following example will
   first reset it, and then set it to exclude /~nobody and /~somebody.
   You can also clear the lists in .wgetrc.

           wget -X " -X /~nobody,/~somebody

   Most options that do not accept arguments are boolean options, so named
   because their state can be captured with a yes-or-no ("boolean")
   variable.  For example, --follow-ftp tells Wget to follow FTP links
   from HTML files and, on the other hand, --no-glob tells it not to
   perform file globbing on FTP URLs.  A boolean option is either
   affirmative or negative (beginning with --no).  All such options share
   several properties.

   Unless stated otherwise, it is assumed that the default behavior is the
   opposite of what the option accomplishes.  For example, the documented
   existence of --follow-ftp assumes that the default is to not follow FTP
   links from HTML pages.

   Affirmative options can be negated by prepending the --no- to the
   option name; negative options can be negated by omitting the --no-
   prefix.  This might seem superfluous---if the default for an
   affirmative option is to not do something, then why provide a way to
   explicitly turn it off?  But the startup file may in fact change the
   default.  For instance, using "follow_ftp = on" in .wgetrc makes Wget
   follow FTP links by default, and using --no-follow-ftp is the only way
   to restore the factory default from the command line.

   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 wget-log.

   -e command
   --execute command
       Execute command as if it were a part of .wgetrc.  A command thus
       invoked will be executed after the commands in .wgetrc, thus taking
       precedence over them.  If you need to specify more than one wgetrc
       command, use multiple instances of -e.

   Logging and Input File Options
   -o logfile
   --output-file=logfile
       Log all messages to logfile.  The messages are normally reported to
       standard error.

   -a logfile
   --append-output=logfile
       Append to logfile.  This is the same as -o, only it appends to
       logfile instead of overwriting the old log file.  If logfile 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 not 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
   --no-verbose
       Turn off verbose without being completely quiet (use -q for that),
       which means that error messages and basic information still get
       printed.

   --report-speed=type
       Output bandwidth as type.  The only accepted value is bits.

   -i file
   --input-file=file
       Read URLs from a local or external file.  If - is specified as
       file, URLs are read from the standard input.  (Use ./- to read from
       a file literally named -.)

       If this function is used, no URLs need be present 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.  If --force-html is not specified, then file should
       consist of a series of URLs, one per line.

       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 "<base href="url">" to the
       documents or by specifying --base=url on the command line.

       If the file is an external one, the document will be automatically
       treated as html if the Content-Type matches text/html.
       Furthermore, the file's location will be implicitly used as base
       href if none was specified.

   --input-metalink=file
       Downloads files covered in local Metalink file. Metalink version 3
       and 4 are supported.

   --metalink-over-http
       Issues HTTP HEAD request instead of GET and extracts Metalink
       metadata from response headers. Then it switches to Metalink
       download.  If no valid Metalink metadata is found, it falls back to
       ordinary HTTP download.

   --preferred-location
       Set preferred location for Metalink resources. This has effect if
       multiple resources with same priority are available.

   -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 "<base href="url">" to
       HTML, or using the --base command-line option.

   -B URL
   --base=URL
       Resolves relative links using URL as the point of reference, when
       reading links from an HTML file specified via the -i/--input-file
       option (together with --force-html, or when the input file was
       fetched remotely from a server describing it as HTML). This is
       equivalent to the presence of a "BASE" tag in the HTML input file,
       with URL as the value for the "href" attribute.

       For instance, if you specify http://foo/bar/a.html for URL, and
       Wget reads ../baz/b.html from the input file, it would be resolved
       to http://foo/baz/b.html.

   --config=FILE
       Specify the location of a startup file you wish to use.

   --rejected-log=logfile
       Logs all URL rejections to logfile as comma separated values.  The
       values include the reason of rejection, the URL and the parent URL
       it was found in.

   Download Options
   --bind-address=ADDRESS
       When making client TCP/IP connections, bind to ADDRESS on the local
       machine.  ADDRESS may be specified as a hostname or IP address.
       This option can be useful if your machine is bound to multiple IPs.

   --bind-dns-address=ADDRESS
       [libcares only] This address overrides the route for DNS requests.
       If you ever need to circumvent the standard settings from
       /etc/resolv.conf, this option together with --dns-servers is your
       friend.  ADDRESS must be specified either as IPv4 or IPv6 address.
       Wget needs to be built with libcares for this option to be
       available.

   --dns-servers=ADDRESSES
       [libcares only] The given address(es) override the standard
       nameserver addresses,  e.g. as configured in /etc/resolv.conf.
       ADDRESSES may be specified either as IPv4 or IPv6 addresses, comma-
       separated.  Wget needs to be built with libcares for this option to
       be available.

   -t number
   --tries=number
       Set number of tries to number. Specify 0 or inf for infinite
       retrying.  The default is to retry 20 times, with the exception of
       fatal errors like "connection refused" or "not found" (404), which
       are not retried.

   -O file
   --output-document=file
       The documents will not be written to the appropriate files, but all
       will be concatenated together and written to file.  If - is used as
       file, documents will be printed to standard output, disabling link
       conversion.  (Use ./- to print to a file literally named -.)

       Use of -O is not intended to mean simply "use the name file instead
       of the one in the URL;" rather, it is analogous to shell
       redirection: wget -O file http://foo is intended to work like wget
       -O - http://foo > file; file will be truncated immediately, and all
       downloaded content will be written there.

       For this reason, -N (for timestamp-checking) is not supported in
       combination with -O: since file is always newly created, it will
       always have a very new timestamp. A warning will be issued if this
       combination is used.

       Similarly, using -r or -p with -O may not work as you expect: Wget
       won't just download the first file to file and then download the
       rest to their normal names: all downloaded content will be placed
       in file. This was disabled in version 1.11, but has been reinstated
       (with a warning) in 1.11.2, as there are some cases where this
       behavior can actually have some use.

       A combination with -nc is only accepted if the given output file
       does not exist.

       Note that a combination with -k is only permitted when downloading
       a single document, as in that case it will just convert all
       relative URIs to external ones; -k makes no sense for multiple URIs
       when they're all being downloaded to a single file; -k can be used
       only when the output is a regular file.

   -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 clobbered, or overwritten,
       upon repeated download.  In other cases it will be preserved.

       When running Wget without -N, -nc, -r, or -p, downloading the same
       file in the same directory will result in the original copy of file
       being preserved and the second copy being named file.1.  If that
       file is downloaded yet again, the third copy will be named file.2,
       and so on.  (This is also the behavior with -nd, even if -r or -p
       are in effect.)  When -nc is specified, this behavior is
       suppressed, and Wget will refuse to download newer copies of file.
       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 or -p, but without -N, -nd, 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 or -p, 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.

       A combination with -O/--output-document is only accepted if the
       given output file does not exist.

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

   --backups=backups
       Before (over)writing a file, back up an existing file by adding a
       .1 suffix (_1 on VMS) to the file name.  Such backup files are
       rotated to .2, .3, and so on, up to backups (and lost beyond that).

   -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 ls-lR.Z 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 prior 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 ls-lR.Z.1, leaving the truncated ls-lR.Z file alone.

       If you use -c on a non-empty file, and the server does not support
       continued downloading, Wget will restart the download from scratch
       and overwrite the existing file entirely.

       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
       changed, as opposed to just appended 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.

   --start-pos=OFFSET
       Start downloading at zero-based position OFFSET.  Offset may be
       expressed in bytes, kilobytes with the `k' suffix, or megabytes
       with the `m' suffix, etc.

       --start-pos has higher precedence over --continue.  When
       --start-pos and --continue are both specified, wget will emit a
       warning then proceed as if --continue was absent.

       Server support for continued download is required, otherwise
       --start-pos cannot help.  See -c for details.

   --progress=type
       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.

       The progress type can also take one or more parameters.  The
       parameters vary based on the type selected.  Parameters to type are
       passed by appending them to the type sperated by a colon (:) like
       this: --progress=type:parameter1:parameter2.

       When using the dotted retrieval, you may set the style by
       specifying the type as dot:style.  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 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).  If "mega" is not enough then you can use the "giga"
       style---each dot represents 1M retrieved, there are eight dots in a
       cluster, and 32 dots on each line (so each line contains 32M).

       With --progress=bar, there are currently two possible parameters,
       force and noscroll.

       When the output is not a TTY, the progress bar always falls back to
       "dot", even if --progress=bar was passed to Wget during invokation.
       This behaviour can be overridden and the "bar" output forced by
       using the "force" parameter as --progress=bar:force.

       By default, the bar style progress bar scroll the name of the file
       from left to right for the file being downloaded if the filename
       exceeds the maximum length allotted for its display.  In certain
       cases, such as with --progress=bar:force, one may not want the
       scrolling filename in the progress bar.  By passing the "noscroll"
       parameter, Wget can be forced to display as much of the filename as
       possible without scrolling through it.

       Note that you can set the default style using the "progress"
       command in .wgetrc.  That setting may be overridden from the
       command line.  For example, to force the bar output without
       scrolling, use --progress=bar:force:noscroll.

   --show-progress
       Force wget to display the progress bar in any verbosity.

       By default, wget only displays the progress bar in verbose mode.
       One may however, want wget to display the progress bar on screen in
       conjunction with any other verbosity modes like --no-verbose or
       --quiet.  This is often a desired a property when invoking wget to
       download several small/large files.  In such a case, wget could
       simply be invoked with this parameter to get a much cleaner output
       on the screen.

       This option will also force the progress bar to be printed to
       stderr when used alongside the --logfile option.

   -N
   --timestamping
       Turn on time-stamping.

   --no-if-modified-since
       Do not send If-Modified-Since header in -N mode. Send preliminary
       HEAD request instead. This has only effect in -N mode.

   --no-use-server-timestamps
       Don't set the local file's timestamp by the one on the server.

       By default, when a file is downloaded, its timestamps are set to
       match those from the remote file. This allows the use of
       --timestamping on subsequent invocations of wget. However, it is
       sometimes useful to base the local file's timestamp on when it was
       actually downloaded; for that purpose, the
       --no-use-server-timestamps option has been provided.

   -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 spider,
       which means that it will not download the pages, just check that
       they are there.  For example, you can use Wget to check your
       bookmarks:

               wget --spider --force-html -i bookmarks.html

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

   -T seconds
   --timeout=seconds
       Set the network timeout to seconds seconds.  This is equivalent to
       specifying --dns-timeout, --connect-timeout, and --read-timeout,
       all at the same time.

       When interacting with the network, Wget can check for timeout and
       abort the operation if it takes too long.  This prevents anomalies
       like hanging reads and infinite connects.  The only timeout enabled
       by default is a 900-second read timeout.  Setting a timeout to 0
       disables it altogether.  Unless you know what you are doing, it is
       best not to change the default timeout settings.

       All timeout-related options accept decimal values, as well as
       subsecond values.  For example, 0.1 seconds is a legal (though
       unwise) choice of timeout.  Subsecond timeouts are useful for
       checking server response times or for testing network latency.

   --dns-timeout=seconds
       Set the DNS lookup timeout to seconds seconds.  DNS lookups that
       don't complete within the specified time will fail.  By default,
       there is no timeout on DNS lookups, other than that implemented by
       system libraries.

   --connect-timeout=seconds
       Set the connect timeout to seconds seconds.  TCP connections that
       take longer to establish will be aborted.  By default, there is no
       connect timeout, other than that implemented by system libraries.

   --read-timeout=seconds
       Set the read (and write) timeout to seconds seconds.  The "time" of
       this timeout refers to idle time: if, at any point in the download,
       no data is received for more than the specified number of seconds,
       reading fails and the download is restarted.  This option does not
       directly affect the duration of the entire download.

       Of course, the remote server may choose to terminate the connection
       sooner than this option requires.  The default read timeout is 900
       seconds.

   --limit-rate=amount
       Limit the download speed to amount 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 is useful when, for whatever
       reason, you don't want Wget to consume the entire available
       bandwidth.

       This option allows the use of decimal numbers, usually in
       conjunction with power suffixes; for example, --limit-rate=2.5k is
       a legal value.

       Note that Wget implements 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 may take some time for this balance to be achieved, so
       don't be surprised if limiting the rate doesn't work well with very
       small files.

   -w seconds
   --wait=seconds
       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.  The waiting interval specified by this function is
       influenced by "--random-wait", which see.

   --waitretry=seconds
       If you don't want Wget to wait between every retrieval, but only
       between retries of failed downloads, you can use this option.  Wget
       will use linear backoff, 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 seconds you specify.

       By default, Wget will assume a value of 10 seconds.

   --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 0.5 and 1.5 * wait seconds,
       where wait was specified using the --wait option, in order to mask
       Wget's presence from such analysis.

       A 2001 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.

   --no-proxy
       Don't use proxies, even if the appropriate *_proxy environment
       variable is defined.

   -Q quota
   --quota=quota
       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 https://example.com/ls-lR.gz, all of the
       ls-lR.gz 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.

   --no-dns-cache
       Turn off caching of DNS lookups.  Normally, Wget remembers the IP
       addresses it looked up from DNS so it doesn't have to repeatedly
       contact the DNS server for the same (typically small) set of hosts
       it retrieves from.  This cache exists in memory only; a new Wget
       run will contact DNS again.

       However, it has been reported that in some situations it is not
       desirable to cache host names, even for the duration of a short-
       running application like Wget.  With this option Wget issues a new
       DNS lookup (more precisely, a new call to "gethostbyname" or
       "getaddrinfo") each time it makes a new connection.  Please note
       that this option will not affect caching that might be performed by
       the resolving library or by an external caching layer, such as
       NSCD.

       If you don't understand exactly what this option does, you probably
       won't need it.

   --restrict-file-names=modes
       Change which characters found in remote URLs must be escaped during
       generation of local filenames.  Characters that are restricted by
       this option are escaped, i.e. replaced with %HH, where HH is the
       hexadecimal number that corresponds to the restricted character.
       This option may also be used to force all alphabetical cases to be
       either lower- or uppercase.

       By default, Wget escapes the characters that are not valid or safe
       as part of file names on your operating system, as well as control
       characters that are typically unprintable.  This option is useful
       for changing these defaults, perhaps because you are downloading to
       a non-native partition, or because you want to disable escaping of
       the control characters, or you want to further restrict characters
       to only those in the ASCII range of values.

       The modes are a comma-separated set of text values. The acceptable
       values are unix, windows, nocontrol, ascii, lowercase, and
       uppercase. The values unix and windows are mutually exclusive (one
       will override the other), as are lowercase and uppercase. Those
       last are special cases, as they do not change the set of characters
       that would be escaped, but rather force local file paths to be
       converted either to lower- or uppercase.

       When "unix" is specified, Wget escapes the character / and the
       control characters in the ranges 0--31 and 128--159.  This is the
       default on Unix-like operating systems.

       When "windows" is given, Wget escapes the characters \, |, /, :, ?,
       ", *, <, >, and the control characters in the ranges 0--31 and
       128--159.  In addition to this, Wget in Windows mode uses + instead
       of : to separate host and port in local file names, and uses @
       instead of ? to separate the query portion of the file name from
       the rest.  Therefore, a URL that would be saved as
       www.xemacs.org:4300/search.pl?input=blah in Unix mode would be
       saved as www.xemacs.org+4300/search.pl@input=blah in Windows mode.
       This mode is the default on Windows.

       If you specify nocontrol, then the escaping of the control
       characters is also switched off. This option may make sense when
       you are downloading URLs whose names contain UTF-8 characters, on a
       system which can save and display filenames in UTF-8 (some possible
       byte values used in UTF-8 byte sequences fall in the range of
       values designated by Wget as "controls").

       The ascii mode is used to specify that any bytes whose values are
       outside the range of ASCII characters (that is, greater than 127)
       shall be escaped. This can be useful when saving filenames whose
       encoding does not match the one used locally.

   -4
   --inet4-only
   -6
   --inet6-only
       Force connecting to IPv4 or IPv6 addresses.  With --inet4-only or
       -4, Wget will only connect to IPv4 hosts, ignoring AAAA records in
       DNS, and refusing to connect to IPv6 addresses specified in URLs.
       Conversely, with --inet6-only or -6, Wget will only connect to IPv6
       hosts and ignore A records and IPv4 addresses.

       Neither options should be needed normally.  By default, an
       IPv6-aware Wget will use the address family specified by the host's
       DNS record.  If the DNS responds with both IPv4 and IPv6 addresses,
       Wget will try them in sequence until it finds one it can connect
       to.  (Also see "--prefer-family" option described below.)

       These options can be used to deliberately force the use of IPv4 or
       IPv6 address families on dual family systems, usually to aid
       debugging or to deal with broken network configuration.  Only one
       of --inet6-only and --inet4-only may be specified at the same time.
       Neither option is available in Wget compiled without IPv6 support.

   --prefer-family=none/IPv4/IPv6
       When given a choice of several addresses, connect to the addresses
       with specified address family first.  The address order returned by
       DNS is used without change by default.

       This avoids spurious errors and connect attempts when accessing
       hosts that resolve to both IPv6 and IPv4 addresses from IPv4
       networks.  For example, www.kame.net resolves to
       2001:200:0:8002:203:47ff:fea5:3085 and to 203.178.141.194.  When
       the preferred family is "IPv4", the IPv4 address is used first;
       when the preferred family is "IPv6", the IPv6 address is used
       first; if the specified value is "none", the address order returned
       by DNS is used without change.

       Unlike -4 and -6, this option doesn't inhibit access to any address
       family, it only changes the order in which the addresses are
       accessed.  Also note that the reordering performed by this option
       is stable---it doesn't affect order of addresses of the same
       family.  That is, the relative order of all IPv4 addresses and of
       all IPv6 addresses remains intact in all cases.

   --retry-connrefused
       Consider "connection refused" a transient error and try again.
       Normally Wget gives up on a URL when it is unable to connect to the
       site because failure to connect is taken as a sign that the server
       is not running at all and that retries would not help.  This option
       is for mirroring unreliable sites whose servers tend to disappear
       for short periods of time.

   --user=user
   --password=password
       Specify the username user and password password for both FTP and
       HTTP file retrieval.  These parameters can be overridden using the
       --ftp-user and --ftp-password options for FTP connections and the
       --http-user and --http-password options for HTTP connections.

   --ask-password
       Prompt for a password for each connection established. Cannot be
       specified when --password is being used, because they are mutually
       exclusive.

   --no-iri
       Turn off internationalized URI (IRI) support. Use --iri to turn it
       on. IRI support is activated by default.

       You can set the default state of IRI support using the "iri"
       command in .wgetrc. That setting may be overridden from the command
       line.

   --local-encoding=encoding
       Force Wget to use encoding as the default system encoding. That
       affects how Wget converts URLs specified as arguments from locale
       to UTF-8 for IRI support.

       Wget use the function "nl_langinfo()" and then the "CHARSET"
       environment variable to get the locale. If it fails, ASCII is used.

       You can set the default local encoding using the "local_encoding"
       command in .wgetrc. That setting may be overridden from the command
       line.

   --remote-encoding=encoding
       Force Wget to use encoding as the default remote server encoding.
       That affects how Wget converts URIs found in files from remote
       encoding to UTF-8 during a recursive fetch. This options is only
       useful for IRI support, for the interpretation of non-ASCII
       characters.

       For HTTP, remote encoding can be found in HTTP "Content-Type"
       header and in HTML "Content-Type http-equiv" meta tag.

       You can set the default encoding using the "remoteencoding" command
       in .wgetrc. That setting may be overridden from the command line.

   --unlink
       Force Wget to unlink file instead of clobbering existing file. This
       option is useful for downloading to the directory with hardlinks.

   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
       fly.srk.fer.hr/robots.txt.

   -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 fly.srk.fer.hr/.  This
       option disables such behavior.

   --protocol-directories
       Use the protocol name as a directory component of local file names.
       For example, with this option, wget -r http://host will save to
       http/host/... rather than just to host/....

   --cut-dirs=number
       Ignore number 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 ftp.xemacs.org/pub/xemacs/.  While the
       -nH option can remove the ftp.xemacs.org/ part, you are still stuck
       with pub/xemacs.  This is where --cut-dirs comes in handy; it makes
       Wget not "see" number 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 beta/ subdirectory will be placed to
       xemacs/beta, as one would expect.

   -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).

   HTTP Options
   --default-page=name
       Use name as the default file name when it isn't known (i.e., for
       URLs that end in a slash), instead of index.html.

   -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.

       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.

   --http-user=user
   --http-password=password
       Specify the username user and password password on an HTTP server.
       According to the type of the challenge, Wget will encode them using
       either the "basic" (insecure), the "digest", or the Windows "NTLM"
       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
       .wgetrc or .netrc, 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.

   --no-http-keep-alive
       Turn off the "keep-alive" feature for HTTP downloads.  Normally,
       Wget asks the server to keep the connection open so that, when you
       download more than one document from the same server, they get
       transferred over the same TCP connection.  This saves time and at
       the same time reduces the load on the server.

       This option is useful when, for some reason, persistent (keep-
       alive) connections don't work for you, for example due to a server
       bug or due to the inability of server-side scripts to cope with the
       connections.

   --no-cache
       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.

   --no-cookies
       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, storing cookies is not on by
       default.

   --load-cookies file
       Load cookies from file before the first HTTP retrieval.  file is a
       textual file in the format originally used by Netscape's
       cookies.txt 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
       cookies.txt 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 ~/.netscape/cookies.txt.

       "Mozilla and Netscape 6.x."
           Mozilla's cookie file is also named cookies.txt, located
           somewhere under ~/.mozilla, in the directory of your profile.
           The full path usually ends up looking somewhat like
           ~/.mozilla/default/some-weird-string/cookies.txt.

       "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 --no-cookies --header "Cookie: <name>=<value>"

   --save-cookies file
       Save cookies to file before exiting.  This will not save cookies
       that have expired or that have no expiry time (so-called "session
       cookies"), but also see --keep-session-cookies.

   --keep-session-cookies
       When specified, causes --save-cookies to also save session cookies.
       Session cookies are normally not saved because they are meant to be
       kept in memory and forgotten when you exit the browser.  Saving
       them is useful on sites that require you to log in or to visit the
       home page before you can access some pages.  With this option,
       multiple Wget runs are considered a single browser session as far
       as the site is concerned.

       Since the cookie file format does not normally carry session
       cookies, Wget marks them with an expiry timestamp of 0.  Wget's
       --load-cookies recognizes those as session cookies, but it might
       confuse other browsers.  Also note that cookies so loaded will be
       treated as other session cookies, which means that if you want
       --save-cookies to preserve them again, you must use
       --keep-session-cookies again.

   --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=header-line
       Send header-line along with the rest of the headers in each HTTP
       request.  The supplied header is sent as-is, which means it must
       contain name and value separated by colon, 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.

       As of Wget 1.10, this option can be used to override headers
       otherwise generated automatically.  This example instructs Wget to
       connect to localhost, but to specify foo.bar in the "Host" header:

               wget --header="Host: foo.bar" http://localhost/

       In versions of Wget prior to 1.10 such use of --header caused
       sending of duplicate headers.

   --max-redirect=number
       Specifies the maximum number of redirections to follow for a
       resource.  The default is 20, which is usually far more than
       necessary. However, on those occasions where you want to allow more
       (or fewer), this is the option to use.

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

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

   --referer=url
       Include `Referer: url' 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.

   --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 agent-string
   --user-agent=agent-string
       Identify as agent-string 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/version,
       version 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 this is not such a bad idea in theory, it has
       been abused by servers denying information to clients other than
       (historically) Netscape or, more frequently, 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.

       Specifying empty user agent with --user-agent="" instructs Wget not
       to send the "User-Agent" header in HTTP requests.

   --post-data=string
   --post-file=file
       Use POST as the method for all HTTP requests and send the specified
       data in the request body.  --post-data sends string as data,
       whereas --post-file sends the contents of file.  Other than that,
       they work in exactly the same way. In particular, they both expect
       content of the form "key1=value1&key2=value2", with percent-
       encoding for special characters; the only difference is that one
       expects its content as a command-line parameter and the other
       accepts its content from a file. In particular, --post-file is not
       for transmitting files as form attachments: those must appear as
       "key=value" data (with appropriate percent-coding) just like
       everything else. Wget does not currently support
       "multipart/form-data" for transmitting POST data; only
       "application/x-www-form-urlencoded". Only one of --post-data and
       --post-file should be specified.

       Please note that wget does not require the content to be of the
       form "key1=value1&key2=value2", and neither does it test for it.
       Wget will simply transmit whatever data is provided to it. Most
       servers however expect the POST data to be in the above format when
       processing HTML Forms.

       When sending a POST request using the --post-file option, Wget
       treats the file as a binary file and will send every character in
       the POST request without stripping trailing newline or formfeed
       characters. Any other control characters in the text will also be
       sent as-is in the POST request.

       Please be aware that Wget needs to know the size of the POST data
       in advance.  Therefore the argument to "--post-file" must be a
       regular file; specifying a FIFO or something like /dev/stdin won't
       work.  It's not quite clear how to work around this limitation
       inherent in HTTP/1.0.  Although HTTP/1.1 introduces chunked
       transfer that doesn't require knowing the request length in
       advance, a client can't use chunked unless it knows it's talking to
       an HTTP/1.1 server.  And it can't know that until it receives a
       response, which in turn requires the request to have been completed
       -- a chicken-and-egg problem.

       Note: As of version 1.15 if Wget is redirected after the POST
       request is completed, its behaviour will depend on the response
       code returned by the server.  In case of a 301 Moved Permanently,
       302 Moved Temporarily or 307 Temporary Redirect, Wget will, in
       accordance with RFC2616, continue to send a POST request.  In case
       a server wants the client to change the Request method upon
       redirection, it should send a 303 See Other response code.

       This example shows how to log in to a server using POST and then
       proceed to download the desired pages, presumably only accessible
       to authorized users:

               # Log in to the server.  This can be done only once.
               wget --save-cookies cookies.txt \
                    --post-data 'user=foo&password=bar' \
                    http://example.com/auth.php

               # Now grab the page or pages we care about.
               wget --load-cookies cookies.txt \
                    -p http://example.com/interesting/article.php

       If the server is using session cookies to track user
       authentication, the above will not work because --save-cookies will
       not save them (and neither will browsers) and the cookies.txt file
       will be empty.  In that case use --keep-session-cookies along with
       --save-cookies to force saving of session cookies.

   --method=HTTP-Method
       For the purpose of RESTful scripting, Wget allows sending of other
       HTTP Methods without the need to explicitly set them using
       --header=Header-Line.  Wget will use whatever string is passed to
       it after --method as the HTTP Method to the server.

   --body-data=Data-String
   --body-file=Data-File
       Must be set when additional data needs to be sent to the server
       along with the Method specified using --method.  --body-data sends
       string as data, whereas --body-file sends the contents of file.
       Other than that, they work in exactly the same way.

       Currently, --body-file is not for transmitting files as a whole.
       Wget does not currently support "multipart/form-data" for
       transmitting data; only "application/x-www-form-urlencoded". In the
       future, this may be changed so that wget sends the --body-file as a
       complete file instead of sending its contents to the server. Please
       be aware that Wget needs to know the contents of BODY Data in
       advance, and hence the argument to --body-file should be a regular
       file. See --post-file for a more detailed explanation.  Only one of
       --body-data and --body-file should be specified.

       If Wget is redirected after the request is completed, Wget will
       suspend the current method and send a GET request till the
       redirection is completed.  This is true for all redirection
       response codes except 307 Temporary Redirect which is used to
       explicitly specify that the request method should not change.
       Another exception is when the method is set to "POST", in which
       case the redirection rules specified under --post-data are
       followed.

   --content-disposition
       If this is set to on, experimental (not fully-functional) support
       for "Content-Disposition" headers is enabled. This can currently
       result in extra round-trips to the server for a "HEAD" request, and
       is known to suffer from a few bugs, which is why it is not
       currently enabled by default.

       This option is useful for some file-downloading CGI programs that
       use "Content-Disposition" headers to describe what the name of a
       downloaded file should be.

   --content-on-error
       If this is set to on, wget will not skip the content when the
       server responds with a http status code that indicates error.

   --trust-server-names
       If this is set to on, on a redirect the last component of the
       redirection URL will be used as the local file name.  By default it
       is used the last component in the original URL.

   --auth-no-challenge
       If this option is given, Wget will send Basic HTTP authentication
       information (plaintext username and password) for all requests,
       just like Wget 1.10.2 and prior did by default.

       Use of this option is not recommended, and is intended only to
       support some few obscure servers, which never send HTTP
       authentication challenges, but accept unsolicited auth info, say,
       in addition to form-based authentication.

   HTTPS (SSL/TLS) Options
   To support encrypted HTTP (HTTPS) downloads, Wget must be compiled with
   an external SSL library. The current default is GnuTLS.  In addition,
   Wget also supports HSTS (HTTP Strict Transport Security).  If Wget is
   compiled without SSL support, none of these options are available.

   --secure-protocol=protocol
       Choose the secure protocol to be used.  Legal values are auto,
       SSLv2, SSLv3, TLSv1, TLSv1_1, TLSv1_2 and PFS.  If auto is used,
       the SSL library is given the liberty of choosing the appropriate
       protocol automatically, which is achieved by sending a TLSv1
       greeting. This is the default.

       Specifying SSLv2, SSLv3, TLSv1, TLSv1_1 or TLSv1_2 forces the use
       of the corresponding protocol.  This is useful when talking to old
       and buggy SSL server implementations that make it hard for the
       underlying SSL library to choose the correct protocol version.
       Fortunately, such servers are quite rare.

       Specifying PFS enforces the use of the so-called Perfect Forward
       Security cipher suites. In short, PFS adds security by creating a
       one-time key for each SSL connection. It has a bit more CPU impact
       on client and server.  We use known to be secure ciphers (e.g. no
       MD4) and the TLS protocol.

   --https-only
       When in recursive mode, only HTTPS links are followed.

   --no-check-certificate
       Don't check the server certificate against the available
       certificate authorities.  Also don't require the URL host name to
       match the common name presented by the certificate.

       As of Wget 1.10, the default is to verify the server's certificate
       against the recognized certificate authorities, breaking the SSL
       handshake and aborting the download if the verification fails.
       Although this provides more secure downloads, it does break
       interoperability with some sites that worked with previous Wget
       versions, particularly those using self-signed, expired, or
       otherwise invalid certificates.  This option forces an "insecure"
       mode of operation that turns the certificate verification errors
       into warnings and allows you to proceed.

       If you encounter "certificate verification" errors or ones saying
       that "common name doesn't match requested host name", you can use
       this option to bypass the verification and proceed with the
       download.  Only use this option if you are otherwise convinced of
       the site's authenticity, or if you really don't care about the
       validity of its certificate.  It is almost always a bad idea not to
       check the certificates when transmitting confidential or important
       data.  For self-signed/internal certificates, you should download
       the certificate and verify against that instead of forcing this
       insecure mode.  If you are really sure of not desiring any
       certificate verification, you can specify --check-certificate=quiet
       to tell wget to not print any warning about invalid certificates,
       albeit in most cases this is the wrong thing to do.

   --certificate=file
       Use the client certificate stored in file.  This is needed for
       servers that are configured to require certificates from the
       clients that connect to them.  Normally a certificate is not
       required and this switch is optional.

   --certificate-type=type
       Specify the type of the client certificate.  Legal values are PEM
       (assumed by default) and DER, also known as ASN1.

   --private-key=file
       Read the private key from file.  This allows you to provide the
       private key in a file separate from the certificate.

   --private-key-type=type
       Specify the type of the private key.  Accepted values are PEM (the
       default) and DER.

   --ca-certificate=file
       Use file as the file with the bundle of certificate authorities
       ("CA") to verify the peers.  The certificates must be in PEM
       format.

       Without this option Wget looks for CA certificates at the system-
       specified locations, chosen at OpenSSL installation time.

   --ca-directory=directory
       Specifies directory containing CA certificates in PEM format.  Each
       file contains one CA certificate, and the file name is based on a
       hash value derived from the certificate.  This is achieved by
       processing a certificate directory with the "c_rehash" utility
       supplied with OpenSSL.  Using --ca-directory is more efficient than
       --ca-certificate when many certificates are installed because it
       allows Wget to fetch certificates on demand.

       Without this option Wget looks for CA certificates at the system-
       specified locations, chosen at OpenSSL installation time.

   --crl-file=file
       Specifies a CRL file in file.  This is needed for certificates that
       have been revocated by the CAs.

   --pinnedpubkey=file/hashes
       Tells wget to use the specified public key file (or hashes) to
       verify the peer.  This can be a path to a file which contains a
       single public key in PEM or DER format, or any number of base64
       encoded sha256 hashes preceded by "sha256//" and separated by ";"

       When negotiating a TLS or SSL connection, the server sends a
       certificate indicating its identity. A public key is extracted from
       this certificate and if it does not exactly match the public key(s)
       provided to this option, wget will abort the connection before
       sending or receiving any data.

   --random-file=file
       [OpenSSL and LibreSSL only] Use file as the source of random data
       for seeding the pseudo-random number generator on systems without
       /dev/urandom.

       On such systems the SSL library needs an external source of
       randomness to initialize.  Randomness may be provided by EGD (see
       --egd-file below) or read from an external source specified by the
       user.  If this option is not specified, Wget looks for random data
       in $RANDFILE or, if that is unset, in $HOME/.rnd.

       If you're getting the "Could not seed OpenSSL PRNG; disabling SSL."
       error, you should provide random data using some of the methods
       described above.

   --egd-file=file
       [OpenSSL only] Use file as the EGD socket.  EGD stands for Entropy
       Gathering Daemon, a user-space program that collects data from
       various unpredictable system sources and makes it available to
       other programs that might need it.  Encryption software, such as
       the SSL library, needs sources of non-repeating randomness to seed
       the random number generator used to produce cryptographically
       strong keys.

       OpenSSL allows the user to specify his own source of entropy using
       the "RAND_FILE" environment variable.  If this variable is unset,
       or if the specified file does not produce enough randomness,
       OpenSSL will read random data from EGD socket specified using this
       option.

       If this option is not specified (and the equivalent startup command
       is not used), EGD is never contacted.  EGD is not needed on modern
       Unix systems that support /dev/urandom.

   --no-hsts
       Wget supports HSTS (HTTP Strict Transport Security, RFC 6797) by
       default.  Use --no-hsts to make Wget act as a non-HSTS-compliant
       UA. As a consequence, Wget would ignore all the
       "Strict-Transport-Security" headers, and would not enforce any
       existing HSTS policy.

   --hsts-file=file
       By default, Wget stores its HSTS database in ~/.wget-hsts.  You can
       use --hsts-file to override this. Wget will use the supplied file
       as the HSTS database. Such file must conform to the correct HSTS
       database format used by Wget. If Wget cannot parse the provided
       file, the behaviour is unspecified.

       The Wget's HSTS database is a plain text file. Each line contains
       an HSTS entry (ie. a site that has issued a
       "Strict-Transport-Security" header and that therefore has specified
       a concrete HSTS policy to be applied). Lines starting with a dash
       ("#") are ignored by Wget. Please note that in spite of this
       convenient human-readability hand-hacking the HSTS database is
       generally not a good idea.

       An HSTS entry line consists of several fields separated by one or
       more whitespace:

       "<hostname> SP [<port>] SP <include subdomains> SP <created> SP
       <max-age>"

       The hostname and port fields indicate the hostname and port to
       which the given HSTS policy applies. The port field may be zero,
       and it will, in most of the cases. That means that the port number
       will not be taken into account when deciding whether such HSTS
       policy should be applied on a given request (only the hostname will
       be evaluated). When port is different to zero, both the target
       hostname and the port will be evaluated and the HSTS policy will
       only be applied if both of them match. This feature has been
       included for testing/development purposes only.  The Wget testsuite
       (in testenv/) creates HSTS databases with explicit ports with the
       purpose of ensuring Wget's correct behaviour. Applying HSTS
       policies to ports other than the default ones is discouraged by RFC
       6797 (see Appendix B "Differences between HSTS Policy and Same-
       Origin Policy"). Thus, this functionality should not be used in
       production environments and port will typically be zero. The last
       three fields do what they are expected to. The field
       include_subdomains can either be 1 or 0 and it signals whether the
       subdomains of the target domain should be part of the given HSTS
       policy as well. The created and max-age fields hold the timestamp
       values of when such entry was created (first seen by Wget) and the
       HSTS-defined value 'max-age', which states how long should that
       HSTS policy remain active, measured in seconds elapsed since the
       timestamp stored in created. Once that time has passed, that HSTS
       policy will no longer be valid and will eventually be removed from
       the database.

       If you supply your own HSTS database via --hsts-file, be aware that
       Wget may modify the provided file if any change occurs between the
       HSTS policies requested by the remote servers and those in the
       file. When Wget exists, it effectively updates the HSTS database by
       rewriting the database file with the new entries.

       If the supplied file does not exist, Wget will create one. This
       file will contain the new HSTS entries. If no HSTS entries were
       generated (no "Strict-Transport-Security" headers were sent by any
       of the servers) then no file will be created, not even an empty
       one. This behaviour applies to the default database file
       (~/.wget-hsts) as well: it will not be created until some server
       enforces an HSTS policy.

       Care is taken not to override possible changes made by other Wget
       processes at the same time over the HSTS database. Before dumping
       the updated HSTS entries on the file, Wget will re-read it and
       merge the changes.

       Using a custom HSTS database and/or modifying an existing one is
       discouraged.  For more information about the potential security
       threats arised from such practice, see section 14 "Security
       Considerations" of RFC 6797, specially section 14.9 "Creative
       Manipulation of HSTS Policy Store".

   --warc-file=file
       Use file as the destination WARC file.

   --warc-header=string
       Use string into as the warcinfo record.

   --warc-max-size=size
       Set the maximum size of the WARC files to size.

   --warc-cdx
       Write CDX index files.

   --warc-dedup=file
       Do not store records listed in this CDX file.

   --no-warc-compression
       Do not compress WARC files with GZIP.

   --no-warc-digests
       Do not calculate SHA1 digests.

   --no-warc-keep-log
       Do not store the log file in a WARC record.

   --warc-tempdir=dir
       Specify the location for temporary files created by the WARC
       writer.

   FTP Options
   --ftp-user=user
   --ftp-password=password
       Specify the username user and password password on an FTP server.
       Without this, or the corresponding startup option, the password
       defaults to -wget@, normally used for anonymous FTP.

       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
       .wgetrc or .netrc, 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.

   --no-remove-listing
       Don't remove the temporary .listing 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
       .listing a symbolic link to /etc/passwd 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 .listing, making
       the globbing/recursion/time-stamping operation fail, or the
       symbolic link will be deleted and replaced with the actual .listing
       file, or the listing will be written to a .listing.number 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 index.html to /etc/passwd and asking
       "root" to run Wget with -N or -r so the file will be overwritten.

   --no-glob
       Turn off FTP globbing.  Globbing refers to the use of shell-like
       special characters (wildcards), 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).

   --no-passive-ftp
       Disable the use of the passive FTP transfer mode.  Passive FTP
       mandates that the client connect to the server to establish the
       data connection rather than the other way around.

       If the machine is connected to the Internet directly, both passive
       and active FTP should work equally well.  Behind most firewall and
       NAT configurations passive FTP has a better chance of working.
       However, in some rare firewall configurations, active FTP actually
       works when passive FTP doesn't.  If you suspect this to be the
       case, use this option, or set "passive_ftp=off" in your init file.

   --preserve-permissions
       Preserve remote file permissions instead of permissions set by
       umask.

   --retr-symlinks
       By default, when retrieving FTP directories recursively and a
       symbolic link is encountered, the symbolic link is traversed and
       the pointed-to files are retrieved.  Currently, Wget does not
       traverse symbolic links to directories to download them
       recursively, though this feature may be added in the future.

       When --retr-symlinks=no is specified, 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 retrieved unless
       this recursive retrieval would have encountered it separately and
       downloaded it anyway.  This option poses a security risk where a
       malicious FTP Server may cause Wget to write to files outside of
       the intended directories through a specially crafted .LISTING file.

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

   FTPS Options
   --ftps-implicit
       This option tells Wget to use FTPS implicitly. Implicit FTPS
       consists of initializing SSL/TLS from the very beginning of the
       control connection. This option does not send an "AUTH TLS"
       command: it assumes the server speaks FTPS and directly starts an
       SSL/TLS connection. If the attempt is successful, the session
       continues just like regular FTPS ("PBSZ" and "PROT" are sent,
       etc.).  Implicit FTPS is no longer a requirement for FTPS
       implementations, and thus many servers may not support it. If
       --ftps-implicit is passed and no explicit port number specified,
       the default port for implicit FTPS, 990, will be used, instead of
       the default port for the "normal" (explicit) FTPS which is the same
       as that of FTP, 21.

   --no-ftps-resume-ssl
       Do not resume the SSL/TLS session in the data channel. When
       starting a data connection, Wget tries to resume the SSL/TLS
       session previously started in the control connection.  SSL/TLS
       session resumption avoids performing an entirely new handshake by
       reusing the SSL/TLS parameters of a previous session. Typically,
       the FTPS servers want it that way, so Wget does this by default.
       Under rare circumstances however, one might want to start an
       entirely new SSL/TLS session in every data connection.  This is
       what --no-ftps-resume-ssl is for.

   --ftps-clear-data-connection
       All the data connections will be in plain text. Only the control
       connection will be under SSL/TLS. Wget will send a "PROT C" command
       to achieve this, which must be approved by the server.

   --ftps-fallback-to-ftp
       Fall back to FTP if FTPS is not supported by the target server. For
       security reasons, this option is not asserted by default. The
       default behaviour is to exit with an error.  If a server does not
       successfully reply to the initial "AUTH TLS" command, or in the
       case of implicit FTPS, if the initial SSL/TLS connection attempt is
       rejected, it is considered that such server does not support FTPS.

   Recursive Retrieval Options
   -r
   --recursive
       Turn on recursive retrieving.    The default maximum depth is 5.

   -l depth
   --level=depth
       Specify recursion maximum depth level depth.

   --delete-after
       This option tells Wget to delete every single file it downloads,
       after 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 /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.

   --convert-file-only
       This option converts only the filename part of the URLs, leaving
       the rest of the URLs untouched. This filename part is sometimes
       referred to as the "basename", although we avoid that term here in
       order not to cause confusion.

       It works particularly well in conjunction with --adjust-extension,
       although this coupling is not enforced. It proves useful to
       populate Internet caches with files downloaded from different
       hosts.

       Example: if some link points to //foo.com/bar.cgi?xyz with
       --adjust-extension asserted and its local destination is intended
       to be ./foo.com/bar.cgi?xyz.css, then the link would be converted
       to //foo.com/bar.cgi?xyz.css. Note that only the filename part has
       been modified. The rest of the URL has been left untouched,
       including the net path ("//") which would otherwise be processed by
       Wget and converted to the effective scheme (ie. "http://").

   -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 --no-remove-listing.

   -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">".

   --strict-comments
       Turn on strict parsing of HTML comments.  The default is to
       terminate comments at the first occurrence of -->.

       According to specifications, HTML comments are expressed as SGML
       declarations.  Declaration is special markup that begins with <!
       and ends with >, such as <!DOCTYPE ...>, that may contain comments
       between a pair of -- delimiters.  HTML comments are "empty
       declarations", SGML declarations without any non-comment text.
       Therefore, <!--foo--> is a valid comment, and so is <!--one--
       --two-->, but <!--1--2--> is not.

       On the other hand, most HTML writers don't perceive comments as
       anything other than text delimited with <!-- and -->, which is not
       quite the same.  For example, something like <!------------> works
       as a valid comment as long as the number of dashes is a multiple of
       four (!).  If not, the comment technically lasts until the next --,
       which may be at the other end of the document.  Because of this,
       many popular browsers completely ignore the specification and
       implement what users have come to expect: comments delimited with
       <!-- and -->.

       Until version 1.9, Wget interpreted comments strictly, which
       resulted in missing links in many web pages that displayed fine in
       browsers, but had the misfortune of containing non-compliant
       comments.  Beginning with version 1.9, Wget has joined the ranks of
       clients that implements "naive" comments, terminating each comment
       at the first occurrence of -->.

       If, for whatever reason, you want strict comment parsing, use this
       option to turn it on.

   Recursive Accept/Reject Options
   -A acclist --accept acclist
   -R rejlist --reject rejlist
       Specify comma-separated lists of file name suffixes or patterns to
       accept or reject. Note that if any of the wildcard characters, *,
       ?, [ or ], appear in an element of acclist or rejlist, it will be
       treated as a pattern, rather than a suffix.  In this case, you have
       to enclose the pattern into quotes to prevent your shell from
       expanding it, like in -A "*.mp3" or -A '*.mp3'.

   --accept-regex urlregex
   --reject-regex urlregex
       Specify a regular expression to accept or reject the complete URL.

   --regex-type regextype
       Specify the regular expression type.  Possible types are posix or
       pcre.  Note that to be able to use pcre type, wget has to be
       compiled with libpcre support.

   -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.

   --follow-ftp
       Follow FTP links from HTML documents.  Without this option, Wget
       will ignore all the FTP links.

   --follow-tags=list
       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 list with this option.

   --ignore-tags=list
       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 list.

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

               wget --ignore-tags=a,area -H -k -K -r http://<site>/<document>

       However, the author of this option came across a page with tags
       like "<LINK REL="home" HREF="/">" and came to the realization that
       specifying tags to ignore was not enough.  One can't just tell Wget
       to ignore "<LINK>", 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.

   --ignore-case
       Ignore case when matching files and directories.  This influences
       the behavior of -R, -A, -I, and -X options, as well as globbing
       implemented when downloading from FTP sites.  For example, with
       this option, -A "*.txt" will match file1.txt, but also file2.TXT,
       file3.TxT, and so on.  The quotes in the example are to prevent the
       shell from expanding the pattern.

   -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 list
   --include-directories=list
       Specify a comma-separated list of directories you wish to follow
       when downloading.  Elements of list may contain wildcards.

   -X list
   --exclude-directories=list
       Specify a comma-separated list of directories you wish to exclude
       from download.  Elements of list 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 below a certain hierarchy will be downloaded.

ENVIRONMENT

   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
   https_proxy
       If set, the http_proxy and https_proxy variables should contain the
       URLs of the proxies for HTTP and HTTPS connections respectively.

   ftp_proxy
       This variable should contain the URL of the proxy for FTP
       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.

EXIT STATUS

   Wget may return one of several error codes if it encounters problems.

   0   No problems occurred.

   1   Generic error code.

   2   Parse error---for instance, when parsing command-line options, the
       .wgetrc or .netrc...

   3   File I/O error.

   4   Network failure.

   5   SSL verification failure.

   6   Username/password authentication failure.

   7   Protocol errors.

   8   Server issued an error response.

   With the exceptions of 0 and 1, the lower-numbered exit codes take
   precedence over higher-numbered ones, when multiple types of errors are
   encountered.

   In versions of Wget prior to 1.12, Wget's exit status tended to be
   unhelpful and inconsistent. Recursive downloads would virtually always
   return 0 (success), regardless of any issues encountered, and non-
   recursive fetches only returned the status corresponding to the most
   recently-attempted download.

FILES

   /etc/wgetrc
       Default location of the global startup file.

   .wgetrc
       User startup file.

BUGS

   You are welcome to submit bug reports via the GNU Wget bug tracker (see
   <https://savannah.gnu.org/bugs/?func=additem&group=wget>).

   Before actually submitting a bug report, please try to follow a few
   simple guidelines.

   1.  Please try to ascertain that the behavior 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, but you might want to double-check the documentation and the
       mailing lists.

   2.  Try to repeat the bug in as simple circumstances as possible.  E.g.
       if Wget crashes while downloading wget -rl0 -kKE -t5 --no-proxy
       http://example.com -o /tmp/log, you should try to see if the crash
       is repeatable, and if will occur with a simpler set of options.
       You might even try to start the download at the page where the
       crash occurred to see if that page somehow triggered the crash.

       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, mail me the relevant
       parts of the file.

   3.  Please start Wget with -d option and send us the resulting output
       (or relevant parts thereof).  If Wget was compiled without debug
       support, recompile it---it is much easier to trace bugs with debug
       support on.

       Note: please make sure to remove any potentially sensitive
       information from the debug log before sending it to the bug
       address.  The "-d" won't go out of its way to collect sensitive
       information, but the log will contain a fairly complete transcript
       of Wget's communication with the server, which may include
       passwords and pieces of downloaded data.  Since the bug address is
       publically archived, you may assume that all bug reports are
       visible to the public.

   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.  This may not
       work if the system administrator has disabled core files, but it is
       safe to try.

SEE ALSO

   This is not the complete manual for GNU Wget.  For more complete
   information, including more detailed explanations of some of the
   options, and a number of commands available for use with .wgetrc files
   and the -e option, see the GNU Info entry for wget.

AUTHOR

   Originally written by Hrvoje NikXiX <hniksic@xemacs.org>.

COPYRIGHT

   Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   2005, 2006, 2007, 2008, 2009, 2010, 2011, 2015 Free Software
   Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
   under the terms of the GNU Free Documentation License, Version 1.3 or
   any later version published by the Free Software Foundation; with no
   Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
   Texts.  A copy of the license is included in the section entitled "GNU
   Free Documentation License".





Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.