Provided by: linkchecker_9.4.0-2_amd64 bug


       linkchecker - command line client to check HTML documents and websites for broken links


       linkchecker [options] [file-or-url]...


       LinkChecker features

       ·      recursive and multithreaded checking,

       ·      output  in  colored  or  normal  text,  HTML,  SQL,  CSV, XML or a sitemap graph in
              different formats,

       ·      support for HTTP/1.1, HTTPS, FTP, mailto:, news:,  nntp:,  Telnet  and  local  file

       ·      restriction of link checking with URL filters,

       ·      proxy support,

       ·      username/password authorization for HTTP, FTP and Telnet,

       ·      support for robots.txt exclusion protocol,

       ·      support for Cookies

       ·      support for HTML5

       ·      HTML and CSS syntax check

       ·      Antivirus check

       ·      a command line and web interface


       The most common use checks the given domain recursively:
       Beware  that  this  checks  the  whole  site which can have thousands of URLs.  Use the -r
       option to restrict the recursion depth.
       Don't check URLs with /secret in its name. All other links are checked as usual:
         linkchecker --ignore-url=/secret
       Checking a local HTML file on Unix:
         linkchecker ../bla.html
       Checking a local HTML file on Windows:
         linkchecker c:\temp\test.html
       You can skip the http:// url part if the domain starts with www.:
       You can skip the ftp:// url part if the domain starts with ftp.:
         linkchecker -r0
       Generate a sitemap graph and convert it with the graphviz dot utility:
         linkchecker -odot -v | dot -Tps >


   General options
       -fFILENAME, --config=FILENAME
              Use   FILENAME   as   configuration   file.    As    default    LinkChecker    uses

       -h, --help
              Help me! Print usage information for this program.

              Read list of white-space separated URLs to check from stdin.

       -tNUMBER, --threads=NUMBER
              Generate no more than the given number of threads. Default number of threads is 10.
              To disable threading specify a non-positive number.

       -V, --version
              Print version and exit.

              Print available check plugins and exit.

   Output options
       -DSTRING, --debug=STRING
              Print debugging output for  the  given  logger.   Available  loggers  are  cmdline,
              checking,  cache,  dns, plugins and all.  Specifying all is an alias for specifying
              all available loggers.  The option can be given multiple times to debug  with  more
              than  one  logger.    For accurate results, threading will be disabled during debug

              Output to a file linkchecker-out.TYPE, $HOME/.linkchecker/blacklist  for  blacklist
              output,  or FILENAME if specified.  The ENCODING specifies the output encoding, the
              default   is   that   of   your   locale.    Valid   encodings   are   listed    at
              The  FILENAME  and  ENCODING parts of the none output type will be ignored, else if
              the file already exists, it will be overwritten.  You can specify this option  more
              than  once.  Valid  file  output  types  are  text,  html, sql, csv, gml, dot, xml,
              sitemap, none or blacklist.  Default is no file output. The  various  output  types
              are documented below. Note that you can suppress all console output with the option
              -o none.

              Do not print check status messages.

              Don't log warnings. Default is to log warnings.

       -oTYPE[/ENCODING], --output=TYPE[/ENCODING]
              Specify output type as text, html, sql,  csv,  gml,  dot,  xml,  sitemap,  none  or
              blacklist.  Default type is text. The various output types are documented below.
              The  ENCODING  specifies  the  output encoding, the default is that of your locale.
              Valid encodings are listed at

       -q, --quiet
              Quiet operation, an alias for -o none.  This is only useful with -F.

       -v, --verbose
              Log all checked URLs. Default is to log only errors and warnings.

       -WREGEX, --warning-regex=REGEX
              Define a regular expression which prints a warning if it matches any content of the
              checked link.  This applies only to valid pages, so we can get their content.
              Use this to check for pages that contain some form of error, for example "This page
              has moved" or "Oracle Application error".
              Note  that  multiple  values can be combined in the regular expression, for example
              "(This page has moved|Oracle Application error)".
              See section REGULAR EXPRESSIONS for more info.

   Checking options
              Read a file with initial cookie data. The cookie data format is explained below.

              Check external URLs.

              URLs matching the given regular expression will be ignored and not checked.
              This option can be given multiple times.
              See section REGULAR EXPRESSIONS for more info.

       -NSTRING, --nntp-server=STRING
              Specify an NNTP server  for  news:  links.  Default  is  the  environment  variable
              NNTP_SERVER. If no host is given, only the syntax of the link is checked.

              Check but do not recurse into URLs matching the given regular expression.
              This option can be given multiple times.
              See section REGULAR EXPRESSIONS for more info.

       -p, --password
              Read  a  password  from console and use it for HTTP and FTP authorization.  For FTP
              the default password is anonymous@. For HTTP there is no default password. See also

       -rNUMBER, --recursion-level=NUMBER
              Check  recursively  all  links  up  to  given  depth.  A negative depth will enable
              infinite recursion.  Default depth is infinite.

              Set the timeout for connection attempts in  seconds.  The  default  timeout  is  60

       -uSTRING, --user=STRING
              Try  the  given  username  for  HTTP  and  FTP  authorization.  For FTP the default
              username is anonymous. For HTTP there is no default username. See also -p.

              Specify  the  User-Agent  string  to  send  to  the  HTTP   server,   for   example
              "Mozilla/4.0". The default is "LinkChecker/X.Y" where X.Y is the current version of


       Configuration files can specify all options above. They can also specify some options that
       cannot be set on the command line.  See linkcheckerrc(5) for more info.


       Note  that  by  default only errors and warnings are logged.  You should use the --verbose
       option to get the complete URL list, especially when outputting a sitemap graph format.

       text   Standard text logger, logging URLs in keyword: argument fashion.

       html   Log URLs in keyword: argument fashion, formatted as HTML.  Additionally  has  links
              to  the  referenced  pages.  Invalid  URLs  have  HTML  and  CSS syntax check links

       csv    Log check result in CSV format with one URL per line.

       gml    Log parent-child relations between linked URLs as a GML sitemap graph.

       dot    Log parent-child relations between linked URLs as a DOT sitemap graph.

       gxml   Log check result as a GraphXML sitemap graph.

       xml    Log check result as machine-readable XML.

              Log  check  result  as  an  XML   sitemap   whose   protocol   is   documented   at

       sql    Log  check  result  as SQL script with INSERT commands. An example script to create
              the initial SQL table is included as create.sql.

              Suitable for cron jobs. Logs the check result into a file  ~/.linkchecker/blacklist
              which  only  contains  entries  with invalid URLs and the number of times they have

       none   Logs nothing. Suitable for debugging or checking the exit code.


       LinkChecker   accepts   Python   regular   expressions.     See
       howto/regex.html for an introduction.

       An addition is that a leading exclamation mark negates the regular expression.


       A  cookie  file  contains standard HTTP header (RFC 2616) data with the following possible

       Host (required)
              Sets the domain the cookies are valid for.

       Path (optional)
              Gives the path the cookies are value for; default path is /.

       Set-cookie (required)
              Set cookie name/value. Can be given more than once.

       Multiple entries are separated by a blank line.  The example below will send  two  cookies
       to  all  URLs  starting  with and one to all URLs starting with

        Path: /hello
        Set-cookie: ID="smee"
        Set-cookie: spam="egg"

        Set-cookie: baggage="elitist"; comment="hologram"


       To use a proxy on  Unix  or  Windows  set  the  $http_proxy,  $https_proxy  or  $ftp_proxy
       environment   variables   to   the   proxy   URL.   The   URL   should   be  of  the  form
       http://[user:pass@]host[:port].   LinkChecker  also  detects  manual  proxy  settings   of
       Internet  Explorer under Windows systems, and gconf or KDE on Linux systems.  On a Mac use
       the Internet Config to select a proxy.  You can also set a comma-separated domain list  in
       the  $no_proxy  environment  variables  to  ignore  any  proxy settings for these domains.
       Setting a HTTP proxy on Unix for example looks like this:

         export http_proxy=""

       Proxy authentication is also supported:

         export http_proxy=""

       Setting a proxy on the Windows command prompt:

         set http_proxy=


       All URLs have to pass a preliminary syntax test.  Minor  quoting  mistakes  will  issue  a
       warning,  all  other invalid syntax issues are errors.  After the syntax check passes, the
       URL is queued for connection checking. All connection check types are described below.

       HTTP links (http:, https:)
              After connecting to the given HTTP server the given path or query is requested. All
              redirections  are  followed,  and  if  user/password  is  given  it will be used as
              authorization when necessary.  All final HTTP  status  codes  other  than  2xx  are
              errors.  HTML page contents are checked for recursion.

       Local files (file:)
              A  regular, readable file that can be opened is valid. A readable directory is also
              valid. All other files, for example device files, unreadable or non-existing  files
              are errors.  HTML or other parseable file contents are checked for recursion.

       Mail links (mailto:)
              A  mailto:  link  eventually resolves to a list of email addresses.  If one address
              fails, the whole list will fail.  For each mail  address  we  check  the  following
                1) Check the adress syntax, both of the part before and after
                   the @ sign.
                2) Look up the MX DNS records. If we found no MX record,
                   print an error.
                3) Check if one of the mail hosts accept an SMTP connection.
                   Check hosts with higher priority first.
                   If no host accepts SMTP, we print a warning.
                4) Try to verify the address with the VRFY command. If we got
                   an answer, print the verified address as an info.

       FTP links (ftp:)

                For FTP links we do:

                1) connect to the specified host
                2) try to login with the given user and password. The default
                   user is ``anonymous``, the default password is ``anonymous@``.
                3) try to change to the given directory
                4) list the file with the NLST command

       Telnet links (``telnet:``)

                We try to connect and if user/password are given, login to the
                given telnet server.

       NNTP links (``news:``, ``snews:``, ``nntp``)

                We try to connect to the given NNTP server. If a news group or
                article is specified, try to request it from the server.

       Unsupported links (``javascript:``, etc.)

                An unsupported link will only print a warning. No further checking
                will be made.

                The complete list of recognized, but unsupported links can be found
                in the linkcheck/checker/ source file.
                The most prominent of them should be JavaScript links.


       There  are  two  plugin types: connection and content plugins.  Connection plugins are run
       after a successful connection to the URL host.  Content plugins are run if  the  URL  type
       has  content  (mailto: URLs have no content for example) and if the check is not forbidden
       (ie. by HTTP robots.txt).  See linkchecker --list-plugins for a list of plugins and  their
       documentation. All plugins are enabled via the linkcheckerrc(5) configuration file.


       Before  descending  recursively into a URL, it has to fulfill several conditions. They are
       checked in this order:

       1. A URL must be valid.

       2. A URL must be parseable. This currently includes HTML files,
          Opera bookmarks files, and directories. If a file type cannot
          be determined (for example it does not have a common HTML file
          extension, and the content does not look like HTML), it is assumed
          to be non-parseable.

       3. The URL content must be retrievable. This is usually the case
          except for example mailto: or unknown URL types.

       4. The maximum recursion level must not be exceeded. It is configured
          with the --recursion-level option and is unlimited per default.

       5. It must not match the ignored URL list. This is controlled with
          the --ignore-url option.

       6. The Robots Exclusion Protocol must allow links in the URL to be
          followed recursively. This is checked by searching for a
          "nofollow" directive in the HTML header data.

       Note that the directory recursion reads all files in that directory,  not  just  a  subset
       like index.htm*.


       URLs on the commandline starting with ftp. are treated like ftp://ftp., URLs starting with
       www. are treated like http://www..  You can also give local files as arguments.

       If you have your system configured to automatically establish a connection to the internet
       (e.g.  with  diald),  it will connect when checking links not pointing to your local host.
       Use the --ignore-url option to prevent this.

       Javascript links are not supported.

       If your platform does not support threading, LinkChecker disables it automatically.

       You can supply multiple user/password pairs in a configuration file.

       When checking news: links the given NNTP host doesn't need to be the same as the  host  of
       the user browsing your pages.


       NNTP_SERVER - specifies default NNTP server
       http_proxy - specifies default HTTP proxy server
       ftp_proxy - specifies default FTP proxy server
       no_proxy - comma-separated list of domains to not contact over a proxy server
       LC_MESSAGES, LANG, LANGUAGE - specify output language


       The return value is 2 when

       ·      a program error occurred.

       The return value is 1 when

       ·      invalid links were found or

       ·      link warnings were found and warnings are enabled

       Else the return value is zero.


       LinkChecker  consumes  memory  for each queued URL to check. With thousands of queued URLs
       the amount of consumed memory can become quite large. This might slow down the program  or
       even the whole system.


       ~/.linkchecker/linkcheckerrc - default configuration file
       ~/.linkchecker/blacklist - default blacklist logger output filename
       linkchecker-out.TYPE - default logger file output name - valid output encodings - regular expression documentation




       Bastian Kleineidam <>


       Copyright © 2000-2014 Bastian Kleineidam