Ubuntu Manpage: duck - the Debian Url ChecKer

NAME

       duck - the Debian Url ChecKer

SYNOPSIS

        duck  [ OPTION ]... [-f file] [-u file] [-c file] [URL]

DESCRIPTION

duck extracts links, email address domains and VCS-* entries from the following files:

o debian/control

o debian/upstream, debian/upstream-metadata.yaml and debian/upstream/metadata

o debian/copyright

o DEP-3 patch files in every directory a series file is found

o systemd.unit files (*.socket, *.device, *.mount, *.automount, *.swap, *.target,
*.path, *.time, *.snapshot, *.slice, *.scope)

o Appstream files (*.appdata)

If an URL is supplied, duck uses dget to download the specified URL and processes the
downloaded source package (*.dsc file) instead of working on the current directory.

It tries to access those VCS-* entries and URLs using the appropriate tool to find out
whether the given URLs or entries are broken or working. If errors are detected, the
filename, fieldname and URL/email of the broken entry are displayed.

duck will search for the default files (see above) and skip them silently, if they cannot
be found. If specific filenames for options -c, -f or -u are given, and one of those
files cannot be found, duck exits with exit code 2.

Email address domains are checked for existing MX records, A records, or AAAA records, in
this order. If none of these 3 are found for a given domain, it is considered broken.

Checks results are displayed with 3 different error levels

O: (OK) Indicates that the given check did not result in an error. Only shown if -n is
used.

I: (Information) Indicates informational warnings, suchs as missing helper tools as
well as failing checks based on searches in unstructured text files, which
sometimes lead to false positives.

E: (Error) Indicates failing checks based on data from well-defined fields (e.g.
Homepage: entry in debian/control).

and 3 different certainty-levels

certain
Data taken from well defined fields. As the format of this field is specified (e.g.
Debian Policy, etc.), it can be checked by the appropriate tools. If this check
then fails, the data in the field is certainly erroneous.

possible
Data extracted using regular expressions (e.g. email addresses, URLs). This might
lead to false positives, so the check result is possibly a false positive.

wild-guess
Data extracted from websites, by using regular expressions. This is still
experimental and probably buggy, hence the "wild-guess".

OPTIONS

-n dry run. Don't run any checks, just show entries to be checked.

-q quiet mode. Suppress all output.

-v verbose mode. This shows all URLs found and the checks run.

--modules-dir=DIRECTORY
specify modules directory. Mostly useful for developing new checks. If this
parameter is specified, only modules defined in this directory are used. You have
to copy all *.pm files from /usr/share/duck/lib/checks to the directory specified.

--color=[WHEN]
Specify when to emit escape sequences to the output. Available options are:

auto Emit color escape codes on STDOUT/STDERR, no color if output is piped
to a file or the current terminal is not capable of displaying colors.

always Always emit color escape codes.

never Never emit color escape codes.

--no-https do not try to find matching https URLs to http URLs. See also the
DUCK_NOHTTPS environment variable.

--no-check-certificate
do not check if SSL certificates autenticity. This is highly discouraged!

--missing-helpers
display list of missing external helper tools and exits.

--version display copyright and version information

-f specify path to control file. This overrides the default debian/control.

-F skip processing of the control file.

-u specify path to upstream metadata file. This overrides the default files
debian/upstream, debian/upstream-metadata.yaml and
debian/upstream/metadata.

-U skip processing of the upstream metadata file.

-c specify path to copyright file. This overrides the default
debian/copyright.

-C skip processing of copyright file.

-P skip processing of patch files.

-A skip processing of appstream metadata files.

-S skip processing of systemd.unit files.

-l filename Process URLs, email addresses, git:// and svn:// entries from the file
specified. Specify one entry per line. This also disables all other check
modules searching for entries in various files.

--disable-urlfix=<fix1,...>
disables the specified url fix(es). An urlfix tries to remove
leading/trailing characters from extracted URLs, like trailing dots or
parentheses. Using this parameter enables all urlfixes minus the specified
ones.

--enable-urlfix=<fix1,...>
enables the specified url fix(es). Using this parameter disabled all
urlfixes minus the specified ones.

The following urlfixes are available:

TRAILING_COLON Removes trailing colon ":" character.

TRAILING_PAREN_DOT Removes the string ")." from the end of the URL.

TRAILING_PUNCTUATION Removes trailing "." and "," characters.

TRAILING_QUOTES Removes trailing single quotes "'" characters. Note: Double
quotes (") are already correctly handled by the used perl regex matchers.

TRAILING_SLASH_DOT Removes the string "/." (without the quotes) from the
end of the URL.

TRAILING_SLASH_PAREN Removes the string "/)" (without the quotes) from the
end of the URL.

--tasks=[number]
Specify the number of checks allowed to run in parallel. Default value is
24. This value must be an integer value >0.

All urlfixes are enabled by default.

ENVIRONMENT VARIABLES

       DUCK_NOHTTPS
              If this variable is set, do not try to find matching https URLs to http URLs.

       XDG_CONFIG_HOME
              if this variable is set, use the config file (if any) $XDG_HOME/duck/duck.conf. The
              default value is $HOME/.config/duck/duck.conf .

       XDG_CONFIG_DIRS
              defines the preference-ordered set of base directories to search for  configuration
              files  in  addition  to  the  XDG_CONFIG_HOME  base  directory.  The directories in
              XDG_CONFIG_DIRS should be separated with a colon ':'.

EXAMPLE

       To run duck, change your working directory to an extracted Debian source package and run:
        duck

EXIT STATUS

       0      Success, no errors

       1      Error(s) detected

       2      User-specified file not found

FILES

       debian/duck-overrides
              Overrides-file in the Debian package source tree. This files contains a list of URL
              regexs  which should not be reported as down/broken. This might be useful in cases,
              where URLs are extracted from old/outdated copyright-files or patches,  which  will
              never  ever  be working, and which will then lead to false positives. Please see an
              example in /usr/share/doc/duck/examples.

       duck.conf
              Config file which contains the regular expressions used to  detect  parked  domains
              and  redirected  websites.  The  default  file is in /etc/duck/duck.conf. duck also
              honors the XDG Base Directory Specification, see the section ENVIRONMENT  VARIABLES
              for details.  Search order for duck.conf is:

              $XDG_CONFIG_HOME/duck/duck.conf (default: $HOME/.config/duck/duck.conf)

              /etc/duck/duck.conf

              /$XDG_CONFIG_DIRS (default: /etc/xdg/duck/duck.conf)

              Please       see       the       XDG       Base       Directory       Specification
              (https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html)  for
              more details.