NAME

       duck - the Debian Url ChecKer

SYNOPSIS

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

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)

       It tries to access those VCS-* entries and URLs using the  approriate  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

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

       -q     quiet mode. Suppress all output.

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

       --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.

       --no-color
              do not colorize output. See also the DUCK_NOCOLOR environment variable.

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

       --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.

ENVIRONMENT VARIABLES

       DUCK_NOCOLOR
              If this variable is set, do not colorize output.

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

CHECK MODULES

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

SEE ALSO

       Please  see  http://duck.debian.net/  for additional information as well as an overview of
       duck checks run on all source packages in Debian/unstable.

                                            2014-10-23                                    DUCK(1)