NAME

       md_src_plugins_validation_README - README

       • infos = Information about validation plugin is in keys below

       • infos/author = Markus Raab elektra@libelektra.org

       • infos/licence = BSD

       • infos/needs =

       • infos/provides = check

       • infos/placements = presetstorage

       • infos/description = Validates key values using regular expressions

       This plugin is a check plugin which checks string values of Keys using regular expressions.

   Usage
       The  validation  plugin  looks  for  two  metakeys.  check/validation gives a regular expression to check
       against. If it is present, check/validation/message may contain an optional humanly readable message that
       will be passed with the error information.

   Implementation
       The implementation consists of a loop checking for every key if it has the mentioned metakey.  The  check
       itself  is done by the POSIX regular expression library with the interface regcomp, regexec, regerror and
       regfree. The flag REG_EXTENDED is passed so that the regular expression will be compiled as  an  extended
       regular  expression. REG_NOSUB gives a better performance and subexpressions cannot be used in this setup
       anyway.

   Exported Methods
       The plugin also exports the function ksLookupRE() that  does  a  lookup  in  a  KeySet  using  a  regular
       expression.  It  starts  from  the  current  cursor of the KeySet and stops when the first value matches.
       Finally, this key is returned.

Version 0.8.14                                   Tue Dec 15 2015      md_src_plugins_validation_README(3elektra)