NAME

       md_src_plugins_validation_READMEREADME
        -

       • 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.