md_src_plugins_validation_README(3) README


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.


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.