Link to OpenGroup regexp syntax specification

[Anne Anderson <Anne.Anderson@Sun.COM>]

The OpenGroup Regular Expression definition is in
http://www.opengroup.org/onlinepubs/007908799/xbd/re.html

This defines "regular expression" syntax and "extended regular
expression" syntax.  I used to know what extended adds, but can't
remember right now.

Anne

On 24 June, Michiharu Kudoh writes: [xacml] URI-match function proposal
 > From: Michiharu Kudoh <KUDO@jp.ibm.com>
 > To: 'xacml' <xacml@lists.oasis-open.org>
 > Subject: [xacml] URI-match function proposal
 > Date: Thu, 24 Jun 2004 01:00:17 +0900
 > 
 > 
 > 
 > 
 > 
 > Here is a draft of the proposed URI-match function.
 > 
 > My motivation is to create a universal match function that satisfies our
 > needs. The following are some proposals and ideas posted on the list:
 > 
 > - URL-match function proposed by Tim
 > - URI-match-with-propagation by me
 > - ** in Ant suggested by Polar
 > - general match function by Seth
 > - Version number metching by Bill
 > 
 > My observation for the requirements of the match function is the following:
 > - We need a generic match function that works on hierarchy.
 > - The scheme should be able to distinguish the hierarchical match from the
 > regular expression match.
 > - The scheme should include sub-tree match as well as single-node (file,
 > directory etc.) match.
 > - The scheme should support various kinds of separator for hierarchy.
 > - The scheme should apply syntax with which many people are familiar.
 > - The scheme should fit with our own purposes.
 > 
 > Of course this is not complete but I believe that this covers several
 > peoples' requirements including me.
 > 
 > The basic idea is the following:
 > - Match function that works on URI syntax (including URL and URN)
 > - Pattern match character includes "*", "?", and "**" (maybe more)
 >   + "*" is used for single-node match.
 >   + "**" is used for sub-tree match (from Ant).
 >   + "?" is used for one-character match.
 > - Hierarchical separators are "/" and ":" (or more).
 > 
 > The following are several examples in my minds:
 > Pattern     String     Match
 > /a          /a         true
 > /a/*        /a         false
 > /a/*        /a/b       true
 > /a/*        /a/b/c     false
 > /a/**       /a         false
 > /a/**       /a/b       true
 > /a/**       /a/b/c     true
 > /a?/*       /a1/b      true
 > /a?/*.html  /a1/xy.html  true
 > a:b:*       a:b:c      true   (":" is URI's colon)
 > a:b:**      a:b:c:d    true
 > http://a.b/x/**  http://a.b/x/y/z  true
 > 
 > ('*' is used in two ways: single hierarchical match e.g. /a/* and any
 > string match e.g. /a/*.html)
 > 
 > One problem I had in the above example is that there is no simple syntax
 > that matches both the indicated node and its sub-tree. For example, if we
 > need to specify a policy that matches to /a and the sub-tree, we need to
 > specify two patterns i.e. /a and /a/**. JSR115 uses /a:/a** where ':'
 > indicates 'or' combination of two patterns that conflicts with patterns for
 > the urn cases above.
 > 
 > So the following is one of the solution for this problem:
 > - Introduce "***" for representing both the indicated node and its
 > sub-tree. For example, /a/*** is a shorthand of /a and /a/**. Thus /a/***
 > matches /a, /a/b, /a/b/c etc.
 > 
 > - In the same way, a:b:*** is a shorthand of a:b and a:b:**. Thus,
 > urn:oasis:names:tc:xacml:*** matches urn:oasis:names:tc:xacml,
 > urn:oasis:names:tc:xacml:1.0, urn:oasis:names:tc:xacml:2.0 etc.
 > 
 > We might allow the following patterns that has wild cards in the middle if
 > we could agree:
 > /a/*/b  matches /a/x/b.
 > /a/**/b  matches /a/x/y/b.
 > 
 > Any comments are welcome.
 > 
 > Best,
 > Michiharu
 > 
 > 
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 > 

-- 
Anne H. Anderson             Email: Anne.Anderson@Sun.COM
Sun Microsystems Laboratories
1 Network Drive,UBUR02-311     Tel: 781/442-0928
Burlington, MA 01803-0902 USA  Fax: 781/442-1692