Re: some thoughts

On Monday 11 November 2002 16.42, Robert Collins wrote:
> On startup run acl tests for :
> open proxy config
> smtp open relay config
> CONNECT to port 80 config
> and error for the first two, warn for the third.

Good ideas, but I think these should only be loud warnings, not
errors.

> regex acl's:
> We could combine multiple regex acls of the same type with regex
> '|' clauses before compiling the regex.. This would make our
> matching more efficient. An extension to this would be to combine
> all the regex acl's of the same type from _access lines into one
> large regex and compile that.

Perhaps, but I would expect several regex libraries to fail miserably
if given a single gigantic regex expression with a zillion of
branches.. This is not a thing you normally do with regex. Almost all
regex patterns in use in the world is relatively small.

Quick check on the GNU libc documentation:

* GNU libc regex apparently has a upper limit of 64KB per compiled
regex. How long regex this translates to obviously depends on the
pattern used.

* The regex(7) manpage says:

  No particular limit is imposed on the length of REs(!).
  Programs intended to be portable should not employ REs
  longer than 256 bytes, as an implementation can refuse to
  accept such REs and remain POSIX-compliant.

Regards
Henrik
Received on Mon Nov 11 2002 - 13:08:53 MST