-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.8 2004/11/10 10:29:56 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.12 2004/11/19 09:45:54 ph10 Exp $
New Features in Exim
--------------------
monitoring the behaviour of the daemon without creating as much output as
full debugging.
+ 9. $host_address is now set to the target address during the checking of
+ ignore_target_hosts.
+
+10. There are four new variables called $spool_space, $log_space,
+ $spool_inodes, and $log_inodes. The first two contain the amount of free
+ space in the disk partitions where Exim has its spool directory and log
+ directory, respectively. (When these are in the same partition, the values
+ will, of course, be the same.) The second two variables contain the numbers
+ of free inodes in the respective partitions.
+
+ NOTE: Because disks can nowadays be very large, the values in the space
+ variables are in kilobytes rather than in bytes. Thus, for example, to
+ check in an ACL that there is at least 50M free on the spool, you would
+ write:
+
+ condition = ${if > {$spool_space}{50000}{yes}{no}}
+
+ The values are recalculated whenever any of these variables is referenced.
+ If the relevant file system does not have the concept of inodes, the value
+ of those variables is -1. If the operating system does not have the ability
+ to find the amount of free space (only true for experimental systems), the
+ space value is -1.
+
+11. It is now permitted to omit both strings after an "if" condition; if the
+ condition is true, the result is the string "true". As before, when the
+ second string is omitted, a false condition yields an empty string. This
+ makes it less cumbersome to write custom ACL and router conditions. For
+ example, instead of
+
+ condition = ${if eq {$acl_m4}{1}{yes}{no}}
+
+ or the shorter form
+
+ condition = ${if eq {$acl_m4}{1}{yes}}
+
+ (because the second string has always defaulted to ""), you can now write
+
+ condition = ${if eq {$acl_m4}{1}}
+
+ Previously this was a syntax error.
+
+12. There is now a new "record type" that can be specified in dnsdb lookups. It
+ is "zns" (for "zone NS"). It performs a lookup for NS records on the given
+ domain, but if none are found, it removes the first component of the domain
+ name, and tries again. This process continues until NS records are found
+ or there are no more components left (or there's a DNS error). In other
+ words, it may return the name servers for a top-level domain, but it never
+ returns the root name servers. If there are no NS records for the top-level
+ domain, the lookup fails.
+
+ For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name
+ servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns
+ the name servers for edu, assuming in each case that there are no NS
+ records for the full domain name.
+
+ You should be careful about how you use this lookup because, unless the
+ top-level domain does not exist, the lookup will always return some host
+ names. The sort of use to which this might be put is for seeing if the name
+ servers for a given domain are on a blacklist. You can probably assume that
+ the name servers for the high-level domains such as .com or .co.uk are not
+ going to be on such a list.
Version 4.43
git://git.exim.org / exim.git / blobdiff