From: Jeremy Harris Date: Mon, 18 Dec 2023 14:37:30 +0000 (+0000) Subject: Docs: more indexing for localhost_number X-Git-Tag: exim-4.98-RC0~105 X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/311d71b8f18d544c79cc3a4cb1dafc206aaa1554 Docs: more indexing for localhost_number --- diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index cc801a3a5..7ac7f5bda 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -16640,15 +16640,21 @@ See also the ACL modifier &`control = suppress_local_fixups`&. Section .option localhost_number main string&!! unset .cindex "host" "locally unique number for" .cindex "message ids" "with multiple hosts" +.cindex multiple "systems sharing a spool" +.cindex "multiple hosts" "sharing a spool" +.cindex "shared spool directory" +.cindex "spool directory" sharing .vindex "&$localhost_number$&" Exim's message ids are normally unique only within the local host. If -uniqueness among a set of hosts is required, each host must set a different +uniqueness among a set of hosts is required +(eg. because they share a spool directory), +each host must set a different value for the &%localhost_number%& option. The string is expanded immediately after reading the configuration file (so that a number can be computed from the host name, for example) and the result of the expansion must be a number in the range 0&--16 (or 0&--10 on operating systems with case-insensitive file systems). This is available in subsequent string expansions via the variable -&$localhost_number$&. When &%localhost_number is set%&, the final two +&$localhost_number$&. When &%localhost_number%& is set, the final four characters of the message id, instead of just being a fractional part of the time, are computed from the time and the local host number as described in section &<>&.