From pflynn at ucc.ie  Tue Apr 12 09:22:03 2016
From: pflynn at ucc.ie (Flynn, Peter)
Date: Tue, 12 Apr 2016 09:22:03 +0000
Subject: [Rarian] gen-seriesid unique or not?
Message-ID: <DB3PR02MB0569E548392101866474B7B8AE950@DB3PR02MB0569.eurprd02.prod.outlook.com>

I have been [ab?]using the command scrollkeeper-gen-seriesid for many
years in web scripts to create temporary unique identifiers for use as
MIME content boundaries in script-generated emails. Each call appears to
generate a different string, which is fine, eg

[root at foo tmp]# scrollkeeper-gen-seriesid
02cdf717-ab00-5295-798e-7f0d08b01ae460
[root at foo tmp]# scrollkeeper-gen-seriesid
01684b7e-e99a-fd12-b258-c2d5f79c0e6150

The command scrollkeeper-gen-seriesid is provided by the
rarian-compat-0.8.1-5.1.el6.x86_64 package on this system (CentOS 6.7
Final).

I just moved some scripts to a new server running the same OS and the
same RPM, and discovered that successive calls there generate the *same*
identifier each time when called from within a script:

---------------------------8<-------------------------testsk
#! /bin/bash

rarian-sk-gen-uuid
rarian-sk-gen-uuid

exit 0
---------------------------8<-------------------------testsk

[root at bar tmp]]# ./testsk
04bab430-6d0a-b5c5-fc5f-c6905f2204a5f0
04bab430-6d0a-b5c5-fc5f-c6905f2204a5f0
[root at bar tmp]#

but when called from the console by hand they're different:

[root at bar tmp]# rarian-sk-gen-uuid
0a49228c-ac63-7326-9dd8-fe782af1baf5e0
[root at bar tmp]# rarian-sk-gen-uuid
082d79ca-7d66-5cae-4913-0b2e6925d825a0

I suspect I am missing something here...is there a seed or
initialisation I need to run? And why should the behaviour be different
on two otherwise identical servers?

///Peter