use strict;
use warnings;
use 5.010;

local $/ = "--\n";

while (<DATA>) {
    if (/^rn: uid:(\S+),/m) {
        my $uid = $1;
        my $count = 0;
        $count++ for /^id-info:/mg;
        say "$uid: $count";
    }
}

__DATA__
--
rn: uid:<user>, <irrelevant-text>
id-info: <URL> | <ID> | <random-string>
creation-time: 1366069064
--
rn: uid:<user>, <irrelevant-text>
id-info: <URL> | <ID> | <random-string>
id-info: <URL> | <ID> | <random-string>
id-info: <URL> | <ID> | <random-string>
creation-time: 1366069064
--
rn: uid:<user>, <irrelevant-text>
id-info: <URL> | <ID> | <random-string>
id-info: <URL> | <ID> | <random-string>
     # random empty line in each entry with 'deletion-time'
deletion-time: 1367949064
creation-time: 1366069064
--