replace mixed-case usernames in a JIRA export file with their lowercase equivalents

gistfile1.sh

#!/bin/bash
#
# grep "Membership.*jira-users" entities.xml
#  -- extract the lines of XML defining members of jira-users. for JIRA 4.4, these lines look like:
#     <Membership id="10002" parentId="10002" childId="10000" membershipType="GROUP_USER" parentName="jira-users" lowerParentName="jira-users" childName="Greg.Boyington" lowerChildName="greg.boyington" directoryId="1"/>
#
# cut -d' ' -f12 
#  -- extract just the childName attribute eg. childName="Greg.Boyington"
#
# awk '{FS="\""; print $2}'
#  -- extract the usernames only eg. Greg.Boyington
#
# sort -fr
#  -- sort the Mixed.Case and lower.case usernames alphabetically, Mixed.Case first
#
# uniq -i
#  -- select only the Mixed.Case usernames
#
# sed -i "s/$u/\L$u/g" entities.xml
#  -- replace all occurrences of $u, the Mixed.Case username, with the lowercase equivalent

cp entities.xml entities.xml.orig
for u in `grep "Membership.*jira-users" entities.xml.orig| cut -d' ' -f12|awk '{FS="\""; print $2}'|sort -fr|uniq -i`; do sed -i "s/$u/\L$u/g" entities.xml; done