merge_plist

plist1

<dict>
  <key>name</name>
  <string>llama</string>
</dict>

plist2

<dict>
  <key>nickname</name>
  <string>brett</string>
</dict>

merged result

<dict>
  <key>name</name>
  <string>llama</string>
  <key>nickname</name>
  <string>brett</string>
</dict>

Gem

gem install merge_plist

Usage (Ruby)

require 'merge_plist'

merged = MergePlist::merge(
  File.read("a.plist"),
  File.read("b.plist"),
  File.read("c.plist"))

Usage (Shell)

merge_plist a.plist b.plist c.plist