$VAR1 = [
          'Only in test1/: different1',
          'Only in test2/: different2',
          'Only in test2//common: common.txt~',
          'Files test1//common/common.txt and test2//common/common.txt differ'
        ];
--- test1//common/common.txt    Wed Mar  8 11:41:08 2017
+++ test2//common/common.txt    Wed Mar  8 11:44:35 2017
@@ -1 +1 @@
-This is a common line
+This is a common line.

##</code><code>##

qwurx [shmem] ~/tmp/diff> diff -ur test1 test2
diff -ur test1/common/common.txt test2/common/common.txt
--- test1/common/common.txt	2017-03-09 12:28:15.215474776 +0100
+++ test2/common/common.txt	2017-03-09 12:28:38.639837796 +0100
@@ -1 +1 @@
-This is a common line
+This is a common line.
Only in test2/common: common.txt~
Only in test1: different1
Only in test2: different2