Not all OSes have a diff that supports "diff -u".

diff --git a/tests/TESTonce b/tests/TESTonce
index 1d826bf8e4053dabde27ef6e8f1cc2de61a59757..c6039b86ca19bf3ff57decfec27f42cf283204b3 100755 (executable)
--- a/tests/TESTonce
+++ b/tests/TESTonce
@@ -12,7 +12,7 @@ $input=$ARGV[1];
 $output=$ARGV[2];
 $options=$ARGV[3];
 
-$r = system "../tcpdump 2>/dev/null -n -r $input $options | tee NEW/$output | diff -uw $output - >DIFF/$output.diff";
+$r = system "../tcpdump 2>/dev/null -n -r $input $options | tee NEW/$output | diff -w $output - >DIFF/$output.diff";
 
 if($r == 0) {
   printf "    %-30s: passed\n", $name;