Here is the Mac (OS X) output:

brucelowther:~ brucelowther$ cat > ~/tmp/test.txt
this is a test
this is a test
this is a test
12345678901234
brucelowther:~ brucelowther$ hexdump -C  ~/tmp/test.txt
00000000  74 68 69 73 20 69 73 20  61 20 74 65 73 74 0a 74  |this is a
+ test.t|
00000010  68 69 73 20 69 73 20 61  20 74 65 73 74 0a 74 68  |his is a 
+test.th|
00000020  69 73 20 69 73 20 61 20  74 65 73 74 0a 31 32 33  |is is a t
+est.123|
00000030  34 35 36 37 38 39 30 31  32 33 34 0a              |456789012
+34.|
0000003c
[download]