Sort options and put in notes for unusable option letters.
Sort the options alphabetically, and put in comments for the options
we're *currently* not using, to note that other versions of tcpdump use
them and that we should only use them for the same purposes.
diff --git a/tcpdump.c b/tcpdump.c
index cd022ad..85ceafb 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -614,11 +614,15 @@
{ NULL, required_argument, NULL, 'C' },
{ NULL, no_argument, NULL, 'd' },
{ NULL, no_argument, NULL, 'D' },
- { NULL, no_argument, NULL, 'L' },
{ NULL, no_argument, NULL, 'e' },
{ NULL, required_argument, NULL, 'E' },
{ NULL, no_argument, NULL, 'f' },
{ NULL, required_argument, NULL, 'F' },
+ /*
+ * NOTE: OS X tcpdump uses -g; we shouldn't use it except for
+ * the same purpose (forcing non--v output for IP to be on one
+ * line, making it more "g"repable).
+ */
{ NULL, required_argument, NULL, 'G' },
{ NULL, no_argument, NULL, 'h' },
{ NULL, no_argument, NULL, 'H' },
@@ -630,14 +634,28 @@
{ NULL, required_argument, NULL, 'j' },
{ NULL, no_argument, NULL, 'J' },
#endif
- { NULL, no_argument, NULL, 'l' },
+ /*
+ * NOTE: OS X tcpdump uses -k; we shouldn't use it except for
+ * the same purpose (printing packet comments in pcap-ng files).
+ */
{ NULL, no_argument, NULL, 'K' },
+ { NULL, no_argument, NULL, 'l' },
+ { NULL, no_argument, NULL, 'L' },
{ NULL, required_argument, NULL, 'm' },
{ NULL, required_argument, NULL, 'M' },
{ NULL, no_argument, NULL, 'n' },
{ NULL, no_argument, NULL, 'N' },
+ /*
+ * NOTE: OpenBSD tcpdump uses -o; we shouldn't use it except for
+ * the same purpose (trying to do OS fingerprinting for
+ * hosts sending TCP SYN packets).
+ */
{ NULL, no_argument, NULL, 'O' },
{ NULL, no_argument, NULL, 'p' },
+ /*
+ * NOTE: OS X tcpdump uses -P; we shouldn't use it except for
+ * the same purpose (writing pcap-ng rather than pcap files).
+ */
{ NULL, no_argument, NULL, 'q' },
#ifdef HAVE_PCAP_SETDIRECTION
{ NULL, required_argument, NULL, 'Q' },
