From d690f8d591806d13c0c0c96ad338dff942191d94 Mon Sep 17 00:00:00 2001
From: Neale Pickett <neale@lanl.gov>
Date: Thu, 12 Jun 2014 12:52:37 -0600
Subject: [PATCH] optimize pcat

---
 Makefile |  4 ++--
 pcat.c   | 24 +++++++++++++++++++++---
 pmerge.c |  2 +-
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 2fe1142..90b775f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
-CFLAGS = -Wall -Werror -Wno-unused-variable
-TARGETS = pmerge puniq p4split pcat 
+CFLAGS += -Wall -Werror -Wno-unused-variable -O2
+TARGETS += pmerge puniq p4split pcat 
 TARGETS += hd pyesc printfesc xor unhex 
 
 all: $(TARGETS)
diff --git a/pcat.c b/pcat.c
index c0afc54..dcd32e1 100644
--- a/pcat.c
+++ b/pcat.c
@@ -20,11 +20,29 @@ ip4_addr(char *addr_s, uint32_t addr)
 	snprintf(addr_s, 16, "%u.%u.%u.%u", (addr >> 24) & 0xff, (addr >> 16) & 0xff, (addr >> 8) & 0xff, (addr >> 0) & 0xff);
 }
 
+void
+print_nybble(uint8_t nybble)
+{
+	if (nybble < 10) {
+		putchar(nybble + '0');
+	} else {
+		putchar(nybble - 10 + 'a');
+	}
+}
+
+/* About 3x faster than printf("%02x", octet); */
+void
+printx(uint8_t octet)
+{
+	print_nybble(octet >> 4);
+	print_nybble(octet & 0xf);
+}
+
 void
 print_payload(struct stream *s)
 {
 	while (s->len) {
-		printf("%02x", read_uint8(s));
+		printx(read_uint8(s));
 	}
 }
 
@@ -163,13 +181,13 @@ void
 pcat(FILE * f)
 {
 	struct pcap_file p;
+	struct pcap_pkthdr hdr;
+	char frame[MAXFRAME];
 
 	if (-1 == pcap_open_in(&p, f))
 		return;
 
 	for (;;) {
-		struct pcap_pkthdr hdr;
-		char frame[MAXFRAME];
 
 		if (-1 == pcap_read_pkthdr(&p, &hdr)) {
 			break;
diff --git a/pmerge.c b/pmerge.c
index d991774..5699237 100644
--- a/pmerge.c
+++ b/pmerge.c
@@ -102,7 +102,7 @@ main(int argc, char *argv[])
 		 * Make sure it'll fit 
 		 */
 		if (cur->next.caplen > sizeof(frame)) {
-			fprintf(stderr, "error: huge frame (size %u)\n", (unsigned int) len);
+			fprintf(stderr, "error: huge frame (size %u)\n", (unsigned int) cur->next.caplen);
 			return EX_SOFTWARE;
 		}