diff --git a/Makefile b/Makefile
index 29db8d2..e7dffcb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,10 @@
 CFLAGS = -Wall -Werror
+TARGETS = pmerge puniq
 
-pmerge: pmerge.o pcap.o
\ No newline at end of file
+all: $(TARGETS)
+
+pmerge: pmerge.o pcap.o
+puniq: puniq.o pcap.o
+
+clean:
+	rm -f $(TARGETS)
diff --git a/pcap.c b/pcap.c
index 7e1770c..e3e6ae9 100644
--- a/pcap.c
+++ b/pcap.c
@@ -1,54 +1,42 @@
 #include <stdio.h>
 #include <sysexits.h>
+#include <string.h>
 #include "pcap.h"
 
 int
-pcap_read_header(FILE *f)
+pcap_open_in(struct pcap_file *ctx, FILE *f)
 {
   struct pcap_file_header h;
-  int                     swap;
 
   if (1 != fread(&h, sizeof(h), 1, f)) {
     h.magic = 0;
   }
 
   if (MAGIC == h.magic) {
-    swap = 0;
+    ctx->swap = 0;
   } else if (bswap32(MAGIC) == h.magic) {
-    swap = 1;
+    ctx->swap = 1;
   } else {
     return -1;
   }
   if ((h.version_major != 2) || (h.version_minor != 4)) return -1;
 
-  if (swap) h.snaplen = bswap32(h.snaplen);
+  if (ctx->swap) h.snaplen = bswap32(h.snaplen);
   if (h.snaplen > MAXFRAME) return -1;
 
-  return swap;
-}
-
-int
-pcap_write_header(FILE *f)
-{
-  struct pcap_file_header h = { MAGIC, 2, 4, 0, 0, MAXFRAME, 1 };
-
-  if (1 != fwrite(&h, sizeof(h), 1, stdout)) {
-    return -1;
-  }
-
+  ctx->f = f;
   return 0;
 }
 
 int
-pcap_open_in(struct pcap_file *ctx, FILE *f)
+pcap_open_out(struct pcap_file *ctx, FILE *f)
 {
-  int ret;
+  struct pcap_file_header h = { MAGIC, 2, 4, 0, 0, MAXFRAME, 1 };
 
-  ret = pcap_read_header(f);
-  if (-1 == ret) return -1;
-
-  ctx->swap = ret;
+  if (1 != fwrite(&h, sizeof(h), 1, f)) return -1;
   ctx->f = f;
+  ctx->swap = 0;
+
   return 0;
 }
 
@@ -69,6 +57,26 @@ pcap_read_pkthdr(struct pcap_file *ctx, struct pcap_pkthdr *hdr)
   return 0;
 }
 
+int
+pcap_write_pkthdr(struct pcap_file *ctx, struct pcap_pkthdr *hdr)
+{
+  if (ctx->swap) {
+    struct pcap_pkthdr ohdr;
+
+    memcpy(&ohdr, hdr, sizeof(ohdr));
+    hdr->ts.tv_sec  = bswap32(hdr->ts.tv_sec);
+    hdr->ts.tv_usec = bswap32(hdr->ts.tv_usec);
+    hdr->caplen     = bswap32(hdr->caplen);
+    hdr->len        = bswap32(hdr->len);
+
+    if (1 != fwrite(&ohdr, sizeof(ohdr), 1, ctx->f)) return -1;
+  } else {
+    if (1 != fwrite(hdr, sizeof(*hdr), 1, ctx->f)) return -1;
+  }
+
+  return 0;
+}
+
 void
 pcap_close(struct pcap_file *ctx)
 {
diff --git a/pcap.h b/pcap.h
index 0c08feb..41ffe6f 100644
--- a/pcap.h
+++ b/pcap.h
@@ -57,10 +57,10 @@ struct pcap_pkthdr {
 #define DUMP_c(v) DUMPf("%s = %c", #v, v)
 #define DUMP_p(v) DUMPf("%s = %p", #v, v)
 
-int pcap_read_header(FILE *f);
-int pcap_write_header(FILE *f);
 int pcap_open_in(struct pcap_file *ctx, FILE *f);
+int pcap_open_out(struct pcap_file *ctx, FILE *f);
 int pcap_read_pkthdr(struct pcap_file *ctx, struct pcap_pkthdr *hdr);
+int pcap_write_pkthdr(struct pcap_file *ctx, struct pcap_pkthdr *hdr);
 void pcap_close(struct pcap_file *ctx);
 
 #endif /* __PCAP_H__ */
diff --git a/pmerge.c b/pmerge.c
index dae49a9..94c0c13 100644
--- a/pmerge.c
+++ b/pmerge.c
@@ -40,7 +40,8 @@ main(int argc, char *argv[])
   struct input_file files[argc-1];
   int               nfiles = 0;
   int               nopen;
-  int               i, ret;
+  int               i;
+  struct pcap_file  out;
 
   if (1 == argc) return usage(0);
 
@@ -58,8 +59,7 @@ main(int argc, char *argv[])
       return EX_NOINPUT;
     }
 
-    ret = pcap_open_in(&cur->p, f);
-    if (-1 == ret) {
+    if (-1 == pcap_open_in(&cur->p, f)) {
       fprintf(stderr, "%s: unable to process\n", fn);
       return EX_IOERR;
     }
@@ -70,14 +70,12 @@ main(int argc, char *argv[])
     }
   }
 
-  ret = pcap_write_header(stdout);
-  if (-1 == ret) {
+  if (-1 == pcap_open_out(&out, stdout)) {
     perror("writing header");
     return EX_IOERR;
   }
 
   nopen = nfiles;
-  DUMP_d(nopen);
   while (nopen) {
     struct input_file *cur = &files[0];
     char               frame[MAXFRAME];
diff --git a/puniq.c b/puniq.c
new file mode 100644
index 0000000..0a5f767
--- /dev/null
+++ b/puniq.c
@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <sysexits.h>
+#include <string.h>
+#include "pcap.h"
+
+int
+main(int argc, char *argv[])
+{
+  int                i;
+  struct pcap_pkthdr hdr[2];
+  char               frame[2][MAXFRAME];
+  int                cur = 0;
+  struct pcap_file   out;
+
+  memset(&hdr, 0, sizeof(hdr));
+  memset(frame, 0, 2 * MAXFRAME);
+
+  if (-1 == pcap_open_out(&out, stdout)) {
+    perror("writing header");
+    return EX_IOERR;
+  }
+
+  i = 1;
+  do {
+    char             *fn = argv[i];
+    FILE             *f;
+    struct pcap_file  p;
+
+    if ((! fn) || (0 == strcmp("-", fn))) {
+      f = stdin;
+    } else {
+      f = fopen(fn, "rb");
+      if (NULL == f) {
+        perror(fn);
+        return EX_IOERR;
+      }
+    }
+
+    if (-1 == pcap_open_in(&p, f)) {
+      fprintf(stderr, "%s: unable to process\n", fn);
+      return EX_IOERR;
+    }
+
+    while (1) {
+      if (-1 == pcap_read_pkthdr(&p, &hdr[cur])) break;
+      if (1 != fread(frame[cur], hdr[cur].caplen, 1, p.f)) break;
+
+      if ((0 == memcmp(&hdr[0], &hdr[1], sizeof(hdr[0]))) &&
+          (0 == memcmp(frame[0], frame[1], hdr[cur].caplen))) {
+        /* Skip this duplicate */
+      } else {
+        if (-1 == pcap_write_pkthdr(&out, &hdr[cur])) break;
+        if (1 != fwrite(frame[cur], hdr[cur].caplen, 1, out.f)) break;
+      }
+      cur = (1 - cur);
+    }
+    pcap_close(&p);
+
+    i += 1;
+  } while (i < argc);
+
+  return 0;
+}