add a new command line option "chop", which will simply cut off the last "n" bytes from each packet. This is required (at least by me) when converting from PacketGrabber files which sometimes seem to include some additional bytes.

sort the usage string, so it will be ordered alphabetically

replace appearances of "frame" and "record" with "packet"

svn path=/trunk/; revision=16981

1 files changed, 39 insertions, 19 deletions

diff --git a/editcap.c b/editcap.c
index 2fd93ebd82..f7fd60c87b 100644
--- a/editcap.c
+++ b/editcap.c
@@ -1,4 +1,4 @@
-/* Edit capture files.  We can delete records, adjust timestamps, or
+/* Edit capture files.  We can delete packets, adjust timestamps, or
  * simply convert from one format to another format.
  *
  * $Id$
@@ -117,7 +117,7 @@ static void add_selection(char *sel)
 
 }
 
-/* Was the record selected? */
+/* Was the packet selected? */
 
 static int selected(int recno)
 {
@@ -210,14 +210,16 @@ static void usage(void)
   int i;
   const char *string;
 
-  fprintf(stderr, "Usage: editcap [-r] [-h] [-v] [-T <encap type>] [-E <probability>]\n");
-  fprintf(stderr, "               [-F <capture type>] [-s <snaplen>] [-t <time adjustment>]\n");
-  fprintf(stderr, "               [-c <packets per file>]\n");
-  fprintf(stderr, "               <infile> <outfile> [ <record#>[-<record#>] ... ]\n");
+  fprintf(stderr, "Usage: editcap [-c <packets per file>] [-C <choplen>] [-E <probability>]\n");
+  fprintf(stderr, "               [-F <capture type>] [-h] [-r] [-s <snaplen>]\n");
+  fprintf(stderr, "               [-t <time adjustment>] [-T <encap type>] [-v]\n");
+  fprintf(stderr, "               <infile> <outfile> [ <packet#>[-<packet#>] ... ]\n");
   fprintf(stderr, "  where\n");
-  fprintf(stderr, "       \t-c <packets per file> If given splits the output to different files\n");
-  fprintf(stderr, "       \t-E <probability> specifies the probability (between 0 and 1)\n");
-  fprintf(stderr, "       \t    that a particular byte will will have an error.\n");
+  fprintf(stderr, "       \t-c <packets per file> split the output to different files\n");
+  fprintf(stderr, "       \t-C <choplen> specifies that each packet should be chopped by\n");
+  fprintf(stderr, "       \t    <choplen> bytes of data at the packet end\n");
+  fprintf(stderr, "       \t-E <probability> specifies the probability (between 0.0 and 1.0 incl.)\n");
+  fprintf(stderr, "       \t    that a particular byte will have an error\n");
   fprintf(stderr, "       \t-F <capture type> specifies the capture file type to write:\n");
   for (i = 0; i < WTAP_NUM_FILE_TYPES; i++) {
     if (wtap_dump_can_open(i))
@@ -225,13 +227,13 @@ static void usage(void)
         wtap_file_type_short_string(i), wtap_file_type_string(i));
   }
   fprintf(stderr, "       \t    default is libpcap\n");
-  fprintf(stderr, "       \t-h produces this help listing.\n");
-  fprintf(stderr, "       \t-r specifies that the records specified should be kept, not deleted, \n");
-  fprintf(stderr, "                           default is to delete\n");
+  fprintf(stderr, "       \t-h produces this help\n");
+  fprintf(stderr, "       \t-r specifies that the packets specified should be kept,\n");
+  fprintf(stderr, "            the default is to delete them\n");
   fprintf(stderr, "       \t-s <snaplen> specifies that packets should be truncated to\n");
-  fprintf(stderr, "       \t   <snaplen> bytes of data\n");
-  fprintf(stderr, "       \t-t <time adjustment> specifies the time adjustment\n");
-  fprintf(stderr, "       \t   to be applied to selected packets\n");
+  fprintf(stderr, "       \t    <snaplen> bytes of data\n");
+  fprintf(stderr, "       \t-t <time adjustment> specifies the time adjustment in seconds\n");
+  fprintf(stderr, "       \t    to be applied to selected packets (e.g. -0.5)\n");
   fprintf(stderr, "       \t-T <encap type> specifies the encapsulation type to use:\n");
   for (i = 0; i < WTAP_NUM_ENCAP_TYPES; i++) {
       string = wtap_encap_short_string(i);
@@ -240,8 +242,10 @@ static void usage(void)
           string, wtap_encap_string(i));
   }
   fprintf(stderr, "       \t    default is the same as the input file\n");
-  fprintf(stderr, "       \t-v specifies verbose operation, default is silent\n");
-  fprintf(stderr, "\n      \t    A range of records can be specified as well\n");
+  fprintf(stderr, "       \t-v specifies verbose operation (slows down output),\n");
+  fprintf(stderr, "       \t    default is silent\n");
+  fprintf(stderr, "\n");
+  fprintf(stderr, "  A single packet or a range of packets can be specified\n");
 }
 
 int main(int argc, char *argv[])
@@ -255,6 +259,7 @@ int main(int argc, char *argv[])
   int opt;
   char *p;
   unsigned int snaplen = 0;             /* No limit               */
+  unsigned int choplen = 0;             /* No chop                */
   wtap_dumper *pdh;
   int count = 1;
   long data_offset;
@@ -268,7 +273,7 @@ int main(int argc, char *argv[])
 
   /* Process the options first */
 
-  while ((opt = getopt(argc, argv, "E:F:hrs:c:t:T:v")) !=-1) {
+  while ((opt = getopt(argc, argv, "c:C:E:F:hrs:t:T:v")) !=-1) {
 
     switch (opt) {
 
@@ -305,6 +310,15 @@ int main(int argc, char *argv[])
       }
       break;
 
+    case 'C':
+      choplen = strtol(optarg, &p, 10);
+      if (p == optarg || *p != '\0') {
+      	fprintf(stderr, "editcap: \"%s\" isn't a valid chop length\n",
+      	    optarg);
+      	exit(1);
+      }
+      break;
+
     case 'h':
     case '?':              /* Bad options if GNU getopt */
       usage();
@@ -445,13 +459,19 @@ int main(int argc, char *argv[])
           (selected(count) && keep_em)) {
 
         if (verbose)
-          printf("Record: %u\n", count);
+          printf("Packet: %u\n", count);
 
         /* We simply write it, perhaps after truncating it; we could do other
            things, like modify it. */
 
         phdr = wtap_phdr(wth);
 
+        if (choplen != 0 && phdr->caplen > choplen) {
+          snap_phdr = *phdr;
+          snap_phdr.caplen -= choplen;
+          phdr = &snap_phdr;
+        }
+
         if (snaplen != 0 && phdr->caplen > snaplen) {
           snap_phdr = *phdr;
           snap_phdr.caplen = snaplen;