Add a --version option, to print just version information.

Also, use #defines starting at 128 (outside the ASCII range) for long
options having no short-option equivalent, and have -h/--help exit with
an exit status of 0 (you just asked for usage information, and you got
it - no fault, no error).

diff --git a/tcpdump.c b/tcpdump.c
index b08e00f1d90943cb7b1449841592a20fed76b7fd..3faf2da731a9ae29f20da7163b910a53598e407a 100644 (file)
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -122,7 +122,8 @@ int32_t thiszone;           /* seconds offset from gmt to local time */
 /* Forwards */
 static RETSIGTYPE cleanup(int);
 static RETSIGTYPE child_cleanup(int);
-static void usage(void) __attribute__((noreturn));
+static void print_version(void);
+static void print_usage(void);
 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
 
 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
@@ -638,12 +639,14 @@ show_devices_and_exit (void)
  * doesn't make sense; it should be --verbosity={N} or something such
  * as that.
  *
- * We do not currently have long options with no corresponding short
- * options; for those, we should define values outside the range of
- * ASCII graphic characters, make that the last component of the
- * entry for the long option, and have a case for that option in the
- * switch statement.
+ * For long options with no corresponding short options, we define values
+ * outside the range of ASCII graphic characters, make that the last
+ * component of the entry for the long option, and have a case for that
+ * option in the switch statement.
  */
+#define OPTION_NUMBER  128
+#define OPTION_VERSION 129
+
 static struct option longopts[] = {
 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
        { "buffer-size", required_argument, NULL, 'B' },
@@ -675,7 +678,8 @@ static struct option longopts[] = {
        { "debug-filter-parser", no_argument, NULL, 'Y' },
 #endif
        { "relinquish-privileges", required_argument, NULL, 'Z' },
-       { "number", no_argument, NULL, 'z' + 1},
+       { "number", no_argument, NULL, OPTION_NUMBER },
+       { "version", no_argument, NULL, OPTION_VERSION },
        { NULL, 0, NULL, 0 }
 };
 
@@ -979,7 +983,8 @@ main(int argc, char **argv)
                        break;
 
                case 'h':
-                       usage();
+                       print_usage();
+                       exit(0);
                        break;
 
                case 'H':
@@ -1257,12 +1262,18 @@ main(int argc, char **argv)
                        username = strdup(optarg);
                        break;
 
-               case 'z' + 1:
+               case OPTION_NUMBER:
                        gndo->ndo_packet_number = 1;
                        break;
 
+               case OPTION_VERSION:
+                       print_version();
+                       exit(0);
+                       break;
+
                default:
-                       usage();
+                       print_usage();
+                       exit(1);
                        /* NOTREACHED */
                }
 
@@ -2243,7 +2254,7 @@ static void verbose_stats_dump(int sig _U_)
 #endif
 
 static void
-usage(void)
+print_version(void)
 {
        extern char version[];
 #ifndef HAVE_PCAP_LIB_VERSION
@@ -2270,6 +2281,12 @@ usage(void)
        (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
 #endif /* WIN32 */
 #endif /* HAVE_PCAP_LIB_VERSION */
+}
+
+static void
+print_usage(void)
+{
+       print_version();
        (void)fprintf(stderr,
 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
        (void)fprintf(stderr,
@@ -2286,7 +2303,6 @@ usage(void)
 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
        (void)fprintf(stderr,
 "\t\t[ -Z user ] [ expression ]\n");
-       exit(1);
 }