Use getopt_long() for the first pass through the argument list.

That way:

	1) we don't have to worry about the system getopt() and our
	   getopt_long(), on platforms that have getopt() but not
	   getopt_long() (Solaris prior to Solaris 10, HP-UX, AIX), not
	   working well together;

	2) if necessary, we can handle long options in the first pass.

Switch to using getopt_long() for the *second* pass for the GTK+ version
of Wireshark.

Use the documented mechanism for resetting the argument parser for the
glibc version of getopt_long(); use the mostly-undocumented-but-at-least-
they-documented-optreset mechanism for the *BSD version.

(We should look into doing only one pass, saving away arguments that
can't fully be processed in the first pass for further processing after
initializing libwireshark.)

Change-Id: Ide5069f1c7c66a5d04acc712551eb201080ce02f
Reviewed-on: https://code.wireshark.org/review/6063
Reviewed-by: Guy Harris <guy@alum.mit.edu>

5 files changed, 278 insertions, 130 deletions

diff --git a/configure.ac b/configure.ac
index 5ebfa04c7f..4a71282f91 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2669,6 +2669,25 @@ AC_CHECK_FUNC(getopt_long,
   [
     GETOPT_LO=""
     AC_DEFINE(HAVE_GETOPT_LONG, 1, [Define to 1 if you have the getopt_long function.])
+
+    #
+    # Do we have optreset?
+    #
+    AC_MSG_CHECKING(whether optreset is defined)
+    AC_TRY_LINK([],
+      [
+        extern int optreset;
+
+        return optreset;
+      ],
+      ac_cv_pcap_debug_defined=yes,
+      ac_cv_pcap_debug_defined=no)
+    if test "$ac_cv_pcap_debug_defined" = yes ; then
+      AC_MSG_RESULT(yes)
+      AC_DEFINE(HAVE_OPTRESET, 1, [Define to 1 if you have the optreset variable])
+    else
+      AC_MSG_RESULT(no)
+    fi
   ],
   GETOPT_LO="wsgetopt.lo")
 AC_SUBST(GETOPT_LO)
diff --git a/tfshark.c b/tfshark.c
index 6004720cea..c0e3749601 100644
--- a/tfshark.c
+++ b/tfshark.c
@@ -793,12 +793,22 @@ main(int argc, char *argv[])
   dfilter_t           *dfcode = NULL;
   e_prefs             *prefs_p;
   int                  log_flags;
-  int                  optind_initial;
   gchar               *output_only = NULL;
 
-/* the leading - ensures that getopt() does not permute the argv[] entries
-   we have to make sure that the first getopt() preserves the content of argv[]
-   for the subsequent getopt_long() call */
+/*
+ * The leading - ensures that getopt_long() does not permute the argv[] entries.
+ *
+ * We have to make sure that the first getopt_long() preserves the content
+ * of argv[] for the subsequent getopt_long() call.
+ *
+ * We use getopt_long() in both cases to ensure that we're using a routine
+ * whose permutation behavior we can control in the same fashion on all
+ * platforms, and so that, if we ever need to process a long argument before
+ * doing further initialization, we can do so.
+ *
+ * XXX - the behavior of a leading - is platform-dependent, so we shouldn't
+ * use it.
+ */
 #define OPTSTRING "-2C:d:e:E:hK:lo:O:qQr:R:S:t:T:u:vVxX:Y:z:"
 
   static const char    optstring[] = OPTSTRING;
@@ -853,11 +863,18 @@ main(int argc, char *argv[])
   /*
    * In order to have the -X opts assigned before the wslua machine starts
    * we need to call getopts before epan_init() gets called.
+   *
+   * In order to handle, for example, -o options, we also need to call it
+   * *after* epan_init() gets called, so that the dissectors have had a
+   * chance to register their preferences.
+   *
+   * XXX - can we do this all with one getopt_long() call, saving the
+   * arguments we can't handle until after initializing libwireshark,
+   * and then process them after initializing libwireshark?
    */
   opterr = 0;
-  optind_initial = optind;
 
-  while ((opt = getopt(argc, argv, optstring)) != -1) {
+  while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
     switch (opt) {
     case 'C':        /* Configuration Profile */
       if (profile_exists (optarg, FALSE)) {
@@ -898,11 +915,6 @@ main(int argc, char *argv[])
   if (print_summary == -1)
     print_summary = (print_details || print_hex) ? FALSE : TRUE;
 
-  optind = optind_initial;
-  opterr = 1;
-
-
-
 /** Send All g_log messages to our own handler **/
 
   log_flags =
@@ -1081,6 +1093,28 @@ main(int argc, char *argv[])
 
   output_fields = output_fields_new();
 
+  /*
+   * To reset the options parser, set optreset to 1 on platforms that
+   * have optreset (documented in *BSD and OS X, apparently present but
+   * not documented in Solaris - the Illumos repository seems to
+   * suggest that the first Solaris getopt_long(), at least as of 2004,
+   * was based on the NetBSD one, it had optreset) and set optind to 1,
+   * and set optind to 0 otherwise (documented as working in the GNU
+   * getopt_long().  Setting optind to 0 didn't originally work in the
+   * NetBSD one, but that was added later - we don't want to depend on
+   * it if we have optreset).
+   *
+   * Also reset opterr to 1, so that error messages are printed by
+   * getopt_long().
+   */
+#ifdef HAVE_OPTRESET
+  optreset = 1;
+  optind = 1;
+#else
+  optind = 0;
+#endif
+  opterr = 1;
+
   /* Now get our args */
   while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
     switch (opt) {
@@ -1088,7 +1122,7 @@ main(int argc, char *argv[])
       perform_two_pass_analysis = TRUE;
       break;
     case 'C':
-      /* Configuration profile settings were already processed just ignore them this time*/
+      /* already processed; just ignore it now */
       break;
     case 'd':        /* Decode as rule */
       if (!add_decode_as(optarg))
@@ -1280,6 +1314,7 @@ main(int argc, char *argv[])
       /* already processed; just ignore it now */
       break;
     case 'X':
+      /* already processed; just ignore it now */
       break;
     case 'Y':
       dfilter = optarg;
diff --git a/tshark.c b/tshark.c
index c6cfb3061b..523e2a245b 100644
--- a/tshark.c
+++ b/tshark.c
@@ -992,12 +992,22 @@ main(int argc, char *argv[])
   e_prefs             *prefs_p;
   char                 badopt;
   int                  log_flags;
-  int                  optind_initial;
   gchar               *output_only = NULL;
 
-/* the leading - ensures that getopt() does not permute the argv[] entries
-   we have to make sure that the first getopt() preserves the content of argv[]
-   for the subsequent getopt_long() call */
+/*
+ * The leading - ensures that getopt_long() does not permute the argv[] entries.
+ *
+ * We have to make sure that the first getopt_long() preserves the content
+ * of argv[] for the subsequent getopt_long() call.
+ *
+ * We use getopt_long() in both cases to ensure that we're using a routine
+ * whose permutation behavior we can control in the same fashion on all
+ * platforms, and so that, if we ever need to process a long argument before
+ * doing further initialization, we can do so.
+ *
+ * XXX - the behavior of a leading - is platform-dependent, so we shouldn't
+ * use it.
+ */
 #define OPTSTRING "-2" OPTSTRING_CAPTURE_COMMON "C:d:e:E:F:gG:hH:" "K:lnN:o:O:PqQr:R:S:t:T:u:vVw:W:xX:Y:z:"
 
   static const char    optstring[] = OPTSTRING;
@@ -1062,12 +1072,19 @@ main(int argc, char *argv[])
 
   /*
    * In order to have the -X opts assigned before the wslua machine starts
-   * we need to call getopts before epan_init() gets called.
+   * we need to call getopt_long before epan_init() gets called.
+   *
+   * In order to handle, for example, -o options, we also need to call it
+   * *after* epan_init() gets called, so that the dissectors have had a
+   * chance to register their preferences.
+   *
+   * XXX - can we do this all with one getopt_long() call, saving the
+   * arguments we can't handle until after initializing libwireshark,
+   * and then process them after initializing libwireshark?
    */
   opterr = 0;
-  optind_initial = optind;
 
-  while ((opt = getopt(argc, argv, optstring)) != -1) {
+  while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
     switch (opt) {
     case 'C':        /* Configuration Profile */
       if (profile_exists (optarg, FALSE)) {
@@ -1112,11 +1129,6 @@ main(int argc, char *argv[])
   if (print_summary == -1)
     print_summary = (print_details || print_hex) ? FALSE : TRUE;
 
-  optind = optind_initial;
-  opterr = 1;
-
-
-
 /** Send All g_log messages to our own handler **/
 
   log_flags =
@@ -1310,6 +1322,28 @@ main(int argc, char *argv[])
 
   output_fields = output_fields_new();
 
+  /*
+   * To reset the options parser, set optreset to 1 on platforms that
+   * have optreset (documented in *BSD and OS X, apparently present but
+   * not documented in Solaris - the Illumos repository seems to
+   * suggest that the first Solaris getopt_long(), at least as of 2004,
+   * was based on the NetBSD one, it had optreset) and set optind to 1,
+   * and set optind to 0 otherwise (documented as working in the GNU
+   * getopt_long().  Setting optind to 0 didn't originally work in the
+   * NetBSD one, but that was added later - we don't want to depend on
+   * it if we have optreset).
+   *
+   * Also reset opterr to 1, so that error messages are printed by
+   * getopt_long().
+   */
+#ifdef HAVE_OPTRESET
+  optreset = 1;
+  optind = 1;
+#else
+  optind = 0;
+#endif
+  opterr = 1;
+
   /* Now get our args */
   while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
     switch (opt) {
@@ -1355,7 +1389,7 @@ main(int argc, char *argv[])
 #endif
       break;
     case 'C':
-      /* Configuration profile settings were already processed just ignore them this time*/
+      /* already processed; just ignore it now */
       break;
     case 'd':        /* Decode as rule */
       if (!add_decode_as(optarg))
@@ -1625,6 +1659,7 @@ main(int argc, char *argv[])
       /* already processed; just ignore it now */
       break;
     case 'X':
+      /* already processed; just ignore it now */
       break;
     case 'Y':
       dfilter = optarg;
diff --git a/ui/gtk/main.c b/ui/gtk/main.c
index 17785d6fc8..a7c53c3e2a 100644
--- a/ui/gtk/main.c
+++ b/ui/gtk/main.c
@@ -40,6 +40,10 @@
 #include <unistd.h>
 #endif
 
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#endif
+
 #ifndef HAVE_GETOPT_LONG
 #include "wsutil/wsgetopt.h"
 #endif
@@ -2160,14 +2164,21 @@ main(int argc, char *argv[])
     guint                go_to_packet = 0;
     search_direction     jump_backwards = SD_FORWARD;
     dfilter_t           *jump_to_filter = NULL;
-    int                  optind_initial;
     unsigned int         in_file_type = WTAP_TYPE_AUTO;
 #ifdef HAVE_GTKOSXAPPLICATION
     GtkosxApplication   *theApp;
 #endif
 
 #define OPTSTRING OPTSTRING_CAPTURE_COMMON "C:g:Hh" "jJ:kK:lm:nN:o:P:r:R:St:u:vw:X:Y:z:"
-
+    static const struct option long_options[] = {
+        {(char *)"help", no_argument, NULL, 'h'},
+        {(char *)"read-file", required_argument, NULL, 'r' },
+        {(char *)"read-filter", required_argument, NULL, 'R' },
+        {(char *)"display-filter", required_argument, NULL, 'Y' },
+        {(char *)"version", no_argument, NULL, 'v'},
+        LONGOPT_CAPTURE_COMMON
+        {0, 0, 0, 0 }
+    };
     static const char optstring[] = OPTSTRING;
 
     cmdarg_err_init(wireshark_cmdarg_err, wireshark_cmdarg_err_cont);
@@ -2281,20 +2292,41 @@ main(int argc, char *argv[])
                       rf_path, g_strerror(rf_open_errno));
     }
 
-    /* "pre-scan" the command line parameters, if we have "console only"
-       parameters.  We do this so we don't start GTK+ if we're only showing
-       command-line help or version information.
-
-       XXX - this pre-scan is done before we start GTK+, so we haven't
-       run gtk_init() on the arguments.  That means that GTK+ arguments
-       have not been removed from the argument list; those arguments
-       begin with "--", and will be treated as an error by getopt().
-
-       We thus ignore errors - *and* set "opterr" to 0 to suppress the
-       error messages. */
+    /*
+     * In order to have the -X opts assigned before the wslua machine starts
+     * we need to call getopt_long before epan_init() gets called.
+     *
+     * In addition, we process "console only" parameters (ones where we
+     * send output to the console and exit) here, so we don't start GTK+
+     * if we're only showing command-line help or version information.
+     *
+     * XXX - this pre-scan is done before we start GTK+, so we haven't
+     * run gtk_init() on the arguments.  That means that GTK+ arguments
+     * have not been removed from the argument list; those arguments
+     * begin with "--", and will be treated as an error by getopt_long().
+     *
+     * We thus ignore errors - *and* set "opterr" to 0 to suppress the
+     * error messages.
+     *
+     * XXX - should we, instead, first call gtk_parse_args(), without
+     * calling gtk_init(), and then call this?
+     *
+     * In order to handle, for example, -o options, we also need to call it
+     * *after* epan_init() gets called, so that the dissectors have had a
+     * chance to register their preferences, so we have another getopt_long()
+     * call later.
+     *
+     * XXX - can we do this all with one getopt_long() call, saving the
+     * arguments we can't handle until after initializing libwireshark,
+     * and then process them after initializing libwireshark?
+     *
+     * Note that we don't want to initialize libwireshark until after the
+     * GUI is up, as that can take a while, and we want a window of some
+     * sort up to show progress while that's happening.
+     */
     opterr = 0;
-    optind_initial = optind;
-    while ((opt = getopt(argc, argv, optstring)) != -1) {
+
+    while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
         switch (opt) {
             case 'C':        /* Configuration Profile */
                 if (profile_exists (optarg, FALSE)) {
@@ -2390,42 +2422,6 @@ main(int argc, char *argv[])
         set_last_open_dir(get_persdatafile_dir());
     }
 
-    /* Set getopt index back to initial value, so it will start with the
-       first command line parameter again.  Also reset opterr to 1, so that
-       error messages are printed by getopt().
-
-       XXX - this seems to work on most platforms, but time will tell.
-       The Single UNIX Specification says "The getopt() function need
-       not be reentrant", so this isn't guaranteed to work.  The Mac
-       OS X 10.4[.x] getopt() man page says
-
-         In order to use getopt() to evaluate multiple sets of arguments, or to
-         evaluate a single set of arguments multiple times, the variable optreset
-         must be set to 1 before the second and each additional set of calls to
-         getopt(), and the variable optind must be reinitialized.
-
-           ...
-
-         The optreset variable was added to make it possible to call the getopt()
-         function multiple times.  This is an extension to the IEEE Std 1003.2
-         (``POSIX.2'') specification.
-
-       which I think comes from one of the other BSDs.
-
-       XXX - if we want to control all the command-line option errors, so
-       that we can display them where we choose (e.g., in a window), we'd
-       want to leave opterr as 0, and produce our own messages using optopt.
-       We'd have to check the value of optopt to see if it's a valid option
-       letter, in which case *presumably* the error is "this option requires
-       an argument but none was specified", or not a valid option letter,
-       in which case *presumably* the error is "this option isn't valid".
-       Some versions of getopt() let you supply a option string beginning
-       with ':', which means that getopt() will return ':' rather than '?'
-       for "this option requires an argument but none was specified", but
-       not all do. */
-    optind = optind_initial;
-    opterr = 1;
-
 #if !GLIB_CHECK_VERSION(2,31,0)
     g_thread_init(NULL);
 #endif
@@ -2546,8 +2542,42 @@ main(int argc, char *argv[])
 /*#ifdef HAVE_LIBPCAP
     fill_in_local_interfaces();
 #endif*/
+    /*
+     * To reset the options parser, set optreset to 1 on platforms that
+     * have optreset (documented in *BSD and OS X, apparently present but
+     * not documented in Solaris - the Illumos repository seems to
+     * suggest that the first Solaris getopt_long(), at least as of 2004,
+     * was based on the NetBSD one, it had optreset) and set optind to 1,
+     * and set optind to 0 otherwise (documented as working in the GNU
+     * getopt_long().  Setting optind to 0 didn't originally work in the
+     * NetBSD one, but that was added later - we don't want to depend on
+     * it if we have optreset).
+     *
+     * Also reset opterr to 1, so that error messages are printed by
+     * getopt_long().
+     *
+     * XXX - if we want to control all the command-line option errors, so
+     * that we can display them where we choose (e.g., in a window), we'd
+     * want to leave opterr as 0, and produce our own messages using optopt.
+     * We'd have to check the value of optopt to see if it's a valid option
+     * letter, in which case *presumably* the error is "this option requires
+     * an argument but none was specified", or not a valid option letter,
+     * in which case *presumably* the error is "this option isn't valid".
+     * Some versions of getopt() let you supply a option string beginning
+     * with ':', which means that getopt() will return ':' rather than '?'
+     * for "this option requires an argument but none was specified", but
+     * not all do.  But we're now using getopt_long() - what does it do?
+     */
+#ifdef HAVE_OPTRESET
+    optreset = 1;
+    optind = 1;
+#else
+    optind = 0;
+#endif
+    opterr = 1;
+
     /* Now get our args */
-    while ((opt = getopt(argc, argv, optstring)) != -1) {
+    while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
         switch (opt) {
             /*** capture option specific ***/
             case 'a':        /* autostop criteria */
diff --git a/ui/qt/main.cpp b/ui/qt/main.cpp
index 2acdb80688..017296a33f 100644
--- a/ui/qt/main.cpp
+++ b/ui/qt/main.cpp
@@ -547,7 +547,6 @@ int main(int argc, char *argv[])
 
     QString locale;
     QString cf_name;
-    int optind_initial;
     unsigned int in_file_type = WTAP_TYPE_AUTO;
 
     // In Qt 5, C strings are treated always as UTF-8 when converted to
@@ -610,21 +609,47 @@ int main(int argc, char *argv[])
     }
     wsApp->emitAppSignal(WiresharkApplication::StaticRecentFilesRead);
 
-
-    /* "pre-scan" the command line parameters, if we have "console only"
-       parameters.  We do this so we don't start Qt if we're only showing
-       command-line help or version information.
-
-        XXX - this pre-scan is done before we start Qt. That means that Qt
-       arguments have not been removed from the argument list; those arguments
-       begin with "--", and will be treated as an error by getopt().
-
-       We thus ignore errors - *and* set "opterr" to 0 to suppress the
-       error messages.*/
-
+    /*
+     * In order to have the -X opts assigned before the wslua machine starts
+     * we need to call getopt_long before epan_init() gets called.
+     *
+     * In addition, we process "console only" parameters (ones where we
+     * send output to the console and exit) here, so we don't start GTK+
+     * if we're only showing command-line help or version information.
+     *
+     * XXX - with the GTK+ version, this pre-scan was done before we started
+     * GTK+, so we hadn't run gtk_init() on the arguments.  That meant that
+     * GTK+ arguments had not been removed from the argument list; those
+     * arguments begin with "--", and would be treated as an error by
+     * getopt_long().
+     *
+     * We thus ignored errors - *and* set "opterr" to 0 to suppress the
+     * error messages.
+     *
+     * That's not the case here - the call to WiresharkApplication's
+     * constructor above does that (WiresharkApplication is a subclass
+     * of QApplication, and QApplication's constructor handles the Qt
+     * arguments).
+     *
+     * This means that there's some UI popped up before here.  Can we
+     * move the call to the constructor after here?
+     *
+     * In order to handle, for example, -o options, we also need to call it
+     * *after* epan_init() gets called, so that the dissectors have had a
+     * chance to register their preferences, so we have another getopt_long()
+     * call later.
+     *
+     * XXX - can we do this all with one getopt_long() call, saving the
+     * arguments we can't handle until after initializing libwireshark,
+     * and then process them after initializing libwireshark?
+     *
+     * Note that we don't want to initialize libwireshark until after the
+     * GUI is up, as that can take a while, and we want a window of some
+     * sort up to show progress while that's happening.
+     */
     opterr = 0;
-    optind_initial = optind;
-    while ((opt = getopt(argc, argv, optstring)) != -1) {
+
+    while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
         switch (opt) {
             case 'C':        /* Configuration Profile */
                 if (profile_exists (optarg, FALSE)) {
@@ -713,43 +738,6 @@ int main(int argc, char *argv[])
                       rf_path, g_strerror(rf_open_errno));
     }
 
-
-    /* Set getopt index back to initial value, so it will start with the
-       first command line parameter again.  Also reset opterr to 1, so that
-       error messages are printed by getopt().
-
-       XXX - this seems to work on most platforms, but time will tell.
-       The Single UNIX Specification says "The getopt() function need
-       not be reentrant", so this isn't guaranteed to work.  The Mac
-       OS X 10.4[.x] getopt() man page says
-
-         In order to use getopt() to evaluate multiple sets of arguments, or to
-         evaluate a single set of arguments multiple times, the variable optreset
-         must be set to 1 before the second and each additional set of calls to
-         getopt(), and the variable optind must be reinitialized.
-
-           ...
-
-         The optreset variable was added to make it possible to call the getopt()
-         function multiple times.  This is an extension to the IEEE Std 1003.2
-         (``POSIX.2'') specification.
-
-       which I think comes from one of the other BSDs.
-
-       XXX - if we want to control all the command-line option errors, so
-       that we can display them where we choose (e.g., in a window), we'd
-       want to leave opterr as 0, and produce our own messages using optopt.
-       We'd have to check the value of optopt to see if it's a valid option
-       letter, in which case *presumably* the error is "this option requires
-       an argument but none was specified", or not a valid option letter,
-       in which case *presumably* the error is "this option isn't valid".
-       Some versions of getopt() let you supply a option string beginning
-       with ':', which means that getopt() will return ':' rather than '?'
-       for "this option requires an argument but none was specified", but
-       not all do. */
-    optind = optind_initial;
-    opterr = 1;
-
     // Initialize our language
     read_language_prefs();
     locale = QString(language);
@@ -855,6 +843,40 @@ int main(int argc, char *argv[])
 
     prefs_p = ws_app.readConfigurationFiles (&gdp_path, &dp_path);
 
+    /*
+     * To reset the options parser, set optreset to 1 on platforms that
+     * have optreset (documented in *BSD and OS X, apparently present but
+     * not documented in Solaris - the Illumos repository seems to
+     * suggest that the first Solaris getopt_long(), at least as of 2004,
+     * was based on the NetBSD one, it had optreset) and set optind to 1,
+     * and set optind to 0 otherwise (documented as working in the GNU
+     * getopt_long().  Setting optind to 0 didn't originally work in the
+     * NetBSD one, but that was added later - we don't want to depend on
+     * it if we have optreset).
+     *
+     * Also reset opterr to 1, so that error messages are printed by
+     * getopt_long().
+     *
+     * XXX - if we want to control all the command-line option errors, so
+     * that we can display them where we choose (e.g., in a window), we'd
+     * want to leave opterr as 0, and produce our own messages using optopt.
+     * We'd have to check the value of optopt to see if it's a valid option
+     * letter, in which case *presumably* the error is "this option requires
+     * an argument but none was specified", or not a valid option letter,
+     * in which case *presumably* the error is "this option isn't valid".
+     * Some versions of getopt() let you supply a option string beginning
+     * with ':', which means that getopt() will return ':' rather than '?'
+     * for "this option requires an argument but none was specified", but
+     * not all do.  But we're now using getopt_long() - what does it do?
+     */
+#ifdef HAVE_OPTRESET
+    optreset = 1;
+    optind = 1;
+#else
+    optind = 0;
+#endif
+    opterr = 1;
+
     /* Now get our args */
     while ((opt = getopt_long(argc, argv, optstring, long_options, NULL)) != -1) {
         switch (opt) {
@@ -896,6 +918,8 @@ int main(int argc, char *argv[])
                 read_keytab_file(optarg);
             break;
 #endif
+
+        /*** all non capture option specific ***/
         case 'C':
             /* Configuration profile settings were already processed just ignore them this time*/
             break;
@@ -909,7 +933,12 @@ int main(int argc, char *argv[])
             /* Not supported yet */
             break;
         case 'l':        /* Automatic scrolling in live capture mode */
+#ifdef HAVE_LIBPCAP
             /* Not supported yet */
+#else
+            capture_option_specified = TRUE;
+            arg_error = TRUE;
+#endif
             break;
         case 'L':        /* Print list of link-layer types and exit */
 #ifdef HAVE_LIBPCAP
@@ -1055,7 +1084,7 @@ int main(int argc, char *argv[])
             }
             break;
         default:
-        case '?':
+        case '?':        /* Bad flag - print usage message */
             print_usage(FALSE);
             exit(0);
             break;