Add a preferences page for capture preferences, so that the user can

directly edit the capture preferences, rather than only being able to
set them implicitly from the values for the most recent capture.

Add a preferences item for the interface on which to capture.

Get rid of some unused variables.

svn path=/trunk/; revision=4510

10 files changed, 305 insertions, 38 deletions

diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 94ba7856b5..07c4e69731 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -1,7 +1,7 @@
 # Makefile.am
 # Automake file for the GTK interface routines for Ethereal
 #
-# $Id: Makefile.am,v 1.36 2001/12/08 09:27:50 guy Exp $
+# $Id: Makefile.am,v 1.37 2002/01/10 07:43:39 guy Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@zing.org>
@@ -31,6 +31,8 @@ CLEANFILES = \
 libui_a_SOURCES = \
 	capture_dlg.c	\
 	capture_dlg.h	\
+	capture_prefs.c	\
+	capture_prefs.h	\
 	color_dlg.c	\
 	color_dlg.h	\
 	colors.c	\
diff --git a/gtk/Makefile.nmake b/gtk/Makefile.nmake
index 54d5f03480..666425a54d 100644
--- a/gtk/Makefile.nmake
+++ b/gtk/Makefile.nmake
@@ -19,6 +19,7 @@ CVARSDLL=-DWIN32 -DNULL=0 -D_MT -D_DLL
 # some functions that have disappeared in gtk+-1.3. I might
 # get around to #ifdef'ing them out in our gtkclist.c.
 OBJECTS=capture_dlg.obj \
+	capture_prefs.obj \
 	color_dlg.obj    \
 	colors.obj       \
 	color_utils.obj  \
diff --git a/gtk/capture_dlg.c b/gtk/capture_dlg.c
index 5a6eb0429a..c96ccb1f75 100644
--- a/gtk/capture_dlg.c
+++ b/gtk/capture_dlg.c
@@ -1,7 +1,7 @@
 /* capture_dlg.c
  * Routines for packet capture windows
  *
- * $Id: capture_dlg.c,v 1.52 2001/12/09 03:20:19 guy Exp $
+ * $Id: capture_dlg.c,v 1.53 2002/01/10 07:43:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -211,9 +211,15 @@ capture_prep_cb(GtkWidget *w, gpointer d)
   if_cb = gtk_combo_new();
   if (if_list != NULL)
     gtk_combo_set_popdown_strings(GTK_COMBO(if_cb), if_list);
-  if (cfile.iface)
+  if (cfile.iface == NULL && prefs.capture_device != NULL) {
+    /* No interface was specified on the command line or in a previous
+       capture, but there is one specified in the preferences file;
+       make the one from the preferences file the default */
+    cfile.iface	= g_strdup(prefs.capture_device);
+  }
+  if (cfile.iface != NULL)
     gtk_entry_set_text(GTK_ENTRY(GTK_COMBO(if_cb)->entry), cfile.iface);
-  else if (if_list)
+  else if (if_list != NULL)
     gtk_entry_set_text(GTK_ENTRY(GTK_COMBO(if_cb)->entry), if_list->data);
   gtk_table_attach_defaults(GTK_TABLE(table), if_cb, 1, 2, 0, 1);
   gtk_widget_show(if_cb);
diff --git a/gtk/capture_prefs.c b/gtk/capture_prefs.c
new file mode 100644
index 0000000000..0039d2900e
--- /dev/null
+++ b/gtk/capture_prefs.c
@@ -0,0 +1,182 @@
+/* capture_prefs.c
+ * Dialog box for capture preferences
+ *
+ * $Id: capture_prefs.c,v 1.1 2002/01/10 07:43:39 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_LIBPCAP
+
+#include <string.h>
+#include <errno.h>
+#include <gtk/gtk.h>
+
+#include <pcap.h>
+
+#include "globals.h"
+#include "capture_prefs.h"
+#include "gtkglobals.h"
+#include "prefs_dlg.h"
+#include "prefs.h"
+#include "prefs-int.h"
+#include "ui_util.h"
+#include "dlg_utils.h"
+#include "pcap-util.h"
+#if 0
+#include "proto_draw.h"
+#endif
+#include "main.h"
+
+static void create_option_check_button(GtkWidget *main_vb, const gchar *key,
+    GtkWidget *main_tb, int table_position, const gchar *label_text,
+    gboolean active);
+
+#define DEVICE_KEY		"device"
+#define PROM_MODE_KEY		"prom_mode"
+#define CAPTURE_REAL_TIME_KEY	"capture_real_time"
+#define AUTO_SCROLL_KEY		"capture_real_time"
+
+#define CAPTURE_TABLE_ROWS 4
+GtkWidget*
+capture_prefs_show(void)
+{
+	GtkWidget	*main_tb, *main_vb;
+	GtkWidget	*if_cb, *if_lb;
+	GtkWidget	*promisc_cb, *sync_cb, *auto_scroll_cb;
+	GList		*if_list;
+	int		err;
+	char		err_str[PCAP_ERRBUF_SIZE];
+
+	/* Main vertical box */
+	main_vb = gtk_vbox_new(FALSE, 7);
+	gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
+
+	/* Main table */
+	main_tb = gtk_table_new(CAPTURE_TABLE_ROWS, 3, FALSE);
+	gtk_box_pack_start(GTK_BOX(main_vb), main_tb, FALSE, FALSE, 0);
+	gtk_table_set_row_spacings(GTK_TABLE(main_tb), 10);
+	gtk_table_set_col_spacings(GTK_TABLE(main_tb), 15);
+	gtk_widget_show(main_tb);
+
+	/* Default device */
+	if_lb = gtk_label_new("Interface:");
+	gtk_table_attach_defaults(GTK_TABLE(main_tb), if_lb, 0, 1, 0, 1);
+	gtk_widget_show(if_lb);
+  
+	if_cb = gtk_combo_new();
+	/*
+	 * XXX - what if we can't get the list?
+	 */
+	if_list = get_interface_list(&err, err_str);
+	if (if_list != NULL)
+		gtk_combo_set_popdown_strings(GTK_COMBO(if_cb), if_list);
+	if (prefs.capture_device)
+		gtk_entry_set_text(GTK_ENTRY(GTK_COMBO(if_cb)->entry),
+		    prefs.capture_device);
+	gtk_table_attach_defaults(GTK_TABLE(main_tb), if_cb, 1, 2, 0, 1);
+	gtk_widget_show(if_cb);
+	gtk_object_set_data(GTK_OBJECT(main_vb), DEVICE_KEY, if_cb);
+  
+	free_interface_list(if_list);
+
+	/* Promiscuous mode */
+	create_option_check_button(main_vb, PROM_MODE_KEY, main_tb, 1,
+	    "Capture packets in promiscuous mode:", prefs.capture_prom_mode);
+
+	/* Real-time capture */
+	create_option_check_button(main_vb, CAPTURE_REAL_TIME_KEY, main_tb, 2,
+	    "Update list of packets in real time", prefs.capture_real_time);
+
+	/* Auto-scroll real-time capture */
+	create_option_check_button(main_vb, CAPTURE_REAL_TIME_KEY, main_tb, 3,
+	    "Automatic scrolling in live capture", prefs.capture_auto_scroll);
+
+	/* Show 'em what we got */
+	gtk_widget_show_all(main_vb);
+
+	return(main_vb);
+}
+
+static void
+create_option_check_button(GtkWidget *main_vb, const gchar *key,
+    GtkWidget *main_tb, int table_position, const gchar *label_text,
+    gboolean active)
+{
+	GtkWidget *hbox, *check_box;
+
+	hbox = gtk_hbox_new(FALSE, 0);
+	gtk_table_attach_defaults(GTK_TABLE(main_tb), hbox, 1, 3,
+	    table_position, table_position + 1);
+
+	check_box = gtk_check_button_new_with_label(label_text);
+	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(check_box), active);
+
+	gtk_box_pack_start( GTK_BOX(hbox), check_box, FALSE, FALSE, 0 );
+	gtk_object_set_data(GTK_OBJECT(main_vb), key, check_box);
+}
+
+void
+capture_prefs_fetch(GtkWidget *w)
+{
+	GtkWidget *if_cb, *promisc_cb, *sync_cb, *auto_scroll_cb;
+	gchar	*if_text;
+	gchar	*if_name;
+
+	if_cb = (GtkWidget *) gtk_object_get_data(GTK_OBJECT(w), DEVICE_KEY);
+	promisc_cb = (GtkWidget *) gtk_object_get_data(GTK_OBJECT(w),
+	    PROM_MODE_KEY);
+	sync_cb = (GtkWidget *) gtk_object_get_data(GTK_OBJECT(w),
+	    CAPTURE_REAL_TIME_KEY);
+	auto_scroll_cb = (GtkWidget *) gtk_object_get_data(GTK_OBJECT(w),
+	    AUTO_SCROLL_KEY);
+
+	if (prefs.capture_device != NULL) {
+		g_free(prefs.capture_device);
+		prefs.capture_device = NULL;
+	}
+	if_text =
+	    g_strdup(gtk_entry_get_text(GTK_ENTRY(GTK_COMBO(if_cb)->entry)));
+	if_name = strtok(if_text, " \t");
+	if (if_name != NULL)
+		prefs.capture_device = g_strdup(if_name);
+	g_free(if_text);
+
+	prefs.capture_prom_mode = GTK_TOGGLE_BUTTON (promisc_cb)->active;
+
+	prefs.capture_real_time = GTK_TOGGLE_BUTTON (sync_cb)->active;
+
+	prefs.capture_auto_scroll = GTK_TOGGLE_BUTTON (auto_scroll_cb)->active;
+}
+
+void
+capture_prefs_apply(GtkWidget *w)
+{
+}
+
+void
+capture_prefs_destroy(GtkWidget *w)
+{
+}
+
+#endif /* HAVE_LIBPCAP */
diff --git a/gtk/capture_prefs.h b/gtk/capture_prefs.h
new file mode 100644
index 0000000000..ba52a851dc
--- /dev/null
+++ b/gtk/capture_prefs.h
@@ -0,0 +1,33 @@
+/* capture_prefs.h
+ * Definitions for capture preferences window
+ *
+ * $Id: capture_prefs.h,v 1.1 2002/01/10 07:43:39 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __CAPTURE_PREFS_H__
+#define __CAPTURE_PREFS_H__
+
+GtkWidget *capture_prefs_show(void);
+void capture_prefs_fetch(GtkWidget *w);
+void capture_prefs_apply(GtkWidget *w);
+void capture_prefs_destroy(GtkWidget *w);
+
+#endif
diff --git a/gtk/gui_prefs.c b/gtk/gui_prefs.c
index 555acc8f15..ac34e11638 100644
--- a/gtk/gui_prefs.c
+++ b/gtk/gui_prefs.c
@@ -1,12 +1,11 @@
 /* gui_prefs.c
  * Dialog box for GUI preferences
  *
- * $Id: gui_prefs.c,v 1.27 2001/12/31 04:41:50 gerald Exp $
+ * $Id: gui_prefs.c,v 1.28 2002/01/10 07:43:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
  * Copyright 1998 Gerald Combs
- *
  * 
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -261,8 +260,6 @@ create_option_check_button(GtkWidget *main_vb, const gchar *key,
     gboolean active)
 {
 	GtkWidget *hbox, *check_box;
-	int menu_index, index;
-	const enum_val_t *enum_valp;
 
 	hbox = gtk_hbox_new(FALSE, 0);
 	gtk_table_attach_defaults(GTK_TABLE(main_tb), hbox, 1, 3,
diff --git a/gtk/prefs_dlg.c b/gtk/prefs_dlg.c
index 093d7f7009..e6fefd3d98 100644
--- a/gtk/prefs_dlg.c
+++ b/gtk/prefs_dlg.c
@@ -1,7 +1,7 @@
 /* prefs_dlg.c
  * Routines for handling preferences
  *
- * $Id: prefs_dlg.c,v 1.34 2001/12/04 07:23:47 guy Exp $
+ * $Id: prefs_dlg.c,v 1.35 2002/01/10 07:43:39 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -58,6 +58,7 @@
 #include "print_prefs.h"
 #include "stream_prefs.h"
 #include "gui_prefs.h"
+#include "capture_prefs.h"
 #include "ui_util.h"
 #include "dlg_utils.h"
 #include "simple_dialog.h"
@@ -72,10 +73,11 @@ static gboolean prefs_main_delete_cb(GtkWidget *, gpointer);
 static void     prefs_main_destroy_cb(GtkWidget *, gpointer);
 static void	prefs_tree_select_cb(GtkCTree *, GtkCTreeNode *, gint, gpointer);
 
-#define E_PRINT_PAGE_KEY  "printer_options_page"
-#define E_COLUMN_PAGE_KEY "column_options_page"
-#define E_STREAM_PAGE_KEY "tcp_stream_options_page"
-#define E_GUI_PAGE_KEY	  "gui_options_page"
+#define E_PRINT_PAGE_KEY   "printer_options_page"
+#define E_COLUMN_PAGE_KEY  "column_options_page"
+#define E_STREAM_PAGE_KEY  "tcp_stream_options_page"
+#define E_GUI_PAGE_KEY	   "gui_options_page"
+#define E_CAPTURE_PAGE_KEY "capture_options_page"
 
 #define FIRST_PROTO_PREFS_PAGE	4
 
@@ -274,7 +276,7 @@ void
 prefs_cb(GtkWidget *w, gpointer dummy) {
   GtkWidget        *main_vb, *top_hb, *bbox, *prefs_nb, *ct_sb, *frame,
                    *ok_bt, *apply_bt, *save_bt, *cancel_bt;
-  GtkWidget        *print_pg, *column_pg, *stream_pg, *gui_pg;
+  GtkWidget        *print_pg, *column_pg, *stream_pg, *gui_pg, *capture_pg;
   gchar            label_str[MAX_TREE_NODE_NAME_LEN], *label_ptr = label_str;
   GtkCTreeNode     *ct_node;
   struct ct_struct cts;
@@ -397,6 +399,21 @@ prefs_cb(GtkWidget *w, gpointer dummy) {
   		GINT_TO_POINTER(cts.page));
   cts.page++;
 
+#ifdef HAVE_LIBPCAP
+  /* capture prefs */
+  frame = gtk_frame_new("Capture");
+  gtk_widget_show(GTK_WIDGET(frame));
+  capture_pg = capture_prefs_show();
+  gtk_container_add(GTK_CONTAINER(frame), capture_pg);
+  gtk_object_set_data(GTK_OBJECT(prefs_w), E_CAPTURE_PAGE_KEY, capture_pg);
+  gtk_notebook_append_page (GTK_NOTEBOOK(prefs_nb), frame, NULL);
+  strcpy(label_str, "Capture");
+  ct_node = gtk_ctree_insert_node(GTK_CTREE(cts.ctree), NULL, NULL, 
+  		&label_ptr, 5, NULL, NULL, NULL, NULL, TRUE, TRUE);
+  gtk_ctree_node_set_row_data(GTK_CTREE(cts.ctree), ct_node,
+  		GINT_TO_POINTER(cts.page));
+  cts.page++;
+#endif
 
   /* Registered prefs */
   cts.notebook = prefs_nb;
@@ -603,6 +620,7 @@ prefs_main_ok_cb(GtkWidget *ok_bt, gpointer parent_w)
   column_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_module_foreach(module_prefs_fetch, &must_redissect);
 
   /* Now apply those preferences. */
@@ -610,6 +628,7 @@ prefs_main_ok_cb(GtkWidget *ok_bt, gpointer parent_w)
   column_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_apply_all();
 
   /* Now destroy the "Preferences" dialog. */
@@ -633,6 +652,7 @@ prefs_main_apply_cb(GtkWidget *apply_bt, gpointer parent_w)
   column_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_module_foreach(module_prefs_fetch, &must_redissect);
 
   /* Now apply those preferences. */
@@ -640,6 +660,7 @@ prefs_main_apply_cb(GtkWidget *apply_bt, gpointer parent_w)
   column_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_apply_all();
 
   if (must_redissect) {
@@ -663,6 +684,7 @@ prefs_main_save_cb(GtkWidget *save_bt, gpointer parent_w)
   column_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_fetch(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_module_foreach(module_prefs_fetch, &must_redissect);
 
   /* Create the directory that holds personal configuration files, if
@@ -700,6 +722,7 @@ prefs_main_save_cb(GtkWidget *save_bt, gpointer parent_w)
   column_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_apply_all();
 
   if (must_redissect) {
@@ -791,6 +814,7 @@ prefs_main_cancel_cb(GtkWidget *cancel_bt, gpointer parent_w)
   column_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_COLUMN_PAGE_KEY));
   stream_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_STREAM_PAGE_KEY));
   gui_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_GUI_PAGE_KEY));
+  capture_prefs_apply(gtk_object_get_data(GTK_OBJECT(parent_w), E_CAPTURE_PAGE_KEY));
   prefs_apply_all();
 
   gtk_widget_destroy(GTK_WIDGET(parent_w));
@@ -820,6 +844,7 @@ prefs_main_destroy_cb(GtkWidget *win, gpointer user_data)
   column_prefs_destroy(gtk_object_get_data(GTK_OBJECT(prefs_w), E_COLUMN_PAGE_KEY));
   stream_prefs_destroy(gtk_object_get_data(GTK_OBJECT(prefs_w), E_STREAM_PAGE_KEY));
   gui_prefs_destroy(gtk_object_get_data(GTK_OBJECT(prefs_w), E_GUI_PAGE_KEY));
+  capture_prefs_destroy(gtk_object_get_data(GTK_OBJECT(prefs_w), E_CAPTURE_PAGE_KEY));
 
   /* Free up the saved preferences (both for "prefs" and for registered
      preferences). */
diff --git a/prefs.c b/prefs.c
index d0cf745757..39fe66c2ae 100644
--- a/prefs.c
+++ b/prefs.c
@@ -1,7 +1,7 @@
 /* prefs.c
  * Routines for handling preferences
  *
- * $Id: prefs.c,v 1.75 2001/12/31 04:41:48 gerald Exp $
+ * $Id: prefs.c,v 1.76 2002/01/10 07:43:37 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -801,6 +801,7 @@ read_prefs(int *gpf_errno_return, char **gpf_path_return,
     prefs.gui_geometry_main_height   =        -1;
 
 /* set the default values for the capture dialog box */
+    prefs.capture_device      = NULL;
     prefs.capture_prom_mode   = TRUE;
     prefs.capture_real_time   = FALSE;
     prefs.capture_auto_scroll = FALSE;
@@ -1073,8 +1074,9 @@ prefs_set_pref(char *prefarg)
 #define PRS_CAP_NAME_RESOLVE "capture.name_resolve"
 
 /*  values for the capture dialog box */
-#define PRS_CAP_REAL_TIME "capture.real_time_update"
-#define PRS_CAP_PROM_MODE "capture.prom_mode"
+#define PRS_CAP_DEVICE      "capture.device"
+#define PRS_CAP_PROM_MODE   "capture.prom_mode"
+#define PRS_CAP_REAL_TIME   "capture.real_time_update"
 #define PRS_CAP_AUTO_SCROLL "capture.auto_scroll"
 
 #define RED_COMPONENT(x)   ((((x) >> 16) & 0xff) * 65535 / 255)
@@ -1322,12 +1324,14 @@ set_pref(gchar *pref_name, gchar *value)
     prefs.gui_geometry_main_height = strtol(value, NULL, 10);
 
 /* handle the capture options */ 
+  } else if (strcmp(pref_name, PRS_CAP_DEVICE) == 0) {
+    if (prefs.capture_device != NULL)
+      g_free(prefs.capture_device);
+    prefs.capture_device = g_strdup(value);
   } else if (strcmp(pref_name, PRS_CAP_PROM_MODE) == 0) {
     prefs.capture_prom_mode = ((strcasecmp(value, "true") == 0)?TRUE:FALSE); 
- 
   } else if (strcmp(pref_name, PRS_CAP_REAL_TIME) == 0) {
     prefs.capture_real_time = ((strcasecmp(value, "true") == 0)?TRUE:FALSE); 
-
   } else if (strcmp(pref_name, PRS_CAP_AUTO_SCROLL) == 0) {
     prefs.capture_auto_scroll = ((strcasecmp(value, "true") == 0)?TRUE:FALSE); 
  
@@ -1738,6 +1742,11 @@ write_prefs(const char **pf_path_return)
 		  name_resolve_to_string(prefs.name_resolve));
 
 /* write the capture options */
+  if (prefs.capture_device != NULL) {
+    fprintf(pf, "\n# Default capture device\n");
+    fprintf(pf, PRS_CAP_DEVICE ": %s\n", prefs.capture_device);
+  }
+
   fprintf(pf, "\n# Capture in promiscuous mode? TRUE/FALSE\n");
   fprintf(pf, PRS_CAP_PROM_MODE ": %s\n",
 		  prefs.capture_prom_mode == TRUE ? "TRUE" : "FALSE");
@@ -1801,6 +1810,7 @@ copy_prefs(e_prefs *dest, e_prefs *src)
   dest->gui_geometry_main_width = src->gui_geometry_main_width;
   dest->gui_geometry_main_height = src->gui_geometry_main_height;
 /*  values for the capture dialog box */
+  dest->capture_device = g_strdup(src->capture_device);
   dest->capture_prom_mode = src->capture_prom_mode;
   dest->capture_real_time = src->capture_real_time;
   dest->capture_auto_scroll = src->capture_auto_scroll;
@@ -1825,6 +1835,10 @@ free_prefs(e_prefs *pr)
     g_free(pr->gui_font_name);
     pr->gui_font_name = NULL;
   }
+  if (pr->capture_device != NULL) {
+    g_free(pr->capture_device);
+    pr->capture_device = NULL;
+  }
 }
 
 static void
diff --git a/prefs.h b/prefs.h
index 3e283042e6..a6eccc3de6 100644
--- a/prefs.h
+++ b/prefs.h
@@ -1,7 +1,7 @@
 /* prefs.h
  * Definitions for preference handling routines
  *
- * $Id: prefs.h,v 1.35 2001/12/31 04:41:48 gerald Exp $
+ * $Id: prefs.h,v 1.36 2002/01/10 07:43:37 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -77,6 +77,7 @@ typedef struct _e_prefs {
   gint     gui_geometry_main_width;
   gint     gui_geometry_main_height;
   guint32  name_resolve;
+  gchar   *capture_device;
   gboolean capture_prom_mode;
   gboolean capture_real_time;
   gboolean capture_auto_scroll;
diff --git a/tethereal.c b/tethereal.c
index e17f5e0fa1..98f31bc5b1 100644
--- a/tethereal.c
+++ b/tethereal.c
@@ -1,6 +1,6 @@
 /* tethereal.c
  *
- * $Id: tethereal.c,v 1.113 2002/01/03 22:03:24 guy Exp $
+ * $Id: tethereal.c,v 1.114 2002/01/10 07:43:37 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -717,24 +717,30 @@ main(int argc, char *argv[])
 
     /* Yes; did the user specify an interface to use? */
     if (cfile.iface == NULL) {
-        /* No - pick the first one from the list of interfaces. */
-        if_list = get_interface_list(&err, err_str);
-        if (if_list == NULL) {
-            switch (err) {
-
-            case CANT_GET_INTERFACE_LIST:
-                fprintf(stderr, "tethereal: Can't get list of interfaces: %s\n",
-			err_str);
-                break;
-
-            case NO_INTERFACES_FOUND:
-                fprintf(stderr, "tethereal: There are no interfaces on which a capture can be done\n");
-                break;
+        /* No - is a default specified in the preferences file? */
+        if (prefs->capture_device != NULL) {
+            /* Yes - use it. */
+            cfile.iface	= g_strdup(prefs->capture_device);
+        } else {
+            /* No - pick the first one from the list of interfaces. */
+            if_list = get_interface_list(&err, err_str);
+            if (if_list == NULL) {
+                switch (err) {
+
+                case CANT_GET_INTERFACE_LIST:
+                    fprintf(stderr, "tethereal: Can't get list of interfaces: %s\n",
+			    err_str);
+                    break;
+
+                case NO_INTERFACES_FOUND:
+                    fprintf(stderr, "tethereal: There are no interfaces on which a capture can be done\n");
+                    break;
+                }
+                exit(2);
             }
-            exit(2);
+            cfile.iface = g_strdup(if_list->data);	/* first interface */
+            free_interface_list(if_list);
         }
-        cfile.iface = g_strdup(if_list->data);	/* first interface */
-        free_interface_list(if_list);
     }
     capture(packet_count, out_file_type);