Editcap: Don't treat plain -F and -T as errors.

The editcap man page says that you can pass in -F and -T without
arguments in order to get a list of valid capture and encapsulation
types. Instead of treating these as errors just print the information to
stdout and return 0.

Adjust the docbook _tools_help targets accordingly.

Change-Id: I590cbd59059dd8965299bef4434f522eff8a4e2c
Reviewed-on: https://code.wireshark.org/review/23741
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

2 files changed, 15 insertions, 15 deletions

diff --git a/docbook/CMakeLists.txt b/docbook/CMakeLists.txt
index 797b14fb0f..157a70b63e 100644
--- a/docbook/CMakeLists.txt
+++ b/docbook/CMakeLists.txt
@@ -107,7 +107,7 @@ list(APPEND WSUG_TOOLS_HELP_FILES ${th_file})
 list(APPEND WSUG_TOOLS_PHONY_DEPS ${th_phony})
 add_custom_command(
 	OUTPUT ${th_phony}
-	COMMAND ${CMAKE_BINARY_DIR}/run/editcap -F > ${th_file} 2>&1 || true
+	COMMAND ${CMAKE_BINARY_DIR}/run/editcap -F > ${th_file}
 )
 set(th_file ${CMAKE_CURRENT_SOURCE_DIR}/wsug_src/editcap-T.txt)
 set(th_phony editcap_T_tools_help)
@@ -115,7 +115,7 @@ list(APPEND WSUG_TOOLS_HELP_FILES ${th_file})
 list(APPEND WSUG_TOOLS_PHONY_DEPS ${th_phony})
 add_custom_command(
 	OUTPUT ${th_phony}
-	COMMAND ${CMAKE_BINARY_DIR}/run/editcap -T > ${th_file} 2>&1 || true
+	COMMAND ${CMAKE_BINARY_DIR}/run/editcap -T > ${th_file}
 )
 
 add_custom_target(update_tools_help
diff --git a/editcap.c b/editcap.c
index 7ea2b348f4..22b44bd9c3 100644
--- a/editcap.c
+++ b/editcap.c
@@ -852,21 +852,21 @@ string_nat_compare(gconstpointer a, gconstpointer b)
 }
 
 static void
-string_elem_print(gpointer data, gpointer not_used _U_)
+string_elem_print(gpointer data, gpointer stream_ptr)
 {
-    fprintf(stderr, "    %s - %s\n",
+    fprintf((FILE *) stream_ptr, "    %s - %s\n",
         ((struct string_elem *)data)->sstr,
         ((struct string_elem *)data)->lstr);
 }
 
 static void
-list_capture_types(void) {
+list_capture_types(FILE *stream) {
     int i;
     struct string_elem *captypes;
     GSList *list = NULL;
 
     captypes = g_new(struct string_elem,WTAP_NUM_FILE_TYPES_SUBTYPES);
-    fprintf(stderr, "editcap: The available capture file types for the \"-F\" flag are:\n");
+    fprintf(stream, "editcap: The available capture file types for the \"-F\" flag are:\n");
     for (i = 0; i < WTAP_NUM_FILE_TYPES_SUBTYPES; i++) {
         if (wtap_dump_can_open(i)) {
             captypes[i].sstr = wtap_file_type_subtype_short_string(i);
@@ -874,19 +874,19 @@ list_capture_types(void) {
             list = g_slist_insert_sorted(list, &captypes[i], string_compare);
         }
     }
-    g_slist_foreach(list, string_elem_print, NULL);
+    g_slist_foreach(list, string_elem_print, stream);
     g_slist_free(list);
     g_free(captypes);
 }
 
 static void
-list_encap_types(void) {
+list_encap_types(FILE *stream) {
     int i;
     struct string_elem *encaps;
     GSList *list = NULL;
 
     encaps = (struct string_elem *)g_malloc(sizeof(struct string_elem) * WTAP_NUM_ENCAP_TYPES);
-    fprintf(stderr, "editcap: The available encapsulation types for the \"-T\" flag are:\n");
+    fprintf(stream, "editcap: The available encapsulation types for the \"-T\" flag are:\n");
     for (i = 0; i < WTAP_NUM_ENCAP_TYPES; i++) {
         encaps[i].sstr = wtap_encap_short_string(i);
         if (encaps[i].sstr != NULL) {
@@ -894,7 +894,7 @@ list_encap_types(void) {
             list = g_slist_insert_sorted(list, &encaps[i], string_nat_compare);
         }
     }
-    g_slist_foreach(list, string_elem_print, NULL);
+    g_slist_foreach(list, string_elem_print, stream);
     g_slist_free(list);
     g_free(encaps);
 }
@@ -1204,7 +1204,7 @@ main(int argc, char *argv[])
             if (out_file_type_subtype < 0) {
                 fprintf(stderr, "editcap: \"%s\" isn't a valid capture file type\n\n",
                         optarg);
-                list_capture_types();
+                list_capture_types(stderr);
                 ret = INVALID_OPTION;
                 goto clean_exit;
             }
@@ -1263,7 +1263,7 @@ main(int argc, char *argv[])
             if (out_frame_type < 0) {
                 fprintf(stderr, "editcap: \"%s\" isn't a valid encapsulation type\n\n",
                         optarg);
-                list_encap_types();
+                list_encap_types(stderr);
                 ret = INVALID_OPTION;
                 goto clean_exit;
             }
@@ -1295,16 +1295,16 @@ main(int argc, char *argv[])
         case '?':              /* Bad options if GNU getopt */
             switch(optopt) {
             case'F':
-                list_capture_types();
+                list_capture_types(stdout);
                 break;
             case'T':
-                list_encap_types();
+                list_encap_types(stdout);
                 break;
             default:
                 print_usage(stderr);
+                ret = INVALID_OPTION;
                 break;
             }
-            ret = INVALID_OPTION;
             goto clean_exit;
             break;
         }