fix netdb bug

1) If netdb calls exit() then tash will be destroyed. so I call 'return' instead of calling exit().
2) Usage message is wrong, showing address options even though HAVE_GETHOSTBYADDR flag is off.

diff --git a/apps/system/netdb/netdb_main.c b/apps/system/netdb/netdb_main.c
index 16fa992..0379a1e 100644 (file)
--- a/apps/system/netdb/netdb_main.c
+++ b/apps/system/netdb/netdb_main.c
@@ -51,28 +51,28 @@
  ****************************************************************************/
 
 /**
-   * @testcase            :gethostbyaddr
-   * @brief               :To get hostname by IP address
-   * @scenario            :
-   * @apicovered          :
-   * @precondition        : 1. Connect to Wi-Fi
-   *                      : 2. Get an IP address
-   *                      : 3. Run netdb
-   *                      :TASH> netdb --ipv4 127.0.0.1
-   * @postcondition       :
-   */
+ * @testcase           :gethostbyaddr
+ * @brief              :To get hostname by IP address
+ * @scenario           :
+ * @apicovered         :
+ * @precondition       : 1. Connect to Wi-Fi
+ *                     : 2. Get an IP address
+ *                     : 3. Run netdb
+ *                     :TASH> netdb --ipv4 127.0.0.1
+ * @postcondition      :
+ */
 
 /**
-   * @testcase            :dns_client
-   * @brief               :To resolve hostname to IP address through DNS server
-   * @scenario            :
-   * @apicovered          :
-   * @precondition        : 1. Connect to Wi-Fi
-   *                      : 2. Get an IP address
-   *                      : 3. Run netdb
-   *                      :TASH> netdb --host <URL>
-   * @postcondition       :
-   */
+ * @testcase           :dns_client
+ * @brief              :To resolve hostname to IP address through DNS server
+ * @scenario           :
+ * @apicovered         :
+ * @precondition       : 1. Connect to Wi-Fi
+ *                     : 2. Get an IP address
+ *                     : 3. Run netdb
+ *                     :TASH> netdb --host <URL>
+ * @postcondition      :
+ */
 
 /****************************************************************************
  * Included Files
@@ -120,21 +120,19 @@
  * Private Functions
  ****************************************************************************/
 
-static void show_usage(FAR const char *progname, int exitcode) noreturn_function;
-static void show_usage(FAR const char *progname, int exitcode)
+static void show_usage(FAR const char *progname)
 {
-       fprintf(stderr, "USAGE: %s --ipv4 <ipv4-addr>\n", progname);
+       fprintf(stderr, "USAGE: %s --host <host-name>\n", progname);
 #ifdef HAVE_GETHOSTBYADDR
+       fprintf(stderr, "       %s --ipv4 <ipv4-addr>\n", progname);
        fprintf(stderr, "       %s --ipv6 <ipv6-addr>\n", progname);
-       fprintf(stderr, "       %s --host <host-name>\n", progname);
 #endif
        fprintf(stderr, "       %s --help\n", progname);
-       exit(exitcode);
 }
 
 /****************************************************************************
-* Public Functions
-****************************************************************************/
+ * Public Functions
+ ****************************************************************************/
 
 int netdb_main(int argc, char *argv[])
 {
@@ -147,17 +145,20 @@ int netdb_main(int argc, char *argv[])
        /* Handle: netdb --help */
 
        if (argc == 2 && strcmp(argv[1], "--help") == 0) {
-               show_usage(argv[0], EXIT_SUCCESS);
+               show_usage(argv[0]);
+               return EXIT_FAILURE;
        }
 
        /* Otherwise there must be exactly two arguments following the program name */
 
        else if (argc < 3) {
                fprintf(stderr, "ERROR -- Missing arguments\n\n");
-               show_usage(argv[0], EXIT_FAILURE);
+               show_usage(argv[0]);
+               return EXIT_FAILURE;
        } else if (argc > 3) {
                fprintf(stderr, "ERROR -- Too many arguments\n\n");
-               show_usage(argv[0], EXIT_FAILURE);
+               show_usage(argv[0]);
+               return EXIT_FAILURE;
        }
 #ifdef HAVE_GETHOSTBYADDR
        /* Handle: netdb --ipv4 <ipv4-addr>  */
@@ -170,7 +171,8 @@ int netdb_main(int argc, char *argv[])
                ret = inet_pton(AF_INET, argv[2], &addr);
                if (ret < 0) {
                        fprintf(stderr, "ERROR -- Bad IPv4 address\n\n");
-                       show_usage(argv[0], EXIT_FAILURE);
+                       show_usage(argv[0]);
+                       return EXIT_FAILURE;
                }
 
                /* Get the matching host name + any aliases */
@@ -192,7 +194,8 @@ int netdb_main(int argc, char *argv[])
                ret = inet_pton(AF_INET6, argv[2], &addr);
                if (ret < 0) {
                        fprintf(stderr, "ERROR -- Bad IPv6 address\n\n");
-                       show_usage(argv[0], EXIT_FAILURE);
+                       show_usage(argv[0]);
+                       return EXIT_FAILURE;
                }
 
                /* Get the matching host name + any aliases */
@@ -221,7 +224,8 @@ int netdb_main(int argc, char *argv[])
 
        else {
                fprintf(stderr, "ERROR -- Unrecognized option: %s\n\n", argv[1]);
-               show_usage(argv[0], EXIT_FAILURE);
+               show_usage(argv[0]);
+               return EXIT_FAILURE;
        }
 
        /* If we get here, then gethostbyname() or gethostbyaddr() was