Updated help information for adig, acountry, and ahost. (#334)

Provide more descriptive help information for various utilities.

Fix By: @anonymoushelpishere

acountry.c

@@ -89,6 +89,7 @@ static void wait_ares(ares_channel channel);
 static void callback(void *arg, int status, int timeouts, struct hostent *host);
 static void callback2(void *arg, int status, int timeouts, struct hostent *host);
 static void find_country_from_cname(const char *cname, struct in_addr addr);
+static void print_help_info_acountry();
 
 static void Abort(const char *fmt, ...)
 {
@@ -129,7 +130,11 @@ int main(int argc, char **argv)
         verbose++;
         break;
       case 'h':
+        print_help_info_acountry();
+        break;
       case '?':
+        print_help_info_acountry();
+        break;
       default:
         Abort(usage);
       }
@@ -624,3 +629,13 @@ static void find_country_from_cname(const char *cname, struct in_addr addr)
     }
   free(ccopy);
 }
+
+/* Information from the man page. Formatting taken from man -h */
+static void print_help_info_acountry() {
+    printf("acountry, version %s \n\n", ARES_VERSION_STR);
+    printf("usage: acountry [-hdv] {host|addr} ...\n\n"
+    "  d : Print some extra debugging output.\n"
+    "  h : Display this help and exit.\n"
+    "  v : Be more verbose. Print extra information.\n\n");
+    exit(0);
+}

adig.c

@@ -177,6 +177,7 @@ static void usage(void);
 static void destroy_addr_list(struct ares_addr_node *head);
 static void append_addr_list(struct ares_addr_node **head,
                              struct ares_addr_node *node);
+static void print_help_info_adig();
 
 int main(int argc, char **argv)
 {
@@ -205,7 +206,7 @@ int main(int argc, char **argv)
   options.flags = ARES_FLAG_NOCHECKRESP;
   options.servers = NULL;
   options.nservers = 0;
-  while ((c = ares_getopt(argc, argv, "df:s:c:t:T:U:")) != -1)
+  while ((c = ares_getopt(argc, argv, "dh?f:s:c:t:T:U:")) != -1)
     {
       switch (c)
         {
@@ -214,7 +215,12 @@ int main(int argc, char **argv)
           dbug_init();
 #endif
           break;
-
+        case 'h':
+          print_help_info_adig();
+          break;
+        case '?':
+          print_help_info_adig();
+          break;
         case 'f':
           /* Add a flag. */
           for (i = 0; i < nflags; i++)
@@ -825,3 +831,26 @@ static void append_addr_list(struct ares_addr_node **head,
   else
     *head = node;
 }
+
+
+/* Information from the man page. Formatting taken from man -h */
+static void print_help_info_adig() {
+    printf("adig, version %s \n\n", ARES_VERSION_STR);
+    printf("usage: adig [-h] [-d] [-f flag] [-s server] [-c class] [-t type] [-T|U port] name ...\n\n"
+    "  d : Print some extra debugging output.\n"
+    "  f : Add a flag. Possible values for flag are igntc, noaliases, norecurse, primary, stayopen, usevc.\n"
+    "  h : Display this help and exit.\n\n"
+    "  T port   : Use specified TCP port to connect to DNS server.\n"
+    "  U port   : Use specified UDP port to connect to DNS server.\n"
+    "  c class  : Set the query class. Possible values for class are NY, CHAOS, HS, IN  (default).\n"
+    "  s server : Connect to specified DNS server, instead of the system's default one(s).\n"
+    "  t type   : Query records of specified type.  \n"
+    "              Possible values for type are A  \n"
+    "              (default), AAAA, AFSDB,  ANY,\n"
+    "              AXFR, CNAME, GPOS, HINFO, ISDN,\n"
+    "              KEY, LOC, MAILA, MAILB, MB, MD,\n"
+    "              MF, MG, MINFO, MR, MX, NAPTR, NS,\n"
+    "              NSAP, NSAP_PTR, NULL, PTR, PX, RP,\n"
+    "              RT,  SIG,  SOA, SRV, TXT, WKS, X25\n\n");
+    exit(0);
+}

ahost.c

@@ -49,6 +49,7 @@
 
 static void callback(void *arg, int status, int timeouts, struct hostent *host);
 static void usage(void);
+static void print_help_info_ahost();
 
 int main(int argc, char **argv)
 {
@@ -76,7 +77,7 @@ int main(int argc, char **argv)
       return 1;
     }
 
-  while ((c = ares_getopt(argc,argv,"dt:hs:")) != -1)
+  while ((c = ares_getopt(argc,argv,"dt:h?s:")) != -1)
     {
       switch (c)
         {
@@ -103,6 +104,11 @@ int main(int argc, char **argv)
             usage();
           break;
         case 'h':
+          print_help_info_ahost();
+          break;
+        case '?':
+          print_help_info_ahost();
+          break;
         default:
           usage();
           break;
@@ -204,3 +210,22 @@ static void usage(void)
   fprintf(stderr, "usage: ahost [-h] [-d] [-s {domain}] [-t {a|aaaa|u}] {host|addr} ...\n");
   exit(1);
 }
+
+/* Information from the man page. Formatting taken from man -h */
+static void print_help_info_ahost() {
+    printf("ahost, version %s \n\n", ARES_VERSION_STR);
+    printf("usage: ahost [-h] [-d] [-s {domain}] [-t {a|aaaa|u}] {host|addr} ...\n\n"
+    "  d : Print some extra debugging output.\n"
+    "  h : Display this help and exit.\n\n"
+    "  s domain : Specify the domain to search instead of \n"
+    "               using the default values from \n"
+    "               /etc/resolv.conf. This option only has an \n"
+    "               effect on platforms that use /etc/resolv.conf\n"
+    "               for DNS configuration; it has no effect on other\n"
+    "               platforms (such as Win32 or Android).\n"
+    "  t type   : If type is \"a\", print the A record (default).\n"
+    "               If type is \"aaaa\", print the AAAA record.  If\n"
+    "               type is \"u\", look for either AAAA or A record\n"
+    "               (in that order).\n\n");
+    exit(0);
+}