--- slookup-1.2.old/slookup.c
+++ slookup-1.2/slookup.c
@@ -19,11 +19,12 @@
  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *	
  */
+                                // Original author
+#define AUTHOR  "Heikki Hannikainen"
+#define LICENSE "GPL license"   // License info string
+                                // Release ID   string
+#define VERSION "1.2-mod-060427"
 
-
-#define VERSION "1.2"
-#define VERSTR  "slookup version " VERSION " by Heikki Hannikainen <hessu@hes.iki.fi> 1998, 2004\n\tThis is free software, redistributable under the GNU GPL v2.\n"
-#define HELPS	"Usage: slookup [-v] [-f <children>] [-p] [-t A|PTR|MX]|NS\n\t-v\tVerbose\n\t-f\tNumber of children to Fork for Fast parallel lookups\n\t-p\tUse persistent TCP connection(s) to DNS server\n\t-t\tSpecify query type\n"
 #define MAXLEN 8192
 #define MAXCHILDREN 128
 
@@ -105,6 +106,38 @@
 	}
 }
 
+//--------------------------------------------------------------------
+
+void usage (void)
+{
+    printf ("slookup %s by %s 1998, 2004 - %s\n",
+        VERSION, AUTHOR, LICENSE);
+
+    puts ("");
+    puts ("Usage:   slookup < list.txt   or   echo foo.com | slookup");
+    puts ("");
+    puts ("For sorted output, append \"| sort\":  slookup < list.txt | sort");
+    puts ("");
+    puts ("The input file [if any] should list one or more domain names or");
+    puts ("IP addresses, one per line.");
+    puts ("");
+    puts ("Options: slookup -f NUMPROCS -p -t TYPE");
+    puts ("");
+    puts ("      -v NUMPROCS - Set number of processes");
+    puts ("      -p          - Use persistent TCP connections");
+    puts ("      -t TYPE     - Specify DNS query type (A, PTR, MX, NS)");
+    puts ("");
+    puts ("\"slookup\" output lines look like this:");
+    puts ("");
+    puts ("      item + response        - where successful");
+    puts ("or    item - error message   - where unsuccessful");
+    puts ("");
+
+    exit (1);
+}
+
+//--------------------------------------------------------------------
+
 /*
  *	Parse arguments
  */
@@ -142,7 +175,7 @@
 		case '?':
 		case 'h':
 		default :
-			fprintf(stderr, "%s%s", VERSTR, HELPS);
+            usage();
 			exit(1);
 	}
 	}
@@ -279,7 +312,7 @@
 	u_char *p, *eom;
 	int ancount, qdcount, nmx, n;
 	int maxmx = 30;
-	u_short type, class, dlen, pref;
+	u_short type, class, dlen, pref = 0;
 	uint32_t ttl;
 	
 	if ((reslen = res_query(s, C_IN, qtype, (u_char *)&res, sizeof(res))) < 0) {
@@ -409,7 +442,8 @@
 	char s[MAXLEN];
 	char *p;
 	int robin = -1;
-	
+
+    if (isatty (fileno (stdin))) usage();
 	parse_args(argc, argv);
 	
 	/* if we want to fork, then fork */