route: document -4 and -6 for route command

man/en_US/route.8

-.TH ROUTE 8 "2008\-10\-03" "net\-tools" "Linux System Administrator's Manual"
+.TH ROUTE 8 "2013\-06\-15" "net\-tools" "Linux System Administrator's Manual"
 .SH NAME
 route \- show / manipulate the IP routing table
 .SH SYNOPSIS
 .B route
-.RB [ \-CFvnee ]
+.RB [ \-CFvnNee ]
+.RB [ \-A
+family
+.RB | \-4 | \-6 ] 
 .TP
 .B route 
 .RB [ \-v ]
 .RB [ \-A
-family] 
+family 
+.RB | \-4 | \-6 ] 
 .B add 
 .RB [ \-net | \-host ] 
 target 
@@ -34,7 +38,8 @@ If]
 .B route 
 .RB [ \-v ] 
 .RB [ \-A
-family]
+family
+.RB | \-4 | \-6 ]
 .B del 
 .RB [ \-net | \-host ] 
 target 
@@ -73,8 +78,17 @@ displays the current contents of the routing tables.
 .SH OPTIONS
 .TP
 .B \-A family
-use the specified address family (eg `inet'; use `route \-\-help' for a full 
-list).
+use the specified address family (eg `inet'). Use 
+.B route \-\-help
+for a full list. You can use 
+.B \-6 
+as an alias for 
+.B \-\-inet6 
+and 
+.B \-4 
+as an alias for 
+.B -A inet
+.
 
 .TP 
 .B \-F

route.c

@@ -68,12 +68,12 @@
 
 static char *Release = RELEASE;
 
-int opt_n = 0;			/* numerical output flag        */
-int opt_v = 0;			/* debugging output flag        */
-int opt_e = 1;			/* 1,2,3=type of routetable     */
-int opt_fc = 0;			/* routing cache/FIB */
-int opt_h = 0;			/* help selected                */
-struct aftype *ap;		/* current address family       */
+int opt_n = 0;     // numerical output FLAG_NUM | FLAG_SYM
+int opt_v = 0;     // debugging output flag
+int opt_e = 1;     // 1,2,3=type of routetable
+int opt_fc = 0;    // routing cache/FIB
+int opt_h = 0;     // help selected
+struct aftype *ap; // selected address family
 
 static void usage(void)
 {
@@ -89,7 +89,7 @@ static void usage(void)
     fprintf(stderr, _("        -F, --fib                display Forwarding Information Base (default)\n"));
     fprintf(stderr, _("        -C, --cache              display routing cache instead of FIB\n\n"));
 
-    fprintf(stderr, _("  <AF>=Use '-A <af>' or '--<af>'; default: %s\n"), DFLT_AF);
+    fprintf(stderr, _("  <AF>=Use -4, -6, '-A <af>' or '--<af>'; default: %s\n"), DFLT_AF);
     fprintf(stderr, _("  List of possible address families (which support routing):\n"));
     print_aflist(1); /* 1 = routeable */
     exit(E_USAGE);