Fix a couple of problems with the help message for the --length option.

* The canonical long-form option name is "length", not "len".

* The default length for UDP should be displayed in bytes not KB.

src/iperf_api.c

@@ -109,7 +109,7 @@ usage()
 void
 usage_long(FILE *f)
 {
-    fprintf(f, usage_longstr, UDP_RATE / (1024*1024), DURATION, DEFAULT_TCP_BLKSIZE / 1024, DEFAULT_UDP_BLKSIZE / 1024);
+    fprintf(f, usage_longstr, UDP_RATE / (1024*1024), DURATION, DEFAULT_TCP_BLKSIZE / 1024, DEFAULT_UDP_BLKSIZE);
 }
 
 

src/iperf_locale.c

@@ -143,7 +143,7 @@ const char usage_longstr[] = "Usage: iperf3 [-s|-c host] [options]\n"
                            "  -t, --time      #         time in seconds to transmit for (default %d secs)\n"
                            "  -n, --bytes     #[KMG]    number of bytes to transmit (instead of -t)\n"
                            "  -k, --blockcount #[KMG]   number of blocks (packets) to transmit (instead of -t or -n)\n"
-                           "  -l, --len       #[KMG]    length of buffer to read or write\n"
+                           "  -l, --length    #[KMG]    length of buffer to read or write\n"
 			   "                            (default %d KB for TCP, dynamic or %d for UDP)\n"
                            "  --cport         <port>    bind to a specific client port (TCP and UDP, default: ephemeral port)\n"
                            "  -P, --parallel  #         number of parallel client streams to run\n"