document -N in documentation and implement small fixes in test suite for macOS

ChangeLog

@@ -2,7 +2,7 @@
   * Version 3.14
   * (feature) Ignore network and broadcast for cidrs /31 and /32 (#102, Martin Topholm)
   * (feature) New option '-M' to set the "Don't Fragment" flag (#91, Don Bowman) 
-  * (feature) New option '-N' to output statistics for netdata (see: http://my-netdata.io/, #10, Costa Tsaousis)
+  * (feature) New option '-N' to output statistics for netdata (see: http://my-netdata.io/, #105, Costa Tsaousis)
   * (feature) New option '-o' to calculate total outage time (#90, @jgerbeck)
   * (bugfix) Exit code should be 2 when the hostname can't be resolved
             (fixes #98, reported by @green-fox)

ci/test-14-ping-internet-hosts.pl

@@ -43,7 +43,7 @@ $cmd->stderr_is_eq("");
 
 # fping6 -A -n
 SKIP: {
-    if(system("/sbin/ifconfig | grep inet6") != 0) {
+    if(system("/sbin/ifconfig | grep inet6.*Scope:Global") != 0) {
         skip 'No IPv6 on this host', 3;
     }
     my $cmd = Test::Command->new(cmd => "fping6 -n -A 2001:4860:4860::8888");

ci/test-issue-56.pl

@@ -1,8 +1,16 @@
 #!/usr/bin/perl -w
 
 # regression testing for github issue #56
+#
+use Test::Command;
+use Test::More;
 
-use Test::Command tests => 3;
+if( $^O eq 'darwin' ) {
+    plan skip_all => 'Test disabled on MacOS';
+    exit 0;
+}
+
+plan tests => 3;
 
 my $cmd1 = Test::Command->new(cmd => "fping -t100 -p100 -C3 255.255.255.255");
 $cmd1->exit_is_num(1);

doc/fping.pod

@@ -135,6 +135,10 @@ Set the "Don't Fragment" bit in the IP header (used to determine/test the MTU).
 
 Same as -d. 
 
+=item B<-N>
+
+Format output for netdata (-l -Q are required). See: http://my-netdata.io/
+
 =item B<-o>
 
 Calculate "outage time" based on the number of lost pings and the interval used (useful for network convergence tests).