Exit code should be 2 when the hostname can't be resolved (fixes #98)

ChangeLog

@@ -1,3 +1,7 @@
+UNRELEASED
+  * (bugfix) Exit code should be 2 when the hostname can't be resolved
+            (fixes #98, reported by @green-fox)
+
 2015-10-21  David Schweikert  <david@schweikert.ch>
   * Version 3.13
   * (bugfix) Fix ICMP errors sometimes causing crashes with fping >= 3.11

ci/test-13-unknown-host.pl

@@ -5,7 +5,7 @@ use Test::Command tests => 6;
 # fping
 {
 my $cmd = Test::Command->new(cmd => "fping nosuchname.example.com");
-$cmd->exit_is_num(1);
+$cmd->exit_is_num(2);
 $cmd->stdout_is_eq("");
 $cmd->stderr_like(qr{^nosuchname\.example\.com: .*not (known|found)});
 }
@@ -13,7 +13,7 @@ $cmd->stderr_like(qr{^nosuchname\.example\.com: .*not (known|found)});
 # fping6
 {
 my $cmd = Test::Command->new(cmd => "fping6 nosuchname.example.com");
-$cmd->exit_is_num(1);
+$cmd->exit_is_num(2);
 $cmd->stdout_is_eq("");
 $cmd->stderr_like(qr{^nosuchname\.example\.com: .*not (known|found)});
 }

src/fping.c

@@ -777,8 +777,9 @@ int main( int argc, char **argv )
         usage(1);
     }
     
-    if( !num_hosts )
-        exit(1);
+    if(!num_hosts) {
+        exit(num_noaddress ? 2 : 1);
+    }
 
     if(src_addr_present) {
         socket_set_src_addr(s, src_addr);