Check return value of getloadavg, fixes #4

2 files changed, 16 insertions, 5 deletions

diff --git a/Changes b/Changes
index fd6f963..55027c5 100644
--- a/Changes
+++ b/Changes
@@ -1,6 +1,9 @@
 Revision history for Perl extension {{$dist->name}}:
 
 {{$NEXT}}
+  [Bug Fixes]
+  - The return value of getloadavg is now checked, #4.
+
   [Documentation]
   - Update POD about changes in version 0.12.
 
diff --git a/CpuLoad.xs b/CpuLoad.xs
index d992234..90105ec 100644
--- a/CpuLoad.xs
+++ b/CpuLoad.xs
@@ -17,11 +17,19 @@ void
 _getbsdload()
     PREINIT:
         double loadavg[3];
+        int    nelem;
     PPCODE:
 #if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__APPLE__) || defined(__linux__)
-        getloadavg(loadavg, 3);
+        nelem = getloadavg(loadavg, 3);
+#else
+        nelem = -1;
 #endif
-        EXTEND(SP, 3);
-        PUSHs(sv_2mortal(newSVnv(loadavg[0])));
-        PUSHs(sv_2mortal(newSVnv(loadavg[1])));
-        PUSHs(sv_2mortal(newSVnv(loadavg[2])));
+        if (nelem != -1) {
+          EXTEND(SP, 3);
+          PUSHs(sv_2mortal(newSVnv(loadavg[0])));
+          PUSHs(sv_2mortal(newSVnv(loadavg[1])));
+          PUSHs(sv_2mortal(newSVnv(loadavg[2])));
+        }
+        else {
+          XSRETURN_UNDEF;
+        }