inc/collectd: consistently return false instead of an empty array or false

This means we have to check the return value of these functions for
example before doing a foreach. We can't just do a foreach and assume the
return value of a function is an array, while it can be false and results
in a PHP warning.

Closes: https://github.com/pommi/CGP/pull/68

3 files changed, 19 insertions, 21 deletions

diff --git a/detail.php b/detail.php
index 4eacc80..33db2b9 100644
--- a/detail.php
+++ b/detail.php
@@ -30,9 +30,7 @@ html_start();
 printf('<fieldset id="%s">', $host);
 printf('<legend>%s</legend>', $host);
 
-$plugins = collectd_plugins($host);
-
-if(!$plugins) {
+if (!$plugins = collectd_plugins($host)) {
         echo "Unknown host\n";
         return false;
 }
diff --git a/host.php b/host.php
index cc6fa50..b398630 100644
--- a/host.php
+++ b/host.php
@@ -15,9 +15,7 @@ printf("<fieldset id=\"%s\">", $host);
 printf("<legend>%s</legend>", $host);
 
 
-$plugins = collectd_plugins($host);
-
-if(!$plugins) {
+if (!$plugins = collectd_plugins($host)) {
         echo "Unknown host\n";
         return false;
 }
diff --git a/inc/collectd.inc.php b/inc/collectd.inc.php
index e364180..5927bf6 100644
--- a/inc/collectd.inc.php
+++ b/inc/collectd.inc.php
@@ -16,7 +16,8 @@ function collectd_hosts() {
                 if(!is_dir($CONFIG['datadir'].'/'.$v))
                         unset($dir[$k]);
         }
-        return($dir);
+
+        return $dir ? $dir : false;
 }
 
 
@@ -35,7 +36,7 @@ function get_host_rrd_files($dir) {
                 $files[] = str_replace($dir.'/', '', $object->getPathname());
         }
 
-        return $files;
+        return $files ? $files : false;
 }
 
 
@@ -47,8 +48,7 @@ function collectd_plugindata($host, $plugin=NULL) {
                 return false;
 
         $hostdir = $CONFIG['datadir'].'/'.$host;
-        $files = get_host_rrd_files($hostdir);
-        if (!$files)
+        if (!$files = get_host_rrd_files($hostdir))
                 return false;
 
         $data = array();
@@ -82,12 +82,13 @@ function collectd_plugindata($host, $plugin=NULL) {
                 $data = $pdata;
         }
 
-        return($data);
+        return $data ? $data : false;
 }
 
 # returns an array of all plugins of a host
 function collectd_plugins($host) {
-        $plugindata = collectd_plugindata($host);
+        if (!$plugindata = collectd_plugindata($host))
+                return false;
 
         $plugins = array();
         foreach ($plugindata as $item) {
@@ -95,7 +96,7 @@ function collectd_plugins($host) {
                         $plugins[] = $item['p'];
         }
 
-        return $plugins;
+        return $plugins ? $plugins : false;
 }
 
 # returns an array of all pi/t/ti of an plugin
@@ -104,7 +105,8 @@ function collectd_plugindetail($host, $plugin, $detail, $where=NULL) {
         if (!in_array($detail, $details))
                 return false;
 
-        $plugindata = collectd_plugindata($host);
+        if (!$plugindata = collectd_plugindata($host))
+                return false;
 
         $return = array();
         foreach ($plugindata as $item) {
@@ -124,10 +126,7 @@ function collectd_plugindetail($host, $plugin, $detail, $where=NULL) {
                 }
         }
 
-        if (empty($return))
-                return false;
-
-        return $return;
+        return $return ? $return : false;
 }
 
 # group plugin files for graph generation
@@ -173,9 +172,12 @@ function plugin_sort($data) {
 function graphs_from_plugin($host, $plugin, $overview=false) {
         global $CONFIG;
 
-        $plugindata = collectd_plugindata($host, $plugin);
-        $plugindata = group_plugindata($plugindata);
-        $plugindata = plugin_sort($plugindata);
+        if (!$plugindata = collectd_plugindata($host, $plugin))
+                return false;
+        if (!$plugindata = group_plugindata($plugindata))
+                return false;
+        if (!$plugindata = plugin_sort($plugindata))
+                return false;
 
         foreach ($plugindata as $items) {