http://osdir.com/ml/network.nagios.devel/2005-12/msg00015.html

--- contrib/check_inodes.pl	2008-01-05 16:42:26.000000000 +0100
+++ contrib/check_inodes.pl.oden	2008-01-05 17:45:28.000000000 +0100
@@ -8,12 +8,12 @@
 #                                                                            #
 ##############################################################################
 
-$filesystem = $ARGV[0];
-$warnpercent = $ARGV[1];
-$critpercent = $ARGV[2];
+my $filesystem = $ARGV[0];
+my $warnpercent = $ARGV[1];
+my $critpercent = $ARGV[2];
 
 #------Find out what kind of syntax to expect
-$systype=`uname`;
+my $systype=`uname`;
 chomp($systype);
 
 #------Make sure we got called with the right number of arguments
@@ -26,7 +26,7 @@
 }#end if
 
 #------This gets the data from the df command
-$inputline = `df -i $filesystem|grep -v "Filesystem"`;
+my $inputline = `df -i $filesystem|grep -v "Filesystem"`;
 
 #------replaces all spaces with a single :, that way we can use split
 $inputline =~ y/ /:/s;
@@ -35,13 +35,14 @@
 #------(at least mine do).  This way I can use this plugin on all my hosts
 #------if neither of these work, add your own in, or if you've got one that
 #------just flat out reports something different...well...perl is your friend.
+my $ipercent;
 SWITCH: {
   if ($systype eq "Linux") {
-    ($fs,$inodes,$iused,$ifree,$ipercent,$mntpt) = split(/:/,$inputline); 
+    $ipercent = (split(/:/,$inputline))[4];
     last SWITCH;
   }#end if
   if ($systype eq "AIX") {
-    ($fs,$blks,$free,$percentused,$iused,$ipercent,$mntpt) = split(/:/,$inputline); 
+    $ipercent = (split(/:/,$inputline))[5];
     last SWITCH;
   }#end if
 }#end switch