diff -r 1c7e99693439 -r bdc967bf50d2 lib/SI/tools.pm
--- a/lib/SI/tools.pm	Fri Jan 29 00:35:46 2010 +0100
+++ b/lib/SI/tools.pm	Sun Jan 31 01:17:32 2010 +0100
@@ -8,7 +8,7 @@
 use Data::Dumper;
 use base "Exporter";
 
-our @EXPORT = qw(&run &verbose &find_by_devid &cat &barf);
+our @EXPORT = qw(&run &verbose &find_by_devid &cat &barf &default);
 
 sub run(@) {
     system(@_);
@@ -16,6 +16,10 @@
       if $?;
 }
 
+sub default($$) {
+    return defined $_[1] ? $_[1] : $_[0];
+}
+
 sub barf(@) { die Dumper @_ }
 
 sub cat($) {