--- a/lib/pvl/cmd.sh	Tue Mar 03 11:17:07 2015 +0200
+++ b/lib/pvl/cmd.sh	Tue Mar 03 11:39:07 2015 +0200
@@ -20,6 +20,7 @@
 
     "$@"
 }
+
 ## Execute command, prefixing its output on stdout with given indent prefix.
 #
 #   indent  "    " $cmd...
@@ -32,3 +33,12 @@
 
     return ${PIPESTATUS[0]}
 }
+
+## Execute a command as root, using sudo if required.
+function cmd_sudo {
+    if [ $UID -eq 0 ]; then
+        cmd "$@"
+    else
+        cmd sudo "$@"
+    fi
+}