only email if file exists

shellbox_from_db

@@ -5,7 +5,7 @@
 # a configuration file for the shellbox service.
 # Create/update /etc/shellbox.d/<port>.conf files
 #
-# $Id: shellbox_from_db,v 1.2 2014/05/21 11:17:31 kapeller Exp $
+# $Id: shellbox_from_db,v 1.3 2014/05/22 07:22:35 kapeller Exp $
 # $Source: /cvs/G/EPICS/App/scripts/shellbox_from_db,v $
 ###############################################################################
 #
@@ -66,7 +66,9 @@ if (wget -qO $tmpfile https://inventory.psi.ch/soap/softioc_info.aspx?host=$host
       echo "### EOF" >> $new_file
       if (! cmp -s $new_file $old_file); then
         subject="SoftIOC #$port on $hostname has changed"
-        diff -u $new_file $old_file | mail -s "$subject" $email
+        if [ -e $old_file ]; then
+          diff -u $new_file $old_file | mail -s "$subject" $email
+        fi
         cp $new_file $old_file
       fi
     fi