proftpd: converting to /bin/sh

Some cleanup

plugins/ftp/proftpd

@@ -1,6 +1,9 @@
-#!/bin/bash
+#! /bin/sh
+# configuration :
+#
+# env.LOGFILE /var/log/proftpd/proftpd.log
 
-if [[ $1 == 'config' ]]; then
+if [ "$1" = 'config' ]; then
 	echo "graph_args --base 1000 -l 0"
 	echo "graph_title Serveur FTP"
 	echo "graph_category Ftp"
@@ -11,8 +14,12 @@ if [[ $1 == 'config' ]]; then
 	echo "failed.draw AREA"
 fi
 
-succes=`cat /var/log/proftpd/proftpd.log | grep -c "successful"`
-failed=`cat /var/log/proftpd/proftpd.log | grep -c "Login failed"`
+LOGFILE=${LOGFILE:-"/var/log/proftpd/proftpd.log"}
+
+succes=$(grep -c "successful" "$LOGFILE" )
+failed=$(grep -c "Login failed" "$LOGFILE" )
 
 echo "succes.value $succes"
 echo "failed.value $failed"
+
+exit 0