#!/bin/bash
N_ARGS=2
E_ERRR=-1
ONE=1
if [ "$#" -ne "$N_ARGS" ] 
then
	echo " Usage: `basename $0` old-pattern new-pattern"
	exit $E_ERR
fi
number=0
for filename in *$1*
do
	if [ -f "$filename" ]
	then
		fname=`basename $filename`
		# elimina il path
		n=`echo $fname | sed -e "s/$1/$2/"`
		echo $n
		mv $fname $n
		let "numero += 1"
	fi
done
if [ "$numero" -eq "$ONE" ] 
then
	echo " File renamed "
else
	echo " Files renamed "
fi
exit 0