问Linux Bash脚本grep错误

EN

askDelete()
{
echo -e "  Still want to delete it? (y/n)\n"
read answer
if [ "$answer" = 'y']; then
    rm $1
else
    echo -e "\nFile was not removed\n"
fi
}

#############################################
clear

#script starts here

echo -e "\n\tCleaner Script\n"

dir=`pwd`

while [ "$choice" -ne 3 ] || [ "$choice" != "quit" ]
    do

    echo -e "\nEnter 1 to delete by filename or type the word file."
    echo -e "\nEnter 2 to delete by a string within a file or type the word string"
    echo -e "\nEnter 3 or quit to exit this program.\n"
    read choice

            case "$choice" in
                    1|"file") echo -e"Enter the name of the file to delete: "
                            read file
                            result=$(find . -name "$file")
                            if [ -z $result ]; then
                                    echo "File not found"
                            else
                                    askDelete $file
                            fi
                            ;;

                    2|"string") echo -e "Enter the sting to delete the files that contain it: "
                                    read searchstring
                                    result=$(find $dir -type f -perm /400)
                                    echo $result
                                    for file in $result;
                                    do
                                            echo -e "String is $searchstring \nFile is $file"
                                            grep –q "$searchstring"  "$file"
                                            if [ $? -eq 0 ]; then
                                                    echo "****MATCH****"
                                                    askDelete $file
                                            fi
                                    done
                            ;;

                    3|"quit") echo -e "Exiting program"
                            break;;
                    *) echo -e "\nChoice not listed";;
            esac
done

Enter the sting to delete the files that contain it:
pizza
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/smith.txt 
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/data2.txt 
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/jones2.txt 
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/cleaner.sh 
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/jones.txt 
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/data.txt
String is pizza
File is /home/hopper/z#/CSCI/CSCI330/Assignments/assign4/smith.txt
grep: pizza: No such file or directory
String is pizza
File is /home/hopper/z#/CSCI/CSCI330/Assignments/assign4/data2.txt
grep: pizza: No such file or directory
String is pizza
File is /home/hopper/z#/CSCI/CSCI330/Assignments/assign4/jones2.txt
grep: pizza: No such file or directory
String is pizza
File is /home/hopper/z#/CSCI/CSCI330/Assignments/assign4/cleaner.sh
grep: pizza: No such file or directory
/home/hopper/z#/CSCI/CSCI330/Assignments/assign4/cleaner.sh:                                              
grep –q "$searchstring"  "$file"
String is pizza
File is /home/hopper/z#/CSCI/CSCI330/Assignments/assign4/jones.txt
grep: pizza: No such file or directory
String is pizza
File is /home/hopper/z#/CSCI/CSCI330/Assignments/assign4/data.txt
grep: pizza: No such file or directory