Linux Bash script grep error

Question

So my professor and I worked on this for about 2 hours and couldn't figure out what the problem was so I am hoping someone can see what we missed.

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

and when I do selection 2 I get to the grep and get this error message with my troubleshooting messages.

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

Grep also works just fine outside the BASH script with the absolute paths. Tested the if statement and if I take out the -eq it does work properly because it reads that grep did successfully run just that the directory was not found. From what I can tell it is ignoring my file and instead is using the string search as the directory.

We ask that questions here have a minimal reproducible example -- the shortest possible code that others can run to produce a problem themselves, with everything unrelated to the specific issue removed. If you're having trouble figuring out exactly where your unexpected behavior happens, run bash -x yourscript to log each line as it runs, and trace through that to find the first line that either (1) is passed a different argument than you expect, or (2) has a different result than you expect. — Charles Duffy
– Charles Duffy, Commented Apr 5, 2018 at 19:39
BTW, in general, instead of foo; if [ $? -eq 0 ]; then you should just do if foo; then. — Charles Duffy
– Charles Duffy, Commented Apr 5, 2018 at 19:41
STRONG SUGGESTION: bash -x yourscript.sh. The "-x" will help you see how your "grep -q" is actually being expanded ... and should quickly show you what's actually going wrong. Here are more details: tldp.org/LDP/Bash-Beginners-Guide/html/sect_02_03.html — paulsm4
– paulsm4, Commented Apr 5, 2018 at 19:41
@paulsm4, please don't link TLDP's documentation -- the ABS in particular is full of outdated information and bad-practice examples. The BashGuide and the bash-hackers' wiki are far more reliable. wiki.bash-hackers.org/scripting/debuggingtips is the page on debugging in the latter, or mywiki.wooledge.org/BashGuide/… in the former. — Charles Duffy
– Charles Duffy, Commented Apr 5, 2018 at 19:42
How can grep –q "$searchstring" "$file" appear in you stdout? — karakfa
– karakfa, Commented Apr 5, 2018 at 19:54

nortoon · Accepted Answer · 2018-04-09 15:55:06Z

3

The dash part of the '-q' argument to grep is a special non-ascii character, probably an en-dash in UTF-8, I didn't look too hard. Grep doesn't interpret the en-dash as starting an option and does a search for the string '–q' in the file list. 'pizza' is in the file list.

This can happen easily if you copy code from a web page or a word doc. Anyway, delete the -q and retype it and you script should work better.

edited Apr 9, 2018 at 15:55

answered Apr 5, 2018 at 21:10

nortoon

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4 Comments

Gordon Davisson Over a year ago

Good eyes. A little copy-and-paste confirms it's an en-dash (unicode U+2013, UTF8: e2 80 93). Also some advice for @ScottSmith: don't edit scripts in text editors that "helpfully" convert dashes, quotes, etc to their fancy unicode versions.

Scott Smith Over a year ago

None of it was copied, the -q is quiet mode and is an option, it works just fine outside of the Bash script and in my professor's code too. thanks for the advice but on our system -q isn't an issue. I was having a permissions issue on one of my directories but I changed it and am still getting this error.

Scott Smith Over a year ago

EDIT: I misread that and thought you said it wasn't an option I'm sorry and you were right. I used my number pad on my keyboard and for some reason on it - and - are different when typed. I even tested it. I deleted and retyped with the numbers and symbols on the keyboard instead and it worked, retried it with my number pad and went back to the same issue. I find that to be really weird but I appreciate the help.

nortoon Over a year ago

Interesting, I've never heard of a keyboard generating a non-ascii dash from either position, I'm glad that can happen, thanks.

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