#/bin/bash
### For the Beginer Linux group
### Read the code ! It is purposely over commented for easy(er) understanding
### I'm not an expert in bash, but the script has been tested and works. Feel free to improve it and share back



bad="bob "   # Text you want to change
location="."  # Where to look for. Put / to look everywhere; . (dot) for the current directory  You may have to run as root for some locations.
bad_files=()  # Create an empty array
RED="\e[5;91m"  # Define blinking (5) red (91)
GREEN="\e[0;92m" # Define normal (0) green (92)
NC='\e[0m' # Define normal (0) to reste the colors

for i in $( grep -ril $bad $location ) # Loop through content of files, with "i" for non-sensitive case. do NOT affect the substitution process later
do echo -e  "\n--------------------------\nIn file $i" # Print the file containing the malicious text
bad_files+=($i) # Store the file name into an array
grep --color=always $bad $i # Shows the bad text found with color highlight
done

echo -e "\n$GREEN List of modified files found: $NC\n ${bad_files}" # print the list of modified files
echo -e "$RED Would you like to correct them ? $NC I'll do a backup first ;) (Yy/Nn)"
read answer  # Expect user input and stores it in the variable "answer"
case $answer in
    y|Y) echo -e "\n Type the full path of a backup directory (default /home/"$USER"/Backup)"
    read backup_dir
    if [ -n "$backup_dir" ]  # Did the user provided an answer
        then mkdir $backup_dir 2>/dev/null # Create the directory provided by the user
            for file in ${bad_files[@]} ; do # Loop through the found files
                cp $file $backup_dir 2>/dev/null # Copy then to the backup directory
                sed -i "s/$bad//g" $file # Substitute/$bad/by_nothing/globally.The "-i" applies the changes in the file
                done
        else backup_dir="/home/$USER/Backup" && mkdir $backup_dir 2>/dev/null # Set backup dir to default if aswer left blank
            for file in ${bad_files[@]} ; do
                cp $file $backup_dir 2>/dev/null
                sed -i "s/$bad//g" $file
                done
    fi
    ;;
n|N)
echo OK, Bye !  ;
;;
esac