Shell Programming and Scripting

#! /bin/bash
# bash v3 or higher

# file with list of items to find in modify_file
list_file=$1
# file for which a modified copy will be created
modify_file=$2
# final output file
new_file='new_'$modify_file

echo "reading values from '$list_file'"
# clear (and implicityly declare) an array
list=()
while read line
do
  echo "adding '$line' to list"
  list+=("$line")
done < $list_file

echo "reading '$modify_file'"
# loop through all the lines in the list_file
while IFS= read -r line <&3
do
   # look for the value in the current line
   # if the value is found on a line, print the substring of $0 skipping the first character
   # otherwise just print the line

   echo "processing line $((++linecnt))"
    # preset the new line
   outline=$line
   # loop through the array values
   for i in "${list[@]}"
   do
      look_for="'$i'"
      # =~ is ERE match, == is glob match
      # $look_for in quotes --> do not interpret special characters in it
      #if [[ $line =~ "$look_for" ]]
      if [[ $line == *"$look_for"* ]]
      then
         outline=${line:1}
         # further matches will do the same, so we can break the loop here
         break
      fi
   done
   # print the new line
   printf "%s\n" "$outline" >&4
done 3< "$modify_file" 4> "$new_file"