Create validated .htaccess rewrite rules in batch using Bash

create_rewrite_rules.sh

#!/bin/sh
# Usage: create_rewrite_rules csv_file url username password
# htaccess login credentials optional
OLDIFS=$IFS
IFS=","
file=$1
path=$2
user=""
pass=""

# Exit if arg2 is not present
if [[ -z "$path" ]]; then
  echo $'\e[1;31m''Script requires a URL' $'\e[0m'
  exit 0
fi

# If arg3 & arg4 are present, set login credentials
if [[ "$3" && "$4" ]]; then
  user="--user=$3"
  pass="--password=$4"
fi

# Loop through CSV file
while read col1 col2 col3 col4 col5
do
  old=$col1
  title=$col2
  region=$col3
  flag=$col4
  new=$col5

  # Skip if urls do not meet the minimum required length
  if [ "${#old}" -lt 10 ] || [ "${#new}" -lt 15 ]; then
    continue
  fi

  # Clean strings (remove line endings added by excel)
  # Check with: echo $old | od -c
  old=$(echo $old | tr -d "\r\n")
  new=$(echo $new | tr -d "\r\n")

  # Remove URL that user has prefixed new path with
  new=${new:32}
  
  # Check HTTP response for old and new URLS
  old_response=$(wget --spider $user $pass $path$old 2>&1 | grep '200 OK')
  new_response=$(wget --spider $user $pass $path$new 2>&1 | grep '200 OK')
  
  # If either response is empty (not "200 OK"), skip row
  if [[ -z "$old_response" || -z "$new_response" ]] ; then
    continue 
  fi

  # Remove first forward slash from old URL
  old=${old:1}

  # Print rewrite rule
  echo "RewriteRule ^$old(/?.*) $new [R=301,L]"
done < $file