#!/bin/bash

# This script will do a filtered diff on two files, and check for changes
# If there are changes it will clear the screen, display the diff,
# And provide a select list as follows:
# 1) cp file1 file2
# 2) cp file2 file1
# 3) vimdiff file1 file2

pattern="$1"
file1="$2"
file2="$3"

#We don't want to have a case like this:
# 's/a'b//
#We need to change that to this:
# 's/a'"'"'b//

pattern=${pattern//\'/\'\"\'\"\'}
if [ "$file2" = "" ]; then
    echo "Usage: prdiff <sed pcommand> <file> <file>"
    exit;
fi

sedcmd1="sed -e '$pattern' $file1"
sedcmd2="sed -e '$pattern' $file2"
echo $sedcmd1
echo $sedcmd2


changed=`diff <(eval $sedcmd1) <(eval $sedcmd2)`

if [ "$changed" != "" ]; then
    clear;
    diff <(eval $sedcmd1) <(eval $sedcmd2)
    PS3="Action: "
    select action in "cp $file1 $file2" "cp $file2 $file1" "vimdiff $file1 $file2"; do
      if [ "$action" != "" ]; then
        $action;
        break;
      fi;
    done;
fi;