codelevy

#!/bin/bash

###
# The prompt that starts things off
###
function start
{
  echo
  echo -e 33[1mSearch and Replace33[0m
  echo
}

###
# Quitting with style
###
function quit
{
  echo
  echo ----------------------------------------
  echo
  exit
}

###
# Takes a collection of strings and prompts the user to pick one.
# Assumes that the leading character of each option is unique, and
# lets the user pick an option by that character.
# The option list is horizontal.
# Does case insensitive matching.
#
# The response is in the global $REPLY variable, and is lowercase.
###
function ask_horizontal
{
  # prompt for the first character of some option
  echo -n 'Choose: '
  for option in $@; do
    option=`echo -n $option | sed s/^./\\\33[1m\\\\33[0m/`
    echo -e -n $option
    echo -n '  '
  done
  echo -n "? "
  read -n1 answer
  echo ''

  # now lookup the original option (full string) and return that
  REPLY=''
  for option in $@; do
    if [[ `echo -n "$option" | grep -Ei "^$answer"` ]]; then
      REPLY=$option
    fi
  done
}

###
# the help text
###
function print_help
{
  cat <<-EOL
        ----------------------------------------------------
        csed: a sed-based recursive search and replace

        syntax: csed (options) <find> <replace>

        options:
          -h       this help message
          -g       use piped-in grep. grep must be formatted
                   with -EHinr

        <find>     an extended regular expression
        <replace>  a string with sed-style backreferences

        ----------------------------------------------------
    EOL
  exit
}

start

###
# Collect script options
###
results=''
while getopts ":hg" flag; do
  case $flag in
    h ) print_help;;
    g )
      # buffer the results list from stdin
      while read line; do
        if [ -z "$line" ]; then continue; fi
        if [ -z "results" ]; then
          results=$line;
        else
          results="$results
$line"
        fi
      done

      # return stdin to the terminal (keyboard)
      exec 0</dev/tty
      ;;
  esac
done
shift $(($OPTIND - 1))

if [ $# -lt 2 ]; then print_help; fi

find=${1////\/}    # escape slashes for the sed expression
replace=${2////\/}    # ditto

if [ -z "$results" ]
then
  # first convert some sed pecularities to grep syntax
  grep_find=${find//\\(/(}
  grep_find=${grep_find//\\)/)}
  results=`grep -EHinr "$grep_find" ./ --color=never`
fi

# set IFS (internal field separator) to newline, so our 'for' loop reads lines
IFS="
"
result_count=`echo -n "$results" | wc -l`
result_counter=0
for line in $results
do
  # we want to parse the following syntax: "^[filename]:[line number]: [line]$"
  file=${line%%:*}      # strip from first : to end
  line=${line#*:}       # strip from beginning to first : (the file part)
  line_num=${line%%:*}    # strip from first : to end
  code=${line#*:}    # strip from beginning to first :

  new_code=`echo $code | sed "s/$find/$replace/g"`
  result_counter=$(($result_counter + 1))

  ######################
  # feedback / preview #
  ######################
  echo -e "[$result_counter/$result_count] ${file}, line ${line_num}"
  echo -n "- "
  echo -e `echo $code | sed -e "s/$find/\\33[1;34m&\\33[0m/g"`
  echo -n "+ "
  echo -e `echo $code | sed -e "s/$find/\\33[1;34m${replace}\\33[0m/g"`

  ######################
  # ask for what to do #
  ######################
  if [[ $replace_all == 'yes' ]]
  then
    action='Replace'
  else
    ask_horizontal 'Replace' 'All' 'Skip' 'Custom' 'Quit'
    action=$REPLY
    echo ''
  fi

  ##############################
  # act according to direction #
  ##############################
  if [[ $action == 'All' ]]
  then
    replace_all=yes
    action='Replace'
  fi

  case "$action" in
    "Custom" )
      echo -n 'enter a custom replace string: '
      read replace2
      sed -e "${line_num}s/$find/$replace2/g" "$file" > /tmp/csed$$ 
        && cat /tmp/csed$$ > $file && rm /tmp/csed$$
      ;;

    "Replace" )
      sed -e "${line_num}s/$find/$replace/g" "$file" > /tmp/csed$$ 
        && cat /tmp/csed$$ > $file && rm /tmp/csed$$
      ;;

    "Quit" )
      quit
      ;;

    "Skip" )
      continue
      ;;

    * )
      ### TODO: reprompt user! well, ok, right now it's just a skip
      continue
      ;;
  esac
done

quit