sstr

#!/bin/bash
#
# @(#) Utility to search strings in files interactively.
#
# Copyright (c) 2010 Shinya Ishida. All rights reserved.
#
# Search a keyword in files located in a directory and its subdirectories.
# The search result is printed with file names and line numbers. Additional
# actions to the search result (extra searches, viewing/editing a file, etc)
# can be applied interactively.

readonly me="$0"
readonly my_base="${me##*/}"
default_dir=$(pwd)
readonly default_dir
readonly tmp_prefix="/tmp/${my_base}.$$"
readonly tmp_init="${tmp_prefix}_init"
readonly tmp_current="${tmp_prefix}_current"
readonly tmp_previous="${tmp_prefix}_previous"
# search options
search_dir="$default_dir"
grep_options='-Inr'
ignore_cases=
quick_undo=
debug_mode=
# variables to store search history
pattern_history=()
ignore_cases_history=()
invert_history=()
last_epoch=-1  # note: can be removed after bash on macOS migrates to version 4

function __clean {
  rm -f "$tmp_prefix"* &>/dev/null
}

function __exit_with {
  local -r msg="${2:-unexpected error}"
  __clean
  case "$1" in
    0)
      exit 0;;
    *)
      echo -e "\033[31mERROR:\033[m $msg" 1>&2
      exit "$1";;
  esac
}

trap '__exit_with 127 ctrl-c' 1 2 3 15

function __toggle_debug_mode {
  if [ "$debug_mode" ]; then
    debug_mode=
    set +x
  else
    debug_mode=y
    set -x
  fi
}

function __get_first_available_command {
  local first
  for c in "$@"; do
    which "$c" &>/dev/null && first="$c" && break
  done
  echo -n "$first"
}

function __print_usage {
  cat <<EOF
usage:
    $my_base [options] <pattern>

options:
    -c          case-sensitive search
    -d dir      search pattern in the directory
    -D          debug mode
    -h          print this help
    -x file     exclude file from pattern search
    -X dir      skip pattern search in the directory

note:
    - Binary files are ignored.
    - Multiple '-x' and '-X' options are accepted.
EOF
  __exit_with 0
}

function __toggle_case_sensitivity {
  ignore_cases=$([ "$ignore_cases" ] && echo '' || echo '-i')
}

function __set_search_dir {
  search_dir="${search_dir:-$1}"
}

function __exclude_file {
  grep_options="$grep_options${1:+ --exclude=$1}"
}

function __exclude_directory {
  grep_options="$grep_options${1:+ --exclude-dir=$1}"
}

function __enable_debug_mode {
  __toggle_debug_mode
}

function __get_hit_count {
  local wc_output
  read -ra wc_output <<< "$(wc -l "$tmp_current" 2>/dev/null)"
  echo "${wc_output[0]}"
}

function __highlight_found_patterns {
  local epoch="$last_epoch"
  while [ "${invert_history[epoch]}" ] && [ "$epoch" -gt 0 ]; do
    ((epoch-=1))
  done
  # shellcheck disable=SC2086
  grep --no-filename --color=always ${ignore_cases_history[epoch]} \
    "${pattern_history[epoch]}" "$tmp_current"
}

pager=$(__get_first_available_command more less)
readonly pager
case "$pager" in
  more|less)
    function __print_found_patterns {
      __highlight_found_patterns | $pager -NR
    };;
  *)
    function __print_found_patterns {
      __highlight_found_patterns | cat -ne
    };;
esac

function __conduct_first_search {
  local pattern="$1"
  ((last_epoch+=1))
  pattern_history[last_epoch]="$pattern"
  ignore_cases_history[last_epoch]="$ignore_cases"
  invert_history[last_epoch]=''
  # shellcheck disable=SC2086
  grep $grep_options $ignore_cases "$pattern" "$search_dir"  > "$tmp_init" || \
    __exit_with 1 'no matches'
  cp -pf "$tmp_init" "$tmp_current"
}

function __search_entries {
  local pattern
  pattern=$(__prompt_input 'pattern')
  ((last_epoch+=1))
  pattern_history[last_epoch]="$pattern"
  ignore_cases_history[last_epoch]="$ignore_cases"
  invert_history[last_epoch]="$*"
  cp -pf "$tmp_current" "$tmp_previous"
  quick_undo=yes
  # shellcheck disable=SC2086
  grep "$@" $ignore_cases "$pattern" "$tmp_previous" > "$tmp_current"
}

function __select_entry {
  local -r hit_count=$(__get_hit_count)
  if [ "$hit_count" -gt 0 ]; then
    local number
    number=$(__prompt_input "number (1-$hit_count)")
    [[ "$number" =~ ^[1-9][0-9]*$ ]] && \
      [ "$number" -le "$hit_count" ] && \
      head "-$number" "$tmp_current" | tail -1
  fi
}

function __print_search_result {
  local -r count=$(__get_hit_count)
  [ "$count" -gt 0 ] && __print_found_patterns
  echo -e "\033[32m$count line(s) matched\033[m"
}

function __print_command_list {
  echo "$command_help"
}

function __prompt_input {
  local input
  echo -en "\033[33m$1: \033[m" >&2 && read -r input
  echo "$input"
}

function __get_command_function {
  local IFS=''
  grep "^$1" <<< "$command_map" | cut -d ' ' -f 2
}

function __execute_command {
  local -r cmd=$(__prompt_input 'command')
  local -r cmd_func=$(__get_command_function "$cmd")
  if [ "$cmd_func" ]; then
    $cmd_func
  else
    __print_command_list
  fi
}

# Command functions
#
# To add a new command, the function must have a comment in the following
# format. This special comment is parsed by this script itself and registered.
# '@func' is a tag to specify the function's name. '@key' is a tag to indicate
# an alphabetical letter assigned to call the function via the prompt. '@desc'
# is a tag for a brief description of the function. This description is
# printed in the command help. The note may contain scripts; i.e., variables,
# $var, and command/function calls, $(command...). Instead, to print letters
# and strings, which have a special meaning for bash script, as they are, they
# must be quoted with single quotation, like '(' and ')'.
#
# Format:
# # @func FUNCTION_NAME
# # @key K
# # @desc A BRIEF DESCRIPTION OF THE FUNCTION IN A LINE
#
# Note:
# - All tags are required, in the order above, for a function to register.
# - Only a tag can be in a line.
# - A tag line must start with '#'.
# - Only spaces, ' ', may be between the '#' and a tag.

# @func ToggleCaseSensitivity
# @key c
# @desc toggle case sensitivity
function ToggleCaseSensitivity {
  __toggle_case_sensitivity
  if [ "$ignore_cases" ]; then
    echo 'ignore cases'
  else
    echo 'consider cases'
  fi
}

# @func ToggleDebugMode
# @key D
# @desc toggle debug mode
function ToggleDebugMode {
  __toggle_debug_mode
  if [ "$debug_mode" ]; then
    echo 'debug mode enabled'
  else
    echo 'debug mode disabled'
  fi
}

# @func EditFile
# @key e
# @desc open a file in editor '('${editor-not available}')'
editor=$(__get_first_available_command vim vi)
readonly editor
case "$editor" in
  vim|vi)
    function EditFile {
      read -r file_name line_num rest < <(__select_entry | tr ':' ' ') && \
        $editor "+$line_num" "$file_name"
    };;
  *)
    function EditFile {
      echo 'no editors: cannot use this command in your environment'
    };;
esac

# @func ShowHelp
# @key h
# @desc show this help
function ShowHelp {
  __print_command_list
}

# @func ListFiles
# @key l
# @desc list files in the current search result
function ListFiles {
  cut -d : -f 1 "$tmp_current" | sort -u
}

# @func SearchEntriesContainingPattern
# @key m
# @desc get lines containing substring matching a specified pattern
function SearchEntriesContainingPattern {
  __search_entries
  __print_search_result
}

# @func SearchEntriesNotContainingPattern
# @key n
# @desc get lines not containing substring matching a specified pattern
function SearchEntriesNotContainingPattern {
  __search_entries -v
  __print_search_result
}

# @func PrintSearchResult
# @key p
# @desc print search result
function PrintSearchResult {
  __print_search_result
}

# @func Quit
# @key q
# @desc quit search
function Quit {
  __exit_with 0
}

# @func RefreshSearch
# @key r
# @desc refresh search result
function RefreshSearch {
  __rerun_searches
  __print_search_result
}

# @func UndoSearch
# @key u
# @desc undo last search
function UndoSearch {
  if [ "$last_epoch" -gt 0 ]; then
    unset 'invert_history[last_epoch]'
    unset 'ignore_cases_history[last_epoch]'
    unset 'pattern_history[last_epoch]'
    ((last_epoch-=1))
    if [ "${quick_undo-}" ]; then
      [ -f "$tmp_previous" ] && cp -pf "$tmp_previous" "$tmp_current"
      quick_undo=
    else
      cp -pf "$tmp_init" "$tmp_current"
      __rerun_searches
    fi
  fi
  __print_search_result
}

# @func ViewFile
# @key v
# @desc open a file in viewer '('${viewer-not available}')'
viewer=$(__get_first_available_command vim vi less more)
readonly viewer
case "$viewer" in
  vim|vi)
    function ViewFile {
      read -r file_name line_num rest < <(__select_entry | tr ':' ' ') && \
        $viewer -R "+$line_num" '+set nu' "$file_name"
    };;
  less|more)
    function ViewFile {
      read -r file_name line_num rest < <(__select_entry | tr ':' ' ') && \
        $viewer "+$line_num" -N "$file_name"
    };;
  *)
    function ViewFile {
      local -r range=10
      read -r file_name line_num rest < <(__select_entry | tr ':' ' ') && \
        cat -n "$file_name" | head -$((line_num + range)) | tail -$((range * 2 + 1))
    };;
esac

function __build_command_list {
  # Note: Using associative arrays seems a better choice to implement this
  # function.  However, it is supported from bash version 4.  The MacOS's
  # default bash (/bin/bash) is version 3.
  local cmd_docs
  cmd_docs=$(grep '^# *@' "$me" | tr '\n' ' ')
  cmd_docs=${cmd_docs//'# '/}
  local IFS=$'\n'
  # shellcheck disable=SC2206
  cmd_docs=(${cmd_docs//@func /$'\n'})
  IFS=' '
  local i=0
  while [ $i -lt "${#cmd_docs[@]}" ]; do
    read -r func_name at_key key at_desc desc <<< "${cmd_docs[i]}"
    [ "$func_name" ] && [ "$desc" ] && [ "$at_key" = '@key' ] && \
      [ "$at_desc" = '@desc' ] && [[ "$key" =~ ^[a-zA-Z]$ ]] && {
      command_map="${command_map+${command_map}$'\n'}$key $func_name"
      command_help="${command_help+${command_help}$'\n'}  $key: $desc"
    }
    ((i+=1))
  done
  readonly command_map="$command_map"
  readonly command_help="$command_help"
}

##### Main routine

__build_command_list || __exit_with 2 'failed initialization'
while getopts 'cd:x:X:hD' flag; do
  case $flag in
    c)
      __toggle_case_sensitivity;;
    d)
      __set_search_dir "$OPTARG";;
    x)
      __exclude_file "$OPTARG";;
    X)
      __exclude_directory "$OPTARG";;
    D)
      __enable_debug_mode;;
    h)
      __print_usage;;
    *)
      __exit_with 5 "see help by '-h' option";;
  esac
done
shift $((OPTIND - 1))

[ -d "$search_dir" ] || __exit_with 3 "directory '$search_dir' not found"
[ "$1" ] || __exit_with 4 'pattern not specified'
__conduct_first_search "$1"
__print_search_result
while true; do
  __execute_command
done