hgrep - grep wrapper for saving header

README.md

hgrep

This script is the grep wrapper for saving header.

Usage

hgrep [OPTIONS ...] [FILES ...]
Options:
  See help or manpage of grep commnand.

Copyright

Copyright (c) 2019 Koichi OKADA. All rights reserved.

License

This script is distributed under the MIT license.

Relations

• Gist / kou1okada / sort.sh

hgrep

#!/usr/bin/env bash

# grep wrapper for saving header.
# Copyright (c) 2019 Koichi OKADA. All rights reserved.
# This script is distributed under the MIT license.

(( 5 <= DEBUG )) && set -x

function function_get_lines () # PAT_FUNC [FILE]
#   Return lines of function about declare, begin and end.
{
  grep -nE "^$1|^{|^}" "${@:2:1}" \
  | grep -A2 -E "^[0-9]+:$1" \
  | grep  -o -E "^[0-9]+"
}

function headtail () # FIRST_LINE LAST_LINE
#   Split lines from FIRST_LINE to LAST_LINE.
{
  head -n+$2 | tail -n+$1
}

function uniqex ()
#   An alternative uniq command which is not required sort
{
  awk '!c[$0]++'
}

function show_options ()
{
  local i
  echo "Options:"
  echo "  OPT0:" ; for i in "${OPT0[@]}" ; do echo "    $i"; done
  echo "  OPT1:" ; for i in "${OPT1[@]}" ; do echo "    $i"; done
  echo "  OPT01:"; for i in "${OPT01[@]}"; do echo "    $i"; done
}

function usage_default () #= [CMD [DISPLAY_NAME]]
#   Auto generate default usage from documentation
# Args:
#   CMD : Whole name of subcommand 
{
  local CMD="${1:-$CMD}"
  local DISPLAY_NAME="${2:-$CMD}"
  local PAT_FUNC_CMD="function +${CMD} *\( *\)"
  local lines src srcs
  
  readarray -t srcs < <(grep -lE "$PAT_FUNC_CMD" "${BASH_SOURCE[@]}" | tac | uniqex)
  [ -z "$srcs" ] && { echo "Error: function ${CMD} is not founded."; exit 1; }

  src="$srcs"
  readarray -t lines < <(function_get_lines "$PAT_FUNC_CMD" "$src")
  cat "$src" \
  | headtail $(( lines[0] )) $(( lines[1] - 1 )) \
  | sed -r -e 's/^(function +)('"$CMD"')( *\( *\))/\1'"$DISPLAY_NAME"'\3/g' \
  | sed -r -e 's/^function +([^ ]+)[^#]*(#=? *(.*))?/Usage: \1 \3/g' \
           -e 's/^#\?? (.*)/\1/g'
  show_options
}

function optparse () # [OPTIONS ...] [ARGUMENTS ...]
#   Parse options of COMMAND, and update conditions for wrapping it.
#   Before call this function, COMMAND must be gotten options with `get_options`.
# Returns:
#   ARGS[@] : positional parameters
#   OPTS[@] : options of COMMAND
{
  local short param KEYDEF
  shopt -q extglob; local extglob=$?; shopt -s extglob
  ARGS=()
  while (( 0 < $# )); do
    short=
    param=
    if   [[ "${1:0:2}" = "--" && "$1" != "${1/=/}" ]];then
      param=1
      set -- "${1%%=*}" "${1#*=}" "${@:2}"
    elif [[ "${1:0:2}" != "--" && "${1:0:1}" = "-" && 2 < "${#1}" ]]; then
      short=1
      param=1
      set -- "${1:0:2}" "${1:2}" "${@:2}"
    fi
    case "$1" in
      -h|--help)
        OPT_HELP="$1"
        ;;&
      --debug)
        OPT_DEBUG="$1"
        ;;&
      $OPT01) # [PARAM]
        if [[ "$param" = 1 ]]; then
          OPTS+=( "$1=$2" )
          shift 2
        else
          OPTS+=( "$1" )
          shift 1
        fi
        ;;
      $OPT1) # PARAM
        OPTS+=( "$1" "$2" )
        shift 2
        ;;
      $OPT0) #
        OPTS+=( "$1" )
        [[ -z "$short" && -n "$param" ]] && {
          echo "Warning: taking a unexpected parameter for $1: $2"
          set -- "${@:1:1}" "${@:3}"
        }
        [[ -n "$short" && -n "$param" ]] && set -- "${@:1:1}" "-${@:2:1}" "${@:3}"
        shift 1
        ;;
      --)
        ARGS=( "${@:2}" )
        shift $#
        ;;
      -*)
        echo "Error: unknown option: $1"
        exit 1
        ;;
      *)
        ARGS+=( "$1" )
        shift 1
        ;;
    esac
  done
  [ "$extglob" = "1" ] && shopt -u extglob
}

function get_options () # <COMMAND>
#   Get options of COMMAND.
# Returns:
#   OPT0  : Options for case statement which take no parameters.
#   OPT1  : Options for case statement which take a parameter.
#   OPT01 : Options for case statement which take a optional parameter.
{
  local tmp opt opts
  OPT0=""
  OPT1=""
  OPT01=""
  readarray -t opts < <("$1" --help|grep -E "^ *-"|sed -r -e 's/^ *//g' -e 's/^((-[^-])?((, +)?--[^ ,]+)*).*/\1/g')
  for opt in "${opts[@]}"; do
    tmp="${opt//\[=*/}"
    tmp="${tmp//=*/}"
    tmp="${tmp// /}"
    tmp="${tmp//,/|}"
    if   [[ "$opt" = "${opt/=/}" ]]; then
      OPT0+="${OPT0:+|}$tmp"
    elif   [[ "${opt}" =~ \[= ]]; then
      OPT01+="${OPT01:+|}$tmp"
    else
      OPT1+="${OPT1:+|}$tmp"
    fi
  done
  OPT0="@($OPT0)"
  OPT1="@($OPT1)"
  OPT01="@($OPT01)"
}

function main () # [OPTIONS ...] [FILES ...]
#   grep wrapper for saving header.
# Options:
#   See help or manpage of grep command as:
#     grep --help
#     man grep
{
  local OPT0 OPT1 OPT01 
  local ARGS OPTS
  local TEMPLATES="" FIELDS="" KEYCOUNT=1
  local filter
  local header
  get_options grep
  optparse "$@"
  if [ -n "$OPT_HELP" ]; then
    usage_default "$FUNCNAME" "${0##*/}"
    return
  fi
  if [ -n "$OPT_DEBUG" ]; then
    filter=( "cat" )
  else
    filter=( sed -r -e 's/^([^,]*,){'"$KEYCOUNT"'}//g' )
  fi
  {
    read header; printf "%s\n" "$header"
    grep "${OPTS[@]}" "${ARGS[@]}"
  } | "${filter[@]}"
}

main "$@"