#!/bin/bash
#
# Syntax:  grepdo [-h] [-a] [-w] [-u] command regexp [file [...]]
#
# Purpose: Performs a grep on the given files and runs the given command
#          on each file that matches the given regular expression regexp.
#          If only one input argument is specified, the grep is performed
#          on all files in the current directory.
#          If the -a flag is specified the command is run on all matching
#          files at once. Otherwise, it is called separately for each matching
#          file.
#          If the option -w is specified, grepem searches for  string  as a
#          word.
#          By default grepdo does a case-insenstive grep. However, if the
#          option -u is specified, grepem distinguishes between upper
#          and lower case letters.

# Created: Aug  6, 2007       by Bart De Schutter
# Last revised: Oct 19, 2007  by Bart De Schutter
#
# See http://www.deschutter.info/util/scripts.html for the latest version of
# this script.

# Status: public
# Category: files

#
# Process input arguments.
#

case_string="-i"
word_string=""
all_at_once=0
while getopts :hawu option
do
   case "$option" in
      h) sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
         exit 1
         ;;
      a) all_at_once=1;;
      w) word_string="-w";;
      u) case_string="";;
      \?) echo >&2
         echo >&2 "Unknown option: $OPTARG"
         echo >&2
         sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
         exit 1
         ;;
   esac
done
shift $(($OPTIND-1))

if [ $# -le 1 ];
then
   echo >&2
   echo >&2 "ERROR: ${0##*/} requires at least 2 input arguments."
   echo >&2
   sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
   exit 1
fi

command=$1
shift

#
# Perform grep and process files that match the given regexp.
#

if [ $all_at_once -eq 0 ]
then
   declare -a lst
   if [ $# -eq 1 ];
   then
      lst=( $(grep -l $case_string $word_string "$1" *) )
   else
      lst=( $(grep -l $case_string $word_string "$@") )
   fi
   if [ $? -eq 1 ]
   then
      echo "No files found that match the given regular expression."
   else
      for fil in "${lst[@]}"
      do
         eval "$command" "$fil"
      done
   fi
else
   if [ $# -eq 1 ];
   then
      lst=$(grep -l $case_string $word_string "$1" *)
   else
      lst=$(grep -l $case_string $word_string "$@")
   fi
   if [ ! -z "$lst" ]
   then
      # Do some processing in order to be able to deal with files that
      # contain a space or a # in their name.
      lst=$(echo "$lst" | sed -e 's/ /\\ /g;s/#/\\#/g' | tr "\n" " " )
      eval "$command" $lst
   else
      echo "No files found that match the given regular expression."
   fi
fi