#!/bin/bash
#
# Syntax:  mass_qr [-h] expr1 expr2 file [...]
#
# Purpose: Replaces expression expr1 by expr2 in files.
#          To get a \/ in one of the strings, use \\\/.
#          The -h flag shows the help info for this command.

# Created: May 11, 2000       by Bart De Schutter
# Last revised: Jan 22, 2002  by Bart De Schutter
#
# See http://www.deschutter.info/util/scripts.html for the latest version of
# this script.

# Status: public
# Category: files

if [ "$1" == "-h" ];
then
   sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
   exit 1
fi

if [ $# -lt 3 ];
then
   echo >&2
   echo >&2 "ERROR: ${0##*/} requires at least 3 input arguments."
   echo >&2
   sed '/^$/q;/^#!/d;s/^# //;s/^#//' $0 >&2
   exit 1
fi

expr1="$1"
expr2="$2"
shift 2

echo >&2
echo >&2 "WARNING: This command will replace string $expr1 with"
echo >&2 "         $expr2 within the given files."
echo >&2 "         The original files are kept as backup (.bak) files."
echo >&2
read -p "Continue? (y/n) [n] " answer
echo >&2
if [ "$answer" != "y" -a "$answer" != "Y" ];
then
   exit 1
fi

for fname in "$@"
do
   bak_file="${fname}.bak"
   if [ -f "$fname" ];
   then
      cp "$fname" "$bak_file"
      sed -e "s/${expr1}/${expr2}/g" \
          "$bak_file" > "$fname"
   else
      echo >&2
      echo >&2 "WARNING: file $fname not found."
      echo >&2
   fi
done