#!/usr/bin/env python

#--------------------------------------------------------------------#
# The script                                                         #
#    (1) does a recursive search of directories,                     #
#    (2) looks for a word in all the files (with a given suffix) and #
#    (3) replaces it with another word.                              #
#--------------------------------------------------------------------#

import re
import os
import sys
import time
from fileinput import input

#-----------------------------------------
# Function to search and replace in a file
#-----------------------------------------

def searchReplaceFile(fileName, oldWord, newWord):
    data = open(fileName).read()
    open(fileName,"w").write( re.sub(oldWord,newWord,data) )

def process(filename, oldWord, newWord, ext):
    if os.path.isdir(filename):
       return processdir(filename, oldWord, newWord, ext)
    else:
        if os.path.normcase(filename).endswith(ext):
           try:
               searchReplaceFile (filename, oldWord, newWord)
           except IOError, msg:
               sys.stderr.write("Can't open: %s\n" % msg)
               return 1

def processdir(dir, oldWord, newWord, ext):
    try:
        names = os.listdir(dir)
    except os.error, msg:
        sys.stderr.write("Can't list directory: %s\n" % dir)
        return 1
    files = []
    for name in names:
        fn = os.path.join(dir, name)
        process(fn, oldWord, newWord, ext)


def usage(msg):
    sys.stderr.write("Usage:\n")
    sys.stderr.write("  %s %s\n" % (sys.argv[0], msg))
    #sys.stderr.write("Try '%s -h' for more information.\n" % sys.argv[0])

n = len(sys.argv[1:])
if (n < 3):
   usage('fileSuffix oldWord newWord')
   sys.exit(1)

EXEC_DIR = os.getcwd()
print EXEC_DIR

ext     = sys.argv[1]
oldWord = str(sys.argv[2])
newWord = str(sys.argv[3])

process(EXEC_DIR, oldWord, newWord, ext)