#!/usr/bin/python

# Name: findTextBlock.py
# Version: 0.2
# Created: 2018-02-03
# Last modified: 2018-02-03

# Usage: findTextBlock.py start_text end_text filename
# Description: The script will display all of the text found in filename
# from start_text to end_text, including start_text and end_text. If less
# than 3 arguments are provided on the command line, the script will prompt
# for the values for start_text, end_text, and filename. A text search string 
# that includes a space or spaces should be enclosed in double quotes if 
# provided on the command line. If a double quote is part of the search text,
# precede it with the backslash escape character on the command line.

import os.path, sys

def parse_file(infile,start_text,end_text):
  with  open(infile) as f:
    alltxt = f.read()
    found_position = alltxt.find(start_text)
    if found_position == -1:
      print "Starting text", start_text, "not found in", infile
      exit()
    # Need to eliminate all text before the starting point; otherwise,
    # if the end text occurs somewhere before the star text, nothing will
    # be printed even though there may be another occurrence of end text
    # later in the file.
    alltxt = alltxt[alltxt.find(start_text):]
    found_position = alltxt.find(end_text)
    if found_position == -1:
      print "Ending text", end_text, "not found after", start_text, "in", infile
      exit()
  return alltxt[alltxt.find(start_text):alltxt.find(end_text)+len(end_text)]

if len(sys.argv) == 4:
   start_text = sys.argv[1]
   end_text = sys.argv[2]
   path_to_file = sys.argv[3]
else:
   start_text = raw_input("Enter starting text: ")
   end_text = raw_input("Enter ending text: ")
   path_to_file = raw_input("Enter file name: ")

if not os.path.isfile(path_to_file):
   exit("Input file not accessible")

print parse_file(path_to_file,start_text,end_text)