#!/bin/bash
#<pre><b>
# Script     : pages
# Version    : 1.0
# Author     : Roland Rashleigh-Berry
# Date       : 22-Jun-2004
# Purpose    : Production script to print pages of a given range
# SubScripts : none
# Notes      : Default is to start at page 1 and print all the pages. You can
#              specify multiple files.
# Usage      : pages -b 2 -e 5 filename
#              pages -b1 -e2 *.lis
#===============================================================================
# OPTIONS:
#-opt- -------------------------------description-------------------------------
#  b   (value)  begin page                                        
#  e   (value)  end page                                          
#===============================================================================
# PARAMETERS:
#-pos- -------------------------------description-------------------------------
#  1   file name(s) or file pattern(s) or both
#===============================================================================
# AMENDMENT HISTORY:
# init --date-- mod-id ----------------------description------------------------
# 
#===============================================================================
# This is public domain software. No guarantee as to suitability or accuracy is
# given or implied. User uses this code entirely at their own risk.
#===============================================================================

# Define give-usage-message-then-exit function. E
usage () {
  echo "Usage: pages -b <begin page> -e <end page> filename" 1>&2
  exit 1
}


# Defaults
valueb=1                            # Default value for begin page                                        
valuee=9999999                      # Default value for end page                                          


# "case" statement for action to take on selected options
while getopts "b:e:" param ; do
  case $param in
   "?") # bad option supplied
        usage
        ;;
   "b") # (value) begin page
        valueb=$OPTARG
        ;;
   "e") # (value) end page
        valuee=$OPTARG
        ;;
  esac
done


# shift to bring first parameter to position 1
shift $(($OPTIND - 1))


# Must be one file at least
if [ $# -lt 1 ] ; then
  echo "Error: (pages) No filenames supplied" 1>&2
  usage
fi


# loop through each file name
for file in "$@" ; do

  gawk '
  BEGIN {pagecnt=1}

  # main block
  {
  # a new page will have a form feed character at the start
  if (substr($0,1,1)=="\f")
    pagecnt++

  # exit if we have gone past the end page
  if (pagecnt>endpage)
    exit

  # output lines from the start page onwards
  if (pagecnt>=startpage)
    {
    # drop the form feed from the start page if it is there
    if (substr($0,1,1)=="\f" && pagecnt==startpage)
      print substr($0,2)
    else
      print $0
    }
    
  }' startpage="$valueb" endpage="$valuee" "$file"

done