lastpara.rb

#!/usr/bin/env ruby -w
=begin
  * Name          : lastpara.rb 
  * Description   : splits a file into paras based on a blank line and prints last one  
  * Author        : rkumar
  * Date          : 2012-12-08 - 12:54 
  * Last update   : 2012-12-08 17:00
  * License       :
    Same as Ruby's License (http://www.ruby-lang.org/LICENSE.txt)

=end

def usage
  e=File.basename($0)
text=<<END
Usage #{e} [-c num] [-r] [-d delim] [--help] file
Prints last (or given) para of given file. Useful for printing
random para from file containing tips/quotes/sigs/notes/log.

Arguments:
  -c <0- >    which para to print (default is last, index starts at 0)
  -d 'delim'    delimiter to use for splitting (blank line between paras)
  -r        print random para
  -h --help prints this help
  Example:
    #{e} quips.txt      # print last tip
    #{e} -c 1 tips.txt  # print first tip
    #{e} -r   tips.txt  # print random tip
    #{e} -d '%%%' -r   tips.txt  # print random tip using %% as delimiter
    
END
  print text
end
num=nil
random= false
delim="\n\n"
# this is a rough approximation of the similar loop I use in shell script
# to avoid optparse and keep it simple. its minimal, and doesn't take combinations like -ltrh
# Loop through as long as there's a '-'
while (ARGV[0][0]=='-')
  arg = ARGV.shift
  case arg
  when '-r'
    random=true
  when '-c','-n'
    # pop off number of para to print
    num=ARGV.shift.to_i
  when '-d','--delimiter'
    # pop off number of para to print
    delim=ARGV.shift
  when '-h', '--help'
    usage
    exit
  else
    print "Wrong argument #{arg} "
    usage
    exit(1)
  end
end
#print "last : #{last}  , rec= #{recursive} "
filename = ARGV[0] || exit(-1);
text = File::read(filename)
paras = text.split(delim)
count = paras.size
num ||= count-1
num = rand(count) if random
#rr = rand(count)
puts paras[num]