Some scripts to work with library of congress call numbers. Eventually to be used in some fashion in Alexandria.

isbn2lcc.rb

#Connects to the library of congress database.
#Given a ISBN, it fetches the LCC.
require 'zoom'
require 'marc'
require 'stringio'

ZOOM::Connection.open('z3950.loc.gov', 7090) do |conn|
  conn.database_name = 'VOYAGER'
  conn.preferred_record_syntax = 'USMARC'

  while true
    print '>> '
    STDOUT.flush
    i = gets.chomp
    puts i
    conn.search("@attr 1=7 #{i}").each_record do |item|
      MARC::Reader.new(StringIO.new(item.raw)).each do |rec|
        puts rec['245']['a']
        puts "#{rec['050']['a']} #{rec['050']['b']}"
      end
    end
  end
end

parsecallno.rb

# Given a list of Libary of congress call numbers, 
# normalizes and sorts them properly.
myfile = File.open('list')

callnos = Array.new

myfile.each do |line|
  callnos << line.chomp
end

@p = /^(?<aclass>[A-Z]{1,3})(?<nclass>\d{1,4})(\ ?)(\.(?<dclass>\d{1,3}))?(?<date>\ [A-Za-z0-9]{1,4}\ )?([\ \.](?<c1>[A-Z][0-9]{1,4}))(\ (?<c1d>[A-Za-z0-9]{0,4}))?(\.?(?<c2>[A-Z][0-9]{1,4}))?(\ (?<e8>\w*)\ ?)?(\ (?<e9>\w*)\ ?)?(\ (?<e10>\w*)\ ?)?/

def ncmp x, y
  if x.nil? and y.nil?
    return 0
  elsif x.nil?
    return -1
  elsif y.nil?
    return 1
  end
  x = x.to_i
  y = y.to_i
  x <=> y
end

def cmp x, y
  x <=> y
end

def sortfunc x, y
  xp = @p.match(x)
  yp = @p.match(y)
  parts = {
    aclass: :cmp,
    nclass: :ncmp,
    dclass: :ncmp,
    date: :cmp,
    c1: :cmp,
    c1d: :cmp,
    c2: :cmp,
    e8: :cmp,
    e9: :cmp,
    e10: :cmp
  }
  parts.each do |part_key, part_value|
    cr = send(part_value, xp[part_key], yp[part_key])
    if cr != 0
      return cr
    end
  end
end

def normalize callno
  cp = @p.match(callno)
  out = cp[:aclass] + cp[:nclass]
  if not cp[:dclass].nil?
    out += ".#{cp[:dclass]}"
  end
  if not cp[:date].nil?
    out += " #{cp[:dclass]} "
  end
  out += ".#{cp[:c1]}"
  if not cp[:c1d].nil?
    out += " #{cp[:c1d]} "
  end
  if not cp[:c2].nil?
    out += " #{cp[:c2]}"
  end
  if not cp[:e8].nil?
    out += " #{cp[:e8]}"
  end
  if not cp[:e9].nil?
    out += " #{cp[:e9]}"
  end
  if not cp[:e10].nil?
    out += " #{cp[:e10]}"
  end
  out
end

callnos.sort!{|a,b| sortfunc(a, b)}

callnos.each do |callno|
  printf "%25s %25s\n", callno.chomp, normalize(callno).chomp
end