48 hours are past so here is my first solution. I’m just coding ruby for
a few days so any feedback is welcome 
My script recognizes 12 different creditcard companys and of course says
if a card could belong to two different companys at the same time or if
it is unknown.
I think the companycheck part could be done better by calling check.call
from a loop but I couldn’t figure out how to pass such an hash:
hash = Hash.new { |hash, key| hash[key] = [] }
raw_data = [ [1,“American Express”],[1,/^34|^37/], [1, “15”],
[2,“Diners CLub Blanche”],[2,/^30[0-5]/], [2, “14”],
[3,“Solo”],[3,/^6334|^6767/],[3,“16”],[3,“18”],[3,“19”]]
raw_data.each { |x,y| hash[x] << y }
to
check = lambda{|reg,c,*d| if number =~ reg: @company += " or " + c if
d.include?(number.length) end }
in a loop. Any idea how to do this?
here the solution:
#!/usr/bin/ruby -w
validate.rb
######################################################
validator for creditcard numbers
by anansi
29/04/07 on comp.lang.rub
[QUIZ] Checking Credit Cards (#122)
######################################################
recognizes:
American Express,
Diners CLub Blanche,
Diners CLub International,
Diners Club US & Canada,
Discover,
JCB,
Maestro (debit card),
Mastercard,
Solo,
Switch,
Visa,
Visa Electron
######################################################
class CreditCard
def initialize(number)
number.scan(/\D/) { |x| # scans number for every not-digit
symbol
puts x + " is no valid credit card
symbol.\nJust digits allowed!!"
exit
}
end
def companycheck(number)
@company= “”
# block check compares the length and sets the company value
check = lambda{|reg,c,*d| if number =~ reg: @company += " or " + c
if d.include?(number.length) end }
# adding a new bank is quite easy, just put a new check.call in
with:
# check.call(regular expressions for the starting
bytes,“Company-name”,length1,length2,…)
# I’m sure this can be done somehow better invoking check.call by a
loop
# but I couldn’t figure out how to pass a array with dynamic
variable count into check.call
check.call( /^34|^37/ , “American Express” , 15 )
check.call( /^30[0-5]/ ,“Diners CLub Blanche”,14)
check.call( /^36/ , “Diners CLub International”,14)
check.call( /^55/ , “Diners Club US & Canada”,16)
check.call( /^6011|^65/ , “Discover”,16)
check.call( /^35/ , “JCB” , 16)
check.call( /^1800|^2131/ , “JCB” , 15)
check.call( /^5020|^5038|^6759/ , “Maestro (debit card)” , 16)
check.call( /^5[0-5]/ , “Mastercard” , 16)
check.call( /^6334|^6767/ , “Solo” , 16 , 18 , 19)
check.call( /^4903|^4905|^4911|^4936|^564182|^633110|^6333|^6759/ ,
“Switch” , 16 , 18 , 19)
check.call( /^4/ , “Visa” , 13 , 16)
check.call( /^417500|^4917|^4913/ , “Visa Electron” , 16)
if @company == “”
puts “Company : Unknown”
else
puts “Company : #{@company.slice([email protected])}”
end
end
def crossfoot(digit)
digit = “%2d” % digit # converts
integer to string
if digit[0] == 32
digit = (digit[1].to_i) -48
else # if the doubled
digit has more than 2 digits
digit= (digit[0].to_i) + (digit[1].to_i) -96 # adds the single
digits and converts back to integer
end
end
def validation(number)
math = lambda { |dig| number[@count-dig]-48 } # block math converts
str to int of the current digit
@duplex = false
@count = number.length
@result = 0
for i in (1…@count)
if @duplex == false # for every first digit from the
back
@result += math.call i # add to result
@duplex = true
else # for every second digit
from the back
@result += crossfoot((math.call i)*2) # mutl. digit with 2, do the
crossfoot and add to result
@duplex = false
end
end
@result.modulo(10)
end
end
begin
if ARGV.length == 0 # checks if argument is
passed
puts “no input\nusage, e.g.: ruby validate.rb 4408 0412 3456 7893”
exit
end
number = ARGV.join(’’).gsub(" “,”") # reads args and kills all
spaces and newlinefeed
my_creditcard = CreditCard.new(number) # checks if just digits are
inputed otherwise: abort.
my_creditcard.companycheck(number) # checks for known or unknown
company
if my_creditcard.validation(number) == 0 # checks validation with
luhn-algo
puts “Validation: successful”
else
puts “Validation: failure”
end
eof
–
greets
(
)
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jgs ) (/
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